[R-390] R-390 RF Gain Control

[Charles Steinmetz]

Jacques wrote:

> I believe that your RF gain control have been replaced and that the wrong
> taper type was used.  [Need REVERSE LOG taper]
>    *   *   *
> If ever the two measured values are about equal, (± 2.5K) what you have is a
> LINEAR taper control and only that suffice to explain why the "control
> range" of your RF gain is so small.

New reverse log pots are not impossible to find.  A very quick internet 
search turned up the following:

           https://www.amazon.com/dp/B07SVMC3VK

The pots in that kit are not the same form factor as the original, but 
they do claim to include 2 pieces of 5k reverse log taper pots, and some 
creativity could probably adapt them to the 390.  There is a guy in 
England on ebay who sells them individually for about 5 euros.

I'm sure a more thorough search would turn up other possibilities.

Best regards,

Charles