Swan 500 Oscillation

Steve Harrison ko0u at OS.COM
Fri Mar 17 00:53:55 EST 2000

At 05:21 AM 2000-03-17 +0000, Dave Hollander wrote:
>Thanks to all who gave me suggestions but none caught the problem. Turns
>out that a bad 7360 tube is causing the oscillation. Removing it from
>the socket  makes the oscillation  go away. And the transmitter won't
>work with out this tube.

Removing the tube and finding an oscillation stops doesn't mean the tube
itself is at fault; it just means the tube is apparently oscillating in the
circuit. Very likely, there is something in the 7360 circuit that has gone
away, resulting in the oscillation problem. That'd be a much cheaper fix
than a new tube.

Check all voltages on the tube. Check or replace all bypass and blocking
capacitors around the tube.

No, there is no pin-compatible replacement for a 7360.

73, Steve K0XP

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