What happens if you reduce the rf output on the k3 to some value below 12 watts. I have the same symptoms and thought it was the KPA500 but after disconnecting the K3S from the rest of the station I accidently determined that if I decreased the RF output to less that 12 watts the receiver is no longer attenuated. I am waiting until Elecraft is on a more normal footing before sending it back for repair.
Marv KG7V -----Original Message----- From: [email protected] <[email protected]> On Behalf Of Mark Goldberg Sent: Sunday, April 18, 2021 3:20 PM To: [email protected] Cc: Elecraft Mailing List <[email protected]> Subject: Re: [Elecraft] KPA500 Question Is the key line indication on all the time? This may be indicative of a stuck key line. There was an unsoldered resistor on mine causing the issue. 73, Mark W7MLG On Sun, Apr 18, 2021, 2:38 PM <[email protected]> wrote: > I just purchased a used KPA500 (SN 0456) from a close friend. The amp > was just back to the factory for several repairs and was thoroughly > tested. The report reads, "KPA500 #0456 meets or exceeds all factory specifications." > My > friend unboxed the amp and made several QSOs to be sure all issues > were fixed. He then personally delivered the amp to my QTH. > Over the weekend I got the amp added to my operating position and was > quite surprised to find that input signals are attenuated > significantly when the amp is switched from STBY to OPER. No, this is > NOT the issue with having the aux cable and the PA key line connected > at the same time. This is with NO PA key, and NO aux cable connected. > The amp has no connection but RF input and output. It is independent > of band. This is with a matched antenna, band switched manually with > the front panel buttons. When I engage OPER the input signal is > attenuated by ~20 dB. > On the TX side, the amp is fine. On most bands I get full rated output > into a dummy load with approx. 20 Watts of drive from the K3. > I noticed on the service report, one of the tests was, "Tested receive > attenuation and IMD." I'm curious about "receive attenuation." This > would seem to be related to my problem. Looking at the block diagram, > I surmise something in the TR switch is malfunctioning. > Before I bug an already-overloaded Elecraft support, I am open to > suggestions. Am I missing something obvious? > TIA es 73, > Jim - WS6X > P.S. Yes, I have read the manual, and scoured the archives. The only > thing I can find regarding input attenuation in the OPER mode involves > incorrect cabling. > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net Please help support this email > list: http://www.qsl.net/donate.html Message delivered to > [email protected] > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
