04-13-2026, 09:22 AM
Hi RodB,
Seems that the control should be swapped out. A 5K pot is not appropriate for use as a tone control in a high impedance tube circuit. you would be better off with a 500K or higher pot, preferably a 1 megohm audio taper pot. Any pot and switch combo of this spec would work.
It is possible that the control currently in this set was used as a volume control in an older non-AVC TRF set where the wiper was grounded and the control shunted the antenna input and increased cathode resistance on the 1st RF amp tube (a common way to control volume in Depression era TRF sets), and as another member (Sorry, I can't remember who) stated, this was probably put in for the power switch function and the pot was not used.
Seems that the control should be swapped out. A 5K pot is not appropriate for use as a tone control in a high impedance tube circuit. you would be better off with a 500K or higher pot, preferably a 1 megohm audio taper pot. Any pot and switch combo of this spec would work.
It is possible that the control currently in this set was used as a volume control in an older non-AVC TRF set where the wiper was grounded and the control shunted the antenna input and increased cathode resistance on the 1st RF amp tube (a common way to control volume in Depression era TRF sets), and as another member (Sorry, I can't remember who) stated, this was probably put in for the power switch function and the pot was not used.
"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
"Let us begin to do good"- St. Francis
Best Regards,
MrFixr55
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