How to check LPF / relay failure that may be lowering power output


sumit basu
 

I get about 12 watts at 80m which progressively goes down to about 6 / 7 watts at 30m when measuring with a watt meter in CW mode. From 20m on-wards the watt-meter momentarily deflects when the key is pressed with ptt clicking in and instantly the needle goes down no transmit power after that. If i try test point 7 on the board with a wire to the watt-meter on 20m i get a deflection indicating about 5 watts progressively going down to 1 watt or less in 10m. Testing from test point 8 for these bands shows no deflection other than when the ptt clicks like earlier. I doubt something with the LPF's and /or the relays, how can i check this. Replacing relays is difficult - can anyone guide me a troubleshoot?
I was calling CQ on CW on 20m with 24 volts to the PA, the meter was showing power output around 25 watts and then came smoke. The transmit / receive was not working after that and after replacing both the 510's, Q15 and K1 things got OK except transmitting on 20m till 10m.
I am using v5 board with the cec 1.2

Sumit Basu
VU2DTF

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