[Amps] TT Centurion _ squeal

[Henry Pfizenmayer]

I have run run into something weird on my TT Centurion -- after its
been on for about a half hour and then  I have it on the air for maybe 5
minutes total of cw - it starts giving an audible squeal about 2 khz - loud
enough I can hear it with phones on - its just audible - no funny business
in output /tuning/carrier etc etc etc - does it no matter what band - Then
when the squeal gets going - (I at first thought maybe fan bearings going )- 
I
can turn the amp off completely - and the squeal keeps going even after the
fan is stopped for about 5 - 10 seconds - at thsi point B+ is about 1600v ,
when B+ gets down under about 500 volts the squeal stops.

It seems like maybe its coming out of one of the filter
capacitors in the stack - but if I key the amp when its still on and
squealing - keying does not change the squeal at all - same key up or key
down !!!! So that sounds like something else - dunno - gonna have to take
the cover off and see if I can localize the noise without getting fried . TT
says they have never heard of this and I talked to the Centurion bench
tech too and he never heard one do that .

 Any ideas ? Amp is fairly new - rcd in Feb 2005 and not very mnay hours on 
it.

 Rgds-- Hank K7HP