[Amps] TT Centuruion oscillation

[Henry Pfizenmayer]

By any chance has anyone experienced self oscillation with a Centurion  key
up after application and removal of drive ? Mine has decided to do this on
40 meters only (into a good 50 ohm dummy load). It is fine on all other
bands. On 40 it appears to tune normally and have normal power out but key
up it continues to put out about 250 watts PF and PR on the internal meter
(nothing is coming out of the amp because the TR  relay  is in  receive.)
Have not determined the freq of oscillation as of right now. Input SWR seems
about normal 1.4 worst case on 40 .

 Once its oscillating - makes no difference if its in operate or standby .
You can kill it by pulling the key lines - or by turning the Orion off. (no-
the Orion is not putting out power key up - and have tried changing the qsk
delays)

 Using Orion driver - have tried changing to ant 2 and keying loop 2 - no
difference. Orion seems perfectly normal in all respects. (output power does
not hang on any band )

Have checked the Centurion input filter band switching voltage to the lpf
board and it is switching ok.  Have the  lpf board out , all solder
connections look fine , 40 meter filter has continuity  - will check the
relay tomorrow .

 Just wonder if anyone has seen this . TT has not seen this and I have tried
several things they suggested on a couple different calls.

Rgds-- Hank K7HP