I'm assembling an amp using the power and output iron from a Fisher 500B receiver (no, I wasn't the ghoul who hacked it up). I have the windings on the power XFMR fairly well sussed out, but wanted to know the color coding for the taps on the output iron. I can extract the imformation with a sine source and oscilloscope, but if someone already has the info, it would save me some trouble. It would also be nice to know which 6.3V winding on the power transformer feeds the power tubes, though I can find that out as well with some effort.
I asked the same question about 500C, which I think is the same color code. Here's the response from Gary Pimm:
Hi Steve,
I needed this info also so I just measured one of the darn things. The Fisher schematics don't have the color codes so they are not much help.
Here goes...
Output trannys:
black common
brown 4 ohm
green 8 ohm
yellow 16 ohm
red B+
blue + plate
blue with white stripe - plate
power tranny:
black pair line
red pair B+
blue & white 6.3 volts for output tubes
green & yellow 6.3 volts for everything else
brown & orange bias supply
Gary
Hi Steve,
I needed this info also so I just measured one of the darn things. The Fisher schematics don't have the color codes so they are not much help.
Here goes...
Output trannys:
black common
brown 4 ohm
green 8 ohm
yellow 16 ohm
red B+
blue + plate
blue with white stripe - plate
power tranny:
black pair line
red pair B+
blue & white 6.3 volts for output tubes
green & yellow 6.3 volts for everything else
brown & orange bias supply
Gary
Thanks for the data - that will save me a load of time tonight. I tried the Fisher schematic first as well, but it was not helpful. I also have complete iron from a 400 receiver, so this will help me get a leg up. However, on that power transformer, both 6.3V filament windings have the same color code.
The 500B iron I have was pretty scratched up, with a little rust under the end bells. The screws for the end bells were a disaster area. I wire-wheeled the end bells clean on all the iron, repainted end bells and lams with metallic cast-iron gray auto retouch paint, and replaced all the ganky rusty screws with new stainless hardware - the results look pretty swank.
The 500B iron I have was pretty scratched up, with a little rust under the end bells. The screws for the end bells were a disaster area. I wire-wheeled the end bells clean on all the iron, repainted end bells and lams with metallic cast-iron gray auto retouch paint, and replaced all the ganky rusty screws with new stainless hardware - the results look pretty swank.
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