From majordomo-owner@berlioz.nsc.com Tue Sep 2 14:06:20 1997 Date: Tue, 2 Sep 97 14:06:19 PDT To: jmoss From: majordomo@berlioz.nsc.com Subject: Majordomo file: list 'laser' file 'laser.9708' Reply-To: majordomo@berlioz.nsc.com Content-Length: 145443 -- >From owner-laser Thu Jul 31 22:42:15 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA02461; Thu, 31 Jul 97 22:42:15 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: laser@qsl.net Date: Fri, 1 Aug 1997 01:34:02 -0400 Subject: Re: [LASER] doug's email addr. Message-Id: <19970801.013405.12886.1.K3PGP@juno.com> References: <199707312122.OAA11803@fmswksn06.azfms.dot> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 1-15,17-18,20-27,31-32,34-35,37-43 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk On Thu, 31 Jul 1997 14:22:50 -0700 c1040@azfms.com (Rusty Carruth) writes: > >Well, sorry for bugging the whole list, but... > >Doug's email address is actually one of: > > music@san-jose.ate.slb.com > music@goodnet.com > >rusty ----- Neither is the Email adr he is sending Email to me from !!!! He sent me Email from the following adr. When I reply to it it bounces! I'm not the only one having this problem.... On Thu, 31 Jul 1997 11:29:34 -0700 Doug Music writes: >John, > >My name is Doug. I've been a consultant for years and use optics >and lasers a lot for industrial physics. > etc...... ----- He seems to get stuff posted to laser@qsl.net yet he isn't on the subscriber list at either qsl.net or berlioz.net ????? How's he getting the list and why is he sending Email from an adr that won't accept incoming traffic ??? I am posting this here since it concerns the list. I'd like to know exactly how someone is getting this list when they aren't subscribed !!! Tell him I GIVE UP since there's no way I can respond to his Email other than posting to the list !!! John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Fri Aug 1 05:48:07 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA11203; Fri, 1 Aug 97 05:48:07 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f From: Rusty Carruth Message-Id: <199708011251.FAA10659@user2.inficad.com> Subject: Re: [LASER] doug's email addr. To: k3pgp@juno.com Date: Fri, 1 Aug 1997 05:51:29 -0700 (MST) Cc: laser@qsl.net, music@san-jose.ate.slb.com In-Reply-To: <19970801.013405.12886.1.K3PGP@juno.com> from "John K3PGP" at Aug 1, 97 01:34:02 am X-Mailer: ELM [version 2.4 PL25] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Reply-To: Rusty Carruth Sender: owner-laser@berlioz.nsc.com Precedence: bulk > On Thu, 31 Jul 1997 14:22:50 -0700 c1040@azfms.com (Rusty Carruth) > writes: > > > >Well, sorry for bugging the whole list, but... ditto. > >Doug's email address is actually one of: > > > > music@san-jose.ate.slb.com ... > Neither is the Email adr he is sending Email to me from !!!! > > He sent me Email from the following adr. When I reply to it it bounces! > I'm not the only one having this problem.... > > On Thu, 31 Jul 1997 11:29:34 -0700 Doug Music > writes: > >John, obviously something is really strange. when I get email from him it comes from music@san-jose.ate.slb.com. Could you send me the entire message (all headers) (and don't bother the group ;-). I'd like to see if I can figure out where the bad header is coming from so we can instruct the folks at Doug's work place what to fix (assuming its coming from there). Thanks! > > He seems to get stuff posted to laser@qsl.net yet he isn't on the > subscriber list at either qsl.net or berlioz.net ????? How's he getting > the list When I see something on the list that I think he'd like to see I send it to him. There's a fair amount of stuff I don't send... > and why is he sending Email from an adr that won't accept > incoming traffic ??? Because somewhere between his keyboard and yours something is messing up his address. I'm going to do a little detective work and see if I can find out what/where... > I am posting this here since it concerns the list. I'd like to know > exactly how someone is getting this list when they aren't subscribed !!! Well, I've told everyone (again ;-) how, now the reason I posted this to the list - is resending messages from the list unacceptable? > Tell him I GIVE UP since there's no way I can respond to his Email other > than posting to the list !!! Well, you COULD email me and I"ll forward - but I'd rather find and fix the bad address problem. If you could email me his ENTIRE email (this COULD be hard - some mail programs insist on stripping off most of the headers - precisely the ones I MUST see ;-( > John > K3PGP@juno.com > http://www.qsl.net/k3pgp > -==- > >From owner-laser Fri Aug 1 07:15:20 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA13035; Fri, 1 Aug 97 07:15:20 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Message-Id: <3.0.1.32.19970801090954.00850bd0@colby.edu> X-Sender: aballen@colby.edu X-Mailer: Windows Eudora Light Version 3.0.1 (32) Date: Fri, 01 Aug 1997 09:09:54 -0500 To: laser@qsl.net From: "Art Allen, KY1K" Subject: [LASER] laser driver chip, update Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Reply-To: "Art Allen, KY1K" Sender: owner-laser@berlioz.nsc.com Precedence: bulk Hi Everyone, I received word from John, PGP, that there was indeed a very simple circuit for driving laser diodes (single chip, very small external component count). I had hoped to have more complete info by now, but thanks to Sharp..well, I'm on 'hold'. Anyway, here's what I have, for better or for worse...... There is indeed a very very nice chip for driving laser diodes, looks like 5 external components. It's called the IR3C02, and it's made by Sharp. Sharp does not have specs for it online, and distributors don't send spec sheets. I am I am sitting here waiting to hear from Sharp regarding specs and app notes. I did call one Sharp distributor-they were only willing to sell in Quan of 50 or more. The good news is that they were willing to sell each chip for $2.01! So, IF (and its a big IF), we can find a dealer who will sell in small quans, then it is likely to be very affordable. It is unknown whether these chips can be modulated (switched totally off and totally on) at the rates we need, they might only be capable of constant 'on'. I did search some online vendor sites yesterday and did not find anyone selling the Sharp IR3C02 IC. I'll update the group when I have more info. GL and good DX...Art... >From owner-laser Fri Aug 1 08:30:24 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA15057; Fri, 1 Aug 97 08:30:24 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Message-Id: <199708011522.KAA10288@ultra.qni.com> From: "Gary Watts" To: "Rusty Carruth" , Cc: Subject: Re: [LASER] doug's email addr. Date: Fri, 1 Aug 1997 10:15:06 -0700 X-Msmail-Priority: Normal X-Priority: 3 X-Mailer: Microsoft Internet Mail 4.70.1160 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Reply-To: "Gary Watts" Sender: owner-laser@berlioz.nsc.com Precedence: bulk Rusty, A simple acknolagement would had been nice on my efforts for you I made three long distance phone calls and a hour of my time trying to get you your REQUESTED information.. Did you get your messages and make your laser meeting ? Rusty, I tried calling you this morning at 08:30 and 08:50 but you were not in the room I left a message for you at the front desk giving you Jim Moss's work and phone numbers >Thinking about dinner, near SFO and some laser talk... >Call me, email me, or whatever... let me know what you think... >Please contact Jim, WB9AJZ at 408-721-6906 (W) or 408-746-2789 (H). I hope you got the message ok and that this was the correct number you were looking for I also call Jim's home but he could not come to the phone so I left him a message with your info Good luck on your meeting.... Maybe I can pick your brain a little later on some Laser stuff :-) TTYL Gary Watts de N0OXV ---------- > From: Rusty Carruth > To: laser@qsl.net > Subject: [LASER] Rusty in San Fran, sorry for global email. > Date: Thursday, July 24, 1997 8:13 AM > > Well, I've sent a message to the OTHER varient of the mailing > list and not seen anything at all, so here goes over HERE > on qsl.net version... > > Hi, all. I've lost my phone numbers for important people, > so here I am in San Fran, subject of a supper today (eek! - today) > with no way to find out where we're going or anything! > > could somebody please call the hotel here and leave a message > at the desk (I'm checking out around noon, after which you > will probably NOT be able to leave me a message) with a contact > phone number for supper? Thanks. > > Rusty Carruth, currently at 415-928-7900 room 708 > > Sorry if the earlier versions of this message have already been > seen by everyone - and especially if 25 people end up calling > the motel! > > Thanks all! rusty >From owner-laser Fri Aug 1 09:46:57 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA17406; Fri, 1 Aug 97 09:46:57 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Date: Fri, 1 Aug 1997 09:41:40 -0700 From: c1040@azfms.com (Rusty Carruth) Message-Id: <199708011641.JAA12380@fmswksn06.azfms.dot> To: gwatts@qni.com Subject: Re: [LASER] doug's email addr. Cc: laser@qsl.net X-Sun-Charset: US-ASCII Reply-To: c1040@azfms.com (Rusty Carruth) Sender: owner-laser@berlioz.nsc.com Precedence: bulk > > > Rusty, > > Did you get your messages and make your laser meeting ? > I'm sorry, I got back and had fallen even further behind - I've not given a report on the supper, or anything. First - thanks to all for their indulgence over our use of the Laser list to organize a meeting. Second, thanks to all, and especially Gary, for all help received getting Jim and I hooked up. (I'm still baffled as to how I could have not had his phone numbers at my home email, since I get the laser there and it forwards to work.... Oh, well, one of life's little mysteries.) Finally, a report. Finding each other was pretty easy, since we had a simplex channel set up, and since I was the only person near the ticket counter fooling with a radio ;-) (Jim and company did not have an HT, so we had to organize while they were in the car) Finding a place to eat was a BIT more difficult, we ended up at a place where Jim ordered some kind of crab salad thing that ended up with dressing that tasted like pepto-bismol. Say - Jim - did you get sick from that stuff?? Of course, we talked about lasers. We compared pocket lasers that we had with us (Mine appears dimmer, but is 670nm, so it is probably just appearance). We also discussed laser records, and it is apparent that there is more than one place that keeps records. I'm supposed to get my info sent off here Real Soon Now... And, finally finally - I never got the following message - I"m doubly sorry I did not acknowledge Gary's efforts - I had thought that Jim had called the motel, not someone from out east! Thanks very much, Gary, for making our meeting possible! You are an example of ham radio at its best - helping others! > Rusty, > I tried calling you this morning at 08:30 and 08:50 but you were not in the > room rusty >From owner-laser Fri Aug 1 11:56:06 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA21570; Fri, 1 Aug 97 11:56:06 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: laser@qsl.net Date: Fri, 1 Aug 1997 14:46:01 -0400 Subject: [LASER] Laser Records Message-Id: <19970801.144721.3494.0.K3PGP@juno.com> References: <199708011641.JAA12380@fmswksn06.azfms.dot> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 0-2,4-8,11-14,16-22 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk On Fri, 1 Aug 1997 09:41:40 -0700 c1040@azfms.com (Rusty Carruth) writes: > >We also discussed laser records, and it is apparent that there is more >than one place that keeps records. I'm supposed to get my info sent off here >Real Soon Now... Rusty: I also have been trying to keep track of laser records. I assume the records posted on my web site are accurate ??? So far most people seem to agree with what is posted there. Do you have anything to add to these listings ??? I found it extremely hard to find the info that I presently have posted there. Wish I had more information... John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Fri Aug 1 15:09:53 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA26980; Fri, 1 Aug 97 15:09:53 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Message-Id: <33E1F530.D6D@alphalink.com.au> Date: Fri, 01 Aug 1997 07:39:44 -0700 From: Derek Weston Organization: Realtime Control X-Mailer: Mozilla 2.02 (Win16; I) Mime-Version: 1.0 To: laser@qsl.net Subject: [LASER] Re: Some thoughts on Laser Safety References: <19970731.125807.14574.4.K3PGP@juno.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Reply-To: Derek Weston Sender: owner-laser@berlioz.nsc.com Precedence: bulk John K3PGP wrote: > > HOWEVER, when using the two lens system the beam directly in front of the > laser is approx. 3.5 inches in diameter. This makes the power density a > LOT lower. I haven't done the math yet, but from probing around with a > wattmeter it appears as though the power density is even lower than the > collimated beam from my 5 mw laser. > As a first approximation: If beam dia with one lens is .1", and beam dia with the two lens arrangement is 3.5", then power density ratio is (.1 ^2) / (3.5 ^2) = .08% Dramatic reduction isn't it. As you say, much less of a hazard. Derek VK3BIJ >From owner-laser Fri Aug 1 15:09:54 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA26981; Fri, 1 Aug 97 15:09:54 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Message-Id: <33E1FB7E.1865@alphalink.com.au> Date: Fri, 01 Aug 1997 08:06:38 -0700 From: Derek Weston Organization: Realtime Control X-Mailer: Mozilla 2.02 (Win16; I) Mime-Version: 1.0 To: laser@qsl.net Subject: [LASER] Optical Power Measurement Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Reply-To: Derek Weston Sender: owner-laser@berlioz.nsc.com Precedence: bulk Like John, I've been experimenting with measuring laser power output. Until John solves the collimated/uncollimated power paradox, the following may be useful to those who have a current need to measure laser power output. Two sensor types have been mentioned in the past for this purpose, PV cells (ie. solar panel cells) and photodiodes. My initial tests used a PV cell directly connected to a digital multimeter set to measure current. There were two problems with this arrangement. 1) The power read from the DMM was very dependant on the temperature of the PV cell. It changed by about 20% if I left the PV cell in the refrigerator for a while, which dropped its temperature to about 4 deg C. 2) The voltage output from the PV cell was quite low, some .2V with a 5 mW laser diode. The result was that the current read on the DMM was very dependant on the internal resistance of the DMM. Switching it between current ranges gave wildly differing current readings. An additional consequence was that the linearity of the measurement system was poor. A second series of tests used a BPW34 silicon photodiode (reverse biased), a 9V battery and the DMM (set to read current) all in series. This appeared to be a lot less temperature sensitive and to have better linearity. Readings also appeared to correlate reasonably well with calculations based on the photodiode manufacturer's A/W and spectral sensitivity data. I'll calibrate this against a commercial unit sometime in the near future. In summary, photodiodes seem to me to be more likely to give useful results for a laser power meter. Derek VK3BIJ >From owner-laser Fri Aug 1 23:26:30 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA10398; Fri, 1 Aug 97 23:26:30 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: laser@qsl.net Date: Sat, 2 Aug 1997 02:14:29 -0400 Subject: Re: [LASER] Optical Power Measurement Message-Id: <19970802.021640.3494.2.K3PGP@juno.com> References: <33E1FB7E.1865@alphalink.com.au> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 1-11,13-14,16-19,23-24,30-31,37-38,42-43,47-52, 56-57,59-60,66-67,71-72,79-80,82-85,89-90,98-99,103-104,107-115 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk On Fri, 01 Aug 1997 08:06:38 -0700 Derek Weston writes: >Like John, I've been experimenting with measuring laser power output. >My initial tests used a PV cell directly connected to a digital >multimeter set to measure current. There were two problems with this >arrangement. >1) The power read from the DMM was very dependant on the temperature >of the PV cell. It changed by about 20% if I left the PV cell in the >refrigerator for a while, which dropped its temperature to about 4 deg >C. >2) The voltage output from the PV cell was quite low, some .2V with a >5 mW laser diode. The result was that the current read on the DMM was >very dependant on the internal resistance of the DMM. Switching it between >current ranges gave wildly differing current readings. >An additional consequence was that the linearity of the measurement system >was poor. ----- To help resolve some of these difficulties I suggest you hang a low value constant load on the Solar Cell and use the DMM as a voltmeter. As long as you keep the load resistor very small you will find the linearity to be excellent. The reason the linearity is so poor with higher impedance loads is the voltage curve flattens out long before the current does. If you run the solar cell into a high impedance load you will find it will develop full voltage with very little light and as a result will become non linear very quickly. By keeping the load resistor low you will keep the voltage developed by the solar cell in a more linear part of the curve. For powers in the 5 mw area I suggest a 10 or 100 ohm load. In fact I have found the linearity so good using this method that I am able to switch ranges by changing the load resistor between 1, 3, 10, 30, 100, and 300 ohms. I don't bother with 1000 ohms as that would only be linear with extremely low power levels, something I'm not interested in at the moment! Once the solar cell starts to develop much more than 0.25 to 0.3 volt or so the linearity starts to flatten out so you're better off keeping the resistor as low as possible and work with lower voltages... I only use the higher value loads for very low power measurements. Perhaps an even better system might be to use a 1 ohm load and a switchable gain op-amp. For now I wanted to avoid having to power the watt meter and at the current power levels I am working at I certainly don't need an amplified wattmeter! ----- As a linearity check you might try the following: Take a low power source such as a 670 nm 1 mw or so laser pen. Aim this at the solar cell and take a reading. My Damark pen usually develops around 310 ua. This means you will measure 31 mv across a 100 ohm load. Note this reading. Now remove the 670 nm 1 mw calibration signal. Apply your 5 mw signal. Take a new reading. Now with the 5 mw signal still applied, simultaneously apply the 1 mw laser pen. (Note: The two signals can be of any wavelength and do NOT need to be the same. It also doesn't matter if the two beams both hit the same part of the solar cell or a applied to different areas.) If the power meter is linear you should see the same increase as before when using the calibration signal by itself. My meter shows EXACTLY a 31 mv increase whether the 5 mw (or 30 mw!) signal is on of off when the 670 nm signal is applied as long as I use the 100 ohm load resistor at the 5 mw level and the 10 ohm resitor when using the 30 mw signal. If I increase the load resistor to 300 ohms and try the same thing the top end of the power curve starts to flatten out. At 1000 ohms it's even worse. This is indicated by the 31 mv change becoming less and less as more signal is applied from the higher power source. At 100 ohms the linearity is excellent at the 5 mw level. However, as you go above 5 mw or so you will have to go to a 10 or even a 1 ohm resistor to keep the system linear. I have used the techniques above to verify linearity up to the 500 mw level. I hope this helps some.... One thing to watch out for is the typical silicon solar cell is a LOT more sensitive to IR (780 to 1000 nm) radiation than it is to 630 to 670 nm. As a result you will need a calibration curve for 650 nm and another one for 800 nm or so if you are going to be doing work in both ranges. Also be aware that the larger the active area of the solar cell the more susceptible it will be to ambient light. I found this out when I accidently broke one into several small pieces. As long as the laser beam was smaller in diameter than the active area of the detector the reading was unaffected. However, the reading on room lighting was a LOT less. As a further note, I noticed that incandescent lights are more visible to the power meter than fluorescent lights are, most likely due to the higher IR radiation emitted by incandescent lights. I am supposed to take all of this over to the local repair shop and calibrate it against their standard. So far I haven't had time to do that. Once I am sure of everything and I have some free time, I'll put this in a small construction article. Lately I've been busy resurfacing a roof and renewing the surface on an exterior wooden porch.... I'm finding out there's more to life than lasers! :-( Now I can't wait till winter brings clear skies and more free time! John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Sat Aug 2 07:53:02 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA20893; Sat, 2 Aug 97 07:53:02 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: laser@qsl.net Date: Sat, 2 Aug 1997 10:43:11 -0400 Subject: [LASER] Schematic Drawing Programs ? Message-Id: <19970802.104328.3350.3.K3PGP@juno.com> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 1-2,4-5,13-21 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk I'm in the process of trying to document some of the circuitry that people have been asking for. Does anyone have any experience with any schematic drawing software, preferably public domain or something that you can try before you buy??? I asked a question similar to the above about HTML editing programs and the response was extremely helpful in getting the web site running. Now I need something similar to handle the schematics. This program should spit out a picture file (.BMP, .GIF, .JPG) etc. suitable for publication on a web page. As long as it outputs some type of graphic file I can handle to the conversion to a suitable (.jpg or .gif) format for the web page using existing software.... As a last resort I can even take a screen snapshot and paste that into another graphic program... Thanks John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Sun Aug 3 00:48:38 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA08235; Sun, 3 Aug 97 00:48:38 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Message-Id: <33E52485.7026@alphalink.com.au> Date: Sun, 03 Aug 1997 17:38:29 -0700 From: Derek Weston Organization: Realtime Control X-Mailer: Mozilla 2.02 (Win16; I) Mime-Version: 1.0 To: laser@qsl.net Subject: [LASER] Beam Alignment Aids - "Bore Sights" Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Reply-To: Derek Weston Sender: owner-laser@berlioz.nsc.com Precedence: bulk "Bore sights" have been mentioned several times on the reflector. Is a bore sight just a long, small diameter piece of tubing? An explanation would be appreciated. Derek VK3BIJ >From owner-laser Mon Aug 4 01:04:03 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA04551; Mon, 4 Aug 97 01:04:03 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Message-Id: <33E5EDCD.24E@slip.net> Date: Mon, 04 Aug 1997 07:57:17 -0700 From: Walt AJ6T Organization: AJ6T X-Mailer: Mozilla 3.0 (Win95; U) Mime-Version: 1.0 To: Derek Weston Cc: laser@qsl.net Subject: Re: [LASER] Beam Alignment Aids - "Bore Sights" References: <33E52485.7026@alphalink.com.au> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Reply-To: Walt AJ6T Sender: owner-laser@berlioz.nsc.com Precedence: bulk Derek Weston wrote: > > "Bore sights" have been mentioned several times on the reflector. > Is a bore sight just a long, small diameter piece of tubing? > An explanation would be appreciated. > Derek VK3BIJ Derek, To me, boresighting means aligning one optical device to another so that that their axes are parallel to each other. In my laser communication setup, I have three items which I want boresighted to each other: the laser transmitter (laser pen), the receiving telescope (Celestron C90 with OPT210 detector), and the small finder telescope that came with the C90. I leave the C90 in a fixed position on a common mounting plate on top of my tripod's pan/tilt head. The finder telescope mounts on the C90, and the laser pen mounts on a small Edmund Scientific two-axis tilt mechanism which is on that same mounting plate. I cannot see through the C90, since the eyepiece is replaced by the OPT210 solid state detector. For alignment, first I find a distant fixed souce which is easy to hear in my receiver (such as a flashing beacon lamp on a tower....click...click....click). I note the position of this visible source in the finder telescope relative to its crosshairs (this is the "hotspot" that I eventually must put on the laser transmitting toward me). Then I find my own transmitter's reflection on a distant a target as far away as I can see (about a quarter mile away or more), and move the laser mount ONLY until the red beam is also on the previously-determined hotspot in the finder telescope. Now my system is "boresighted," and I can move the entire assembly together, knowing that if I can see the other fellow's laser on the hotspot, he will also be receiving my transmitted beam. With practice this works pretty well. I always have to realign my equipment after I transport it up to the mountaintop. A cruder form of boresighting could be done with a hollow tube instead of the finder telescope. All of my work so far has been line-of-sight stuff, but this same alignment should work for backscatter or cloudbounce. 73, Walt, AJ6T >From owner-laser Mon Aug 4 08:20:27 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA11951; Mon, 4 Aug 97 08:20:27 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: laser@qsl.net Date: Mon, 4 Aug 1997 11:10:53 -0400 Subject: [LASER] Laser Diode Modulator Update Message-Id: <19970804.111055.6326.0.K3PGP@juno.com> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 0-1,6-7,16-22 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk I have updated the laser diode shunt modulator on my web page. After having an IgFet develop a gate to drain short (which caused the drive voltage to be applied directly to the laser diode!) I added a diode clamp circuit and current limit circuit to the input of the Fet. Fortunately no damage was done as the drive circuit is also current limited! NOTE: This circuit may appear over designed, but since I am using it with some rather expensive diodes the extra complexity and protection are in my mind worth the extra effort. You may elect to use something simpler when using cheaper laser diodes. Maybe all you need is a resistor and a battery but sooner or later you will wish you gave some thought to a little extra protection for the laser diode as they seem to respond to the slightest circuit disturbance and signify that a fault has occurred by turning into expensive LEDs at the most inopportune time! No matter what goes wrong it will end up costing you $$$ ! :-( John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Mon Aug 4 09:00:16 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA13053; Mon, 4 Aug 97 09:00:16 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Message-Id: <3.0.1.32.19970804105317.00866100@colby.edu> X-Sender: aballen@colby.edu X-Mailer: Windows Eudora Light Version 3.0.1 (32) Date: Mon, 04 Aug 1997 10:53:17 -0500 To: laser@qsl.net From: "Art Allen, KY1K" Subject: [LASER] high voltage batteries? Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Reply-To: "Art Allen, KY1K" Sender: owner-laser@berlioz.nsc.com Precedence: bulk Hi Everyone, I'd like to run a PM tube on batteries and I'm not sure that anyone makes suitable types. I need voltages anywhere from 60 to 100 volts at currents in the microamp range. Obviously, the low current demand allows for non-traditional battery types-home brew types would be FB and I have considered multiple stage zinc/copper 'potatoe' type current sources. The current sources should be very cheap, or rechargable and need to be compact (no car batteries allowed). Yes, Im aware that PM tubes can be run on batteries and special PS units-that's not what I want to do. Any ideas? Remember, to claim the prize, it has to be reasonably priced. Creativity and originality count too. In the old days, they used to make 45 volt batteries to make the minus voltages to put on the grids of tubes (for portable receivers hi hi). Any ideas/suggestions? Thanks...Art... >From owner-laser Mon Aug 4 09:55:26 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA14575; Mon, 4 Aug 97 09:55:26 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: laser@qsl.net Date: Mon, 4 Aug 1997 12:45:02 -0400 Subject: [LASER] Jameco Laser Parts ! Message-Id: <19970804.124503.5134.1.K3PGP@juno.com> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 4-5,8-9,14-20 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk Jameco now stocks a Laser Diode collimating lens / mount / heatsink for $7.95. Part # 126244 These look like they are made for the larger (9mm) diodes. If you have a 5.6 mm diode you will either need an adapter ($2 from Meredith) or buy the same assembly as above from Oatley in Australia who stocks both the 5.6 and 9 mm versions of the above. Jameco also carries a laser driver board for $9.95. Part # 126711. From the pix it looks like the typical two transistor feedback regulator. Not sure what provisions are made for different diode polarities though. They also have a 660 nm 4 mw module with a 0.2mrad divergence that uses a 3-element GLASS lens for $53.95. Part # 133292 This is a LOT better than what the typical single element plastic collimation lens produces. Just keep in mind that although you will have higher power density using something like this it will also be more difficult to aim. John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Tue Aug 5 11:17:56 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA29831; Tue, 5 Aug 97 11:17:56 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f From: daveaa1a@xensei.com Date: Tue, 5 Aug 1997 14:11:10 -0400 Message-Id: <199708051811.OAA11803@xensei2.xensei.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Subject: [LASER] Simple goof proof MODULATOR To: laser@qsl.net X-Mailer: SPRY Mail Version: 04.00.06.17 Reply-To: daveaa1a@xensei.com Sender: owner-laser@berlioz.nsc.com Precedence: bulk GUDDAY light bugs.. Well here is my final stop on a modulator for these sensitive little diodes.. I'll draw it out here as best I can and try for one with pix on the web site: www.qsl.net/aa1a Simple theory: Between 6 and 28 volts DC is applied to the input of a common 3 terminal voltage regulator.. (7805 etc) The output is taken from the COMMON connection with a feedback resistor tied to the 'normal' output lead.. THIS MAKES A CURRENT REGULATOR INSTEAD OF A VOLTAGE REGULATOR..... Now we set the feedback resistor value by connecting approx. 100 ohm (variable) between the common and output leads of the regulator. Now tie approx. 50 ohms LOAD between the Negative DC supply and the common lead of the voltage regulator.. Place a milliammeter in series with this load and adjust R variable to cause 100 milliamps flow in load.. Now make the load larger and smaller right down to a short circuit and see the 100 ma. stay constant.. OK, now we can bias our laser diodes this way and it only took 4 parts (regulator-pot.-meter-diode) and makes it goof proof.. Make sure you are starting from minimum when the diode gets connected here. ( I am minus 1 Diode ) Next lets tie a IRF series power mosfet across the laser diode.. We will bias it with a 50k pot tied across the Common to the DC input, taking a 1k resistor from the arm and tying it back to the mosfet gate.. Where we already set up laser bias current in the first example we will now adjust the mos modulator to cause the laser current to decrease down to about 60 ma. There is still 100 ma. flowing out of the regulator but now it is shared by the diode and the mos transistor.. 60ma. diode , 40ma. mos transistor.. When the mos transistor is hi-z the current goes to 100ma at the diode and when the mos transistor is conducting hardest at the peak of the audio/data/video signal then the current in the laser goes down.. OUI.. AM modulation.. Should be good for many mhz. wide signal/data/video rates.. Here tis: 100 ohm var. <-set to max IN OUT ( approx ) laser diode + 6-28 VDC---------[_7805_]------/\/\/\/\-----: current with : : modulator COMMON : : shut off :--------:-------:--------------:----/\/\/\/\/--: : : 50k /\ : : :D : :From owner-laser Tue Aug 5 12:34:36 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA02956; Tue, 5 Aug 97 12:34:36 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: laser@qsl.net Date: Tue, 5 Aug 1997 15:25:22 -0400 Subject: Re: [LASER] Simple goof proof MODULATOR Message-Id: <19970805.152533.13142.0.K3PGP@juno.com> References: <199708051811.OAA11803@xensei2.xensei.com> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 0-15,17-18,22-23,29-30,37-38,41-42,46-47,52-53, 59-60,63-65,68-74 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk On Tue, 5 Aug 1997 14:11:10 -0400 daveaa1a@xensei.com writes: > >GUDDAY light bugs.. > >Well here is my final stop on a modulator for these >sensitive little diodes.. > >I'll draw it out here as best I can and try for one >with pix on the web site: www.qsl.net/aa1a ----- Dave: Very happy to hear you have had such good luck with this circuit. I used the 7805 as a constant current regulator when I first started out but had a couple of problems with it. I noticed that you have no bypass capacitors on the 7805. Mine turned into an oscillator when I tried to run it without bypass caps. When I added the bypass caps I had problems with overshoot when the circuit was turned on. Ended up eventually eating the laser diode! Although I have to admit that it's rare for a 7805 to fail I have had them short. Under these conditions you will apply full voltage to your laser diode as there is no clamp protection circuit. At the very least you should have a current limit resistor on the input, a zener clamp diode, and some sort of bypassing to reduce the possibility of oscillations. I guess when you are working with less expensive laser diodes you can assume that nothing will go wrong and rely on the 7805. However, since I am now working with some diodes that cost around $300 each I don't feel like trusting them to a 49 cent 7805 voltage regulator and have gone overboard in the protection department. I feel a little safer when there's more between the 12 volt rail and my laser diode than just the junction of a series pass transistor in a 7805 voltage regulator! You might also consider a 78L05 or 79L05 as these are internally current limited to 100 ma. Some people use them but I find them to get hotter than I like when carrying 75 ma or so... The IRF510 can be made a bit more linear if a small unbypassed resistor is stuck in the source lead to supply a bit of negative feedback. This will help if you are running multiple signals through the laser or doing something where very high linearity is required. At 100 ma you may be exceeding the manufactures rated operating current for your laser diode. You can do this for short periods of time but it eventually takes it's toll as the laser diode power output will start to drop. I guess it depends on how long you want it too last vs how much power you want to get out of it. Speaking of going overboard on design, I thought I thought of everything when I built my modulator. Well guess what? If you overdrive the gate of the IRF511, (a simple jolt of static electricity into the modulator input is all that is required) the gate will short to the drain. This causes the voltage going in the gate to come out the drain and go directly into the laser diode! After discovering this I added a diode clamp circuit to the gate input of the IRF511. This probably isn't a bad idea since the IRF511 has an insulated gate and is susceptible to this type of damage. ***** NOTE: Please take all of the above as constructive ideas !!! :-^) Although this is an excellent circuit it isn't as foolproof as you might think ! ***** John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Tue Aug 5 15:44:15 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA08630; Tue, 5 Aug 97 15:44:15 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f From: daveaa1a@xensei.com Date: Tue, 5 Aug 1997 18:37:02 -0400 Message-Id: <199708052237.SAA21464@xensei2.xensei.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Subject: Re: [LASER] Simple goof proof MODULATOR To: k3pgp@juno.com (John K3PGP) Cc: laser@qsl.net X-Mailer: SPRY Mail Version: 04.00.06.17 Reply-To: daveaa1a@xensei.com Sender: owner-laser@berlioz.nsc.com Precedence: bulk On Tue, 5 Aug 1997, k3pgp@juno.com (John K3PGP) wrote: >I noticed that you have no bypass capacitors on the 7805. Mine turned >into an oscillator when I tried to run it without bypass caps. It's a given to have pure DC (battery) or by-passed manufactured DC.. Not on the OUTPUT side of the current regulator though, it will limit bandwidth.. Maybe a hundred pf. or so across the diode and even a reverse diode for overshoots but this circuit looks pretty resistive to me at these frequencies.. It tends to be real stable.. >oscillations. Hasn't happened here yet.. >am now working with some diodes that cost around $300 each I don't feel >like trusting them to a 49 cent 7805 voltage regulator and have gone If I had a 300 buck diode would probably feel same way but simple, straightfoward and lotsa head room on parts makes this modulator a beginner and intermediate users delight.. >The IRF510 can be made a bit more linear if a small unbypassed resistor >is stuck in the source lead to supply a bit of negative feedback. This Have fun with the refinements folk's.. I was trying to save time and money with all these store bought rigs.. Gate bias puts this thing right in the middle of the linear range.. >At 100 ma you may be exceeding the manufactures rated operating current >for your laser diode. You can do this for short periods of time but it Yes, pay attention to manufacturers specs.. 78ma is max on latest batch of 650nm diodes.. >Speaking of going overboard on design, I thought I thought of everything >when I built my modulator. Well guess what? If you overdrive the gate >of the IRF511, (a simple jolt of static electricity into the modulator This is a good place for a ferite bead to dampen any vhf oscillations.. >Although this is an excellent circuit it isn't as foolproof as you might >think ! Careful !! 73s de dave >From owner-laser Tue Aug 5 17:40:35 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA12544; Tue, 5 Aug 97 17:40:35 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Date: Tue, 5 Aug 1997 17:29:01 -0700 (PDT) From: Clifford Buttschardt To: Laser newsgroup Subject: Re: [LASER] Simple goof proof MODULATOR In-Reply-To: <19970805.152533.13142.0.K3PGP@juno.com> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Reply-To: Clifford Buttschardt Sender: owner-laser@berlioz.nsc.com Precedence: bulk Hi Dave (AA1A) and all. Got you latest modification of a laser regulator circuit. Even adding two caps to prevent the 7805 from oscillating, I must say that the effort of drawing a schematic needs praise! Cliff K7RR >From owner-laser Tue Aug 5 18:39:57 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA14171; Tue, 5 Aug 97 18:39:57 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: laser@qsl.net Date: Tue, 5 Aug 1997 21:30:05 -0400 Subject: Re: [LASER] Simple goof proof MODULATOR Message-Id: <19970805.213017.13886.0.K3PGP@juno.com> References: <199708052237.SAA21464@xensei2.xensei.com> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 0-11,13-14,18-19,21-22,26-27,32-33,37-38,43-44, 49-50,56-57,61-62,64-70 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk On Tue, 5 Aug 1997 18:37:02 -0400 daveaa1a@xensei.com writes: >On Tue, 5 Aug 1997, k3pgp@juno.com (John K3PGP) wrote: > >I noticed that you have no bypass capacitors on the 7805. Mine >turnedinto an oscillator when I tried to run it without bypass caps. > >It's a given to have pure DC (battery) or by-passed manufactured DC.. >Not on the OUTPUT side of the current regulator though, it will limit >bandwidth.. ----- That's exactly when I had the most trouble with this circuit, when running from a battery !!! The thing was absolutely stable on the bench supply but when I hooked it up to the 12 volt gell cell the 7805 turned into an oscillator and blew the laser diode! It had a 12 vdc square wave coming out of it !!! It was oscillating up around 50 Khz or so... I think the 7805 went critical with the added lead inductance of the longer leads going to the battery. After adding a capacitor to the input side of the 7805 the oscillation stopped but then I started having troubles with turn on spikes getting into the laser diode. This seems to vary with different manufacture 7805's. You can add quite a bit of capacitance to the output terminal as well without rolling off the high frequency response too much as the impedances at this point are pretty low, but this seemed to agrivate the turn on transients and varied depending on the particular 7805 I was using. Like you I have built this circuit and have had it perform flawlessly. But on other occasions it has done the unexpected. I'd hardly call it a goof proof circuit but neverless it's a good starting point. With a few refinements I'm sure one can tame it down. My only reason for bringing all this up is to make people aware of what can happen with even the simplest of circuits and to be on the lookout for them when setting things up... I've had enough unexpected accidents with this circuit that I no longer trust it with my more expensive diodes... However, I do use a 7805 in a current limiter circuit just like this (but with bypass capacitors) in the main supply feeding the 'protected' modulator that runs my laser Tx. It is hoped that if all else fails it will limit the current to a safe 1 amp. My laser carries DC ratings to 1.3 amps and can take more in pulse mode. Those series pass transistors always make me nervous though. All you need is for one to short out and whatever is on the other end is totally lost unless some type of clamp circuit is used. I've seen a few rather expensive HF radios fried like this when the pass transistor in the power supply shorted. A simple crowbar circuit would have saved a several hundred dollar repair bill! Just give a few thoughts to what if before you fire up your next project and I'm sure you will be rewarded no matter what circuit you use... There's more than one way to do this and that's what makes all this so interesting :-^) !!! PS - When I speak of linearity I was refering to laser optical power output vs modulator input and NOT the current that is going to the diode. John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Tue Aug 5 19:37:01 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA15546; Tue, 5 Aug 97 19:37:01 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: laser@qsl.net Date: Tue, 5 Aug 1997 22:27:55 -0400 Subject: [LASER] NOTICE - Laser list move to be completed tomorrow night ! Message-Id: <19970805.222759.13886.1.K3PGP@juno.com> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 0-3,6-7,12-13,19-22,24-25,27-28,30-31,34-37,42-43, 45-54,57-60,62-63,67-68,73-74,76-85 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk * * * N O T I C E * * * N O T I C E * * * N O T I C E * * * NOTICE - Laser list move to be completed tomorrow night ! As many of you may or may not be aware the laser newslist has been operating in a transitional phase over the past couple of months as we have slowly been moving from laser@berlioz to laser@qsl. Many of you have been pioneers and immediately made the jump from sacred ground at berlioz to uncharted waters at qsl.net. Those of you that did were rewarded with a much faster response system. Others chose the safer route and remained behind at berlioz. Still others wanted to play it safe and subscribed to BOTH lists! Well the day is rapidly approaching when we are going to say goodbye to our old friend at berlioz. If all goes as planned those of you still subscribed at berlioz will automatically be moved to qsl.net sometime around 3 am EDST Thursday morning. Again if all goes as planned you will never notice the change. It will be the same old gang but you will notice a lot faster response from the list. ----- If you are presently subscribed to laser@qsl.net DO NOTHING! You're already here! If you are presently subscribed to laser@berlioz DO NOTHING! You will be moved automatically to laser@qsl.net. If you are presently subscribed to BOTH lists you will be UNsubscribed from berlioz and will remain subscribed to laser@qsl.net. The bottom line is DO NOTHING. It will make my job a LOT easier if everyone stays where they are now. If you start moving around you may get lost in the shuffle! ----- Jim and I have been doing extra work to keep everything working as smoothly as possible on both lists. This meant DOUBLE the work load for both of us. We had hoped that everyone would have made the move on their own by now. Since this hasn't happened I will be doing it for you on Thursday morning at approx. 3 am EDST. When the move is completed a test message will be sent from laser@qsl.net to all subscribers. It will look like this: * * * N O T I C E * * * N O T I C E * * * N O T I C E * * * T H E M O V E H A S B E E N C O M P L E T E D ! ! ! Send messages to be echoed to laser@qsl.net. To subscribe or unsubscribe send an Email to majordomo@qsl.net. In the body of the Email type subscribe or unsubscribe. For help send Email to K3PGP@juno.com. If you don't get this message by Saturday morning, or you noticed that you are no longer getting anything from the laser list please contact me via Email at: K3PGP@juno.com and I will see to it that the problem is correctly immediately. I will also Email any posts that you have missed so you are up to date. Keep in mind that the move will occur at approx. 3 am Thursday morning but the test message won't go out till later as Jim will have a LOT of work to do a berlioz to complete the move before I can issue the test message. Hopefully if all goes as planned none of you will notice anything except faster service. The only thing that may affect you is if you have been sending traffic to be echoed to laser@berlioz.nsc.com. After the change you MUST send your traffic to laser@qsl.net. Most of you are already doing this.... Both Jim and I will continue as syops. Nothing is changing except the list address! Thanks.... John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Wed Aug 6 10:21:34 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA06769; Wed, 6 Aug 97 10:21:34 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f From: daveaa1a@xensei.com Date: Wed, 6 Aug 1997 13:15:30 -0400 Message-Id: <199708061715.NAA14009@xensei2.xensei.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Subject: [LASER] Re: Simple "ALMOST"goof proof MODULATOR To: laser@qsl.net X-Mailer: SPRY Mail Version: 04.00.06.17 Reply-To: daveaa1a@xensei.com Sender: owner-laser@berlioz.nsc.com Precedence: bulk By popular demand, I return with version 1.01.. of the simple effective locally prepared laser diode modulator.. It contains real, not assumed input caps.. 100uf + 1uf. + .1.. > >Here tis: 100 ohm var. <-set to max > IN OUT ( approx ) laser diode > + 6-28 VDC--:------[_7805_]------/\/\/\/\-----: current with > ----- : : modulator > C1 ----- COMMON : : shut off > :-:--------:-------:--------------:----/\/\/\/\/--: > : : 50k /\ : > : :D : : [ ma. meter ] IRF :---: gate 1K : to : > : 510 :]--:-/\/\/\/\-------: 60 : > : mos :---: : : ma. : > : :S : : : : > __:__ : : ===== : > \ / : ----- 1 uf. ===== : > \ / }}}}}} : ----- : : > ====:==== : : : : > : : Mod. Input : : > - Common------:------------------------------------------------ > * C1 eliminates the k3pgp effect.. Happy Lighting de dave >From owner-laser Wed Aug 6 20:30:41 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA23444; Wed, 6 Aug 97 20:30:41 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Message-Id: <33EA2F27.4EC7@alphalink.com.au> Date: Thu, 07 Aug 1997 13:25:11 -0700 From: Derek Weston Organization: Realtime Control X-Mailer: Mozilla 2.02 (Win16; I) Mime-Version: 1.0 To: laser@qsl.net Subject: [LASER] 115200 kbs Laser Transceiver Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Reply-To: Derek Weston Sender: owner-laser@berlioz.nsc.com Precedence: bulk All details required for construction (including PCB design) are on the web at http://alphalink.com.au/~derekw/upntcvr.htm Derek VK3BIJ >From owner-laser Thu Aug 7 07:57:21 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA09043; Thu, 7 Aug 97 07:57:21 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Message-Id: <199708071353.JAA11429@ns1.qsl.net> Comments: Authenticated sender is From: w1_k_sorter@qsl.net To: pesims@ix.netcom.com Date: Thu, 7 Aug 1997 10:51:07 +0000 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Subject: [LASER] Re: sub mini PV arrays? Cc: mikeS@electron-tubes.co.uk, Phototubes@aol.com, IanHarper@astec.co.uk, pmitchell@hamamatsu.com, laser@qsl.net In-Reply-To: <33E8FB4C.F0284FDD@ix.netcom.com> X-Mailer: Pegasus Mail for Win32 (v2.53/R1) Reply-To: w1_k_sorter@qsl.net Sender: owner-laser@berlioz.nsc.com Precedence: bulk > Date: Wed, 06 Aug 1997 18:31:40 -0400 > From: Paul Sims > Reply-to: pesims@ix.netcom.com > To: w1_k_sorter@qsl.net > Subject: Re: sub mini PV arrays? > K sorter wrote: > > > > Hi Everyone, > > > > It's me again. > > > > I'm hesitant to post this here, because the posts here are about LARGE > > and POWERFULL arrays (watts ++). > > > > I have an application that requires 1kv dc @ 100ua (in 10 equally > > spaced steps). Actually, the 100ua spec is for 100 percent of full > > ratings for my electronic device, and the solar cells would NEVER have > > to supply that much, 1 picoamp to 5 microamps is a more typical > > 'load'. > > > > Anyway, micropower inverters are very very poor in terms of > > effeciency, so I was wondering if any knows of a source for sub > > miniature PV arrays that could be placed in series to provide the > > needed power as stated above. I'm thinking of multiple cells on a > > chip, each cell being about .1 inch by .1 inch. > > > > Ideas/suggestions? > > > > Thanks de K > > How much are you willing to pay for such a device? > I could build one, but it would be expensive -- especially > for a one-off. If you are interested, give me a call. > > Paul Sims > Product Development Manager > AstroPower, Inc. > Solar Park > Newark, DE 19716 > (302) 366-0400 > Hi Paul, My budget is very limited and you probably couldn't make a single unit to fit within my budget. Can you give me a rough idea how much 10 arrays of (about) 70 cells each might cost (they need to be series connected on the substrate, or have solder terminals so that I can series connect them). Each has to produce 100 microamps @ 80 to 100 volts under illumination by an LED(s) or laser diode. I have no idea what the actual area of each cell needs to be. I need to be able to connect each 80 to 100 volt unit in series to ultimately produce about 1 kv and need access to each unit as each of the 100 volt modules needs to go to separate stages of the PM tube. There are MANY MANY MANY other applications which need high voltage at very very low currents, and electronic dc to dc converrter that run on small batteries are VERY VERY expensive! My guess is that an alternative flea power PV supply that could be mass produced could be very very marketable and profitable. What happens with low power dc to dc converters? The basic problem is that they need a step up transformer and an electronic feedback system to maintain a constant voltage. This electronic feedback system is a real power hog, the device itself uses 5 percent of the power produced and the control circuit uses the other 95 percent. This precludes portable operation and locks you into a BIG battery or other LARGE power source. This is not a problem for higher power dc to dc converters, but for flea power sources, it is a BIG problem (it is a power hog, and power supplies that produce regulated HV are VERY VERY expensive and use proprietary designs. I can tell you that there is probably a VERY VERY large demand for this type of power supply. In my case, I want to run a PM tube with it. Hamamatsu has a voltage source that runs on a battery that draws low current, but it is $300 dollars and is NOT available as an individual component for experimenters and they will not sell it separately (they require you to purchase the unit with socket, wired, high voltage potted, sealed and ready to run). This is not good, you need to spend 300 dollars for EACH DIFFERENT PM tube type you want to power-NG. Can you give me your best guess on the cost of 10 modules if made for me only. Also, can you give me a guess as to how much each module would cost if it was mass produced (assuming for the moment that it is marketable)? Many thanks. Art ----------------------- w1_k_sorter@qsl.net www.qsl.net/w1_k_sorter/ ----------------------- >From owner-laser Thu Aug 7 11:25:09 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA14949; Thu, 7 Aug 97 11:25:09 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f From: daveaa1a@xensei.com Date: Thu, 7 Aug 1997 14:18:54 -0400 Message-Id: <199708071818.OAA30892@xensei2.xensei.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Subject: Re: [LASER] Re: sub mini PV arrays? To: w1_k_sorter@qsl.net Cc: laser@qsl.net In-Reply-To: <199708071353.JAA11429@ns1.qsl.net> X-Mailer: SPRY Mail Version: 04.00.06.17 Reply-To: daveaa1a@xensei.com Sender: owner-laser@berlioz.nsc.com Precedence: bulk A micro-tesla 1kv divided in a decade will do it.. How small?? Alternate is using a present square wave in some equipment to make hi-dc with multiplier to charge large cap/zener combo.. The input is keyed on automatically at intervals to keep at 1kv.. Bleed off into pmt is much slower than recharge cycle.. See watchdog timers and wake up divices on the shelf now.. I'll stick to my 9v ni-cad batteries in a series case.. Simple, works good and longer mtbf.. 73s de dave 'where's my prize' >From owner-laser Thu Aug 7 16:36:15 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA24461; Thu, 7 Aug 97 16:36:15 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: laser@qsl.net Date: Thu, 7 Aug 1997 19:27:11 -0400 Subject: [LASER] Re: Simple "ALMOST"goof proof MODULATOR Message-Id: <19970807.192714.4038.1.K3PGP@juno.com> References: <199708061715.NAA14009@xensei2.xensei.com> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 0-8,10-11,13-14,16-17,19-20,23-26,32-33,36-37,40, 42-43,46-47,51-52,57-60,63,66-69,72,74-77,81-82,89-90,95-101 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk On Wed, 6 Aug 1997 13:15:30 -0400 daveaa1a@xensei.com writes: > >* C1 eliminates the k3pgp effect.. > W - O - W ! ! ! My very own effect! Actually it's been rumored that the only way to totally eliminate the k3pgp effect if to UNsubscribe him from the laser list :-^) !!! Seriously, I do have one more caution. (You knew it was coming didn't you!) It concerns the use of a Ma meter connected in series with the laser diode. I have done this in the past and sometimes I got away with it and sometimes I didn't! It seems that SOME meters have the nasty habit of an inductive kickback when the current is shunted to ground via the IRF510 modulator. This can get particularly nasty when driven with a square wave. Here's what I've been able to learn... Sensitive meters that use a low value shunt and series resistor to the movement seem to NOT have this problem. A typical example would be a 50 ua meter with a series resistor to a very low value shunt resistor that is used as the current sensor. This works ALL the time with no problem and is where I got the idea of using a 1 or 10 ohm resistor in series with the diode that I hang a voltmeter across to measure the current. HOWEVER, I managed to find some 100 ma meters at a local hamfest in which the basic movement was 100 ma, NO SHUNT was used. Perfect for my laser projects, or so I thought! When a meter like this is used in this circuit the inductive kickback from the meter movement when the current is stopped will SOMETIMES be enough to zap the laser diode! You should have seen it with an 800 Hz BPSK signal going through it! Placing back to back 1N4007's across the meter did damp the spike but it wasn't enough to fix the problem. Placing a capacitor across the meter also helped but still didn't totally eliminate the problem. After blowing up two laser diodes (wasn't sure at first what was going on!) I finally gave up on it and stuck a 10 ohm resistor in series with the diode and used my battery operated DVM to measure the voltage across the resistor and derive the current from that. After thinking over all the above I went back and designed a 0 to 100 Ma meter around a 0 to 100 ua meter movement. I used the 10 ohm series resistor to the laser diode and connected the 100 ua meter movement across it using a series resistor to the meter which I adjusted to make the scale read 0 to 100 ma. Had no more problems.... I use a similar scheme with the 500 mw laser but use a 1 ohm current sensing resistor and a 20 ua meter movement as the operating current is around 1 amp! This puts the needle straight up when operating normally plus the same meter can be switched to the photodiode where it's shunted to read 0 to 2 ma as the photodiode current is 1.6 ma during normal operation. ----- My only reason for the posts concerning this circuit is to try to prevent anyone building it from blowing up a laser diode and not understanding what went wrong. If you have this info before you start you stand a lot better chance of success as you might be able to prevent an accident BEFORE it happens! ----- PS - I recently started adding a 1N4007 with REVERSE polarity across my laser diodes and THREE 1N4007's in series across the laser diode in the forward direction. (Two didn't allow for the typical 1.7 volts across the laser diode.) The reverse diode prevents any accidental reverse bias (up to 0.7 volt or so) and the three diodes in series limit the forward voltage to 2.1 volts or so. Maybe not enough to totally protect the laser diode but it goes a long way toward clamping the voltage from a static discharge or if an alligator clip should land in the wrong place! Also hung a .01 ufd across it for fast rise stuff. Doesn't seem to hurt the 800 Hz BPSK signal... Maybe I should get a job designing those $500 toilet seats for the military. I seem to be able to take a simple circuit and turn it into a protected nightmare ! :-^) Do you think it would be a good idea to put a diode clamp circuit on my solar panel so when the sun goes supernova - Ah, maybe on second thought... John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Sat Aug 9 23:01:58 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA18236; Sat, 9 Aug 97 23:01:58 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: laser@qsl.net Date: Sun, 10 Aug 1997 01:54:58 -0400 Subject: [LASER] Laser 'Star Wars' Weapon Article Message-Id: <19970810.015502.22542.1.K3PGP@juno.com> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 0-1,5-6,9-16 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk Thought you heard the last of the Star Wars defense plan? Well guess again as it's alive and well according to a six page article in the September 1997 Popular Science, Page 68, "Sabers of Light, New laser weapons breathe life into an old Star Wars plan for missile defense." One of the lasers described is a Chemical Oxygen Iodine Laser (COIL) that uses hydrogen peroxide, chlorine gas, and iodine! The output is at 1.3 microns (1300 nm). John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Mon Aug 11 07:15:05 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA25990; Mon, 11 Aug 97 07:15:05 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Message-Id: <33D6E85F.2114@pop.inficad.com> Date: Wed, 23 Jul 1997 22:30:07 -0700 From: Rusty Carruth Organization: Descomp Computer Consulting X-Mailer: Mozilla 3.0Gold (Win95; U) Mime-Version: 1.0 To: laser@qsl.net Subject: [LASER] Rusty in SF Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Reply-To: Rusty Carruth Sender: owner-laser@berlioz.nsc.com Precedence: bulk Well, rats. I get to SF and I cannot find anybodys phone number. If somebody has any contact info for our supper tomorrow (Thurs) in SF near the airport, please call me at the hotel TONIGHT (leave a message at the desk if they'll let you, I'm going to bed reall soon now - thanks). I'm at 415-928-7900. room 708. Rusty Carruth Thanks! If nobody gets this before I check out in the morning, I'll still check the desk around noon, and every once in a while after that till I get a message.... thanks! rusty >From owner-laser Mon Aug 11 08:22:09 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA28349; Mon, 11 Aug 97 08:22:09 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: laser@qsl.net Date: Mon, 11 Aug 1997 10:53:12 -0400 Subject: [LASER] 7805 failure mode ??? Message-Id: <19970811.111455.11878.0.K3PGP@juno.com> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 1-4,6,8-10,12,14-18,21-22,27-38 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk Ever wonder why you sometimes see a 1N4007 hooked ACROSS a 7805, from input to output ??? >reverse-bias protection: > >Occasionally, there exists the possibility that the input voltage to the >regulator can collapse faster than the output voltage. This could occur, >for example, when the input supply is crowbarred during an output >overvoltage condition. If the output voltage is greater than >approximately 7 V, the emitter-base junction of the series pass element >(internal or external) could break down and be damaged. To prevent this, >a diode shunt can be employed. > >David Brunover I suppose for this to happen you would have to have a fairly large capacitor hanging on the OUTPUT of the 7805, something that most of our laser regulator circuits do NOT use... You MIGHT also be able to prevent this failure mode with a diode in series with the input to the 7805. That would prevent the crowbar from shorting the input to ground and has the advantage that if the diode shorts it doesn't route the input voltage around the regulator and right to the laser diode! Food for thought though!!! Thanks... John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Tue Aug 12 00:57:37 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA05768; Tue, 12 Aug 97 00:57:37 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: laser@qsl.net Date: Tue, 12 Aug 1997 03:46:06 -0400 Subject: [LASER] Laser Printer Message-Id: <19970812.035208.6334.0.K3PGP@juno.com> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 2-5,9-10,13-14,18-19,23-24,29-30,32-41 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk This doesn't directly concern lasers, but since we seem to have a log of people on here that work with lasers in different fields I thought I would try this question here. ----- In the past I've been tearing apart junked laser printers to get the laser out of them! However, just recently I was given one that I think is worth saving but I'm not exactly sure how to proceed. I was hoping that someone on here could offer some advice... The printer is an NEC Silenwriter 2 Model 90 with Postscript installed. The unit powers up and after approx. 10 or 15 seconds the front panel LCD says RESETTING. I went over to a friends house that has the same model printer and we swapped the CPU board and my printer works just fine but his then says RESETTING ! So I think it's safe to assume that the problem is on the CPU board. Al chips that were socketed (including the Postscript add on board) were swapped without changing the condition. His feeling was there was a bad RAM chip on my CPU board. However, these are surface mount and soldered in place. Anyone have any ideas on how to proceed from here? Any service shops that for a fee will swap out a CPU board for this printer? I don't mind doing board repairs myself as long as I have some idea as to which part is bad. There are two many RAM chips on the CPU board to start unsoldering them at random especially since there are surface mount! Anyone know how to contact NEC about this? I don't know if they would do anything about this anyway but it's worth a shot... Thanks... John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Fri Aug 15 15:35:01 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA21342; Fri, 15 Aug 97 15:35:01 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Message-Id: <199708152227.RAA24134@ultra.qni.com> From: "Gary Watts" To: "John K3PGP" , Subject: Re: [LASER] Laser Printer Date: Fri, 15 Aug 1997 17:27:39 -0500 X-Msmail-Priority: Normal X-Priority: 3 X-Mailer: Microsoft Internet Mail 4.70.1155 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Reply-To: "Gary Watts" Sender: owner-laser@berlioz.nsc.com Precedence: bulk John & the Group I have not received any messages on the laser list since the 12th Is the just hitting a low traffic time or is it me ? Looking for ways to build a sensitive receiver to start playing with cloud bounce Thanks Gary ---------- > From: John K3PGP > To: laser@qsl.net > Subject: [LASER] Laser Printer > Date: Tuesday, August 12, 1997 2:46 AM > > This doesn't directly concern lasers, but since we seem to have a log of > people on here that work with lasers in different fields I thought I > would try this question here. > > ----- > > In the past I've been tearing apart junked laser printers to get the > laser out of them! However, just recently I was given one that I think > is worth saving but I'm not exactly sure how to proceed. I was hoping > that someone on here could offer some advice... > > The printer is an NEC Silenwriter 2 Model 90 with Postscript installed. > The unit powers up and after approx. 10 or 15 seconds the front panel LCD > says RESETTING. > > I went over to a friends house that has the same model printer and we > swapped the CPU board and my printer works just fine but his then says > RESETTING ! So I think it's safe to assume that the problem is on the > CPU board. > > Al chips that were socketed (including the Postscript add on board) were > swapped without changing the condition. His feeling was there was a bad > RAM chip on my CPU board. However, these are surface mount and soldered > in place. > > Anyone have any ideas on how to proceed from here? Any service shops > that for a fee will swap out a CPU board for this printer? I don't mind > doing board repairs myself as long as I have some idea as to which part > is bad. There are two many RAM chips on the CPU board to start > unsoldering them at random especially since there are surface mount! > > Anyone know how to contact NEC about this? I don't know if they would do > anything about this anyway but it's worth a shot... > > > Thanks... > > > John > K3PGP@juno.com > http://www.qsl.net/k3pgp > -==- >From owner-laser Sat Aug 16 01:08:42 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA06917; Sat, 16 Aug 97 01:08:42 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: gwatts@qni.com, laser@qsl.net, daveaa1a@xensei.com Date: Sat, 16 Aug 1997 04:02:29 -0400 Subject: [LASER] Laser List Activity Message-Id: <19970816.040232.3710.1.K3PGP@juno.com> References: <199708152227.RAA24134@ultra.qni.com> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 0-17,20-21,28-29,35-36,40-41,47-48,50-56 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk On Fri, 15 Aug 1997 17:27:39 -0500 "Gary Watts" writes: >John & the Group >I have not received any messages on the laser list since the 12th >Is the just hitting a low traffic time or is it me ? > >Looking for ways to build a sensitive receiver to start playing with >cloud >bounce > >Thanks >Gary ----- Gary: The list does this from time to time. In my own case I'm trying to get a bunch of outdoor work done before the weather turns colder. I'm about half way through replacing the roof on the house. The porch project is just about done. My laser EME project demands a LOT cleaner atmosphere than we currently have and it will have to wait till colder temperatures bring clearer skies as I need all the help I can get with the amount of laser power that I currently have. It's even tough getting troposcatter to work with all the haze and pollution in the in the atmosphere. If I fire the laser straight up into the haze and pollution it can be heard over the horizon but the range is a LOT less than what I was getting under clearer skies. The 500 mw laser isn't in use as of yet. All I have mounted to the system currently is the 5 mw 780 nm and 30 mw 827 nm lasers. The 500 mw 815 nm laser is presently 40 inches long with all the required optics etc. for EME. I was recently given a gold front surface mirror and I may consider changing it over to a folded arrangement to get the length down to a more manageable 20 inches! Hang in there as there is some good info on here from time to time. This time of year it can get a little dry as a lot of the regulars on the laser list are probably doing similar work that needs to be done before winter. I'm planning on writing up the receive front end on the web site as soon as I get some free time. I may also have some cheap PIN diodes available for this project in the near future. The laser power meter calibration was supposed to be verified this week but the guy wasn't available. Hopefully that will also get done shortly as I have several people and publication items on hold because of this. PS - Dave: The three legged fuse project will be taken care of as soon as the power meter calibration is verified! John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Mon Aug 18 08:34:21 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA25979; Mon, 18 Aug 97 08:34:21 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Message-Id: <199708181428.KAA18709@ns1.qsl.net> From: w1_k_sorter@qsl.net (K sorter) To: laser@qsl.net Subject: [LASER] submini power source needed Date: Mon, 18 Aug 1997 18:27:08 GMT X-Newsreader: Forte Free Agent 1.0.82 Reply-To: w1_k_sorter@qsl.net (K sorter) Sender: owner-laser@berlioz.nsc.com Precedence: bulk My friends, I have need for a somewhat specialized power supply and haven't been able to find the answer within the PM Tube industry, so I thought I would run it up the flagpole here, so to speak. Power supplies for PM Tubes are VERY EXPENSIVE and Hamamatsu makes the power supply I need (almost). They have developed the Cockdroft-Walton multiple stage voltage doubler power supply, but refuse to make it available in a form that can be utilized for non-Hamamatsu PM Tubes. So, I am currently searching for an alternative to the Cockcroft-Walton supply, the most obvious solution is to RUN THE TUBE DIRECTLY from batteries. --------------------- I need a power source as follows: Each stage needs to supply (about) 100 volts DC at picoamp to 100 microamp amplitude (100 microamp current draw would be VERY RARE, typical operating current draw is less than 5 microamp, and the tube will spend 99 percent of it's life drawing 10 picoamps or less). 10 of these stages are needed to produce voltage taps at 1000v, 900v, 800v, 700v and so on, down to zero volts. --------------------- My first thought was to check out the nicad battery suppliers, but they only have 1.5 v and 9 v cells, and they don't have any miniature versions. I could not find a single vendor who had any interest in anything other than 1.5 and 9 v cells. In light of the VERY MODEST current demands of the PM Tube, I wondered if it might be possible to actually fabricate small electro-chemical batteries on a printed circuit board (or similar technique) and to then put the boards in series when needed. Obviously, lead-acid as used in car batteries would be a good place to start, but each cell needs its electrolyte to be physically isolated from the other cells, making microfabrication somewhat more complicated. I do not run the PM Tube often, so I don't mind if the battery stack requires some occasional maintenance (a maintenance free 'battery' is not required). I'd love to find some ni-cad watch battery sized cells, they are stackable and rechargeable-but they just aren't available. Any ideas from the group regarding how to make compact low current dc power sources by using electrochemical reactions? I do need the power source to be reasonably compact. Art, KY1K >From owner-laser Thu Aug 21 23:49:42 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA19915; Thu, 21 Aug 97 23:49:42 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Date: Fri, 22 Aug 1997 02:43:12 -0400 From: Mark Hughes Subject: [LASER] source of laser diodes To: Laser reflector Message-Id: <199708220243_MC2-1DD6-CA25@compuserve.com> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=ISO-8859-1 Content-Disposition: inline Reply-To: Mark Hughes Sender: owner-laser@berlioz.nsc.com Precedence: bulk Hi there, I am looking for a reasonable source of visible laser diodes / modules. hear in the UK, I have been quoted 49 pounds ( $75) for a 5mW diode or 60 pounds abt $90 for a 1 mW module I am told that in the far east and elsewhere laser pointers are availabe for as little as 10 pounds ($15) So far, though I have not been able to obtain any. I have got a couple of IR lasers surplus over here, but need some visible= gear Can anyone help source some at sensible prices? Thanks, Mark Hughes GM4ISM nr Glasgow markhughes1@compuserve.com >From owner-laser Fri Aug 22 07:59:54 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA00388; Fri, 22 Aug 97 07:59:54 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: laser@qsl.net Date: Fri, 22 Aug 1997 10:11:40 -0400 Subject: Re: [LASER] source of laser diodes Message-Id: <19970822.104753.3494.0.K3PGP@juno.com> References: <199708220243_MC2-1DD6-CA25@compuserve.com> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 1-18,22-23,27-28,34-35,39-40,45-51 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk On Fri, 22 Aug 1997 02:43:12 -0400 Mark Hughes writes: >Hi there, I am looking for a reasonable source of visible laser diodes >modules. hear in the UK, I have been quoted 49 pounds ( $75) >for a 5mW diode or 60 pounds abt $90 for a 1 mW module >I am told that in the far east and elsewhere laser pointers are >availabe for as little as 10 pounds ($15) >So far, though I have not been able to obtain any. >I have got a couple of IR lasers surplus over here, but need some >visible gear Can anyone help source some at sensible prices? >Thanks, >Mark Hughes GM4ISM nr Glasgow > >markhughes1@compuserve.com ----- Mark: Try going down the *Laser Vendor list on my web page. I've seen 15 mw diodes there for as little as $USD 20.00 ! 5 mw diodes are cheaper but keep in mind that most of these places are 'surplus' dealers and stock changes almost daily. Recently I have been dealing with Oatley in Australia for bare diodes. You need to send them Email to get the current exchange rate as the prices are in $AUS dollars. When sent to the states $AUS 1.00 ~ $USD $0.75. If you want a laser pointer, I can order a couple from Damark and send them to you if you can't find what you want elsewhere. They're $25.00 each. There's a description of how to modulate these on my web page under: *A $25 Multi-Mode Laser Pen Transmitter! These are 670 nm approx. 1 to 2 mw. The power can be increased by using more voltage but you stand a good chance of destroying the diode if you take this too far! Jim - GM4RJX and Simon - GM4PLM have already asked about having me order some of the Damark pens for them. Perhaps you should get together with them and I can send one order to one of you and save everyone some shipping costs! Keep in mind that most PIN diodes are MORE sensitive to IR. If your objective is laser com you might be better off sticking with IR laser diodes depending on the type of detector you plan on using. I've had much better results with most detectors using IR 780 to 830 nm laser diodes. John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Fri Aug 22 08:00:11 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA00398; Fri, 22 Aug 97 08:00:11 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: gwatts@qni.com, laser@qsl.net Date: Fri, 22 Aug 1997 10:47:34 -0400 Subject: [LASER] PMTs Message-Id: <19970822.104753.3494.1.K3PGP@juno.com> References: <199708220510.AAA27764@ultra.qni.com> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 0-28,30-31,34-35,40-41,46-47,53-54,58-59,63-64, 70-71,75-76,78-83,89-92,96-99,104-105,107-110,112-113,116-117,119-125 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk On Fri, 22 Aug 1997 00:10:32 -0500 "Gary Watts" writes: > >Hello Jim and John >Where can I pick up a pmt >How much should I expect to pay for it >what should come with it >and what else would I need to get audio from it > >Myself and another person "Dale Lam" have been playing with some >635 laser pens with 555 chips to transmit tones >we have not been able to do any real long distance other than 0.6 >mile direct because we cant find any good clean shots >we do live about three miles apart >hills and many trees between us >my current receive is a 3 1/2" X 3 1/2" fresnal lens >into a photo-transistor and a single op amp >to a amplified speaker >I believe it is doing pretty good because We can hear one of those >12,000 mcd Bright Diodes >being modulated with tone ,reflected off of a stop sign that was about > >600" away > >Gary ----- Gary: To put it mildly phototransistors are about the poorest detector you could use for laser com. Only a solar cell is worse! Before you go for a PMT I suggest that you try a PIN diode and a good preamp. This is all that I am using here for cloud bounce, troposcatter, and EME. The secret to making a PIN diode work correctly is in the preamp. My most sensitive setup so far is a PIN diode with no load resistor and no bias into an MPF-102 feeding a 2N5088 low noise NPN transistor. This setup is equal to my best PMT at room temp. If I cool the assembly to 17 degrees C it's approx. 10 db better than the PMT. NOTE: The above setup is for NIGHTTIME use only! For daylight use you may need to bias the PIN diode and use a load resistor, both of which will destroy weak signal capabilities. During daylight hours you aren't going to work much in the way of weak signals anyway, at least not with a simple setup... I KNOW there are PMTs out there that work extremely well in the red and IR region. However, I have tested 193 PMTs of different types and manufacturer and ALL suffered from red droop. ALL of the PMTs were EXTREMELY sensitive in the 350 to 450 nm region. The response peaks in this range for most PMTs and falls off very sharply by the time you get to the 600 to 800 nm range where most lasers operate. If you really think you want a PMT be sure it has extended red response. I've been looking for over ten years for one of these and haven't been able to find one other than what's available new for approx. $900 to $1000 !!! These do show up from time to time on the surplus market but they seem to be extremely rare. If you want a Hamamatsu PMT to play around with, MWK has some for $20.00. However, they also have poor red response. This is NOT a defect! It's simply a characteristic of most PMTs. PS - When using a fresnel lens you need to use a detector with a fairly large active area as most fresnels do NOT focus down to a small dot. Try setting up that 12,000 mcd LED some distance away from the fresnel and use the fresnel to focus the image on a piece of white paper. Compare this to the diameter of your detector. Anything that doesn't hit the detector is wasted signal! It's been my experience that you will need a detector with approx. a 1/4 active area to make the best use of most fresnels... Since you are using a rather small fresnel this problem may not be as severe as with the larger fresnels. Edmund Sci. 1-800-728-6999 has an excellent 11 inch square fresnel for $12 to $13 depending on focal length. As far as the PMT questions: >Where can I pick up a pmt Wish I could help you here. Other than MWK, mentioned above, I don't know of a source. Most of the MWK PMTs suffer from improper handling and light damage. ALL have severe red droop. I've seen some other surplus dealers selling PMTs and power supply for approx. $100. Based on my experience I wouldn't buy anything like this unless I had the option to return it for a FULL refund! >How much should I expect to pay for it I wouldn't pay any more than $10 to $20 at most for a PMT. And that's only if the tube is in a box (protected from light) and guaranteed good. If the PMT has been laying around exposed to room light or daylight, I wouldn't touch it! >what should come with it You will need a regulated power supply of approx. -1000 VDC. There should also be a resistor divider on the socket of the PMT assembly. You can build both of these yourself but it's rather time consuming... The HV supply only needs to supply current in the microamp range but it has to have EXTREMELY low ripple and EXTREMELY good regulation. The PMT also need to be shielded from EVERYTHING! Mine are built inside a sealed tin can. >and what else would I need to get audio from it The signal is developed across a load resistor to ground when using a negative HV supply. All you need is an audio amp.... It's my opinion that due to light polution here on the east coast, I don't have dark enough skies to make full use of a PMT even if I did have one that worked at 800 nm! Happy hunting. I hope your experience with finding suitable PMTs is better than mine! John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Fri Aug 22 08:59:20 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA02408; Fri, 22 Aug 97 08:59:20 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Date: Fri, 22 Aug 97 08:38:37 PDT From: jmoss@berlioz.nsc.com (Jim Moss) Message-Id: <9708221538.AA01750@berlioz.nsc.com> To: laser@qsl.net Subject: [LASER] PMT's and laser pens Reply-To: jmoss@berlioz.nsc.com (Jim Moss) Sender: owner-laser@berlioz.nsc.com Precedence: bulk I'm in agreement with what John says. PMT's are hard to find with good red response. I have been lucky and have shared that with several here on the reflector, by finding a small group of PMTs with IR response (in the past... they are all "in use?" now). I keep looking at every PMT I find, and checking it against the catalogs to see if we can get lucky again. When and if I ever find some more I'll be sure to share with the group! I've not tried playing with cloud bounce with my PIN diode setup. I will try that next time we have some clouds. (some are due this weekend) Signals on the PMT were drowned by general light from the city, until I added a 40nM filter in front of the PMT. Signal/noise improved dramaticly. Laser pens go on and off sale regularly here at discount electronic stores. Fry's electronics in Sunnyvale, CA (1-408-735-6918) often has special deals, which I try to let everyone know about. There is one on sale this weekend (sales there usually run 3 days only), for $29.99. I have one of this model, and tested it. I found it to be 2.3mW and on 661nM. There is no "module" in this one, just a direct connect from the diode to 2 1.5v batteries. The lens assembly is "cheap plastic" not a brass assembly. Divergence is near 1mR and the pattern is variable with different pointers, but generally "OK", not round. This pen has been on sale in the past for 19.99, so it might be best to keep waiting, or look at the one John mentioned from Damark. Other pens with modules, generally cost more and have features like "blink" mode. They also seem to have better lens assemblies (brass). BTW - Fry's has a 2.5GB ATA3 hard drive from Seagate on sale this weekend for $164! Jim WB9AJZ >From owner-laser Mon Aug 25 19:00:44 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA16767; Mon, 25 Aug 97 19:00:44 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Message-Id: <3402250C.2CD6@prodigy.net> Date: Mon, 25 Aug 1997 19:36:28 -0500 From: KC5AN Organization: Prodigy Internet X-Mailer: Mozilla 3.0 (Win95; I) Mime-Version: 1.0 To: Laser Reflector Subject: [LASER] need simple filter for 120 Hz Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Reply-To: KC5AN Sender: owner-laser@berlioz.nsc.com Precedence: bulk I would appreciate any info on a simple, passive filter that will attenuate 120 Hz, but not affect 800 Hz & up. Thanks, John kc5n North Texas >From owner-laser Mon Aug 25 19:03:43 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA16906; Mon, 25 Aug 97 19:03:43 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Message-Id: <1.5.4.32.19970825225409.006ed5e0@wms.luminet.net> X-Sender: jjeffers@wms.luminet.net X-Mailer: Windows Eudora Light Version 1.5.4 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Mon, 25 Aug 1997 17:54:09 -0500 To: laser@qsl.net From: James Jefferson Subject: [LASER] Surplus PIN diode Reply-To: James Jefferson Sender: owner-laser@berlioz.nsc.com Precedence: bulk I just received a copy of "Concord Components" catalog. Two items that caught my eye (and I'm looking for opinions on) are: "Photo Diode - PIN type Made by TOSHIBA V(Reverse) = 20V Max I(Short Circuit) = .9 Amp 4mm Diameter" These list for $0.55 is 1-9 quantity and $0.45 is 10+ quantify "Fibre Optic LED Great for experiments!!! Couples 150 micro-watts of optical power into standard 100/140 cable though a standard ST connector. Made by HONEYWELL" $5.95 in 1-5 quantify and $5.25 in 6+ quantify On a different note ... I say a 3M demonstration at the Minnesota State Fair yesterday. The talk was geared more towards non-technical people but it was still interesting to say the least! They brought along a 35mw IR laser as well as bunches of HE-NE lasers .... I tried talking the guys out of a tour of their facility but they said that 'for safety reasons and proprietary reasons we can't allow that', I did manage to snag some e-mail addresses. I think I've found a inexpensive source for 5mw 670nm laser diodes... I believe the price is at aprox $9. I'll post more details later. 73's de James Jefferson KB0THN cjeffers@luminet.net http://www.luminet.net/~cjeffers/ Jim's KB0THN Satellite Page! >From owner-laser Tue Aug 26 09:28:47 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA09357; Tue, 26 Aug 97 09:28:47 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Date: Tue, 26 Aug 97 09:11:14 PDT From: jmoss@berlioz.nsc.com (Jim Moss) Message-Id: <9708261611.AA08627@berlioz.nsc.com> To: KC5AN@prodigy.net Subject: Re: [LASER] need simple filter for 120 Hz Cc: laser@qsl.net Reply-To: jmoss@berlioz.nsc.com (Jim Moss) Sender: owner-laser@berlioz.nsc.com Precedence: bulk John, Do you just want to get rid of 120, or would you like to filter the offending light signal giving you the 120? An AF high pass filter will work well for the 120 reduction at audio. raising the value of the coupling cap into your AF amp will help a bit. But you can get a 40nM BW light filter for fairly cheap. The filters in the HeNe barcode guns have good pass band of 630-670nM. And a local store here has some that are 650 +/- 20nM (don't work well at 670, ok at 632) for <$1. These help your entire front end S/N, as does a more selective input optics (for area of sky covered). Most of the urban sky noise is not in the 670 area... check out: http://www.nightline-inc.com/nightline/nightvision/index.html it has a nice graphic of what light wavelengths are causing the noise. http://www.qsl.net/k3pgp http://www.qsl.net/wb9ajz/laser/laser.html Jim WB9AJZ/6 >From owner-laser Tue Aug 26 10:57:02 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA12690; Tue, 26 Aug 97 10:57:02 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Message-Id: <3.0.1.32.19970826125135.007fe800@colby.edu> X-Sender: aballen@colby.edu X-Mailer: Windows Eudora Light Version 3.0.1 (32) Date: Tue, 26 Aug 1997 12:51:35 -0500 To: laser@qsl.net From: "Art Allen, KY1K" Subject: [LASER] 120 hz filter + other Cc: KC5AN@prodigy.net Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Reply-To: "Art Allen, KY1K" Sender: owner-laser@berlioz.nsc.com Precedence: bulk The most obvious choice is the TOKO THB111A. It is a plug and play unit and needs very few descrete components. It is also VERY EXPENSIVE. I'm hoping for a better solution, but for now, I think this is it. With a hi gain chip, it in not uncommon for the feedthough coupling (input to output stray C) and power supply coupling to degrade the ultimate rejection of the chip itself. If you do end up going this route, make sure you build the audio filter in its own enclosure to shield it and to keep your component layout clean. Treat it as though it was an rf circuit, or else you might not get the full benefit. You need to do the same for your receiver chip-some users on this list noted that the opa2xx integrated PD/AMP assy's need shielding at high gain, otherwise they pickup ac from the air. Make sure your preamp is clean and properly shielded before dropping your hard earned $$ into a special chip for filtering. I would filter the incomming light first-if that didn't give me the results I needed, THEN I'd look towards electronic filtering. Incidently, our problem of filtering low audio frequencies OUT of our passband is not unlike the filtering that is done for microphone preamps, except we MIGHT need higher rejection. If you have slight/medium 60/120 hz interference, the answer might be as close as a mic preamp schematic in the Handbook. Better filters are written up in the older handbooks too-these are based on 88 uhy chokes that used to be common. The QRP handbook has a nice filter based on this concept, its REAL EASY to build too. I'm currently building a PM tube front end that has 100X more sensitivity than I could ever hope to possibly use-but I'll make it practical by stacking some optical filters in front of it. I'm hoping (maybe wishfull thinking) that I won't have to do electronic bandpass filtering at all hi hi. Hey, by the way, I sent my PD and front end to John, and he rated it relative to his best front end. He told me several months ago that I was the only one that took him up on his offer to quantify receiver sensitivity. Would someone please send him a built OPA2XX type front end, so that he can quantify its sensitivity. I'm dieing to know how good (or how bad) mine is relative to the OPA2XX devices. I have also received info from Sharp on their laser diode driver chips. They make 2 units, one for common anode and one for anode to cathode type diodes. Both require positive and negative voltage supplies. I'm going to try and get a sample of each and will report back on the results. In the meantime, if anyone wants the schematic of their chip, I'd be glad to supply it. I also have a question re: PM tubes. I've discovered that the voltage divider string wastes ALOT of power supply current, and have concluded that the resistor values could be much higher in value IF we were willing to sacrifice some LARGE SIGNAL handling and linearity. Personally, I am interested in small signals anyway, so I'd very much appreciate knowing HOW LARGE I can actually make those resistors in order to get lower power consumption by the divider string. Any ideas? Also, anyone using APD's? Keep them lasers lit and good dx....Art... >From owner-laser Tue Aug 26 18:33:36 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA28686; Tue, 26 Aug 97 18:33:36 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Date: Tue, 26 Aug 1997 21:19:05 -0400 (EDT) From: Wayne R Hilliard X-Sender: woody@woody.test.test To: LAser messages Cc: woody@sover.net Subject: [LASER] digital laser printer Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Reply-To: Wayne R Hilliard Sender: owner-laser@berlioz.nsc.com Precedence: bulk Hello all it's been a while since I've posted here but I have been reading the messages. Now for the question, I picked up a Digital laser printer for $2.00 at a local ham-fest. I've pulled the laser out of it and it is a modular assembly with a pc board on it that says ld drv on it. The are no ic's on the board but has two devices that are some sort of transistor or the like. There is also a 9 pin edge connector on the board and I should be able to supply the voltages needed to it. Anybody has any experience with using these things that I might need to know? Thanks in advance! Wayne Hilliard "If computers are making the world a global village, KA1CXD and I can't figure out how to use one, does that woody@sover.net make me the global village idiot ?" Shoe >From owner-laser Wed Aug 27 06:59:30 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA20434; Wed, 27 Aug 97 06:59:30 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Message-Id: <3.0.1.32.19970827085228.00804810@colby.edu> X-Sender: aballen@colby.edu X-Mailer: Windows Eudora Light Version 3.0.1 (32) Date: Wed, 27 Aug 1997 08:52:28 -0500 To: Wayne R Hilliard From: "Art Allen, KY1K" Subject: Re: [LASER] digital laser printer Cc: laser@qsl.net In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Reply-To: "Art Allen, KY1K" Sender: owner-laser@berlioz.nsc.com Precedence: bulk At 09:19 PM 08/26/1997 -0400, you wrote: >Hello all it's been a while since I've posted here but I have been reading the >messages. Now for the question, I picked up a Digital laser printer for $2.00 >at a local ham-fest. I've pulled the laser out of it and it is a modular assembly >with a pc board on it that says ld drv on it. The are no ic's on the board but >has two devices that are some sort of transistor or the like. There is also a 9 >pin edge connector on the board and I should be able to supply the voltages >needed to it. Anybody has any experience with using these things that I might >need to know? Thanks in advance! > > Hey Wayne- STOP right now!!!!! DON'T tear that printer apart any further- While the power supplies are still functional in that printer, go in and measure the polarity and amplitude of each one of the inputs (with the laser driver assy in place). Then, take the laser driver out and trace the circuit board out to develop a schematic diagram. The power supply inputs will be easy to spot once you look at the pcb, they are larger in diameter and have electrolytic caps bypassing them to ground. Once you know the power supply inputs, you can figure out the digital control inputs fairly easily by experimenting. Hope this helps... I did a similar reverse engineering job on the timeline module, but was unable to get the driver going because I couldn't figure out what voltage to put on each of the power supply inputs-so the driver module sits in a box downstairs-useless. You are fortunate, you have the entire printer available for in circuit measurements and quantification. Incidently, I'm looking for the rotating front surface mirror and driver motor assy from a laser printer. Is the mirror from yours for sale? GL and good dx. Art. >From owner-laser Wed Aug 27 07:55:27 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA22199; Wed, 27 Aug 97 07:55:27 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: laser@qsl.net Date: Wed, 27 Aug 1997 10:47:20 -0400 Subject: Re: [LASER] need simple filter for 120 Hz Message-Id: <19970827.104722.5014.6.K3PGP@juno.com> References: <3402250C.2CD6@prodigy.net> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 0-11,14-15,18-19,23-24,27-28,33-34,38-39,44-45, 50-51,57-58,63-64,66-72 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk On Mon, 25 Aug 1997 19:36:28 -0500 KC5AN writes: >I would appreciate any info on a simple, passive >filter that will attenuate 120 Hz, but not affect >800 Hz & up. > >Thanks, >John >kc5n >North Texas ----- You might want to cover the lens on your receiver with a non conducting piece of material and make sure the hum is coming from man made light and not from direct electrical pickup. If you still have the hum with the lens covered you have a shielding problem and this should be corrected before going to a filter either electrical or optical. Most of my optical front ends are built in tin cans or PC board soldered together to make a shielded box. You can try wrapping your front end in aluminum foil then ground the foil to the preamp to see if the hum goes away. If it does you need better shielding! Of course hum can also come from the power supply. You might want to power the system from batteries to make sure this isn't a problem. You may find that you have a combination of all three problems! As far as electrical filtering is concerned, I just reduced the capacitors in my preamp so that it rolled off everything below 500 Hz or so. About the same thing as done in a mic preamp as suggested by Art. I find filters with sharp cutoffs extremely irritating to listen to and much prefer the gentle roll off of small coupling capacitors. The study of the spectrum from man made light is a most interesting topic in itself. If you look closely at the spectrum you will find that it not only contains 120 Hz but many harmonics of 60 Hz with the 3rd, 5th and 7th usually the strongest. However, I have on occasion seen ONLY the 9th harmonic show up or other weird things like only the 5th with the 2nd and all others absent! On one occasion I remember seeing only the 2nd and 6th !!! If you look at any of the spectrographs on my web page you will see evidence of the harmonic content from man made light scattering back from the atmosphere. It's very interesting to look at clouds during the night and observe the resulting spectrum using VE2IQ's FFT program. It seems every light source has it's own particular signature. When pointing the system near the horizon I can watch the various harmonics of the 60 Hz lighting vary as different sources from the ground bounce off the bottom of the clouds. Once you do this you'll become aware of the fact that a simple 120 Hz notch filter will NOT eliminate the problem as there is a LOT of energy in the higher harmonics as well and these harmonics vary over time! A 60 hz comb filter (has a notch every 60 Hz) seems to work well as do many of the optical filters mentioned here although most do have some insertion loss. All the above assumes that you are indeed being troubled by man made light. My guess is this is NOT the case and that you need to beef up the electrical shielding and/or power supply decoupling. A properly shielded front end will produce only a hiss with no evidence of hum when the lens is covered. PS - 800 Hz BPSK, SSB, and any type of subcarrier system seems to be immune to all these hum effects, electrical, optical, or otherwise. John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Wed Aug 27 08:16:20 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA22904; Wed, 27 Aug 97 08:16:20 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: laser@qsl.net Date: Wed, 27 Aug 1997 11:09:41 -0400 Subject: Re: [LASER] digital laser printer Message-Id: <19970827.110952.5014.9.K3PGP@juno.com> References: X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 1-7,9-10,13-14,17-18,23-24,29-36 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk On Tue, 26 Aug 1997 21:19:05 -0400 (EDT) Wayne R Hilliard writes: >The are no ic's on the board but has two devices >that are some sort of transistor or the like. There >is also a 9 pin edge connector on the board Wayne: The circuit you describe sounds like the classic two transistor feedback regulator. The laser diode has an internal photodiode and this signal goes back to the base of one of the transistors and is used to regulate the laser power. Be careful when determining the connections. If you disturb the regulator or accidently interrupt the feedback signal the laser diode will be destroyed! You might want to use a current limited power supply when doing tests. Set it for around 75 ma or so. You can use a 7805 circuit like the one described by Dave AA1A if you don't have a current limited bench supply. Connect the output of the 7805 (used as a current limiter) to the laser printer board and NOT directly to the laser diode! I wouldn't run it without current limiting until you're sure the circuit is hooked up and regulating correctly. However, if you go to the trouble of building up some type of current limiter it wouldn't hurt to just leave it in the circuit as a 'protection' device! Just set it slightly above the normal operating current or the laser assembly. John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Wed Aug 27 08:19:14 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA23069; Wed, 27 Aug 97 08:19:14 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Date: Wed, 27 Aug 1997 08:17:54 -0700 From: c1040@azfms.com (Rusty Carruth) Message-Id: <199708271517.IAA13302@fmswksn06.azfms.dot> To: laser@qsl.net Subject: [LASER] Yet another visit to California, San Fran to be exact. X-Sun-Charset: US-ASCII Reply-To: c1040@azfms.com (Rusty Carruth) Sender: owner-laser@berlioz.nsc.com Precedence: bulk Well, Its happening again. October 1 and 2 I'll be in San Fran again, this time I'm staying near the airport. I arrive early the 1st for meeting from 8:30 to 5 or so (both days), then leave around 7 or 8 (from the airport) Don't know if anybody wants to repeat our last exercise or not (meeting somewhere for supper on the 2nd, in this case) - if anyone wants to then email me and we'll figure out the details (and this time I *promise* to keep the contact information where I can find it! - thanks again to all who helped last time! (and especially the long distance help!)) rusty >From owner-laser Wed Aug 27 14:18:08 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA07244; Wed, 27 Aug 97 14:18:08 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Date: Wed, 27 Aug 1997 17:04:14 -0400 (EDT) From: Wayne R Hilliard X-Sender: woody@woody.test.test To: laser Subject: [LASER] laser diode Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Reply-To: Wayne R Hilliard Sender: owner-laser@berlioz.nsc.com Precedence: bulk Ok folks here's the scoop. I re-armed all safety interlocks on the laser printer hooked up the laser diode module and proceeded to make measurements! I got all the way across the 9 pin connector recording the voltages, I went back to verify one voltage and promptly shorted out a -12 volt pin to a 5 volt pin. Now my question is this, how can I tell if the laser is lasing any longer. With an ambient light level in the room, I can detect a red glow on a radio shack infrared detector card at about 4 feet. I can also detect it at about 4 feet with a burr brown device with no power applied to the detector. For comparison I tried a tv remote control, I need to be within about 6 inches to hear it. Also the are no optical lenses that I know of collimating the beam. Also I saw an ic of some sort on the underside of the pc board. Maybe a op-amp? hence the +12 and -12 voltages? Any ways I was hoping that you guys might be able to give me some ideas on whether I have a laser or just a infrared led!! Thanks in advance. Wayne Hilliard "If computers are making the world a global village, KA1CXD and I can't figure out how to use one, does that woody@sover.net make me the global village idiot ?" Shoe >From owner-laser Wed Aug 27 16:28:16 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA12661; Wed, 27 Aug 97 16:28:16 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: laser@qsl.net Date: Wed, 27 Aug 1997 19:20:10 -0400 Subject: Re: [LASER] Easy Mounting Receiver Message-Id: <19970827.192013.6694.6.K3PGP@juno.com> References: <199708271701.NAA28442@xensei2.xensei.com> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 0-6,8-9,11-12,14-17,19-25 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk On Wed, 27 Aug 1997 13:01:46 -0400 daveaa1a@xensei.com writes: > >I took the liberty of getting hollered at for >sending pix on here.. Who did the hollering? Maybe the 'other' reflector isn't the best place for the pix of a laser front end. You know those low freq. guys! I have no problem with this as long as they are less than 40 k and it isn't a daily thing. As far as I remember I think I have the cutoff set to 40,000 bytes and your pix was 42.5 k. I'll see if I can tell the system to send it anyway! The shot was a little far away to show much detail. It would have been better if the receiver just filled the pix. John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Wed Aug 27 22:11:10 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA23939; Wed, 27 Aug 97 22:11:10 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Message-Id: <1.5.4.32.19970827165709.006e9e08@wms.luminet.net> X-Sender: jjeffers@wms.luminet.net X-Mailer: Windows Eudora Light Version 1.5.4 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Wed, 27 Aug 1997 11:57:09 -0500 To: laser@qsl.net From: James Jefferson Subject: [LASER] Concord Components Reply-To: James Jefferson Sender: owner-laser@berlioz.nsc.com Precedence: bulk I've gotten a number of request for information on Concord Components Concord Components 1-800-871-1749 PO Box 65, Concord, NE 68728 FAX (402)-584-2615 INFORMATION (402)-584-2310 Their catalog just landed in my mailbox a week ago so I have no prior experiece dealing with these people. -Jim Jefferson KB0THN cjeffers@luminet.net http://www.luminet.net/~cjeffers/ >From owner-laser Thu Aug 28 00:12:05 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA27497; Thu, 28 Aug 97 00:12:05 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f From: daveaa1a@xensei.com Date: Wed, 27 Aug 1997 13:01:46 -0400 Message-Id: <199708271701.NAA28442@xensei2.xensei.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Subject: [LASER] Easy Mounting Receiver To: laser@qsl.net Cc: bpsk@qsl.net X-Mailer: SPRY Mail Version: 04.00.06.17 Reply-To: daveaa1a@xensei.com Sender: owner-laser@berlioz.nsc.com Precedence: bulk Gudday..!!.. Been kinda quiet lately so I figured on sending a little bandwidth in the form of a receiver that is made from PVC drain, end caps, and unions.. Then a trip to the hardware store will find 'inch and a half' pvc coupling with stainless pipe insert.. I cut a 1.5 x 3" pc board and mount the PD rite dead middle and wire back from there.. Different 'heads' plug in.. The one shown is a low noise front end and broadbanded.. Another is a subcarrier receiver, then the reverse feed laser diode out of this unit.. Anyway, it's cheap/easy/fun.. Also easy to focus if you change modes.. 'it's built rite into the drain pipe adaptor' I took the liberty of getting hollered at for sending pix on here.. Look for some better pix soon, will put on the page.. 'qsl.net/aa1a' Hope y'all havin a good time.. 73s de dave - aa1a >From owner-laser Thu Aug 28 02:27:26 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA01995; Thu, 28 Aug 97 02:27:26 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: laser@qsl.net Date: Wed, 27 Aug 1997 23:03:49 -0400 Subject: Re: [LASER] laser diode Message-Id: <19970827.230356.19710.1.K3PGP@juno.com> References: X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 1-15,20,24-25,30-31,34-35,38-39,43-44,47-48,57-58, 61-62,69-70,77-78,81-87 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk On Wed, 27 Aug 1997 17:04:14 -0400 (EDT) Wayne R Hilliard writes: >I went back to verify one voltage and promptly >shorted out a -12 volt pin to a 5 volt pin. >Now my question is this, how can I tell if the >laser is lasing any longer. >With an ambient light level in the room, I can >detect a red glow on a radio shack infrared >detector card at about 4 feet. I can also >detect it at about 4 feet with a burr brown >device with no power applied to the detector. >For comparison I tried a tv remote control, >I need to be within about 6 inches to hear it. >Also the are no optical lenses that I know of >collimating the beam. Are you sure there is no collimation lens? All the laser printers I've torn apart do have a lens mounted right in front of the laser diode. It's usually mounted in a small cylinder and the lens is approx. 1/16 in diameter. It's easily mistaken as part of the heatsink! There's usually an allen head set screw to allow focusing the lens. Without a lens the beam from the laser diode will be EXTREMELY wide, something like 25 degrees or more in one direction and much narrower in the other, maybe 8 to 10 degrees or so. If this is what you are observing then the diode probably doesn't have a lens. However, if the size is much smaller and the beam is fairly circular or egg shaped you most likely have a lens in the system. You might want to explore right in front of the diode out to a couple of feet and see if the beam steadily grows in size or if it appears to go through a focus. At focus it should be EXTREMELY small and fairly circular. Usually you will need to move the lens closer to the diode for free space use as the laser was focused at a much shorter distance when used in the printer. You should have no problem seeing the laser beam without using the Radio Shack IR card. Although I can't speak for the diode you are using, most are 780 nm but it can be anywhere in the 780 to 830 nm region. There is a tremendous roll off in human eye response in this region and I'm not sure we all have the same abilities in this region. I have no problem seeing my laser printer heads when aimed across the room at a white target. You may have to look around till you find it though! BE CAREFUL! Just because you have difficulty seeing the beam doesn't mean it isn't dangerous. NEVER look directly at the output of the diode or reflections from a shiny object! PS - If you have any type of modern camcorder use it to look at the reflected beam. CCD's have much better response in this range than the human eye. You can use this outdoors with it zoomed to max. to focus on a distant target and use the TV monitor to adjust the lens on the laser for the smallest size. It helps to use a black and white TV for this test (better resolution) and adjust the briteness and contrast so the picture doesn't bloom or saturate on the laser beam. The picture may appear somewhat washed out when set up for this test. Use the farthest target you can for this setup. After you see the IR laser diode output on a CCD camera you will begin to appreciate just how much power is there and you will immediately understand why you have to be careful with your eyes! As far as whether you still have a laser diode or an expensive LED, it sounds like all is still OK. However, I've blown my share of diodes and it's possible to damage them in a way where the output power is simply reduced and not totally destroyed. If you looked at the beam BEFORE the accident and it still looks about the same I'd say all is OK but it sounds like you didn't do this test before the accident so don't have anything to compare to ??? You can get a rough idea of power output by using a Radio Shack solar cell into a 10 ohm resistor. Hang a digital voltmeter across the 10 ohm resistor and use ohms law to figure out the current. You should be seeing approx. 3 or 4 ma with the typical laser printer head aimed at the photocell. (.03 to .04 vdc) The exact reading is quite linear in this power range when using the 10 ohm load and will depend directly on laser ouput power. If you need a replacement IR laser diode I may have a few available. Not sure if they will fit you mounting arrangement though. They come in two sizes. 9.0 mm and 5.6 mm. John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Fri Aug 29 06:20:06 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA22957; Fri, 29 Aug 97 06:20:06 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Message-Id: <2NPk8AAdupB0Ew2D@hatton.demon.co.uk> Date: Fri, 29 Aug 1997 10:51:25 +0100 To: laser@qsl.net From: Jim Hatton Subject: [LASER] Front End Mime-Version: 1.0 X-Mailer: Turnpike Version 3.03a Reply-To: Jim Hatton Sender: owner-laser@berlioz.nsc.com Precedence: bulk Hi, I am in the experimental stage of playing with laser communications and have played around with simple receivers using phototransistors. I realise the limitations of such receivers and would be grateful if someone could point me to a decent front end design. I have some fairly high spec PIN photodiodes and would prefer to use them, so I am looking for a design which uses a PIN diode rather than a PMT. Thanks in advance. Jim GM4RJX jim hatton EMail jim@hatton.demon.co.uk WWW http://www.hatton.demon.co.uk >From owner-laser Fri Aug 29 14:04:18 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA09858; Fri, 29 Aug 97 14:04:18 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f From: daveaa1a@xensei.com Date: Fri, 29 Aug 1997 12:44:39 -0400 Message-Id: <199708291644.MAA18952@xensei2.xensei.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Subject: [LASER] IR boards To: laser@qsl.net X-Mailer: SPRY Mail Version: 04.00.06.17 Reply-To: daveaa1a@xensei.com Sender: owner-laser@berlioz.nsc.com Precedence: bulk Gudday... I am about to receive some discarded fiber optic boards that transmit 1330 and 1550 nm.. tx power is from 1 to 10 mw.. Also the receive boards are the same frequencies.. Does anyone know: How these frequencies operate in free space compared to what we are using now at near IR..??.. The bandwidth is good enough for 45 megabits.. That solves the bandwidth question but how sensitive can they be compared to Photo Diodes..??.. tnx de dave - aa1a * picked up THE LASER COOKBOOK, by Gordon McComb, a TAB production.. It ain't high tech but good info.. has 88 practical projects.. >From owner-laser Fri Aug 29 17:38:11 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA17739; Fri, 29 Aug 97 17:38:11 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Date: Fri, 29 Aug 97 17:26:52 PDT From: jmoss@berlioz.nsc.com (Jim Moss) Message-Id: <9708300026.AA17530@berlioz.nsc.com> To: daveaa1a@xensei.com Subject: Re: [LASER] IR boards Cc: laser@qsl.net Reply-To: jmoss@berlioz.nsc.com (Jim Moss) Sender: owner-laser@berlioz.nsc.com Precedence: bulk Dave, I salvaged a bunch of 10MbpS stuff... the specs on the RX diods is -7dBm for 10 MbpS... Not very sensitive, but fast. I've tried them lower, and they do work (mine were 780nm). >From owner-laser Sat Aug 30 00:46:10 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA29810; Sat, 30 Aug 97 00:46:10 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: laser@qsl.net Date: Sat, 30 Aug 1997 03:38:51 -0400 Subject: Re: [LASER] IR boards Message-Id: <19970830.033853.9286.3.K3PGP@juno.com> References: <199708291644.MAA18952@xensei2.xensei.com> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 0-21,26-27,33-34,37-38,41-42,46,48-51,54-60 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk On Fri, 29 Aug 1997 12:44:39 -0400 daveaa1a@xensei.com writes: > >Gudday... > >I am about to receive some discarded fiber optic >boards that transmit 1330 and 1550 nm.. tx power >is from 1 to 10 mw.. >Also the receive boards are the same frequencies.. > >Does anyone know: > >How these frequencies operate in free space >compared to what we are using now at near IR..??.. > >The bandwidth is good enough for 45 megabits.. >That solves the bandwidth question but how sensitive >can they be compared to Photo Diodes..??.. > >tnx de dave - aa1a ----- The ones I saw were designed for short haul (FREE SPACE) analog (NTSC) video links of approx. 1 to 2 miles. Propagation is excellent at 1300 to 1500 BUT as you no doubt know as the bandwidth goes up the range goes down so compared to what you are doing at 650 & 780 nm these are NOT DX weak signal systems! The good ones have an optical filter on the receiver so they can run fairly well in daylight. You probably don't have this if yours were designed for fiber optic use and NOT free space! If you redo the PIN diode bias and preamp so it's narrowband the range will increase dramatically BUT it will no longer run high speed data, nor will it work in daylight. Seems like we've been here before!!! Many of these units use some sort of integrated front end and can't be modified so you're pretty much stuck with the original specs. It probably depends on how old they are. Unlike the 780-830 nm stuff however, you can't see the beam at all and even CCD cameras are pretty dead! About the only thing that works is one of those cheap Radio Shack IR cards or SOME of the night vision tubes. PIN diodes basically come in two ranges. 700-900 nm and 1300-1500 nm. There are some other oddballs like those with extended UV response, etc. The 1300-1500 nm diodes will work at 780 nm but the response will be down a bit. I'd have to check my data book but I think most of the 700-900 diodes are silicon and the 1300-1500 diodes are GaAs. ----- PS - To everyone sending me Email, I am SLOWLY catching up. The past two days have been sunny and I'm making good progress on the outdoor projects! John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Sat Aug 30 06:06:40 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA07648; Sat, 30 Aug 97 06:06:40 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Message-Id: <3.0.1.32.19970830080117.007fa5c0@colby.edu> X-Sender: aballen@colby.edu X-Mailer: Windows Eudora Light Version 3.0.1 (32) Date: Sat, 30 Aug 1997 08:01:17 -0500 To: laser@qsl.net From: "Art Allen, KY1K" Subject: [LASER] Sharp tech info Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Reply-To: "Art Allen, KY1K" Sender: owner-laser@berlioz.nsc.com Precedence: bulk Hi Everyone, Sharp makes PD's and laser diodes-they claim to be the #1 in this field. They DO NOT have a WWW site for optoelectronics but they do have a free fax on demand system. The fax on demand is still under development and alot of laser stuff isn't on it yet. The number is 800-833-9437. enjoy, and good dx... Art. >From owner-laser Sat Aug 30 07:14:52 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA09602; Sat, 30 Aug 97 07:14:52 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Message-Id: <3.0.1.32.19970830090823.00809390@colby.edu> X-Sender: aballen@colby.edu X-Mailer: Windows Eudora Light Version 3.0.1 (32) Date: Sat, 30 Aug 1997 09:08:23 -0500 To: laser@qsl.net From: "Art Allen, KY1K" Subject: [LASER] 1.3 and 1.5 um laser propagation Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Reply-To: "Art Allen, KY1K" Sender: owner-laser@berlioz.nsc.com Precedence: bulk Jim and Dave, 1.3 and 1.5 um lasers will propagate better in air beacuse they are scattered less due to the longer wavelength. For LONG HAUL free air, these wavelenghts will get though the atmosphere better than HE or 780 nm IR! The best info I have to quantify the difference in propagation is that the erp at the receiver is 16+ times better every time the wavelength is doubled (assumes all other factors remain constant). A 1.5 um laser compared to a HE-NE is going to provide (1.5/.632)^4 increase in erp-an erp of 31.7! The difference between hene and IR (780 nm) is (780/632)^4 - and increase of 2.3 in erp! Please note, this relies on a somewhat gross oversimplification and rounding of Rayleigh and Mia and some major assumptions are made in order to come up with these figures. These figures are just a better estimate than an estimate that is made without taking into consideration these factors. Does this sound like a run-a-round? YEP, you bet-one could spend their entire life coming up with a better approximation!!!! If I remember correctly, there was a problem with 1.3 or 1.5-I can't remember details, but it had something to do with some absorption or adsorption of an atmospheric gas (cant remember which one) that peak at that lambda. One of those freqs is limited severely in the atmosphere due to this factor, wish my memory was better. Incidently, optics for these frequencies are specialized and not widely available and there are losses when visible lambda optics are used at 1.3 and 1.5. TX and RX products in this frequency range are usually fibre optic. Interfacing to and from fibre optic is easier said than done, I think the best interface has a 3 db+ loss FOR EACH transition. Also, GaAs has higher leakage than Si-this means higher dark current in the PD's and thus they aren't as sensitive on receive. These products are probably not well suited for ultra long range laser communication because practial considerations cancel out the gains provided by the decreased atmospheric attenuation. Hope this helps- GL and good dx. Art. >From owner-laser Sat Aug 30 08:05:38 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA11092; Sat, 30 Aug 97 08:05:38 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f Date: Sat, 30 Aug 1997 10:59:46 -0400 (EDT) From: "C. W. Wright" X-Sender: wwright@wayne.betaweb.com To: John K3PGP Cc: laser@qsl.net Subject: Re: [LASER] Easy Mounting Receiver In-Reply-To: <19970827.192013.6694.6.K3PGP@juno.com> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Reply-To: "C. W. Wright" Sender: owner-laser@berlioz.nsc.com Precedence: bulk > I have no problem with this as long as they are less than 40 k and it > isn't a daily thing. It would be *much* better if he/people could email the pictures to you, and then you put them on your laser web site. Then just post the url of the picture to this email list. In this way, only people interested in the pictures will receive them, also the web broswer automatically displays pictures. Many of us have to go through several steps to display a picture sent by email. -Wayne K3ap >From owner-laser Sat Aug 30 09:21:13 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA13216; Sat, 30 Aug 97 09:21:13 PDT X-Authentication-Warning: ns1.qsl.net: majordom set sender to owner-laser@qsl.net using -f To: laser@qsl.net Date: Sat, 30 Aug 1997 12:13:48 -0400 Subject: [LASER] Man-Made light solution... Message-Id: <19970830.121350.17350.1.K3PGP@juno.com> X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 0-1,3-18,21-22,27-32,34-35,38-52,54-59 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk To those of you struggling with man-made light.... I though you would get a kick out of reading this. It's something I never thought of myself but seems to work just fine! John K3PGP@juno.com http://www.qsl.net/k3pgp ---------- Forwarded message begins here ---------- Date: Sat, 30 Aug 1997 08:33:16 -0100 From: Bill Hollenbach : To: "astro@lists.mindspring.com" Subject: Re: [ASTRO] Re: ATM Streetlight control? Hi There, I thought I would share a sneaky little thing with you all. Most lights in the streets are switched on with a "photo cell". It is normally a white little gadget mounted somewhere on one of the streetlight poles. Enter one 4" f 12 Newtonian on a special mount. Align scope on sensor. Remove eyepiece and insert bright little light, focussing on the detector. Sensor detects light. Sensor thinks it is day and operates relay in switch house. Streetlights go out. Dark skies appear from nowhere in the heart of suburbia. :-> Happy astronomers do observing. Amazingly, as you pack up, the street lights go back on. As I work for an electrical supply company, I know that these detectors develop intermittened faults. :-> The neighbours in our area have been most co-operative, and normally tell me the following day about the street lights going out. I then test it, and Lo and Behold, there is nothing wrong. heheheheheheh Regards. -- Bill Hollenbach Cederberg Observatory ah52@solo.pipex.co.za http://aztec.co.za/exinet/travel/misc/cederobs.html http://www.cs.uct.ac.za/~iwebb/obs/ Lat: 32:30.11' (S) Long: 19:15.20' (E) GPS POSITION " We are stardust " Durbanville, Cape Town South Africa ---------- Forwarded message ends here ---------- PS - Lasers work great as a substitute for the flashlight, something we all usually happen to have handy!!! Pretty neat, huh ??? -==- >From owner-laser Sat Aug 30 17:25:01 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA26362; Sat, 30 Aug 97 17:25:01 PDT X-Authentication-Warning: ns3.qth.net: majordom set sender to owner-laser@qth.net using -f Message-Id: <3408AE09.3D6AD12D@qsl.net> Date: Sat, 30 Aug 1997 19:34:33 -0400 From: K3TKJ Organization: http://www.qsl.net X-Mailer: Mozilla 3.01Gold (X11; I; Linux 2.0.28 i486) Mime-Version: 1.0 To: alllists@qsl.net Subject: [LASER] ALL Lists Moved To QTH.Net References: <3.0.3.32.19970830231344.007707a8@mailhost.primenet.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Reply-To: K3TKJ Sender: owner-laser@berlioz.nsc.com Precedence: bulk ****ATTENTION**** All QSL.NET REFLECTOR USERS All mailing lists have been moved to QTH.Net for system administration reasons. QSL.Net is now the web server. QTH.Net is the mailing list server. Send commands to: Majordomo@QTH.Net Send Postings to QTH.NET and NOT QSL.NET The old addresses may work temporarily, but please update your address books now! All questions, suggestions, complaints should be directed to K7ON@QSL.NET Brian is the majordomo-owner and master of all the lists Brian Short k7on@qsl.net http://www.qsl.net/k7on 1994 E Laguna Dr Tempe, Az 85282 (602)839-3484 73, Al K3TKJ ======================================================================= Got a ham license? Want a free homepage? Want a free e-mail that is YOURCALL@QSL.NET? http://www.qsl.net/signup.html ======================================================================= >From owner-laser Sat Aug 30 18:27:52 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA28536; Sat, 30 Aug 97 18:27:52 PDT X-Authentication-Warning: ns3.qth.net: majordom set sender to owner-laser@qth.net using -f Message-Id: <3.0.3.32.19970831012134.01054460@mailhost.primenet.com> X-Sender: shortckt@mailhost.primenet.com X-Mailer: QUALCOMM Windows Eudora Pro Version 3.0.3 (32) Date: Sun, 31 Aug 1997 01:21:34 +0100 To: alllists@qsl.net From: "Brian K. Short" Subject: [LASER] All Mailing Lists at QTH.Net Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Reply-To: "Brian K. Short" Sender: owner-laser@berlioz.nsc.com Precedence: bulk So far, so good, I think all problems were fixed. ---- All QSL/QTH email mailing lists are now served by QTH.Net and the web pages remain on QSL.Net. Lists previously at QTH.Net were not changed. You do not need to rejoin if you are reading this. Address all future posts to QTH.Net All future commands go to: majordomo@QTH.Net No action is required except to update your address book for future reference. Everyone was moved along with the mailing lists. Brian Short k7on@qsl.net http://www.qsl.net/k7on 1994 E Laguna Dr Tempe, Az 85282 (602)839-3484 >From owner-laser Sun Aug 31 11:15:21 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA17667; Sun, 31 Aug 97 11:15:21 PDT X-Authentication-Warning: ns3.qth.net: majordom set sender to owner-laser@qth.net using -f To: laser@qth.net Date: Sun, 31 Aug 1997 14:05:39 -0400 Subject: [LASER] File Transfers Message-Id: <19970831.140656.11678.7.K3PGP@juno.com> References: X-Mailer: Juno 1.38 X-Juno-Line-Breaks: 1-7,9-14,16-17,19-20,29-30,35-36,42-43,45-48,51-52, 54-55,57-65 From: k3pgp@juno.com (John K3PGP) Reply-To: k3pgp@juno.com (John K3PGP) Sender: owner-laser@berlioz.nsc.com Precedence: bulk On Sat, 30 Aug 1997 10:59:46 -0400 (EDT) "C. W. Wright" writes: > >It would be *much* better if he/people could >email the pictures to you, and then you put >them on your laser web site. Then just post >the url of the picture to this email list. >In this way, only people interested in the >pictures will receive them, also the web broswer >automatically displays pictures. Many of us have >to go through several steps to display a picture >sent by email. > >-Wayne K3ap This has been suggested many times but there are a few reasons why I can't make it work as you suggest right now. # 1 - juno.com will refuse any attachments much over 40 k so there is no way for people to Email these files to me. # 2 - The present situation is (hopefully) temporary as Al (K3TKJ) has been trying to implement an anonymous ftp directory for us [LASER] and the [BPSK] reflector for the past couple of months with no success. This would solve the problem as all files could go there and then could be moved to the various web sites if needed or simply left in the LASER directory where anyone could access them. The directory is there but no one can upload using anonymous logon. Al is aware of the problem but as far as I know the project is no longer being worked on. It only seems to work with a password which of course can't be made public! # 3 - Extracting these files can be a one step process. If you are using DOS you can write a batch file to do this. If you are using WinDOZE :-^) 3.1 or 95 there are many public domain programs that make extraction a simple click on the item process. Similar public domain software is available for the Mac. Like I said I don't mind it as long as it isn't a daily thing. I don't see where someone posting a picture here once in a while should cause any problem. If you choose to NOT view the pix you can use the delete key to dump it just like any other post. However, if we start getting overrun with these long posts then of course the system can be programmed to reject these. As it is right now anything up to 40,000 bytes is fine with both me and the system as well as juno.com. ----- NOTE: laser@qsl.net has been moved to laser@qth.net. Hopefully this will be our final destination. You do NOT need to do anything on your part other than update where you are sending posts. Instead of sending to laser@qsl.net you should now send to laser@qth.net. Anything going to majordomo will of course now go to majordomo@qth.net. This was done to balance the load on the servers and should make for even faster response times! Soon we should be processing mail at the speed of laser, I mean light! John K3PGP@juno.com http://www.qsl.net/k3pgp -==- >From owner-laser Sun Aug 31 17:41:32 1997 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA26731; Sun, 31 Aug 97 17:41:32 PDT X-Authentication-Warning: ns3.qth.net: majordom set sender to owner-laser@qth.net using -f Message-Id: From: "Jim Baize" To: Subject: Re: [LASER] File Transfers Date: Sun, 31 Aug 1997 19:37:16 -0400 Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-Msmail-Priority: Normal X-Mailer: Microsoft Outlook Express 4.71.1008.3 X-Mimeole: Produced By Microsoft MimeOLE Engine V4.71.1008.3 Reply-To: "Jim Baize" Sender: owner-laser@berlioz.nsc.com Precedence: bulk There is a way to send binary files via "plain text" e-mail. It is a process called uuencode / uudecode. The process used to be used by UNIX machines but the software has been ported to DOS. Binary files can be encoded into plain text, then be broken into multiple e-mail messages so as to bypass such size restrictions. At the receiving end, the messages are recombined and decoded back into the binary file. I used to use it on Juno. The following excerpt will tell you how to get more information about this. "This document is now available from several automated mail servers. "To get the latest edition, send e-mail to one of the addresses below. " "To: mail-server@rtfm.mit.edu (for US, Canada & South America) "Enter only this line in the BODY of the note: " send usenet/news.answers/internet-services/access-via-email " "To: mailbase@mailbase.ac.uk (for Europe, Asia, etc.) "Enter only this line in the BODY of the note: " send lis-iis e-access-inet.txt" I hope this helps. Jim KB9JYE Every silver lining has a cloud. -----Original Message----- >On Sat, 30 Aug 1997 10:59:46 -0400 (EDT) "C. W. Wright" > writes: >> >>It would be *much* better if he/people could >>email the pictures to you, and then you put >>them on your laser web site. Then just post >> >>-Wayne K3ap > >This has been suggested many times but there are a few reasons why I >can't make it work as you suggest right now. > ># 1 - juno.com will refuse any attachments much over 40 k so there is no >way for people to Email these files to me. > ># 2 - The present situation is (hopefully) temporary as Al (K3TKJ) has >been trying to implement an anonymous ftp directory for us [LASER] and > ># 3 - Extracting these files can be a one step process. If you are using >DOS you can write a batch file to do this. If you are using WinDOZE :-^) >3.1 or 95 there are many public domain programs that make extraction a >simple click on the item process. Similar public domain software is >available for the Mac. >