After a "normal" night of EME last night, tonight while warming everything up I noticed a sudden drop of rx signal of about 10db on the WSJT waterfall. I got the WSJT level set correctly again by increasing LIN OUT to the computer. Here's where it gets wierd:
1) I can still receive the very loud signals of locals.
2) When I hook up the XG3 to the antenna connector, I get an S8 signal indication on the K3 at -33dbm, an S1 signal at -73 dbm, and nothing at -107dbm.
3) Disconnecting the antenna completely has no effect on the noise level displayed on WSJT or the P3, but the loud local signals drop out. Not normal.
4) Turning the external preamp on and off has no effect on noise level either. Preamp confirmed good. Bypassing it physically has no effect. Not normal.
5) TX works normally. SWR is normal.
All measurements made in CW mode with AGC OFF. Could I have had a partial failure of the XV-144 in rx mode without a total failure? Or am I missing something due to sleep deprivation?