The potentiometer wasn't marked other than with a manufacturer's number.
It measured 211k across the ends, and mid-way on the rotor the
resistance from the slider to either side was 176k/35k, so I think it's
safe to call it a "220k log".
73,
Steve G3TXQ
On 07/02/2011 14:34, NL7VL wrote:
Hi Steve,
So you're saying that the double-gang notch pot on the Corsair I is a
220K? That's about how it measured out with the ohm meter, but it does
say 500K on the schematic. Jerry's right about things showing up on the
case of the pots, but all I saw was what looked to be an OEM part
number or something like it. Please let us know how it goes.
There are a few DDS mods for the oldies out there - like N4YG's mod. I
have a Corsair II PTO that I will be investigating this week. It's kind
of a crap-shoot with those things: The Century 21 I have stays within
50hz after warm-up, but it was rebuilt no so long ago. Going with the
DDS + display combo heads off future problems with the original display,
too. Not a bad idea. I had thought about using a "Huff-and-Puff" or some
kind of fast response phase lock loop on the PTO, but maybe that's not
the way to go.
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