?I should add: If I connect a small wire to my K2 antenna and press tune, it shows a strong signal on any of my receivers at that frequency. So somethings coming out of the K2. Either the ouput signal is low OR the K2 RF detector just doesn't measure it correctly for the ALC circuit. Brian Denley http://home.comcast.net/~b.denley/index.html
----- Original Message ----- From: "Brian Denley" <b.den...@comcast.net> To: <d...@w3fpr.com> Cc: "Elecraft Reflector" <elecraft@mailman.qth.net> Sent: Sunday, September 19, 2010 10:26 PM Subject: Re: [Elecraft] [K2] No Transmit Power > ?I am just about at the end of my rope trying to get this K2 to transmit. > Nothing is coming out of the transmitter because nothing seems to be going > into the PA circuit. The receiver circuits all work fine. All RF board > transistors and diodes check out fine as far as DC is concerned but my RF > probe does not function and I am unable to find the fault. I suspect the > T/R switch or whatever circuit generates the RF signal in the first place > but the trouble shooting help in the manual does not go yery deep on those > issues. What is my next step? Does Elecraft offer a repair service? I > have been at this for 4 weeks now with no progress at all. > Thanks > Brian Denley > http://home.comcast.net/~b.denley/index.html > > > ----- Original Message ----- > From: "Don Wilhelm" <w3...@embarqmail.com> > To: "Brian Denley" <b.den...@comcast.net> > Cc: "Elecraft Reflector" <elecraft@mailman.qth.net> > Sent: Tuesday, September 07, 2010 11:08 PM > Subject: Re: [Elecraft] [K2] No Transmit Power > > >> On 9/7/2010 10:16 PM, Brian Denley wrote: >>> Don: >>> I brought home a DSO5054A (very nice 500 MHz Agilent scope!) and I was >>> able >>> to take the better measurements. My measurements were in P-to-P but I >>> have >>> divided them by 2.8 for RMS comparison:\ >>> (all measurments Keydown) >>> >>> 1.) VPWR line (pin 2 of U8 on control board): 5.0 volts >>> this >>> is >>> HIGH >>> >>> 2.) Xmit Mixer Output (pin 4 of U10): 28 mV >>> >>> 3.) Buffer Output (pin 6 of U9): 121 mV >>> >>> 4.) Band-Pass Filter Output (W6): 42 mV >>> >>> 5.) T-R Switch #1 Output (anode of D1): 41 mV >>> >>> 6.) Pre-Driver Output (collector of Q5): 34 mV this >>> seems >>> LOW > >>>7.) Driver Input (base of Q6): 34 mV > >>>8.) Driver Output (collector of Q6): 179 mV this is >>>VERY LOW > >>>9.) PA Inputy (base of Q7): 80 mV >>>this >>>seems HIGH > >>>10.) PA input (base of Q8): 80 mV this >>>seems HIGH > >>>11.) RF Detector Input (anode of D9): 143 mV this is VERY >>>LOW > >>>on my own I also measured: > >>>12.) base of Q5: 43 mV > >>>13.) out of C107 43 mV > >>>all of the DC voltages in column 1 on page 17 are normal > > ______________________________________________________________ > 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 ______________________________________________________________ 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
