Measured voltages over the PIN-diodes D26 & D27. In Rx: 0,72 VDC. over both. In Tx, the voltages varied a bit around 0,4-0,6 VDC.
While in TX, even with power set to 0,0W, one of the transistors in the LPA is getting quite hot. Cools down when switching over to Rx. P-T On Fri, 14 Aug 2020 at 17:59, Per-Tore Aasestrand <p...@ieee.org> wrote: > Hi, > > Still working on finding a solution to the below problem. > > Elecraft support said: > > "Since you are hearing signals, on frequency is presumed, only attenuated > ~30 dB, > The SYNTH circuit is not the first place I would look." > > Any suggestion wrt where to look first? > I guess it must be somewhere on the RF Board. > > Where can I find the PCB layouts with components id's? > > 73, > > Per-Tore > LA7NO > > --------------- > > The K3 suddenly stopped working. > One day all OK, the next day serious problems. > > Serial no.: 07818. > It has ATU and 100 W PA installed, and also a P3 connected. > Both K3 and P3 were earlier well calibrated. > Supply: 14,5 VDC. > > Symptoms: > - Rx seriously reduced sensitivity, only strong signals to be heard. > - No Tx output. Tuning not successful, no SWR indicated (only the 3 > hyphens). > - Same on all bands. > - All displays, controls and menus apparently working normal. > - Mic-gain & ALC normal indication on SSB. > > All menu settings seem to be OK. > > Connected an XG3 and injected a -73 dBm signal. > It showed up on all bands with signal level about -100 dBm, so around 30 dB > attenuation. > > Connected a LP-100A and a 50 ohm dummy load. > Whatever we tried, the LP-100A indicated zero power out on all bands. > Same on both Ant1 and Ant2. > Bypassed the ATU: no change. > Set power to < 10 W, effectively bypassing the PA: no change. > > It is clearly something that is common for both Rx and Tx. > It is independent of the selected band. > Apparently not related to ATU or PA. > > So, it could be some relay problem, or related to the SWR bridge or > LP-filters. > > Hope you can give some helpful ideas on how to proceed. > > ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com
