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Coronado 962A
RodB
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City: Roseville, MN
#1

07-17-2024, 11:25 AM
I'm looking at replacing an output transformer for this farm radio. It has 2 1Q5s in parallel driving a SE OPT. The 1Q5 has a suggested plate load of 8k. If the tubes are in parallel then can I be okay using an OPT with a 4K primary impedance?
(This post was last modified: 07-17-2024, 12:44 PM by RodB.)
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Arran
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#2

07-17-2024, 05:10 PM
Just out of curiosity is there an economy switch that shuts off one of the 1Q5 tubes to save on battery life? I couldn't find a 962A on N.A only a 962 so I assume it's similar. I think you would be right about the plate load impedance being 4000 Ohms, but I'm sure someone else will chime in.
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Arran
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RodB
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#3

07-17-2024, 05:20 PM
There doesn't seem to be a switch to turn off one of the 1Q5s. The schematic at NA is the correct one. The A suffix is for speaker size as noted in the schematic.
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  1. The PHILCO Phorum
  2. Various and Sundry Categories
  3. Other Radios (Non-Philco)