In article ,
Roger D Johnson wrote:
While we are on the subject of DX-40s, I have one with a problem
that's driving me nuts. In AM mode, just sitting at idle, the plate
current pulses up about every second or so. The scope shows a pulse
on the plate of the second 12AX7 audio stage. It's acting like some
sort of relaxation oscillator. I've rebuilt the audio section to no
avail. Anyone have an idea what the heck is going on?

Bad caps.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."