From majordomo-owner@berlioz.nsc.com Mon Mar 3 15:54:04 1997 Date: Mon, 3 Mar 97 15:54:03 PST To: jmoss From: majordomo@berlioz.nsc.com Subject: Majordomo file: list 'laser' file 'laser.9608' Reply-To: majordomo@berlioz.nsc.com Content-Length: 40837 -- >From owner-laser Wed Aug 7 10:57:51 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA08599; Wed, 7 Aug 96 10:57:51 PDT Date: Wed, 7 Aug 96 10:57:48 PDT From: jmoss (Jim Moss) Message-Id: <9608071757.AA08593@berlioz.nsc.com> To: laser Subject: Another Personal Best Sender: owner-laser@berlioz.nsc.com Precedence: bulk Walt (AJ6T) and I (WB9AJZ) ran a laser sked on Saturday evening during the UHF contest. We planned to run from Mt Diablo to Loma Prieta (N CAL) a distance of 53 miles. Unfortunately, I found out we needed a campsite on the Mt Diablo to stay past sunset (oops). So I found a good ridge location closer to home. We ran 20.4 mile (extending our old personal records of 17miles). I targetted Walt first. He copied 559 with heavy QSB. After re aligning he targetted me and was 599 with some QSB. Main issues were again aiming, but really not too bad after checking calibration between the scopes and laser. (less than 15 minutes) Both of us have built "fine tuning" mechanisms that allow small adjustments with screws to aid in the process. We think the heavy QSB from my end may have been due to instability of the mount or aiming hardware. We also found that it will come from peaking on a ring rather than the main beam. Walt was running a BurrBrown OPT210 rx mounted thru a telescope and 4mW on 670nM, modulated at 800 Hz for MCW (laser pointer). I was running an unknown Pin diode rx with an 8" parabolic mirror and the same laser setup. Plans over the next couple months will focus on working a number of grids from Loma Prieta (CM97BC I think), as well as, extending the range, and improving the aiming hardware. Jim WB9AJZ/6 CM87xi PS: Don't forget to use lasers in the upcoming 10GHz and up contest! >From owner-laser Wed Aug 7 14:31:34 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA15644; Wed, 7 Aug 96 14:31:34 PDT X-Nvlenv-01Date-Transferred: 07-Aug-1996 16:50:50 -0400; at X-WB-XN-AREA.XN X-Nvlenv-01Date-Transferred: 7-Aug-1996 16:48:39 -0400; at X-XN-NGM-SMTP.XN X-Nvlenv-01Date-Posted: 07-Aug-1996 16:50:36 -0400; at X-WB-0129-MS4.XN Date: Wed, 7 Aug 1996 13:48:08 PDT From: Tony_Werdein@xn.xerox.com (Werdein,Tony) To: laser@berlioz.nsc.com Subject: How to modulate a laser from a high volume printer? Message-Id: <"B9FA083281AA677C@X-WB-0129-MS4.XN"@-SMF-> Sender: owner-laser@berlioz.nsc.com Precedence: bulk Seeing at how I work at Xerox and have acquired a laser w/ power supply <5.0 mw> the question I have is: does anybody know how I would go about modulating the beam w/out mirrors? Normally the printer modulates the beam by using a lcd shutter assy, but since I want to put a carrier wave on the beam for voice style comm, would anybody know how to go about doing what I'm looking for? I would imagine w/ a semiconductor laser setup you would just modulate the beam by turning it on & off, sort of cw style, but voice??? One note the high voltage leads go from the pwr supply via high voltage cables directly to the laser, and the pwr supply gets plugged into the wall. Would you use an isolation xfrmer on the laser side and put a carrier via that method? Any help would be great, even guess's. 73 N2TRV Tony In the land of Imaging, Rochester NY >From owner-laser Tue Aug 13 18:42:27 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA22628; Tue, 13 Aug 96 18:42:27 PDT Date: Tue, 13 Aug 96 18:42:25 PDT From: jmoss (Jim Moss) Message-Id: <9608140142.AA22620@berlioz.nsc.com> To: laser Subject: New people, uWave contest Sender: owner-laser@berlioz.nsc.com Precedence: bulk All, We have had several people add to the list server over the last week. Say hi! Who's going to be out with lasers during the microwave contest??? AJ6T and WB9AJZ will likely be out and about in the SF Bay Area. I'll likely rove around to see if Walt (AJ6T) and I can get up to 5 grids from Loma Prieta (about 4000ft) just south of San Jose at CM97BC. Jim WB9AJZ/6 CM87xi Sunnyvale, CA. >From owner-laser Wed Aug 14 10:09:08 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA07555; Wed, 14 Aug 96 10:09:08 PDT From: daveaa1a@pcix.com Date: Wed, 14 Aug 1996 13:05:55 -0400 Message-Id: <199608141705.NAA12723@m3.pcix.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Subject: Re: New people, uWave contest To: jmoss@berlioz.nsc.com (Jim Moss), laser@berlioz.nsc.com In-Reply-To: <9608140142.AA22620@berlioz.nsc.com> X-Mailer: SPRY Mail Version: 04.00.06.17 Sender: owner-laser@berlioz.nsc.com Precedence: bulk Will be out with Laser Rx/Tx in FN51 FN41 FN42 during August.. QRV de Dave AA1A >From owner-laser Fri Aug 16 11:00:58 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA09905; Fri, 16 Aug 96 11:00:58 PDT Date: Fri, 16 Aug 96 11:00:56 PDT From: jmoss (Jim Moss) Message-Id: <9608161800.AA09899@berlioz.nsc.com> To: laser Subject: WSWSS sprint Wednsday, 21 August 1996 Sender: owner-laser@berlioz.nsc.com Precedence: bulk another chance for some hilltop laser Q's? Jim WB9AJZ/6 CM87xi ----- Begin Included Message ----- >From vhf-owner@w6yx.stanford.edu Fri Aug 16 10:34:19 1996 From: n7stu@psnw.com Date: Fri, 16 Aug 1996 09:06:05 -0700 (PDT) X-Sender: n7stu@mail.psnw.com X-Mailer: Windows Eudora Light Version 1.5.4 (16) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: vhf@w6yx.stanford.edu Subject: WSWSS sprint Wednsday, 21 August 1996 Cc: cq-contest@tgv.com Sender: owner-vhf@w6yx.stanford.edu Content-Length: 3330 The First Annual WSWSS VHF and Above Sprint 7 P.M. to 11 P.M. local time, Wed. August 21, 1996 The Western States Weak Signal Society presents the First Annual WSWSS VHF and Above Sprint. The object is to QSO as many stations in as many different grids as possible on the bands 50 MHz and up during the four hour contest period. Classes: Single Operator, Multi-Operator, Low Power (25 watts or less) and Rover. A rover is one or two amateurs operating from more than one grid; no captive rovers or "grid circling" allowed. Exchange: ARRL four character grid locators. Signal reports are optional. Scoring: Same as the ARRL June VHF QSO Party. Awards: The highest entry from each ARRL-defined Region (West Coast, Midwest, etc.) and the highest entry from each ARRL section within the West Coast Region only, in each of the above classes will receive a handsome award certificate from the Western States Weak Signal Society. LOG SUBMISSION DETAILS (A) Entries must be postmarked no later than 30 days after the end of the contest. No late entries can be accepted. Use ARRL June VHF QSO Party forms, a reasonable facsimile, or submit your entry on diskette. Mail your entry to NI6G, or send your entry to ni6g@psnw.com via the Internet. (1) Official entry forms are available for download from http://www.psnw.com/~n7stu under the filename wswsslog.zip (10,490 bytes). (2) You may submit your contest entry on diskette in lieu of paper logs. The floppy diskette must be IBM compatible, MS-DOS formatted, 3.5 inch (40 or 80 track). The log information must be in an CT (v.7 or v.8) .bin file or an ASCII file, following the ARRL Suggested Standard File Format, and contain all log exchange information (band, mode, date, time in UTC, call of station worked, exchange sent, exchange received, multipliers [marked the first time worked] and QSO points). One entry per diskette. An official summary sheet or reasonable facsimile with signed contest participation disclaimer is required with all entries. (3) Entries sent via Internet should include a summary sheet file in lieu of a paper summary sheet. (4) Entries with more than 200 QSOs total must include cross-check sheets (dupe sheets). All diskettes become the property of the WSWSS and are not returnable. Send logs, summary sheet, and S.A.S.E. within 30 days to Erik Dean NI6G, 3813 N. State Av., Fresno, CA 93722. Results will be posted by Oct. 31 in the WSWSS Newsletter. Further information and/or a copy of the announcement for your club newsletter can be obtained by SASE to NI6G at his callbook address or contact Erik @ ni6g@psnw.com. The latest official version of the rules can be found at: http://www.psnw.com/~n7stu/sprint.html 73, Robert N7STU/YB2ARO, DM07aa/OI52ee **************************************************************************** *********** NOTE NEW ADDRESS & URL EFFECTIVE 1 JULY, 1996 **************************************************************************** *********** n7stu@psnw.com http://www.psnw.com/~n7stu (Norcal WSWSS activities & N7STU/YB2ARO homepages) ------ Submissions: vhf@w6yx.stanford.edu Subscription/removal requests: vhf-request@w6yx.stanford.edu Human list administrator: vhf-approval@w6yx.stanford.edu ----- End Included Message ----- >From owner-laser Sat Aug 17 09:39:40 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA01656; Sat, 17 Aug 96 09:39:40 PDT Date: Sat, 17 Aug 1996 09:30:00 -0700 (PDT) From: Walter Miller Reply-To: Walter Miller To: "Werdein,Tony" Cc: laser@berlioz.nsc.com Subject: Re: How to modulate a laser from a high volume printer? In-Reply-To: <"B9FA083281AA677C@X-WB-0129-MS4.XN"@-SMF-> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-laser@berlioz.nsc.com Precedence: bulk On Wed, 7 Aug 1996, Werdein,Tony wrote: > Seeing at how I work at Xerox and have acquired a laser w/ power supply > <5.0 mw> the question I have is: does anybody know how I would go > about modulating the beam w/out mirrors? > > Normally the printer modulates the beam by using a lcd shutter assy, > but since I want to put a carrier wave on the beam for voice style > comm, would anybody know how to go about doing what I'm looking for? Tony, It is very difficult to modulate an ordinary HeNe laser by varying the tube current. The problem is that the plasma discharge is unstable at very low current (when the power output is low), and the tube tends to blink out. Once the tube is on and lasing, the power output is almost at its maximum value. In other words, there is no good sloping region of Pout versus I suitable for modulation. The tube really wants to be either full on or off, and the transition between those states is not well defined. I am aware of some special tubes that were made with an unusual bore geometry which resulted in a more linear Pout vs I characteristic. These tubes were used for amplitude modulation. The AM was achieved by sampling the light output (leakage off the back mirror sometimes was used instead of a beamsplitter on the main output) and controlling it to the desired value in a feedback loop. This is a complicated and fussy technique, and requires the special tube. The more conventional approach mentioned in your message using an external shutter is more straightforward and does not require a special tube. All of the HeNe laser communication work I have heard about used an external chopper to key the beam on and off at an audio rate for CW transmission with direct detection of the audio note. I dont think it is worthwhile to play around with HeNe tubes now that solid state lasers are readily available. They are MUCH easier to deal with. Jim Moss, WB9AJZ, and I have made 20 mile laser CW QSOs using 5 mW 670nm red pointer lasers. Keying this laser on and off at 800 Hz and directly detecting the audio note is fairly easy, and allows us to get out in the field for the really hard part: pointing the lasers accurately enough to hit the other guys receiving optics. Jim and I will try for another QSO this weekend in the 10 GHz and up contest. Good luck and 73, Walt ------------------------------------------------------------------------ Walter Miller, AJ6T Saratoga, CA USA CM87 Reply to aj6t@slip.net >From owner-laser Mon Aug 19 09:09:16 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA07597; Mon, 19 Aug 96 09:09:16 PDT Date: Mon, 19 Aug 96 09:09:14 PDT From: jmoss (Jim Moss) Message-Id: <9608191609.AA07591@berlioz.nsc.com> To: laser Subject: WSWSS sprint Wednsday, 21 August 1996 Sender: owner-laser@berlioz.nsc.com Precedence: bulk ----- Begin Included Message ----- >From jmoss Fri Aug 16 11:00:55 1996 To: laser Subject: WSWSS sprint Wednsday, 21 August 1996 Content-Length: 3888 another chance for some hilltop laser Q's? Jim WB9AJZ/6 CM87xi ----- Begin Included Message ----- >From vhf-owner@w6yx.stanford.edu Fri Aug 16 10:34:19 1996 From: n7stu@psnw.com Date: Fri, 16 Aug 1996 09:06:05 -0700 (PDT) X-Sender: n7stu@mail.psnw.com X-Mailer: Windows Eudora Light Version 1.5.4 (16) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: vhf@w6yx.stanford.edu Subject: WSWSS sprint Wednsday, 21 August 1996 Cc: cq-contest@tgv.com Sender: owner-vhf@w6yx.stanford.edu Content-Length: 3330 The First Annual WSWSS VHF and Above Sprint 7 P.M. to 11 P.M. local time, Wed. August 21, 1996 The Western States Weak Signal Society presents the First Annual WSWSS VHF and Above Sprint. The object is to QSO as many stations in as many different grids as possible on the bands 50 MHz and up during the four hour contest period. Classes: Single Operator, Multi-Operator, Low Power (25 watts or less) and Rover. A rover is one or two amateurs operating from more than one grid; no captive rovers or "grid circling" allowed. Exchange: ARRL four character grid locators. Signal reports are optional. Scoring: Same as the ARRL June VHF QSO Party. Awards: The highest entry from each ARRL-defined Region (West Coast, Midwest, etc.) and the highest entry from each ARRL section within the West Coast Region only, in each of the above classes will receive a handsome award certificate from the Western States Weak Signal Society. LOG SUBMISSION DETAILS (A) Entries must be postmarked no later than 30 days after the end of the contest. No late entries can be accepted. Use ARRL June VHF QSO Party forms, a reasonable facsimile, or submit your entry on diskette. Mail your entry to NI6G, or send your entry to ni6g@psnw.com via the Internet. (1) Official entry forms are available for download from http://www.psnw.com/~n7stu under the filename wswsslog.zip (10,490 bytes). (2) You may submit your contest entry on diskette in lieu of paper logs. The floppy diskette must be IBM compatible, MS-DOS formatted, 3.5 inch (40 or 80 track). The log information must be in an CT (v.7 or v.8) .bin file or an ASCII file, following the ARRL Suggested Standard File Format, and contain all log exchange information (band, mode, date, time in UTC, call of station worked, exchange sent, exchange received, multipliers [marked the first time worked] and QSO points). One entry per diskette. An official summary sheet or reasonable facsimile with signed contest participation disclaimer is required with all entries. (3) Entries sent via Internet should include a summary sheet file in lieu of a paper summary sheet. (4) Entries with more than 200 QSOs total must include cross-check sheets (dupe sheets). All diskettes become the property of the WSWSS and are not returnable. Send logs, summary sheet, and S.A.S.E. within 30 days to Erik Dean NI6G, 3813 N. State Av., Fresno, CA 93722. Results will be posted by Oct. 31 in the WSWSS Newsletter. Further information and/or a copy of the announcement for your club newsletter can be obtained by SASE to NI6G at his callbook address or contact Erik @ ni6g@psnw.com. The latest official version of the rules can be found at: http://www.psnw.com/~n7stu/sprint.html 73, Robert N7STU/YB2ARO, DM07aa/OI52ee **************************************************************************** *********** NOTE NEW ADDRESS & URL EFFECTIVE 1 JULY, 1996 **************************************************************************** *********** n7stu@psnw.com http://www.psnw.com/~n7stu (Norcal WSWSS activities & N7STU/YB2ARO homepages) ------ Submissions: vhf@w6yx.stanford.edu Subscription/removal requests: vhf-request@w6yx.stanford.edu Human list administrator: vhf-approval@w6yx.stanford.edu ----- End Included Message ----- ----- End Included Message ----- >From owner-laser Mon Aug 19 10:18:47 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA08628; Mon, 19 Aug 96 10:18:47 PDT Date: Mon, 19 Aug 96 10:18:45 PDT From: jmoss (Jim Moss) Message-Id: <9608191718.AA08622@berlioz.nsc.com> To: laser Subject: testing Sender: owner-laser@berlioz.nsc.com Precedence: bulk checking mailserver To get a list of commands from the mailserver send a mail to majordomo@berlioz.nsc.com in the body of the message type: help Jim >From owner-laser Mon Aug 19 12:03:22 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA11233; Mon, 19 Aug 96 12:03:22 PDT Date: Mon, 19 Aug 96 12:03:20 PDT From: jmoss (Jim Moss) Message-Id: <9608191903.AA11227@berlioz.nsc.com> To: laser Subject: Re: How to modulate a laser from a high volume printer? Sender: owner-laser@berlioz.nsc.com Precedence: bulk forwarding for John. Some reason the mailserver didn't send it out. Jim WB9AJZ ----- Begin Included Message ----- >From K3PGP@msn.com Sun Aug 18 20:37:46 1996 Date: Mon, 19 Aug 96 03:33:54 UT From: "John Yurek" To: "Laser Messages" Subject: Re: How to modulate a laser from a high volume printer? Content-Length: 1667 On Wed, 7 Aug 1996, Werdein,Tony wrote: > Seeing at how I work at Xerox and have acquired a laser w/ power supply > <5.0 mw> the question I have is: does anybody know how I would go > about modulating the beam w/out mirrors? > > Normally the printer modulates the beam by using a lcd shutter assy, > but since I want to put a carrier wave on the beam for voice style > comm, would anybody know how to go about doing what I'm looking for? I missed the original post but thanks to Walt I got the basic question. I agree with everything that Walt has told you. However, if you still want to play with modulating a laser beam you will find a construction article for a laser modulator in the following article: Scientific American 1970 Nov, pg 120 - A modulator is constructed for laser light Most any library should have this. Call around. If you want it and can't find it I am willing to copy it for you. All I ask is SASE with extra postage because of the number of pages. This is a brute force method. The article describes an audio amplifier with two 6146's running with 800 volts on the plates feeding a solenoid of wire wound around a glass rod. The laser light is passed through the glass rod. I don't know how much audio output this amp has but you could do the same a LOT easier today with off the shelf audio amps. The drawing shows a 0-20 amp meter in series with the coil around the glass rod so apparently you really have to drive this thing with a LOT of audio! This may be more than you want to get into but it does make interesting reading! John K3PGP@MSN.COM PS - Any more of those 5.0 mw lasers floating around? ----- End Included Message ----- >From owner-laser Mon Aug 19 12:04:55 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA11258; Mon, 19 Aug 96 12:04:55 PDT Date: Mon, 19 Aug 96 12:04:53 PDT From: jmoss (Jim Moss) Message-Id: <9608191904.AA11250@berlioz.nsc.com> To: laser Subject: Marine layers Sender: owner-laser@berlioz.nsc.com Precedence: bulk All, Walt (AJ6T) and I (WB9AJZ) couldn't make contact on Saturday on laser, due to a layer of clouds between Santa Cruz and Loma Prieta... OH well... Resked! Jim WB9AJZ/6 CM87xi >From owner-laser Mon Aug 19 15:29:49 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA15214; Mon, 19 Aug 96 15:29:49 PDT Date: Mon, 19 Aug 96 21:41:07 UT From: "John Yurek" Message-Id: To: "Laser Messages" Subject: Re: How to modulate a laser from a high volume printer? Sender: owner-laser@berlioz.nsc.com Precedence: bulk On Wed, 7 Aug 1996, Werdein,Tony wrote: > Seeing at how I work at Xerox and have acquired a laser w/ power supply > <5.0 mw> the question I have is: does anybody know how I would go > about modulating the beam w/out mirrors? > > Normally the printer modulates the beam by using a lcd shutter assy, > but since I want to put a carrier wave on the beam for voice style > comm, would anybody know how to go about doing what I'm looking for? I missed the original post but thanks to Walt I got the basic question. I agree with everything that Walt has told you. However, if you still want to play with modulating a laser beam you will find a construction article for a laser modulator in the following article: Scientific American 1970 Nov, pg 120 - A modulator is constructed for laser light Most any library should have this. Call around. If you want it and can't find it I am willing to copy it for you. All I ask is SASE with extra postage because of the number of pages. This is a brute force method. The article describes an audio amplifier with two 6146's running with 800 volts on the plates feeding a solenoid of wire wound around a glass tube filled with liquid. The laser light is passed through the liquid. I don't know how much audio output this amp has but you could do the same a LOT easier today with off the shelf audio amps. The drawing shows a 0-20 amp meter in series with the coil around the glass tube so apparently you really have to drive this thing with a LOT of audio! This may be more than you want to get into but it does make interesting reading and demonstrates just how hard it is to modulate laser light! John K3PGP@MSN.COM PS - Any more of those 5.0 mw lasers floating around? >From owner-laser Mon Aug 19 15:29:47 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA15208; Mon, 19 Aug 96 15:29:47 PDT Date: Mon, 19 Aug 96 21:46:46 UT From: "John Yurek" Message-Id: To: "Laser Messages" Subject: Determining Max Laser Diode Current Sender: owner-laser@berlioz.nsc.com Precedence: bulk Jim & Walt: In one of your previous posts you mentioned, "Jim Moss, WB9AJZ, and I have made 20 mile laser CW QSOs using 5 mW 670nm red pointer lasers." I have been thinking seriously about purchasing one of these to replace a very old HeNe system. I have noticed the kits that sell for $25 which consist of the diode, collimating lense, and regulator and also the lasers 'pens' that come in 650 and 670 nm models with powers from 3 to 5 mw. I know that the 650 appears quite a bit brighter to eye. However, for communications using a detector and amp (non eyeball QSO!) I assume that it doesn't make much difference. I only ask this because the 670 nm models can be had much cheaper these days (around $25 for 3 to 5 mw model) than the 650 nm models. Are there any specific models / sources that you recommend? Should I pay the premium price for the 650 nm model? Somehow I don't trust some of the ads that I see as far as power output and wavelength are concerned and that is why I ask! Are you using any special optics with these pens to collimate the beam? How do these pens compare to the old HeNe tubes in this repect. I assumed that the diodes had more beam spread. Also do you know how to determine the maximum safe current for a CW laser diode? I just came back from the Warren hamfest today and ended up with the guts out of some laser copiers or scanners of some sort. I paid a buck a piece for them! One appears to have an open diode. However, when I hook the other one up to my bench supply and bring it up to 20 to 40 ma I see an extremely well collimated red beam coming from it. This really surprised me since inside the assembly it said "CAUTION: Invisible laser beam"! I assumed it was going to be further down in the IR range and had my IR detector all set up but I appear to be getting more output in the visible red spectrum than I am in the IR range. (The IR detector shows pratically no IR!) Since the beam spread is very small, I assume that it really is in the lasing mode and not just a bright LED! However, I KNOW that when running correctly these diodes run on the verge of destruction so I need to know how to determine the maximum safe current. I haven't tried any DX yet but shooting across the basement at 30 ma the beam is smaller than from my HeNe but somewhat dimmer. I plan to build a feedback regulator for it very soon. RIght now I'm just powering it from the bench supply with a series current limiting resistor. The beam becomes visible at 18 ma (really sounds low for a laser diode!) but comes up VERY fast as I increase the current. I've had it up to 50 ma for a quick test and didn't notice any power creep so I think it can and should be run higher. However, I don't want to take it any higher till I get the regulator done. (This diode does have three leads on it so I assume that there is a built in detector. The third lead is brought out on the power connector.) Can you or anyone else help me out? Thanks John K3PGP@MSN.COM >From owner-laser Mon Aug 19 17:48:23 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA20367; Mon, 19 Aug 96 17:48:23 PDT Date: Mon, 19 Aug 96 17:48:18 PDT From: jmoss (Jim Moss) Message-Id: <9608200048.AA20330@berlioz.nsc.com> To: laser Subject: laser pointer source Sender: owner-laser@berlioz.nsc.com Precedence: bulk John, FRY's in Sunnyvale and Cupertion CA have a 600 ft range 4.5 mW laser pointer that runs on 2 aaa batteries (670nM) for $39, or a 3mW for 29 (last week). The 670 is dimmer to the eye but you can get more wattage per dollar. The detector likes longer wavelengths better anyway! (assuming you use IR pin diodes) lenses are included in the package and seem to have a beam divergence around 1mR. I can't help with the diode current, maybe someone else can. I was talking with KD6BQ who is working on lidar systems and he says many eye's can see red down to 810nM or so assuming there is good power. Don't look INTO the beam (he is referring to dots on a wall)! mail reflector seemed to be stopped up for a while yesterday and today. I didn't do anything, it just caught up itself this afternoon. I was about to contact our admin people but... now it works! Jim WB9AJZ/6 CM87XI >From owner-laser Tue Aug 20 10:11:24 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA08919; Tue, 20 Aug 96 10:11:24 PDT To: jmoss@berlioz.nsc.com Cc: laser@berlioz.nsc.com Date: Tue, 20 Aug 1996 16:50:45 UTC Subject: Re: laser pointer source Message-Id: <19960820.165046.6934.3.artky1k@juno.com> References: <9608200048.AA20330@berlioz.nsc.com> X-Mailer: Juno 1.00 X-Juno-Line-Breaks: 0-1,3-8,10-11,13-14,17-18,23-28 From: artky1k@juno.com (Art B Allen) Sender: owner-laser@berlioz.nsc.com Precedence: bulk On Mon, 19 Aug 96 17:48:18 PDT jmoss@berlioz.nsc.com (Jim Moss) writes: >The detector likes longer wavelengths better anyway! (assuming you use IR >pin diodes) lenses are included in the package and seem to have a beam >divergence around 1mR. Jim, 1 milliradian from a solid state laser ??? Really? Sounds to good to be true- When u compare it side by side with a HE-NE, is the beam really as tight or tighter than a HE-NE (at 200 or 300 feet)? If this is really the case, I would really suggest that EVERYONE purchase one of these little gems immediately, even by HE-NE standards, that is a very tight beam! I'm not actually sure if the collimation of a solid state laser is limited by the optics or not. But I would think that the physical dimensions separating the layers relative to the lamba of the emmissions would be the real limiting factor, and its pretty hard to overcome that one. Tell us more- 73 and GL...Art.... >From owner-laser Tue Aug 20 19:09:32 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA18519; Tue, 20 Aug 96 19:09:32 PDT Date: Wed, 21 Aug 96 02:03:37 UT From: "John Yurek" Message-Id: To: "Laser Messages" Subject: IR Laser Diodes Sender: owner-laser@berlioz.nsc.com Precedence: bulk Well I finally tested all the junk I brought back from the Warren Hamfest and it turns out that BOTH of the laser diode assemblies have good diodes in them. After testing them I took the diodes out of the heatsink and as I suspected there are no numbers on them. So I don't really know just what these things are. On the scanner assembly it said "Caution invisible laser beam". I can see it just fine but I had the funny feeling that there was a LOT more energy there then it appeared. I think these diodes are borderline between IR and visible red because the IR detector that I was using didn't seem to like them too much either. Soooooo, I got out my CCD 8 mm camcorder and took a look through the color viewfinder and WOW! Boy are these diodes ever bright in the viewfinder!!! I can see refections off of stuff that I can't see with my eye! I know that most CCD's respond rather well blow the visible spectrum and in this case it's impressive. Now I can't wait to get it outside! I now have a regulator built up and I'm running the diodes at 50 ma. I've run them at this current for an extended period of time with no creep in power so I THINK this current is safe (????) but I think they can be run somewhat higher. An interesting experiment: The beam out of these things is around 3/32 inch in diameter when shot across the basement (30 feet or so). One is a perfect circle the other is somewhat egg shaped. I pulled the collimation lens off the egg shaped one and stuck an old 16 mm projection lens in front of it and the spot size at 30 feet is now so small in diameter that I can't estimate it's size without some kind of measuring device. It is small!!! ! won't be able to tell exactly what I have until I take the thing outside. This tells me that perhaps most of these cheap diode systems are probably limited by the lens that is on them. This is most likely intentional. If you focused the beam too tightly it wouldn't make much of a laser pointer would it??? Most people would have trouble trying to locate a pin head sized spot! One of the assemblies is from Toshiba and has LA004 on it, RGA R-50V-0 as well as some other numbers. The diode looks like a TO5 transistor can, has three leads on one end and a window where the light comes out on the other. Unfortunately there are no numbers on the diode but it most likely is some kind of Toshiba diode. Total investment so far $3.00. Each diode assembly was a $1.00 and I also bought the projection lens for $1.00. If anyone has any ideas on determining the current for these diodes let me know! Thanks John K3PGP@msn.com >From owner-laser Tue Aug 20 20:31:29 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA18975; Tue, 20 Aug 96 20:31:29 PDT Date: Tue, 20 Aug 96 20:31:27 PDT From: jmoss (Jim Moss) Message-Id: <9608210331.AA18969@berlioz.nsc.com> To: laser Subject: Re: laser pointer source Sender: owner-laser@berlioz.nsc.com Precedence: bulk Art, I'm actually using a spotting scope now, not rifle scopes. I have a 500mm with a 25x eyepiece. I know Walt is using his telescope, don't know the power. So we are well beyond the 5-7x stuff at this point. Based on signal strengths at 20 miles, I'm quite confident of doing 50, and the charts predict we can make 100. One BAD thing I noticed about the laser pointers is the beam shape. Looking at the pattern on a wall (30 ft) you can see that there are 3 sets of rings, then an inner ring surrounding a rectangle. This can be very confusing at long distance as the inside rectangle and first ring intersect at the top and sides, resulting in 4 holes at top left/right and bottom left/right. If you align on a ring or near a hole, you can easily get heavy QSB as the signal bends around or due to vibration on the xmt side. Jim WB9AJZ/6 >From owner-laser Wed Aug 21 00:27:09 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA20579; Wed, 21 Aug 96 00:27:09 PDT Date: Wed, 21 Aug 1996 00:20:47 -0700 (PDT) From: Walter Miller To: Art B Allen Cc: jmoss@berlioz.nsc.com, laser@berlioz.nsc.com Subject: Re: laser pointer source In-Reply-To: <19960820.165046.6934.3.artky1k@juno.com> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-laser@berlioz.nsc.com Precedence: bulk On Tue, 20 Aug 1996, Art B Allen wrote: > 1 milliradian from a solid state laser ??? Really? Sounds to good to be > true- > > When u compare it side by side with a HE-NE, is the beam really as tight > or tighter than a HE-NE (at 200 or 300 feet)? > > If this is really the case, I would really suggest that EVERYONE purchase > one of these little gems immediately, even by HE-NE standards, that is a > very tight beam! > > I'm not actually sure if the collimation of a solid state laser is > limited by the optics or not. But I would think that the physical > dimensions separating the layers relative to the lamba of the emmissions > would be the real limiting factor, and its pretty hard to overcome that > one. > > Tell us more- > > 73 and GL...Art.... > Art, Your message prompted me to make some side-by-side comparisons of my 5 mW 670 nm laser diode and an old HeNe laser from my junk box. Hmmmm....first to find the old laser box in the garage. Then to weed out the 12 volt switching supplies labelled "BAD" or "BLINKS"....Then to lash together a tube, supply and battery with clip leads without electrocuting myself (I even put a fuse in the +12v lead). The first tube and supply just sizzled...no discharge. The second tube (labelled "LASES 10May85" when it was already 6 years old) and second supply actually worked. I placed this lashup on a chair in the backyard, right next to the tripod which holds the laser diode and Celestron C-90 receiving optics used to make QSOs with WB9AJZ over a 20 mile path. I traced the cross sections of both beams at the far end of my backyard "range" which was 39 big steps or 117 feet from the lasers. The HeNe laser beam was a nice round spot, about 3.75 inches in diameter. It was a classic TEM00 mode, very clean with no spurious sidelobes. The laser diode spot, on the other hand, was very different in appearance. Its profile consisted of a bright central oval about 1 inch by 1.6 inches, surrounded by a lovely series of dark and light rings extending over a diameter of about 6.5 inches. The diodes central spot was much brighter than the other rings. The beamwidth of the HeNe laser was about 2.7 milliradians [3.75/(117*12)]. The beamwidth of the central spot of the diode laser was about .93 milliradians using an average spot diameter of 1.3 inches [1.3/(117*12)]. Jim and I chose to ignore the fringes of the diode laser pattern, hence the quoted beamwidth of about 1 milliradian. By eye, it appears that more than half of the total power is contained inside this central spot. By the way, Jim and I have discussed the possibility that some of our pointing difficulties during field tests at 15-20 miles have been caused by trying to peak up on a ring, rather than on the central spot. In any event, these 670 nm laser diodes are EXTREMELY bright to the naked eye at a distance of 20 miles, when the laser is actually pointing at you. 73, Walt ------------------------------------------------------------------------ Walter Miller, AJ6T Saratoga, CA USA CM87 Reply to aj6t@slip.net >From owner-laser Wed Aug 21 12:04:32 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA29956; Wed, 21 Aug 96 12:04:32 PDT Date: Wed, 21 Aug 96 19:04:18 UT From: "John Yurek" Message-Id: To: "Laser Messages" Subject: Source for Pulsed IR Laser Diodes? Sender: owner-laser@berlioz.nsc.com Precedence: bulk Does anyone know of a source for pulsed laser diodes. These were popular a few years ago and were showing up on the surplus market for something like $5.00 apiece. These diodes required a power supply to pulse them at anything from 5 to 80 amps! I believe they were GaAs and ran in the avalanche mode emitting IR around 900 nm. Many years ago both Scientific American and Ham Radio magazines had construction articles based on them. Thanks K3PGP@msn.com >From owner-laser Fri Aug 23 09:01:24 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA20155; Fri, 23 Aug 96 09:01:24 PDT Date: Fri, 23 Aug 96 09:01:20 PDT From: jmoss (Jim Moss) Message-Id: <9608231601.AA20138@berlioz.nsc.com> To: laser Subject: Re: laser pointer source Sender: owner-laser@berlioz.nsc.com Precedence: bulk Just happened into Radio Shack yesterday for some batteries, their cheapest laser is now 29.99 on sale... I don't have specs. Jim WB9AJZ >From owner-laser Mon Aug 26 11:34:12 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA25962; Mon, 26 Aug 96 11:34:12 PDT Date: Mon, 26 Aug 96 11:34:10 PDT From: jmoss (Jim Moss) Message-Id: <9608261834.AA25955@berlioz.nsc.com> To: laser Subject: laser sources + info Sender: owner-laser@berlioz.nsc.com Precedence: bulk All, By the way... As was pointed out to me a while ago... to send to the mail reflector send to: laser@berlioz.nsc.com Guess this is not currently in our info when you subscribe. Jim WB9AJZ CM87xi Sunnyvale, CA ----- Begin Included Message ----- >From daveaa1a@pcix.com Fri Aug 23 12:10:00 1996 From: daveaa1a@pcix.com Date: Fri, 23 Aug 1996 15:07:11 -0400 Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Subject: Re: laser pointer source To: jmoss@berlioz.nsc.com (Jim Moss) X-Mailer: SPRY Mail Version: 04.00.06.17 Content-Length: 611 Hi Jim, Glad to see someone else travelling same road. Radio Shack OK but have been seeing single diodes for 5 bux at 650nm at swap meets. Think surplus stuff is coming down better. Bought so printer scanners off a place in Torrance, Ca. for 20 bux and did well with 12 mile DX was still loud and clear. Not too many hills here. Just modulating A1, A2, A3 fir now.. Trying to broadband Rx to see Video/Data Lemme know if you need address of Surplace place. They also include heavy aluminum casting good for box, PC board with connector and Collimator with IR diode.. Real bargain.. 73 de Dave Riley AA1A ----- End Included Message ----- >From owner-laser Fri Aug 30 13:49:44 1996 Return-Path: Received: by berlioz.nsc.com (4.1/SMI-4.1) id AA23051; Fri, 30 Aug 96 13:49:44 PDT Date: Fri, 30 Aug 96 21:10:42 UT From: "John Yurek" Message-Id: To: "Laser Messages" Subject: Sharp LT-022MC Specs Sender: owner-laser@berlioz.nsc.com Precedence: bulk Does anyone out there have a spec sheet on a Sharp LT-022MC Laser Diode? I was told this is a 670 nm diode but I don't believe it since it looks very dim. I know the diode is working correctly because my CCD camera and my IR detector tell me that there is a LOT of energy coming out of the diode and it collimates just fine. I suspect these may be a 780 nm diodes. I have tested two of them with identical results. I am very curious about this since this diode was bought from a company advertising them nationally as a 5 mw 670 nm diode. They sent a spec sheet with it for a 670 nm diode but unfortunately the spec sheet is for a 670-5I (???) diode. The diode has Sharp LT-022MC stamped on it. If it turns out that it is being misrepresented I'll post the name of the company here so no one else ends up with the same problem. In any event I would really like to know what this diode is. Thanks John K3PGP@msn.com PS - I've searched for a web site with Sharp laser diode specs but so far all I've come up with is Toshiba specs.