+++++++++++++++++++ See also Troubleshooting +++++++++++++++++++ From: "Charles Bland" Organization: Entropy Reduction, Inc To: elecraft at mailman.qth.net Date: Sun, 28 Jul 2002 19:36:37 -0700 Subject: Re: [Elecraft] Nuts, I broke my K2 Reply-To: BlandRanch at BlandRanch.net > After looking over the schematics, I'm wondering if I blew the > 8v and/or 5v regulators. Anybody have ideas? At the risk of sounding trite........ Check the outputs of the 5 and 8 volt regs....... :-) Chuck From: Jon Mitchell Send reply to: jonathan.s.mitchell at verizon.net To: elecraft at mailman.qth.net Subject: [Elecraft] Nuts, I broke my K2 Date sent: Sun, 28 Jul 2002 22:12:13 -0400 > > D'oh! After 3 trouble-free years, I broke my K2 (#340)! > > After giving it a bit too much EMF (ie, voltage), I am getting > the following symptoms: > -- What sounds like square wave audio from the speaker > -- Much higher rx current; ~300 mA > -- S-meter pegged at S9+40 > -- Display button press reads: E 25.5 i 5.10 > -- All buttons and VFO seem to work fine > -- RX works, but audio level is down (probably due to ALC > being triggered) > -- AF gain control has no effect on the square wave audio > -- RF gain control has no effect on the square wave audio but > does work on RX signals > -- HI CUR warning even when in CW Test mode (current ~250 mA) > -- When TX into dummy load, radio resets > > No worries, though! This is a prime reason as to why I bought > a K2 -- it was great to build, it's super fun to operate, and > now I'll see how easy it is to fix! > > After looking over the schematics, I'm wondering if I blew the > 8v and/or 5v regulators. Anybody have ideas? > > I recorded the audio and put it on my 'K2 boo-boo' web page > at http://jmitch.homeip.net:8080/radio/fixk2/index.html > (as long as Verizon doesn't drop me; try again later if > you can't get through...) > > Thanks for any help, > -- Jon +++++++++++++++++ Reply-To: From: "Ron D'Eau Claire" To: , Subject: RE: [Elecraft] Nuts, I broke my K2 Date: Sun, 28 Jul 2002 20:02:05 -0700 When something like that happens (or some failure that isn't obviously isolated to an individual circuit by the symptoms) the smartest first move is to start checking all the power supply voltages. You're right. The regulators are the first place to start. The K2 has a very serious "Achilles Heel" when it comes to fixing something like that with minimum resources - all that darned logic. If you took out a part of the MCU or other logic, it might be a bit tricky to isolate exactly which bit went bad just looking at symptoms. Once I started fixing radars and navigation gear that didn't depend upon tubes I started carrying a spare board set whenever possible. Not because the solid-state analog circuits were any harder to troubleshoot. In general they were easier than their tube predecessors. The spare boards were invaluable to help isolate the defective logic circuits. Maybe you have a fellow K2 owner not to far away who might consent to a board swap once you KNOW the voltages are okay! Ron AC7AC K2 # 1289 ++++++++++++++++ Date: Mon, 29 Jul 2002 09:57:28 +0200 From: Ingo Meyer DK3RED To: Elecraft Subject: [Elecraft] Re: Nuts, I broke my K2 Hello Jon, My first sugestion was the RF Output Detector at the RF board. This part are direct on the antenna. The second idea is the T-R Switch also at the RF board. This area controls the TX/RX switch and is the second sensitive part after the antenna input. -- 72/73 de Ingo, DK3RED Don't forget: the fun is the power! dk3red at t-online.de http://www.t-online.de/~dk3red DL-QRP-AG #824 http://www.dl-qrp-ag.de +++++++++++++++ Reply-To: "Jim W7RY" From: "Jim W7RY" To: "Jim W7RY" , Cc: "Gary Surrency" Subject: Re: [Elecraft] K2 #2740 13 Khz Off Frequency FIXED Date: Mon, 19 Aug 2002 22:17:00 -0700 Well I got it going... Did a VFO linearization (AKA, CAL-PLL)... That fixed it. I don't know why it required it twice.....??... But its going now and working great! The second time took much shorter that the 1st time ? (I don't know why)?? I was able to calculate the error taking readings at the test points... at 7.000 MHz indicated on the VFO dial....TP-1 was 11.9000.78 and TP-2 was 4.913.55 (subtract these two and get 6987.23 (~13 KHz low). It was Gary from Elecraft suggested that I do the CAL-PLL (VFO linearization) again... Why did the 1st attempt not take ?? The 4.0000 MHz MCU has always been within about +- 2 Hz. I checked and set it with my Motorola R-2014 service monitor. One thing I did do, was re-wind the T-5 VFO torroid. I did not have the 2nd winding (green 5 turn winding) in the exact middle of the 1st winding. After doing this, it made no difference in the frequency error. Just running CAL-PLL fixed it. Onward and upward!! 73 and thanks! Jim W7RY #2740 ----- Original Message ----- From: "Jim W7RY" To: Sent: Friday, August 16, 2002 7:21 PM Subject: [Elecraft] K2 #2740 13 Khz Off Frequency > Well... I have # 2740 running as a 40 meter receiver... But, it receives > exactly 13Khz off frequency (VFO reads high). > > There is another peculiar thing.... at 11.5 KHz above the injected > frequency, there is a "birdie". The birdie moves much faster than the > fundamental at +13 KHz above. > > I have verified that all of the crystals AS SUPPLIED are installed in the > correct locations... > > I have also verified that the 4.00 MHz reference is within 1 or 2 Hz. > > All of the checks and alignments that are shown in "Alignment and Test Part > II" starting on page 57 are correct and line up perfectly. > > The parts list spells out X1 and X2 to be a 12.069 MHz. My kit contained > crystals that are marked 12.09-S. > In addition, X5 through X11 are marked 4.9136-S. > > > The receiver works great! Very sensitive. > The signal I am injecting is at a level of -105dBm. (Not overloading the > receiver). > > Any ideas ? > > Thanks and 73 > Jim W7RY ++++++++++++++++ From: "Don Brown" To: "Elecraft" Date: Wed, 16 Oct 2002 14:42:12 -0500 Subject: [Elecraft] Radio Troubleshooting Hi There at least 2 good methods of troubleshooting a radio (or any other an= alog circuit). One is signal tracing and the other is signal injection. S= ignal tracing is good when a circuit is a generating device such as a tra= nsmitter. In this type of circuit the device provides a signal internally= to trace with an indicating piece of test equipment. This would be somet= hing like a RF probe and DMM or a wide band scope. The approach should be= to split the circuit in half and make a test to see if the signal is the= re. If not then split the half in half and make another test. If the sign= al is there at the one half point then go forward about another 1/4 of th= e circuit and make another test. This should get you to the failed circui= t quickly. The other method is the signal injection technique. In this technique a s= ignal generator is injected a various points in the circuit and you look = or listen for an output. This works on amplifying circuits like audio and= RF, IF amplifiers. The one half method from above works here also except= you are providing a signal at the test points and in the case of a radio= you listen to the speaker for the signal. This is the method described b= y Tom on the Elecraft website under Quick and Dirty Signal Tracing. The a= ntenna signal source is good (and cheap) but I find a noise generator is = more convenient. You can make up a probe with a length of RG-174 cable wi= th a small value capacitor in series with the probe tip similar to the K2= counter probe to connect to the noise generator (or you can use a scope = probe). Then touching various test points in the radio with the probe sho= uld cause a loud hissing noise in the speaker or phones. Because the sign= al is broad band noise it will drive any circuit from audio to VHF even i= f it is a tuned circuit. Once you have the circuit stage isolated then get out your DMM and magnif= ying glass and look for bad solder joints, missing or wrong value parts o= r open, shorted or bad parts in that order. If you have isolated the circ= uit there will usually be only few parts to look at as a potential proble= m The K2 has a number of test points built in to make these tests. They are= the "W" jumpers for the options. For a receiver problem I would start at= W3 first then W5 then W6 then W1 and the antenna connector last. When th= e signal is lost then go back a little to isolate the bad circuit. Digital circuits need a little different method but that's another story = ;-) I hope some of you find this useful Don Brown KD5NDB +++++++++++++++ From: "Bill Magruder" To: Date: Fri, 18 Oct 2002 13:00:31 -0700 Organization: Microsoft Corporation Subject: [Elecraft] K2 #2862 Passed Alignment and Test Part II Everyone; Well I made it to Page 61 of the K2 Manual and everything is going fairly smoothly. Got stuck on the VCO Alignment where you "adjust Inductor L30 until the voltage at R30 reads 6.0 volts". First try I was only getting a maximum of 4.5 volts. Well I scratched my head and started checking. Noticed I had swapped Diodes D39 with D33, must have got the numbers confused in my head. Everything else looked OK. Still couldn't get more than 4.5 volts. So this morning I pulled transformer T5 and rewound it. Now I got 5.5 volts, gained 1 volt, progress in the right direction but still not good enough. What should I do next? Check more components, check voltages, pull T5 and rewind it for the 3rd time? I was running out of ideas so I finally broke down and emailed support at elecraft.com. Talk about good support Gary emailed me back in less than 30 minutes, "Compressing the red turns will increase the VCO voltage and spreading the turns will decrease the VCO voltage" Eureka, now that make sense, I made the mistake of spreading the turns trying to make sure I had 80 or 90% core coverage. I reached in with the plastic tuning and compressed the red windings and in 10 minutes I have the voltage set at 6.000 volts. Great kit and great support, now on to Assembly, Part III only 10 more pages to go. Thanks for all the help, Bill KD7KST ++++++++++++++ From: "Don Brown" To: "n3drk" , "elecraft" Subject: Re: [Elecraft] wrong vco voltage reading Date: Thu, 7 Nov 2002 08:51:21 -0600 Hi The readings in my manual came out to around 4.6 v for 28000 and 5.8 for 28800. Sounds like you have a bad or unsoldered joint around K13, K14, or K15 or one of the capacitors close by. I have found it easy to miss a pin on the relays when soldering them. That's why I always go over them twice. Don Brown ----- Original Message ----- From: "n3drk" To: "elecraft" Sent: Thursday, November 07, 2002 8:07 AM Subject: [Elecraft] wrong vco voltage reading > I am doing the part 2 alignment and test and on page 58, the vco voltage > readings. I am having trouble with the ten meter band. My reading for 28000 > is 8.27 and will not change regardless how much i adjust T5 slug. Now on > 28800 the reading is 5.55 and it will change when the slug of T5 is > adjusted. > > Now 10 minutes ago just the opposite occured. 28800 was "stuck" at 8.27 and > 28000 it was at 5.55 > > I am stumped and all other bands and frequencies adjust and within the > 1.5-7.5 volt range. > > Does anyone know what is going on here. > > Thanks in advance fellows > > john > +++++++++++++++++ Date: Mon, 18 Nov 2002 01:23:25 +0100 To: elecraft at mailman.qth.net From: "C. van Ravenswaaij" Subject: [Elecraft] Transmitter alignment, no output on 80 and 20 mtrs, high/low currents, solution found Hi all, Thanks Tom, Peter and Rich for your helpful advice. I checked L16 and L17 first. L17 looked suspicious, so resoldered it. No luck. After desoldering L16 I found out that one of the leads was not stripped well enough. Fixed this and there it was: 2.3 watts at 1 ampere. Now on to the final assembly and all the extra's. Best regards, Cornel PA3BTS +++++++++++++++++++ From: "Steve & Anne Ray" To: "Elecraft" Date: Mon, 18 Nov 2002 21:11:59 -0500 Subject: [Elecraft] Bottom Cover and Filter Setup I just completed the latest mod to improve the filter response on SSB, and while checking the filter response decided to check the CW filters, they all seemed to be off a 100 Hz or so. Kind of strange I thought, but I just reset them using Spectrogram. I then put the covers back on and tried a couple of calls on CW, well I was having trouble zero beating the signals. In fact they were off the amount I had "Fixed them" . Lesson learned set up the filters with the bottom cover on. 2nd dumb thing, when setting up the USB and LSB filters make sure the Audio Filter is switched out and you take the audio from the speaker jack. This I did, but it is also important to remember to switch it in, before putting all the screws in for the top after you have done the alignment. Steve Ray K4JPN ex K1VKW EM82ep Warner Robins GA Elecraft K2 1422 & KPA-100 Heath Fan HW-101, HW-8 ++++++++++++++++ From: "Wolf-Ruediger Juergens" To: Subject: Re: [Elecraft] K2 #2857 2. Part complete - but audio to low Date: Sun, 15 Dec 2002 08:53:49 +0100 Organization: Privat > Signals are strong but I think audio is to low. AF-Gain is 12 o'clock and with > full RF-gain and Pre on it's not so bad but my K1 is much louder. Found the reason, D3 was installed in the wrong direction. After setup the filters several times, the audio level is much better now. I will setup again all filters using spectrogram after finished the next assembly part. 72 de Wolf, DL2WRJ ++++++++++++++++ Date: Mon, 16 Dec 2002 08:16:34 -0500 From: "Robert C. Abell" Reply-To: abellve3xm at sympatico.ca To: support at elecraft.com, elecraft at mailman.qth.net, AG5Q at attbi.com, ssj at nc.rr.com, k4zm at comcast.net Subject: [Elecraft] Re: K2 S/N 02676 Hi Current on tune Thanks again to everyone who replied to my call for help. Bob - AG5Q led me on the right path. Q4 a 2N7000 on the Controller board was the culprit. As soon as it was replaced I had immediate joy. My problem was in not looking at anything other than the RF board. Merry Xmas to all, and to all a Good Nite. 73, Bob Abell ARRL, RAC, NJQRP , K2's 2062 & 2676 ++++++++++++++++++ Date: Mon, 23 Dec 2002 04:22:15 -0500 (Eastern Standard Time) From: "n3drk" To: "elecraft" Subject: [Elecraft] no menu button -Problem Solved I sent in a post of my menu button not working. What i found and still do= nt understand what this has to do with it, is my cw paddle had a mono plug a= nd the k2 calls for a stereo plug. Once i switched it the menu button works correctly now. Just to be sure i inserted the mono plug and once again no Menu button functions.=0D =0D john=20 --__--__-- Orig Msg: Date: Mon, 23 Dec 2002 03:51:41 -0500 (Eastern Standard Time) From: "n3drk" To: "elecraft" Subject: [Elecraft] no menu button Upon completing part 2 of the k2, the Menu worked completely. All steps w= ere taken as per the manual. (Rev C) Now i am completing Part 3 testing and alignment. 40 meter and the transmitter alignment has been completed and everything in this respect is good.=0D =0D The problem i have is the "Menu" button does not work. When i tap or hold nothing happens. This function worked well in part 2. All other buttons o= n the front panel work. Any suggestions what i can do? Would a reboot of th= e eprom to default to factory settings correct this problem.=0D =0D Perplexed=0D =0D thanks=0D =0D john=20 ++++++++++++++++++ From: "Thomas Martin" To: elecraft at mailman.qth.net Date: Fri, 27 Dec 2002 17:24:52 +0100 Subject: Re: [Elecraft] K2 Alignm.&Test, Part I, unexpected display of 160m band -- PROBLEM SOLVED Cc: support at elecraft.com Hello, finally I found an error I made which was responsible for the false 160m band display during Test and Alignment, Part I of K2 S/N 3105. I installed R65 (10 kOhm) at the location of R63. R65 (...well if present) pulls the 160RY signal at J14 (Pin 16) to 6V. Looking to the schematic of the K160RX option this signal is fed back from K160RX to the RF Board as 160RY (Pin 16). Taking into account only signal 160RY [and assuming RXRY or RY COM to be 0V] the voltage at 160RY will be about 0V if (...as in my case) R65 is not present or if R65 is present and the K160RX option is installed (there is a voltage divider consisting of R65 and the two coils [in series] of relays K1, 2 on the option board and the signal at the junction of R65 and the two coils is 160RY). So it's not "astonishing" that the I/O controller decided that the option was present. Installing R65 at the correct location solved the problem. Thanks to all members of the elecraft e-mail list who responded to my question. Now back to Assembly of RF Board, Part II. 73 Thomas, DF7TV -- Thomas Martin, Stuttgart, Germany http://www.qsl.net/df7tv ++++++++++++++++ From: "Don Brown" To: "Gregg R. Lengling" , Subject: Re: [Elecraft] Query on BFO alignment Date: Fri, 27 Dec 2002 11:42:46 -0600 Hi I would go forward with the building. You are close enough to the bottom end. If there is a problem it will show up when you try to align the filters with spectrogram. If you need more range you can add a 47pf cap in parallel C174 and a 120pf cap in parallel with C173 to increase the range. Add the caps to the bottom of the board Don Brown KD5NDB ----- Original Message ----- From: "Gregg R. Lengling" To: Sent: Friday, December 27, 2002 11:19 AM Subject: [Elecraft] Query on BFO alignment I'm in the process of building my Christmas present from my wife....K2 S# 3075 (with all the options...she's a big spender), and I'm doing just fine. I was just doing the BFO Test and I've got a range of 3.77kHz which according to the book is good (must be equal to or greater than 3.6kHz). However the BFO high freq is >=4916.3 (actual reading 4916.86) but the BFO Low Freq. is supposed to be <= 4912.7kHz (actual reading is 4913.09)....now that means my low reading is meeting spec....is this a problem. The 4MHz oscillator calibration is done properly (Used an IFR1200S to smell the oscillator and the IFR is in calibration). So is any of this minor descrepancy a problem...or should I just continue onward???? Thanks in advance .... Gregg R. Lengling, W9DHI PSYCHOLOGY: The science of inventing words for things that do not exist. ++++++++++++++++ From: "Larry Lavery" To: Date: Mon, 27 Jan 2003 21:27:13 -0500 Subject: [Elecraft] Re:Elecraft] K2/100 & AGC pumping - solved Eureka... Took off the right panel and found the ribbon cable between the Control board and amplifier folded nicely on top of the SSB option board. Repositioned the cable and the noise disappeared. FYI... the noise coincided with the Tx data going to the computer which travels through that ribbon cable. Sure is nice to have the K2 in top form again. Thanks to all for the hints! cheers.. Larry, WW2J ++++++++++++++++++ From: Skip Cubbedge To: "'Elecraft at mailman.qth.net'" Subject: FW: [Elecraft] K2 Display Problem Date: Fri, 31 Jan 2003 10:04:54 -0700 Thanks for the responses on this problem. Fellow K2 owner Gary/WA0SPM found an unsoldered pin 1 on my LCD driver chip, which happens to be the serial data line to the LCD. This was the intermittent problem! After installing a white wire (didn't want to risk removing the LCD or wedging a soldering iron under it), the radio works perfectly and reliably. We tuned up the filters using the spectrum analysis software/procedure, and it sounds fantastic. I'm another ecstatic customer of Elecraft. Keep up the good work, both Elecraft and it's devoted followers! 73 de Skip / K0UE -----Original Message----- From: Skip Cubbedge [mailto:scubbedge at digitalglobe.com] Sent: Tuesday, January 28, 2003 10:44 AM To: Elecraft at mailman.qth.net Cc: Mike Lewis; Gary Geissinger Subject: [Elecraft] K2 Display Problem All, I am having a problem with the display on my newly completed K2 (s/n 3103). The radio functions properly in every way, except that sometimes the LCD stays blank after I turn the radio on. I have noticed that if I press down on the 5 MHz crystal area of the control board with my finger, and then turn the radio on, sometimes it will come back to normal, and stay that way for a long period of time. But then, after a period of normal operation, sometimes the frequency number will lock up (even though I can still tune the radio), or go to some funny set of characters, like a decimal point only or something like that, or just go blank again. Subsequent power cyclings do not clear the problem. I have gone through troubleshooting steps 060 and 052. The bar graph signal strength meter always functions normally. I'm looking for words of wisdom from the K2 Community. Intermittent problems are the most fun, aren't they? Thanks and 73, Skip / K0UE ++++++++++++++++ Date: Mon, 03 Mar 2003 12:07:28 +0000 To: Elecraft From: Brendan Minish Subject: RE: [Elecraft] K2 Tuning 'glitches' every 5 Khz Cc: Elecraft Just to close this thread, I have fixed the Glitches and along the way learned the following ! 1/ a PLL reference oscillator range of 9.1 kHz or more is sufficient (Wayne) 2/ You should put the top cover on BEFORE running cal PLL (Eric) In all CAL PLL attempts since the BFO mod I had run CAL PLL with the top cover off, re-running it with the top cover down on a well warmed up K2 has eliminated the glitches. 73 Brendan EI6IZ +++++++++++++++++