Re: [Elecraft] K2 SSB problem--follow-up
Doug, Well, stuff like that happens to all of us at one time or another. When it happens to me, I just jot down a "Dear Dummy" note to myself and go on with life. Glad to hear you found it. 73, Don W3FPR Doug Heacock wrote: > Boy, is my face red. For the benefit of those who helped with suggestions > concerning my SSB issue (power output pegging and out of control on PTT), I > must confess that when I began looking at this again (for the first time in > several years), I had completely forgotten that when I removed the SSB > adapter years ago, I put the two jumper wires and the C167 capacitor back > (as the instructions say to do). But because I tacked them to the *bottom* > of the RF board, I didn't see them until last night, when I decided to > remove the bottom cover of the K2 case to nose around a bit on the RF board. > > I've removed the jumpers and the cap, and the out-of-control power output > problem is gone. I still don't know whether my SSB adapter is working > properly, because I don't actually have a real mic wired up yet (I've just > been using the dot key line as PTT)--I'll get a little electret element > wired up soon and give it a shot. > > Thanks again to those who offered suggestions--even though I was barking up > the wrong tree because of my own oversight, I learned a lot along the way! > > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K2 SSB Problem
Hi Don, I have found three resistors with a wrong value (R7, R9 and R4). I installed the resistors with the correct values but the problem is always present. The current increase step by step until it does catch up the value 4A and the radio gone on Hi current protection when I push PTT on the microphone. It is possible that the Q1 transistor is the cause of this problem? Thanks for your help '73, IZ1DUG Fabio -- Initial Header --- >From : "Don Wilhelm" [EMAIL PROTECTED] To : "[EMAIL PROTECTED]" [EMAIL PROTECTED] Cc : Date : Sat, 28 Jul 2007 15:19:50 -0400 Subject : Re: [Elecraft] K2 SSB Problem > Have you removed C167 from the RF Board? > If you have removed it, there may be a problem with the ALC circuits on > the KSB2 - check D1, D2 - look at the schematic and identify the > components associated with Q1 and be certain all have the correct valus > and are well soldered. > > 73, > Don W3FPR > > [EMAIL PROTECTED] wrote: > > Hi Don thanks for answer. > > > > I checked diodes D3, D4, D5 and are correctly installed. I make some test > > after the check for supply you more informations. I turn on the K2 on SSB, > > I push the PTT, speak into microphone and I have : power output OK, the > > s-meter follows the voice but the current increase and arrived at Hi Cur > > limit (also without speak into the microphone). Push the PTT is sufficient > > for have a current absorbed but the wattmeter don´t show any power out. > > I hope that these additional information are sufficient to comprise the > > cause of this problem. > > > > Thanks for your help > > > > '73 de IZ1DUG Fabio > > > > > > -- Initial Header --- > > > >>From : "Don Wilhelm" [EMAIL PROTECTED] > > To : "[EMAIL PROTECTED]" [EMAIL PROTECTED] > > Cc : "elecraft" elecraft@mailman.qth.net > > Date : Sat, 28 Jul 2007 08:17:10 -0400 > > Subject : Re: [Elecraft] K2 SSB Problem > > > > > > > > > > > > > > > >> Fabio, > >> > >> I cannot be specific, but the most probable area causing that trouble is > >> the area of Q2 and Q3 (those direct the BFO signal either to the > >> balanced modulator in SSB mode or back to the RF board for CW) or the > >> balanced modulator U5. > >> > >> Check carefully to be certain diodes D5, D4 and D3 are inserted in the > >> proper direction and in the correct holes. > >> > >> 73, > >> Don W3FPR > >> > >> [EMAIL PROTECTED] wrote: > >>> Hi, > >>> > >>> I just finished installing the KSB2 module on my K2 QRP version (full > >>> optional). I go to operate for the first time but when I push the PTT I > >>> get this problem: the current absorbed increases (the voltage decrease) > >>> until it exceeds the value 4 A (set at this value after some test) and > >>> the K2 switch off. The current and the voltage values reading on the K2 > >>> display and on the multimeter are the same. I have this problem on all > >>> band but only in SSB mode (K2 works correctly on CW mode with full power > >>> 10-13W). The problem is repeated every time when I push the PTT. > >>> I use the microphone Heil MH-2. > >>> Any suggestions? > >>> > >>> Good weekend > >>> > >>> Ciao, > >>> > >>> IZ1DUG, Fabio > >>> > >>> K2/QRP #1702 and K2/100 #5909 > > > > > > -- > > Scegli infostrada: ADSL gratis per tutta l´estate e telefoni senza canone > > Telecom > > http://click.libero.it/infostrada > > > > > > > -- Leggi GRATIS le tue mail con il telefonino i-mode di Wind http://i-mode.wind.it/ ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] K2 SSB Problem
Hi Don thanks for answer. I checked diodes D3, D4, D5 and are correctly installed. I make some test after the check for supply you more informations. I turn on the K2 on SSB, I push the PTT, speak into microphone and I have : power output OK, the s-meter follows the voice but the current increase and arrived at Hi Cur limit (also without speak into the microphone). Push the PTT is sufficient for have a current absorbed but the wattmeter dont show any power out. I hope that these additional information are sufficient to comprise the cause of this problem. Thanks for your help '73 de IZ1DUG Fabio -- Initial Header --- >From : "Don Wilhelm" [EMAIL PROTECTED] To : "[EMAIL PROTECTED]" [EMAIL PROTECTED] Cc : "elecraft" elecraft@mailman.qth.net Date : Sat, 28 Jul 2007 08:17:10 -0400 Subject : Re: [Elecraft] K2 SSB Problem > Fabio, > > I cannot be specific, but the most probable area causing that trouble is > the area of Q2 and Q3 (those direct the BFO signal either to the > balanced modulator in SSB mode or back to the RF board for CW) or the > balanced modulator U5. > > Check carefully to be certain diodes D5, D4 and D3 are inserted in the > proper direction and in the correct holes. > > 73, > Don W3FPR > > [EMAIL PROTECTED] wrote: > > Hi, > > > > I just finished installing the KSB2 module on my K2 QRP version (full > > optional). I go to operate for the first time but when I push the PTT I > > get this problem: the current absorbed increases (the voltage decrease) > > until it exceeds the value 4 A (set at this value after some test) and the > > K2 switch off. The current and the voltage values reading on the K2 > > display and on the multimeter are the same. I have this problem on all band > > but only in SSB mode (K2 works correctly on CW mode with full power > > 10-13W). The problem is repeated every time when I push the PTT. > > I use the microphone Heil MH-2. > > Any suggestions? > > > > Good weekend > > > > Ciao, > > > > IZ1DUG, Fabio > > > > K2/QRP #1702 and K2/100 #5909 > -- Scegli infostrada: ADSL gratis per tutta lestate e telefoni senza canone Telecom http://click.libero.it/infostrada ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] K2 SSB Problem
Fabio, I cannot be specific, but the most probable area causing that trouble is the area of Q2 and Q3 (those direct the BFO signal either to the balanced modulator in SSB mode or back to the RF board for CW) or the balanced modulator U5. Check carefully to be certain diodes D5, D4 and D3 are inserted in the proper direction and in the correct holes. 73, Don W3FPR [EMAIL PROTECTED] wrote: Hi, I just finished installing the KSB2 module on my K2 QRP version (full optional). I go to operate for the first time but when I push the PTT I get this problem: the current absorbed increases (the voltage decrease) until it exceeds the value 4 A (set at this value after some test) and the K2 switch off. The current and the voltage values reading on the K2 display and on the multimeter are the same. I have this problem on all band but only in SSB mode (K2 works correctly on CW mode with full power 10-13W). The problem is repeated every time when I push the PTT. I use the microphone Heil MH-2. Any suggestions? Good weekend Ciao, IZ1DUG, Fabio K2/QRP #1702 and K2/100 #5909 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] K2 SSB problem
Hi Gerhard, Most reports of "FM'ing" I have been aware of have been due to a low power supply voltage and/or the voltage varying with the load. I have not heard a K2 with this problem, but it might be worth checking the power supply. gl Trev G3ZYY In message <[EMAIL PROTECTED]>, Gerhard Schwanz <[EMAIL PROTECTED]> writes Hi group! I have a little problem with SSB it seems. During the contest last weekend someone told me I had "frequency modulation" on my signal. Not knowing what this should mean I at least thought I would check the signal when bands are quieter. I just did. And although the audio sounds ok there is maybe a little problem. Sending a 1kHz audio signal the receiving station could hear the same signal at +1kHz and -1kHz with -20dB max. These signals should be at least -40dB, correct? Question. How do I fix this? Thanks! Gerhard Schwanz DH3FAW mailto:[EMAIL PROTECTED] http://www.gs-personal.de ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com -- Trevor Day UKSMG #217 www.uksmg.org ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] K2 SSB problem
Gerhard, There could be a problem, or there may be no problem at all. What is the audio source and level that you are driving into the mic jack? If it is not a pure sine wave or the level is too high, it will have harmonics or (if too high a level) can cause harmonics if the balanced modulator is being overdriven. Sorry, but there is just not enough information in your note to allow me to venture even a guess. In any case, harmonics of the modulating audio are not any indication of frequency modulation - frequency modulation would cause a variation in the frequency of the carrier plus/minus the modulating frequency. 73, Don W3FPR > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Gerhard Schwanz > Sent: Friday, April 01, 2005 4:25 AM > To: elecraft@mailman.qth.net > Subject: [Elecraft] K2 SSB problem > > > Hi group! > > I have a little problem with SSB it seems. During the contest last weekend > someone told me I had "frequency modulation" on my signal. Not > knowing what > this should mean I at least thought I would check the signal when > bands are > quieter. I just did. And although the audio sounds ok there is maybe a > little problem. Sending a 1kHz audio signal the receiving station > could hear > the same signal at +1kHz and -1kHz with -20dB max. These signals should be > at least -40dB, correct? > > Question. How do I fix this? > > Thanks! > > > > Gerhard Schwanz > DH3FAW > mailto:[EMAIL PROTECTED] > http://www.gs-personal.de > > > ___ > Elecraft mailing list > Post to: Elecraft@mailman.qth.net > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
