RE: [Elecraft] Preamp, Attenuator on K2 #4901
Jim, Other than a faulty solder connection or an incorrect resistor value (R74, R75, R76, R77), I can think of only 2 things that might cause the PreAmp to not work - T6 could be connected incorrectly or the windings shorted together, or C146 may be faulty. Try tacking a 0.01 uF capacitor across R77 (bottom of the board) as a check for an open C146 and if that doesn't fix things, try rewinding T6. 73, Don W3FPR -Original Message- I just finished K2 #4901 and it works great. The only thing I have a question on is the preamp setting. When the annunciator is on over the preamp, it seems as though background noise goes down and the signal strength is reduced. In fact, there seems to be little difference between the preamp and att settings. I've been through the schematic and carefully reviewed the parts installed for the preamp and I can't see anything wrong. Has anyone experienced this problem, if it is one? 73 and thanks. Jim, K4ZMV -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.322 / Virus Database: 266.11.16 - Release Date: 5/24/2005 ___ 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] Preamp, Attenuator on K2 #4901
W3FPR - Don Wilhelm wrote: Other than a faulty solder connection or an incorrect resistor value (R74, R75, R76, R77), I can think of only 2 things that might cause the PreAmp to not work - T6 could be connected incorrectly or the windings shorted together, or C146 may be faulty. Try tacking a 0.01 uF capacitor across R77 (bottom of the board) as a check for an open C146 and if that doesn't fix things, try rewinding T6. -Original Message- I just finished K2 #4901 and it works great. The only thing I have a question on is the preamp setting. When the annunciator is on over the preamp, it seems as though background noise goes down and the signal strength is reduced. Jim-- Definately what Don said. I was in exactly the same situation as you: Margaret Leber wrote: After reworking a couple of suspect joints in the preamp section and removing and reinstalling T6, the preamp in K2 1641 is now working. 73 de Maggie K3XS Editor, Phil-Mont Mobile Radio Club Blurb - http://www.phil-mont.org Elecraft K2 #1641 -- -/___. _)Margaret Stephanie Leber CCP, SCJP/The art of progress / /(, /| /| http://voicenet.com/~maggie SCWCD/ is to preserve order/ ---/ / | / | _ _ _` _ AOPA 925383/ amid change and to / --/ ) / |/ |_(_(_(_/_(_/__(__(/_ K3XS / preserve change amid/ -/ (_/ '.-/ .-/ARRL 39280 /order.-A.N.Whitehead/ /(_/_(_/___AMSAT 32844_/[EMAIL PROTECTED]/ ___ 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
