Stewart-Warner reactance dimmer
S-W model R-1822 has a "reactance dimmer" (item 2) with a 6.3 v lamp that
illuminates the band indicators. The bandswitch physically moves the
nameplates over the lamp. The transformer primary appears to be open, and a
10K resistor across it does provide a little signal to the speaker. C21 &
C14 are listed as 10 mfd, 25 v and 0.1 mfd, 150 v, and both are absent. I
am suspicious that C21 of that value doesn't belong, since the schematic has
misidentified a C22 elsewhere. Schematic is from Nostalgia Air.
This radio had been severely hacked, but the beautiful cabinet has kept me
picking away at it for a long time.
I've found a little about reactance dimmers but nothing about use in a tube
radio, mostly fluorescent dimmers. I'd really appreciate any explanation of
the function here and especially thoughts about the caps that parallel the
primary.
Thanks,
Dave Burson
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