[Elecraft] Elecraft K3 Problem

[Per-Tore Aasestrand]

 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.