[R-390] Audio Gain Pots?

[Charles Steinmetz]

Jacques wrote:

>Sorry to rain on the parade, but I just checked the pots I kept from two
>R390A Moto "junk" units, and 2 are audio taper, the 2 others are linear.

By design, the line and local pots are both audio taper.  If you find 
a radio with one or both linear pots, it usually means those pots 
have been replaced somewhere along the way by someone who didn't know 
the difference.  I have seen some radios with linear pots that looked 
like they might be original, leading me to speculate that a batch of 
linear pots snuck through into production from time to time.  Or 
perhaps Motorola mistakenly made all of their radios with one linear pot??

In any case, both pots *should* be audio taper, and if you replace a 
pot you should use audio taper even if the pot you remove is linear.

Best regards,

Charles