[Hallicrafters] S-20R schematic

[W4AWM at aol.com]

Hi Skip,

The SM18 accessory meter for the S-20R had a sensitivity of 0 - 1 MA.  
Connections were as follows:

Pin 1:   Ground
Pin 2:   B+  This runs through a 25Meg resistor in series with one end of a 
10 Meg
           pot. The other end of the pot is in series with a 20 Meg resistor 
to ground.
           The positive side of the meter is connected to the pot wiper.      

Pin 3:   NC
Pin 4:   Negative side of the meter
Pin 5:   One side of the pilot lamp.  The other side of the lamp is grounded

Hope this helps.

73,

John,  W4AWM