[Heathkit] More. . .AT-1 woes

[bfetters at aol.com]

Thanks for all the inputs re: my AT-1.  Consensus is that getting 10-15 watts out is about normal.  I'll leave well enough alone on this issue.

Found another problem when I turned on a receiver to listen to the signal.

When I turn on the B+ switch to operate, the unit self oscillates.  I can hear it softly in the receiver and when I key the AT-1, the tone changes a bit and gets louder.  Checked for a leaky cap from the key to ground and it seemed okay.  Also disconnected the small cap from the cathode to ground of the 6L6.  (The 6L6 cathode is keyed.)  When I turn the driver variable condenser I get a slight change in pitch/intensity of the self oscillation.

Any thoughts on how to get this self oscillation stopped?

Thanks again.

Buck

W0LC