[Premium-Rx] OT: Harris RF-110A A6?

[W2HX]

Hello all. Been troubleshooting a bias supply problem for over 6 months. I'm
close to the end of my rope doing the component-level troubleshooting so I
thought I'd send out a call.

Anyone have a spare A6 board that they would care to sell?  I might as well
get a spare A5 board too in case the problem is somewhere there. I don't
think it is.

Let me know what you have!
thanks

73 Eugene W2HX

PS. In case you're interested in the details:

1. The final bias is fine in AB1 mode. The problem is only in CW/RATT mode.
2. overtime, the bias increases until the tubes start to conduct. Typical
range for the grid voltage in CW/RATT goes from -90VDC when first started up
and slowly drifts to about -72 and the tubes are conducting.
3. I have pulled the tubes, so this is not the cause
4. I do not have to have the HV on for the bias voltage to shift
5. I have replaced several components over time with no improvement