[Boatanchors] Hammarlund Super Pro 150 question

[McDonald, J Douglas]

Look at the circuit. Its supplying a GRID, not cathode, bias,
to the RF-IF, from across a 4K voltage divider, involving megohm size resistors. 50K looks appropriate. A lower value would
begin to perturb the voltage divider. 10K would perturb it a lot.
A higher value would work OK up to say 100K.

If there is a voltage chart, you could try 50K and see if the voltages are right, or 10K and see if they are wrong.

Or you could measure the broken pieces with an ohmmeter and add them up and use the obvious standard value. You might even be able to verify if linear taper is correct, which it likely is.

This is not rocket science.

Doug McDonald
________________________________

 Wally,

FWIW, the sensitivity control in the SP-200 is 50K per the manual.

Al

On 4/12/2021 7:06 PM, Wally Gibbons wrote:
>  Greetings,
> I'm overhauling a SP150 I got a few years ago. The sensitivity control is
> bad.