++++++++++++++++ See also KPA Build Notes -- Sometimes I'm not sure which is more appropriate - dwn ++++++++++++++++ Date: Sun, 26 May 2002 05:06:24 -0400 (EDT) From: kc4kgu at ENTERZONE.NET To: Elecraft Subject: [Elecraft] The K2/100 #2490 Saga For those of you who have been following the ongoing saga of K2/100 #2490, I have good news and bad news. The good news is that I found the problem. The bad news is that Gary, Wayne and Eric are probably going to have me taken out and shot for not finding it before now! As it turns out, I had a bad solder joint on RP1 pin-1. So, if you build a KPA100 and have the "works QRP or QRO but NOT both" issue, that is the first place I would look. Note: If I am not heard from after this email, please direct the police to the three above mentioned people! 73 de John - KC4KGU K2/100 #2490 ++++++++++++++++++ Date: Sun, 26 May 2002 10:56:18 -0700 From: Wayne Burdick Organization: Elecraft To: kc4kgu at ENTERZONE.NET Cc: Elecraft Subject: [Elecraft] Re: K2/100 fan runs a LOT! John, What revision of firmware do you have? This was addressed in the latest revision (supposedly). If you did recently change KPA100 firmware, remember that you must re-do your CAL tPA setting using the menu. This is explained in the manual. 73, Wayne N6KR kc4kgu at ENTERZONE.NET wrote: > > I have noticed that the FAN in the KPA100 will run on HIGH continiously > once it has begun. It will start out on LOW but, once you TX a few times, > it switches to HIGH and just runs and runs and runs. I've not TX'd in > about an hour and the fan has yet to switch back to LOW or OFF. ++++++++++++++++++++ From: "Bob Henderson" To: Subject: Re: [Elecraft] KPA-100 under test Date: Wed, 29 May 2002 06:16:42 -0000 I hope I haven't had you folks scratching your heads too much! My problem was finger trouble. Don't you just hate it when you have to own up to that! Somehow whilst setting Fan HiLo and Fan Hi I managed to switch off the KPA-100 in the menu. For those that may be interested I can confirm that the fan doesn't work when you do this. Duh! The KPA-100 is complete and producing a nice clean 100 W on all 9 bands. Congratulations Wayne & Eric you've done it again. Super job! 73 Bob 5B4AGN > ----- Original Message ----- > From: "Bob Henderson" > To: > Sent: Tuesday, May 28, 2002 8:46 AM > Subject: [Elecraft] KPA-100 under test > > > > Hi > > > > I was one of the lucky ones who got to bring back a KPA-100 kit from > Dayton. > > The kit is assembled and currently under test. However, I have hit a snag > > and would appreciate a bit of help. > > > > Testing so far has progressed to Page 46 - Fan Test routine. > > > > The fan does not operate with fan mode set to either FAN LoHi or FAN Hi. > > The fan itself is ok as it operates briefly when the K2 is powered up. > > Looking at the cct diagram on page 62 it is apparent that U2 pin 11 (/out > 7) > > should be low to drive the fan at low speed and U2 pin 12 (/out 6) should > be > > low to drive it at full speed. These signals are both unconditionally > high > > on my KPA-100. Outputs RC7 & RC6 from U1 are required to go high to > operate > > the fan at low/high speed. These outputs are both unconditionally low. > U1 > > & U2 are otherwise operational as my low pass filter switching is > operating > > correctly. My fault finding has ground to a halt at this point as I don't > > know what input is required at U1 to turn the fan on. > > > > Can someone point me in the right direction please? > > > > Many thanks. > > > > Bob 5B4AGN ++++++++++++++++++ Date: Wed, 29 May 2002 04:05:06 -0400 (EDT) From: kc4kgu at ENTERZONE.NET To: elecraft at mailman.qth.net Subject: Re: [Elecraft] K2/100 + KSB2 + MH2 questions OK. For those of you who have been following the strange problems I've been having with K2/100 #2490, I have good news and bad news. The good news is that I have isolated BOTH of the problems I had reported. The BAD news is that it appears to be a "John - KC4KGU" issue. The problem with the K2/100 being able to do QRP or QRO but not BOTH was finally traced to a bad solder joint on RP1 pin-1. The problem with "choppy TX audio" appears to be the attributable to my voice characteristics and the frequency response of the Heil MH2. Tonight, while experimenting with the K2/100 trying to find SSB settings that would produce acceptable audio at acceptable power averages, I tried using my Kenwood microphone, I belileve it's an MC-43S but, since there is no model number on it, I can't be certain. The Kenwood microphone produces BEUTIFUL TX audio, keeps the average output up at acceptable levels and doesn't exhibit the "clipping" that the MH2 does with my voice. So, if anyone has the Kenwood microphone that comes with the TS-2000, in MINT condition that they would like to trade for a Heil MH2 in MINT condition, I will be happy to do so. 73 de John - KC4KGU K2/100 #2490 +++++++++++++++++++ To: elecraft at mailman.qth.net Date: Wed, 29 May 2002 11:40:34 -0700 From: Gary L Surrency Subject: [Elecraft] KC4KGU: MH2 mic with K2/100 Hi John, Sounds like you may have a bad MH2 mic. We'll send you a replacement right away so you can compare it with the MH2 mic you now have. If there still seems to be a problem, we'll probably want to take a look at your rig if we can't resolve it with either email or phone support. I have two Kenwood mics here, a MC-43 hand mic and a MC-60 desk mic. Both work well with the K2/100, but the Elecraft MH2 mic has more drive, and works and sounds better on the air. I've not noticed the odd behavior you reported with the MH2 mic and the KPA100 installed. 73, Gary Surrency AB7MY Elecraft Technical Support support at elecraft.com ++++++++++++++++++++ Reply-To: "Don Wilhelm" From: "Don Wilhelm" To: "Earl Ritchie" , Subject: Re: [Elecraft] KPA100 - T3 Date: Sun, 2 Jun 2002 17:36:21 -0400 Earl, Swap the numbering for pins 2 and 3 on the schematic - they appear to be wrong!!! The figure in the text is correct. T3 has the red wire designated as pins 2 and 4, and the green wire uses 1 and 3. Yes, T3 terminals 2 and 4 are at the same relative end of their windings. In general, if there is a conflict between the text and the schematic, the text is correct. I guess we KPA100 field testers missed this error in the schematic - sorry, but the KPA100 works FB when assembled from the written instructions. 73, Don Wilhelm - Wake Forest, NC W3FPR home page: http://www.qsl.net/w3fpr/ QRP-L # 485 K2 SN 0020 mailto: w3fpr at arrl.net *** Life is what happens when you're making other plans -- Mike Cross *** ----- Original Message ----- > I am trying to put T3 on the board. The picture on P.27 shows the red > wire going to pads #2 & 4. The schematic shows it going to #3 & 4. > Schematic also shows #2 coming out the same end of the transfmr. It > seems to me that the picture on P.27 has 3 leads marked incorrectly. > Would someone please tell me where I am going wrong . 73 Earl > +++++++++++++++++++++ Date: Sun, 2 Jun 2002 17:49:04 -0400 (EDT) From: kc4kgu at ENTERZONE.NET To: Earl Ritchie Cc: elecraft at mailman.qth.net Subject: Re: [Elecraft] KPA100 - T3 On Sun, 2 Jun 2002, Earl Ritchie wrote: > I am trying to put T3 on the board. The picture on P.27 shows the red > wire going to pads #2 & 4. The schematic shows it going to #3 & 4. > Schematic also shows #2 coming out the same end of the transfmr. It > seems to me that the picture on P.27 has 3 leads marked incorrectly. > Would someone please tell me where I am going wrong . 73 Earl Earl, You're absolutely right! In this case, I believe that the schematic has the pads numbered incorrectly. The picture on pg.27, top left, is the appropriate wiring for T3 with red going to #2 & 4 and green going to #1 & 3. 73 de John - KC4KGU K2/100 #2490 ++++++++++++++++++ Date: Fri, 07 Jun 2002 09:10:55 -0700 From: Vic Rosenthal Organization: Transparent Software To: Unifiedtx at aol.com, Elecraft Subject: Re: [Elecraft] No Sidetone on K2 Unifiedtx at aol.com wrote: > > Is this RS232 > mod necessary when installing the KPA100? Yes. > Cutting the trace at U6 pin 25 I believe has killed > my sidetone Activate the menu and select ST L (sidetone level). Hit Display to allow you to change the sidetone source; change it to U8-4. That will restore the sidetone with this mod. However, you must have a firmware level high enough to support the KIO2 for this to work (I'm not sure what version that is). Vic K2VCO +++++++++++++++++++++++ Reply-To: "Jim Brown" From: "Jim Brown" To: Cc: Date: Sat, 15 Jun 2002 14:04:21 -0500 Subject: [Elecraft] KPA100 Progress Wayne, et al. Making good progress on my KPA100. Finished assembly part I and checkout. Only problem encountered is on page 23, voltage chart, last line. It states U6 pin 1 should be 0 to 0.1v, and mine measured 315mv. Gary emailed the answer in about an hour -- it should read U6 pin 6 (pin 1 is unused). This is not yet in the errata. Have (painfully) wound and installed L1-L16. Time invested so far is about 12 hours. While I am at the keyboard, I would like to join the others in thanking you for bringing both the K2 and the KPA100 to market. The kits are a joy to build. The K2's performance exceeds all of my expectations and is a real joy to use. I've had great success using it on 20m mobile at 15W as well as at home in conjunction with my SB-220 (at 200W or so). I would recommend you product and service to anyone.... Regards, Jim Brown, K5JAZ +++++++++++++++++ From: "Todd Gahagan" To: "NB1B" Cc: Subject: Re: [Elecraft] WA7U-KPA100 Date: Sat, 22 Jun 2002 11:00:55 -0600 Thanks Dennis, I just tried this again. I can't go to high power to adjust R26 and 27 because it keeps shutting down and the relays chatter. I think I understand what you are saying but not positive. I have tried setting these pots with 5 watts, 20 watts, and also 30-40 watts but whenever I go above about 50 relays chatter and the output goes to zero. ----- Original Message ----- From: "NB1B" To: "Todd Gahagan" Sent: Saturday, June 22, 2002 10:17 AM Subject: Re: [Elecraft] WA7U-KPA100 > I had the same type problem, except that I couldn't get more than 50 watts > out on any band. Even though your settings on R26 and R27 seem correct, > they aren't. I was placing the unit in tune, then adjusting them and > watching the output, and it just wasn't increasing. > > Based on Gary's suggestion, I adjusted the pots, then put it in full power > tune, then adjusted the pots, then put it in full power tune, and kept > repeating this until I had the proper power out on the K2 display as on the > Bird, and the rig reliably showed the proper SWR. If you do this, keep the > Hi Pwr Tune short- 1 or 2 seconds is all you need to read the Power out. > > Gary said that the ALC on the Xmit, coupled with the SWR detection circuits, > will aggressively shut down the power if the settings aren't correct. > > Good Luck. > > Dennis NB1B > > ----- Original Message ----- > From: "Todd Gahagan" > To: "Surrency, Gary" > Cc: > Sent: Saturday, June 22, 2002 11:51 AM > Subject: [Elecraft] WA7U-KPA100 > > > > > > > > I seem to be having more than my share of problems with the amp project. > > Everything checks out perfectly. Got the new firmware yesterday and it is > > installed. > > Everything seems to be working just as it should until I get to the > Transmit > > Tests portion. Anytime I go over about 60watts the PA shuts down and I > get > > the High Reflected status in the K2 LCD. It then drops to an intermittent > > 35 watts power output. I have checked all coax cables, Heathkit Cantenna > > dummy load, SWR bridge that I am using and can find no problems with them. > I > > have rechecked the SWR bridge null 3 times. I have also closely checked > T4 > > and surrounding components. All of T4s lead are correctly placed and > > resistance checks show that the leads soldered properly. I did use > prewound > > toroids. I would appreciate any ideas. Thanks, Todd-WA7U > > +++++++++++++++++ Reply-To: From: "Ron D'Eau Claire" To: "'Todd Gahagan'" Cc: Subject: RE: [Elecraft] WA7U-KPA100 Date: Sat, 22 Jun 2002 10:36:17 -0700 I seem to be having more than my share of problems with the amp project. Everything checks out perfectly...Anytime I go over about 60watts the PA shuts down and I get the High Reflected status in the K2 LCD. It then drops to an intermittent 35 watts power output. Thanks, Todd-WA7U Is your power supply voltage holding up under the current load? I have played with a KPA100 and noticed that it reported High Reflected on some bands looking into a good dummy load. Turned out that the power supply was sagging on some bands at 100 watts and that was fooling the amp into reporting a High Reflected and shutting down. Ron AC7AC K2 # 1289 +++++++++++++++++ From: "Todd Gahagan" To: Cc: Subject: Re: [Elecraft] WA7U-KPA100 Date: Sat, 22 Jun 2002 11:44:27 -0600 Thanks Ron, I'm using an Astron 50 amp supply. Doesn't seem to sag much. I'm wondering about having possibly blown one of the 2n7000 transistors. Looks like that could be a possibility if I'm not mistaken. Todd ++++++++++++++++++ From: "Todd Gahagan" To: "Todd Gahagan" , Cc: Subject: Re: [Elecraft] WA7U-KPA100(problem solved) Date: Sat, 22 Jun 2002 12:08:23 -0600 Found a bad connection between the KPA100 power cable and the power supply. I was getting a voltage drop that was causing the problem. Now getting 100 watts no problem. Boy do I feel better. Thanks to the list for all the thoughts. Todd ++++++++++++++++++++ Date: Sat, 22 Jun 2002 09:07:47 -1000 From: John Buck To: elecraft at mailman.qth.net Subject: [Elecraft] KPA100 K2 1242 is now ready for field day with the KPA100 upgrade. -- snip -- The only test problem I had was a cockpit problem when I used a key with a mono plug on it. This hangs up the K2, locks in transmit, and ignores the menu button. You must use a stereo plug or else only push in the mono plug half way. Aloha, John KH7T ++++++++++++++++ From: "Charles Bland" Organization: Entropy Reduction, Inc To: elecraft at mailman.qth.net Date: Sat, 22 Jun 2002 22:54:20 -0700 Reply-To: BlandRanch at BlandRanch.net Subject: [Elecraft] A tip when calibrating your KPA100 Long Story short...... If you don't get the R26/R27 calibration done properly, your power and current measurements will be way off and you will get weird results from the K2. Make sure you have a known accurate wattmeter. I had a problem and ended-up buying a Diamond SX200. I repeated the calibration procedures and my problems cleared-up. Chuck Bland #1924/100 +++++++++++++++ Date: Mon, 24 Jun 2002 19:02:59 -0700 From: Eric Swartz WA6HHQ - Elecraft Organization: Elecraft To: Hank Kohl K8DD Cc: elecraft at mailman.qth.net Subject: Re: [Elecraft] K2/100 at N8AHZ for FD... Hi Hank, Sounds like you need to replace your early KPA100 Field Test firmware with the production release versions we recently sent all Field Testers. (PA 1.06 and K2 2.02F). The production code corrects the erratic keying sidetone and fan control issues present in the early test code. 73, Eric WA6HHQ ====== Hank Kohl K8DD wrote: > > K2 #850 with KPA100 in Grayling MI. 80/40 dipole at about 40'. > > 90% of all QSO's were CW and 90% of all QSO's were on 40M. > About 700 QSO's total with the K2 in 15 hours (storms and oversleeping!). > > Saturday night while the two radios were running a total rate of 200/hour > (networked NA logging program) I had to stop and turn the K2 fan to Hi > because it was very hot - uncomfortable to the touch. We also had to drop > it down to about 80 watts because the keying would become erratic on 40M > even though the K2 and the MFJ-971 showed 1.1:1 SWR. > > 73 Hank K8DD ++++++++++++++++++ From: "Don Brown" To: "Michael E Dobson" , "Elecraft" Subject: Re: [Elecraft] KPA100 -- Hi Curr.60W All Bands Date: Thu, 4 Jul 2002 15:46:10 -0500 Hi It is critical to set R26 properly. Try turning R26 a little clockwise an= d see if the power comes up. You may want to set R26 at 50 watts out to f= ind the best setting. You must go out of tune and back into tune then mov= e the power pot after making any adjustment of R26 so the adjustment is v= alid. If your external wattmeter is not accurate (many are not) it is dif= ficult to get the right setting on R26. Use a scope, if you have one with= at least twice the bandwidth of the measured frequency. You should read = 141 volts pk to pk at 50 watts across the 50 ohm load or 200 volts pk to = pk at 100 watts Set the current limit in the cal current menu to 3 to 3.5= amps. Don Brown KD5NDB ----- Original Message ----- From: Michael E Dobson Sent: Thursday, July 04, 2002 2:59 PM To: elecraft at mailman.qth.net Subject: [Elecraft] KPA100 -- Hi Curr.60W All Bands I'm at the point in construction where you begin testing the transmit output. I cannot get more than about 60W on any band without getting a Hi Curr warning. I think I have the bias set correctly but it drifts up for a bit so it may not be set correctly. Any suggestions? 73, Mike WA3KYY K2 #2221 ++++++++++++++++++ To: DolfinDon at msn.com Cc: elecraft at mailman.qth.net Date: Thu, 4 Jul 2002 17:17:59 -0400 Subject: Re: [Elecraft] KPA100 -- Hi Curr.60W All Bands From: Michael E Dobson Hi Don, I made the Cal Curr change per the eratta sheet before I started the alignments. I suspect that R26 is the problem. I do not have either a well calibrated watt meter nor a scope handy so my intial 5 W calibration of R26 is likely way off. Another ham near me has a Bird Wattmeter that he says I can borrow so I guess I need to wait for the meter before doing any more testing and alignment. 73, Mike WA3KYY K2 #2221 almost QRO ++++++++++++++++++++++ Date: Fri, 05 Jul 2002 07:42:32 -0500 To: "Michael E Tucker" , From: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Subject: Re: [Elecraft] K2/100 #2700 Michael: >During my test and alignment phase, I noticed that when setting the power to >11 Watts with the PA on, the voltage display drops to 8.5V, 3.4-3.5A and >the fan comes on immediately. When returning briefly to the tune mode, >the fan slows down as if the voltage feeding it drops but returns to >normal speed when I exit the tune mode. There are no error codes in the >PA menu. It sounds as though your power supply is having problems supplying the required amount of current. Sounds as though the supply is going into 'foldback' mode. The fan may well turn on when the PA is enabled... especially if the setting for TPa is not set properly. Originally, when I set TPa, I forgot to CONVERT Farenheit to Centigrade, so this caused the fan to turn on ALL THE TIME. Ensure that TPa has been (fairly) accurately set, and that the FAN parameter is set to NORmal, otherwise, the fan will run at one speed or the other any time the PA is enabled. >I have a feeling that the power transistors have been damaged somehow but >further checks will have to wait until I get home Saturday. For now I >have the PA turned off and will continue at QRP power levels until I >figure out what the problem is. Look to the power supply and TPa first. >Another thing I have noticed is that while in tune mode with the PA off, >the power reading on the LCD says I have an output of about 16 Watts but >my external Wattmeter reports less than 10. Also the LCD display reports >just over 12V but only about 1.8A. You're still using the KPA100's wattmeter circuitry... better check your calibration. >With the exception of the power output problem with the KPA100, all the >other tests are okay (I haven't gotten to the the voltage checks on the >board yet). >The radio "talks" to the computer via K2 Remote and N1MM logger without any >problems. I kinda doubt you have as many real 'problems' as you might think you do. GL OM, Tom Hammond N0SS ++++++++++++++++++ Date: Fri, 05 Jul 2002 07:18:44 -0700 From: Phil Wheeler Organization: Outstanding To: Michael E Tucker Cc: Elecraft at mailman.qth.net Subject: Re: [Elecraft] K2/100 #2700 Michael E Tucker wrote: >I completed the KPA100 today but for the time being the K2 is still running QRP. >During my test and alignment phase, I noticed that when setting the power to >11 Watts with the PA on, the voltage display drops to 8.5V, 3.4-3.5A and the fan >comes on immediately. > In addition to the power supply, check the cable from the supply to the PA. I had a poor connectin that caused a low voltage (around 11 V) until I discovered why. 73, Phil ++++++++++++++++++ To: andrew at utahdesign.com Cc: elecraft at mailman.qth.net Date: Sat, 6 Jul 2002 15:12:16 -0400 Subject: Re: [Elecraft] KPA100 SWR adjustment problem From: Michael E Dobson Andrew, Check T4 for correct orientation of the leads. This torroid is part of the RF and SWR sensing circuits and it is critical that it be properlly installed. If the leads are correct, check for <1 ohm between pads 1 & 4 of T4. Do not test with your DMM probes touching the wires. Also, R26/27 should be at their mid-points for the SWR calibration, they will be adjusted in a later step using a calibrated wattmeter. 73, Mike WA3KYY On Fri, 5 Jul 2002 23:19:23 -0600 "Andrew" writes: > I got to the part during KPA100 assembly where the SWR reading is > adjusted. With a 20W 50 ohm dummy load that has been tested good on > other rigs, the K2 (with KPA100 attached) gives a 0.1 9.9-1 reading > in tune mode with the power control set to 5.0 W. The lowest SWR > reading I can get by adjusting C1 is 7.0-1 (actually the only two > readings I can get are 9.9-1 and 7.0-1, nothing in between). By > turning R26 and R27 fully counterclockwise, I can get a reading of > 1.0-1, but the forward power remains at 0.1. When I hook a DMM up > to U5 pin 1, I see a minimum of about 35 mV with R26 and 27 at their > midpoints, and a min. of 4.5 mV with R26/27 fully counterclockwise. > Receive seems to be fine on all bands with the antenna hooked up to > the KPA100's jack. Current in tune mode is about 900 mA, and about > 400 mA in receive mode. All of the tests done on the KPA100 up to > this point have been fine, but I have not yet done any voltage > checks (except the ones done during normal assembly). Does anybody > have any ideas? > > Thanks & 73, > Andrew AC7CF > K2 1637 > K1 508 ++++++++++++++++++ To: vze2gmp4 at verizon.net Cc: andrew at utahdesign.com, elecraft at mailman.qth.net Date: Sat, 6 Jul 2002 21:25:54 -0400 Subject: Re: [Elecraft] KPA100 SWR adjustment problem From: Michael E Dobson On Sat, 6 Jul 2002 15:34:31 -0400 Helmut Usbeck writes: > On Saw,turday 06 July 2002 15:12, Michael E Dobson wrote: > > > Also, R26/27 should be at their mid-points for the SWR > calibration, they will be adjusted in a later step using a calibrated wattmeter. > > The ass'y manual says these pots should be all the way clock-wise. > Is the above an "official" change to the adjustment or something you tried > that makes the calibration easier. It's official, p15 KPA100 manual Rev A "Install trimmers R26 and R27 (100k, "104") near spekaer cutout. .....Set the trimmers to their midpoints." R6, the bias trimmer is set fully counter-clokwise. 73, Mike WA3KYY K2 #2221 ++++++++++++++++ From: "Christian GONDARD" To: "elecraft" Date: Thu, 18 Jul 2002 17:47:41 +0100 Subject: [Elecraft] KPA100 Hi K2'ers & K1'ers Just this message to say that my K2 #644 is now QRO with a brand new KPA100 under the top cover. I needed 22 hours of assemblying time to get a fully functionning kit, without any trouble.As usual, a lot of time is required (at least for me !) to read a read again every step described in the manual in order to be sure to fully understand them, and to avoid any future desoldering/soldering operations : see below !!. I encountered only a small difficulty after completing the VFO ALC modification which is proposed with the KPA100 kit. It requires 4 new components on the K2 main RF board : 3 replacements and 1 new component. After the modification, I loosed the TX power ... After some good advices from Gary, I found the culpritt : the linear pad between C154 and a connected resistor was cut from the circular pad at one of C154 lead : effect : no more VFO TX signal and nothing on all the TX line. I need only the RF probe and a DVM to find the fault; the faulty pad was very difficult to see with a magnifying glass .. I repaired it with a 5 mm long component lead. Thanks again to the Elecraft team for the wonderfull design and services I am now waiting for the KAT100 !! 73's Chris / F6FTB / K2 #644 +++++++++++++++++++ Date: Fri, 19 Jul 2002 21:49:57 +1200 From: Ron Willcocks To: Elecraft reflector Subject: [Elecraft] Help!!...I'm in trouble... Hi all, Today I have been putting the KPA100 together, and I have had the K2 apart and changed the MCU to the later version, and also replaced the PIC in the SSB module to the later version. While I had the control board out I did the mod to enable the IO port, so I didn't have to pull it out again. On turn on it booted up in the usual way and appeared to be going Ok, so I put it to one side and carried on with the KPA. Got as far as the first test driveon that and it did everything it should, so I gave up for the night and decided to have a contact or two. No such luck. While the K2 appears to be going OK it certainly isn't. The receive signal strength is down, and if I operate the paddles in CW, the DAHS work but the DITS aren't home and holding the paddles that side appears to make the received noise increase! I am also getting zilch output from the transmitter section. If I do a TUNE the ATU works and I get a match , but if I press and hold TUNE/ DISPLAY it shows .1F 00r. Everything appears to be plugged in correctly, I did a CAL PLL, and I had to select U8-4 to get my sidetone back after the IO mod. Have I selected/not selected something in the menu?...or have I butchered something . At present I am open to suggestions.....Can anyone help? Cheers (?)...Ron ZL1TW +++++++++++++++++++ Date: Fri, 19 Jul 2002 08:16:15 -0500 To: "Don Brown" , "Ron Willcocks" , "Elecraft" From: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Subject: Re: [Elecraft] Help!!...I'm in trouble... RON: DON'T FORGET TO WRITE DOWN ALL OF YOUR BFO SETTINGS BEFORE YOU DO THE RESET! Tom N0SS At 06:46 AM 7/19/02, Don Brown wrote: >Hi > >I think I would do a master reset to re-initialize the EEPROM. Installing >new firmware or installing the mod may have corrupted the information in >the EEPROM. To do the reset turn off the K2 hold the 4-5-and 6 button and >turn back on. This will reset everything to factory defaults. You will >need to do the calibration and reset your filters. > >Don Brown >KD5NDB +++++++++++++++++++ Date: Sat, 20 Jul 2002 09:26:58 +1200 From: Ron Willcocks To: Elecraft reflector Subject: [Elecraft] More Re: Help! i'm in trouble Hi Folk, Well it pains me to have to admit it, but the problem I reported was self inflicted. Many thanks to the many replies I had.It just shows how valuable the reflector is. Andrew AC7CF go to the top of the class !! Your suggestion was spot on. Now the problem.......I reluctantly report my indiscretion in case it helps someone who arrives at the same sticky spot. I installed the SSB upgade chip in BACK TO FRONT. (sigh)...and I was trying to be so careful too..... However, turning it around, made the set spring into life. I just hope the chip has a sense of humour and keeps going now. Thanks again to all who responded. Cheers......Ron ZL1TW To advise anyone who didn't read my "Help" message, the fault I had was weak reception, and the DIT paddle didn't work but did increase the sound level when depressed. I also had no transmit. All this happened after I did the KPA100 upgrade mods on the Control board, and upgraded the SSB PIC chip. I thought I had a Control board problem and didn't double check the SSB module! +++++++++++++++++ From: "g3pjt" To: "John Grebenkemper, KI6WX" , Date: Tue, 6 Aug 2002 09:43:44 +0100 Subject: [Elecraft] Re: Instability on 7MHz with KPA100 - follow up and a cure ? John, I seem to have 'cured' the problem and will post this comment to the reflector today. Following the suggestion of Phil Wheeler who said it might be due to feedback from RFC10 to the 7MHz input citcuits through the cutout in the shield to clear the nuts which secure J2-SO239. Phil recommended I position RFC10 as close as possible to the PCB ie as far as possible from the other 7MHz circuits. I looked at mine and I had in fact already done this But I did not see any reason why I could not blank out the cutout with a better fitting screen. I therefore made from a piece of thin brass a shaped screen which filled the cutout except for 2 notches to clear the nuts securing J2. I soldered the brass to the screen. I also positioned the entire screen as close to the back panel as the clearance hole in the screen would allow. This seems to have cured the problem. I have not removed the brass to see if the oscillation returns! I do not have access to a spec anal here so I could not find out where the oscillation was - I didn't fancy manually tuning my GC RX whilst the amp was blasting away at 150 watts output ! Thanks for the help, I will let you know if it returns. 73 Bob G3PJT ----- Original Message ----- From: "John Grebenkemper, KI6WX" To: "g3pjt" Sent: Monday, August 05, 2002 9:53 PM Subject: Re: [Elecraft] Instability on 7MHz with KPA100 > > Bob; > Does the oscillation continue even when you aren't transmitting a signal? > Do you have access to a spectrum analyzer to see what frequencies are > present in the oscillation? I was involved in the KPA100 field test and > took a careful look stability issues. > -John > KI6WX ++++++++++++++++ From: "Rick Tilton" To: "Doug Person" Cc: "Elecraft" Subject: RE: [Elecraft] KPA-100 Problems Date: Sun, 11 Aug 2002 21:38:48 -0400 Hi Doug! I would reccomend that you check Z1. I had a similar problem in that it worked great for a little while then my power dropped to what the K2 would do on its own. Could not get the bias voltage adjusted either. I had used too small of a wire for Z1 and burned it right into. Could not tell it until I moved the ferrite beads and found it in the middle of a bead. May not be it but worth a shot and would be a very simple and cheap fix. Good Luck! 73... Rick Tilton ARS - N4WYK n4wyk at arrl.net n4wyk at amsat.org Foothills of NC APRS and Satellite Website http://www.n4wyk.com > -----Original Message----- > OK. Some progress. I had installed P6 backwards on the K2. So I simply > reversed J1 and suddenly had lots of noise coming from 40 meters. For a > moment I had full K2 output on the power meter. Then I hit tune again and > nothing. Even with nothing, I was getting some action on C1. But, > sometimes the SWR shows on the display and sometimes it doesn't. Now I'm > back to a state of having receive through the KPA-100 but no RF > getting back out to the antenna - even though momentarily I did. > > Doug -- W4DXV > K2 #1920 K1 #1297 > ++++++++++++++++++ From: JTrager316 at aol.com Date: Fri, 16 Aug 2002 20:19:22 EDT To: elecraft at mailman.qth.net Cc: MTrager1 at optonline.net Subject: [Elecraft] Re: ALC with CW and SSB problem solved! With an oscilloscope, I noticed the VRFDet voltage had a much faster attack time with the K2 by itself, then with the KPA100. I then knew the problem was with the KPA100... In a matter of minutes, I traced the problem to C70 on the KPA100. The detector voltage attack time (at the cathode of D16) was much faster... but slowed down at C70. Don't know how I did it, but C70 was 0.1uF "104", instead of the correct value of 0.001uF "102"! A BIG difference. Thanks to all of you who took the time to test your own K2/100's... John N2KBE +++++++++++++++++++ To: K6TFZ at aol.com, elecraft at mailman.qth.net Date: Sun, 18 Aug 2002 19:09:50 -0700 Subject: Re: [Elecraft] Strange behavior K2/ 100 From: k6se at juno.com I wrote: "RF getting into the voltage and current sensing circuits on the control board is a known problem, particularly on 160 and 80 meters. There is a recommended mod to either replace or parallel C42 (0.01mFd) on the control board with a 0.1 mFd capacitor to alleviate this problem. . . " ========== Geoff, K6TFZ wrote: "I have in front of me my K2 Modifications for use with the KPA100 dated June 12, 2002 Rev. A (applicable to all K2 Rev. A RF boards). I do not see the modification which you describe above. I also just checked the Elecraft website and was not able to find the mods you describe above. I would appreciate you directing me to the location where this known problem is described." ========== You won't find the mod on the Elecraft site. The info about it was given to me by Gary, who is the support for Elecraft, when I queried him about the voltage and current fluctuations indicated on the K2 readout when transmitting on 80m and 160m. He said it was a common problem and suggested the mod. Elecraft apparently considers the problem significant enough that they include a 0.1 mFd capacitor with the KPA100 kit to replace C42 on the control board, evidently because higher power would amplify the problem. Page 20 of the KPA100 manual has a step which says, "Locate C42 on the K2 Control board, which is near the voltage selector switch, S1. If the present value of this capacitor is .01 uF ('103'), replace it with an 0.1 uF capacitor ('104'). NOTE: If you have an older Control board (rev XC) that does not include C42, solder the 0.1 uF capacitor between pins 4 and 8 of U3 (LMC6842), on the Control board)." 73, de Earl, K6SE ++++++++++++++++++ From: Rolf.Schroeder at t-online.de (Rolf =?iso-8859-1?q?Schr=F6der?=) To: Jeremiah J McCarthy , elecraft at mailman.qth.net Date: Fri, 4 Oct 2002 16:48:21 +0200 Subject: [Elecraft] Re: Smoke Generator on KPA100 Am Freitag, 4. Oktober 2002 16:29 schrieb Jeremiah J McCarthy: > If R-10 is cooked, don't you think you should research the area around > T-5 instead of T-3? Maybe I wasn't clear enough, it was on the KPA100 were the R10 was fried,= it=20 is in the circuit of the high voltage bias supply, this is why I was look= ing=20 for T3.=20 But now there is something that confuses me a little: According to page 27 of the KPA 100 manual, The green winding has the "pi= ns" 1=20 and 3 and the red winding has the "pins" 2 and 4. According to page 62 of= the=20 same manual, pins 1 and 2 should be the ends of the same wire as well as = 3=20 and 4 should be the ends of the same wire. Seems to be a contradiction to= =20 me... There is no short circuit to ground, as I checked it with my DMM.=20 Continuity is there as described in the manual and T3 is wired according = to=20 the manual on page 27.=20 Any feedback is welcome. Well, and I will not hurry because this usually = makes=20 disasters bigger... --=20 Best Regards Mit freundlichen Gr=FC=DFen Rolf Schr=F6der They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety.=20 - Benjamin Franklin, 1759 -=20 +++++++++++++++ From: "Don Brown" To: "Jeremiah J McCarthy" , "Elecraft" Date: Fri, 4 Oct 2002 10:02:33 -0500 Subject: [Elecraft] Re: Elecraft digest, Vol 1 #295 - 11 msgs - smoked R10 Hi I think you have R10 in the K2 confused with R10 in the KPA100. Rolf was = working on the KPA100 when R10 smoked. I would look for a diode in backwa= rds (D1-D8), a bad Q8 or T3 shorted or installed wrong. T3 is a bifilar w= ound toroid and it is easy to strip the twisted wires too far allowing th= em to short. Also check that U4 is installed correctly and look for solde= r bridges around U4 and the HV supply. Don Brown KD5NDB ++++++++++++++++ From: "Don Brown" To: , "Elecraft" Subject: Re: [Elecraft] Re: Smoke Generator on KPA100 Date: Fri, 4 Oct 2002 10:23:40 -0500 HI I have built 4 KPA100 and the diagram on page 27 works. The schematic on = page 62 appears to be incorrect on the wire numbers. I would look for a b= ad or backwards diode (D1-D8), bad Q8, U14 installed backwards or a solde= r bridge around the HV supply or U4. Recheck T3 there could be a short be= tween the windings. =20 Don Brown KD5NDB ++++++++++++++++ From: "Ken Wagner" To: Subject: Re: [Elecraft] KPA100 Date: Fri, 4 Oct 2002 12:21:02 -0400 This is addressed in the Errata Sheet. 73, Ken K3IU ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ----- Original Message ----- From: "Jeremiah J McCarthy" To: Sent: Friday, October 04, 2002 12:46 PM Subject: [Elecraft] KPA100 | Has anyone noticed that the pin callouts for T-3 in the schematic on P 67 | are incorrect? ++++++++++++++++++ From: Marteinn Sverrisson Date: Sat, 19 Oct 2002 13:25:42 +0000 To: elecraft at mailman.qth.net Subject: [Elecraft] Unstability in KPA100, cured I have observed instability in my K2/KPA100 rig, sometimes the KPA100 goes into oscillation, and the ALC goes way up, I observe this on SSB and CW as well, with about 90W out. The antennas I use, a dipole and vertical, are just 15m and 10m from the rig. Both antennas use common mode 1:1 Baluns to choke off RF currents. On some bands there is strong RF field in the shack as indicated on the Field Strenth Meter in the shack and this coincides with the unstability. I can cure this problem by inserting a 2Watt 270 Ohm resistor in the input circuit on KPA100 as suggested by WA7GXD in his article "Remoting the KPA100 into the EC2 Enclosure" This reduces the overall gain in the transmitter section and now there is no oscillation. This mod does not affect output power of the KPA100. 73 TF3MA Matti +++++++++++++++++ From: WA9GQT at aol.com Date: Sat, 7 Dec 2002 21:26:24 EST To: elecraft at mailman.qth.net Subject: [Elecraft] Re:160 Meter Problems since KPA100 Added Hello to All! I was able to resolve the 160 meter problem. It would only do it with KPA100 installed either QRP or QRO. Found problem with 160 meter low pass filter section. Receiver would cut out when pressing on L1 toroid. Retinned & resoldered L1 to board. Also found 1 pin of relay K3 not soldered. I think this was the real culprit. I guess it helps to solder connections! Remember to check and recheck all solder connections; it does definitely save time. 73, Rod WA9GQT K2 #1900 QRO capable with KPA100 now ++++++++++++++ From: "Don Brown" To: , "Jay & Jac" Subject: Re: [Elecraft] KPA100 power question.. Date: Wed, 11 Dec 2002 15:23:10 -0600 Hi This is a tricky adjustment. You need to slightly re-adjust the power control after each very small adjustment of R26 or you can go out of and into tune after each adjustment. By doing this you make the firmware readjust the ALC. The idea is to set 50 watts on the external wattmeter and then move R26 in small steps so the K2 display reads the same as the external wattmeter. Check it at 100 and 10 watts also. The external wattmeter needs to be accurate and many are not, so if you have a scope you can check the wattmeter by reading the peak to peak voltage across the dummy load. 10 watts will be 63.3 volts across the 50 ohm load 50 watts will be 141.4 volts across the 50 ohm load or 100 watts will be 200.0 volts across the 50 ohm load. Of course the dummy load needs to be accurate also for this to work. One very accurate meter I use is the OHR WM-2 QRP meter with a modified OHR 100 watt dummy load to change it to a 100 watt 20 db attenuator. One watt full scale on the meter is 100 watts out. I described the modifications on an earlier post but if anyone is interested I will repost it. It only requires one resistor and a BNC connector. Don Brown KD5NDB ----- Original Message ----- From: "Jay & Jac" To: Sent: Wednesday, December 11, 2002 2:04 PM Subject: [Elecraft] KPA100 power question.. > Hello all, > > I just completed the KPA100 on K2 #279. All went well until I did a power > output calibration at 50 watts at a friends house who has an accurate > wattmeter. > > The problem is I cannot seem to adjust R26 to match the actual 50 watts (as > shown on the watt meter) to the power control on the K2. The power control > pot on the K2 shows 12 watts lower than is actually being put out > consistantly throughout it's upper range. > > Have I made a cockpit error somewhere? > > Jay, W6JDB +++++++++++++++