[grandntl]

If anyone has a 91-121 or 91/221 ( broadcast only) radio and you want to check, please see if your on/off switch has an extra "on" position (far right) that affects the sensitivity. The schematic and 44RF cathode tube socket data don't make sense as shown, thank you Terry, but 25 volts with the switch off and 5 volts with it on could account for this. The schematic and tube voltage data are here: http://www.nostalgiaair.org/Resources/884/M0013884.htm
Bob