[R-390] Scratchy Static

[Drew P.]

Steve Hobensack  wrote:


"After my 63 Imperial warms up, there is a low level scratching in the speaker. It is there when the local gain and rf gain control is all the way down. I have isolated the problem to the audio deck, specifically the 5814 audio driver tube to the 6ak6 local gain audio output. It is not present on the line gain side of the circuitry. Before I begin clipping and testing, is there a troublesome component that others have found? The problem is still there after tube substitution."

A possible cause could be the plate load resistor for the 5814 audio amplifier stage.  High value carbon composition resistors sometimes go intermittent or open in circuits impressing a relatively high voltage.

Drew