[MrFixr55]

Hi Rick,

The volume control on the Model 20 has 2 sections and does 2 seperate things:

• One part of the control, the 5000 Ohm section, shunts the antenna input from minimum shunt at full volume to maximum shunt (shorting antenna to ground) at minimum volume setting.
  

• The other part of the control, the 250 Ohm section, varies cathode bias on the 1st and 2nd RF Amp, thereby adjusting the gain of these stages, from minimum bias at full volume to maximum bias at minimum volume.
  

Ohm the 2 sections end to end.  You may find that antenna (5000 Ohm) sections to be open or miswiring at the 250 Ohm section.  If the 250 Ohm section is open someone may have rewired the set to bypass that pot and provide fixed bias to the RF stages.

Troubleshoot by measuring between ground and either of the 2 "end" terminals (the resistance element connections).  There should be several volts (maybe somewhere around 25V?).  Measuring between chassis ground and the cathodes of either of the RF Amp tubes, the voltage should vary while rotating the poet from min to max.

If the pot has only 1 section, determine if it shunts the antenna or if it varies the RF amp bias.

Hope this helps.