These sets tend to be all the same: two RF stages, a detector, and two AF stages. The usual plate voltage on the detector is 45V and 90V for the other four tubes.
This set has 45V on the RF stages, in addition to the detector. (The AF stages have 90V.) I can't recall ever encountering such an arrangement. I don't have it back together yet, so it's not ready to try. I guess I'll wait see how it performs, but perhaps rewire the RF-stage plate voltages if I think it's necessary.
I'm wondering if, possibly, the lower plate voltage on the RF tubes was to cure some pesky oscillation?
This is a weird brand-name set (Beckley-Ralston), and no schematic is available.
Doug
Thanks
Lou
:I'm working on a battery-powered TRF - a typical 3-dialer with five '01A tubes.
:
:These sets tend to be all the same: two RF stages, a detector, and two AF stages. The usual plate voltage on the detector is 45V and 90V for the other four tubes.
:
:This set has 45V on the RF stages, in addition to the detector. (The AF stages have 90V.) I can't recall ever encountering such an arrangement. I don't have it back together yet, so it's not ready to try. I guess I'll wait see how it performs, but perhaps rewire the RF-stage plate voltages if I think it's necessary.
:
:I'm wondering if, possibly, the lower plate voltage on the RF tubes was to cure some pesky oscillation?
:
:This is a weird brand-name set (Beckley-Ralston), and no schematic is available.
:Doug