[R-390] AF/RF Gain Control

[Fernando]

Hello. 

I have a Motorola 390A with these control experiencing dead spots.

I have disassembled them and cleaned the contactors and 

resistance tracks. They are supposed to be linear but 

these have the tracks starting as a narrow path then widening

to the end. Letting me know that they are tappered.

The AF control has the resistance deposited on a wafer,

the RF control has the resistance deposited on the inner

perimeter of the case with a wiper.

Anyhoot, looking to purchase both of these.

The RF (R103) pot is  5k ohm 2W linear and the AF (R105) pot is 2.5k ohm linear.

Or any pointer for new ones. I have scanned the net but

have only seen ones with a locking nut.

 
Fernando N2FQ/6
n2fq at sbcglobal.net