[rghines1]

Did a repair job for a customer years ago on a Crosley "Fiver" that used this circuit, so my memory is fuzzy. The volume control was open as well. Think I used a 5K ohm 2 watt wirewound control. A 10K would likely work too. No audio taper available so used a linear taper instead. Most of the volume control will likely be in the last 1/3 of control's rotation. The taper of the original was likely type II. This is defined as 90% resistance at 50% rotation measured as follows: From the front of the radio, terminals down, measure between the left-hand and center terminals.

The fixed resistance of the original control had to simulated with 1/2 watt resistor between the control and chassis. Don't recall the resistance but likely in the range of 100 to 500 ohms. Without the fixed resistor you got a strange muted region at the low end of the volume control.

A 210K control is far too high since cathode current of the 1st IF stage passes through the control too and would cut off the tube.

The Mallory/Yaxley book shows Mallory part no. E7 for a replacement but no specs are given.

Try contacting Mark Oppat at http://www.oldradioparts.net who has many old radio controls.


MALLORY TAPERS:
#1 = audio taper
#2 = logrithmic right hand taper
#3 = left/right taper (ant., Shunt & Bias Circuits)
#4 = linear taper

Appears another vendor at http://oldradioparts.com has the Mallory E7 control. Does have a $20 dollar minimum.