[PAradiogeek]

One of the things I will need to do soon is to replace the candohm. The schematic shows that this resistor includes 202 ohm, 8 ohm, and 35 ohm resistence elements. Unfortunately, none of the documentation indicates a power rating for these resistors. I did some calculations, but the physical sizes are huge and will make it difficult to fit my replacement into the available space. If someone is willing to double check my work, including my assumptions, I would really appreciate it. So here goes.

Riders schematic says that total power is 65W.
The heater current power consumption is as follows
Tube. Current. Voltage. Power
6K7. .3A. 6.3v. 1.89W
6K7. .3A. 6.3v. 1.89W
6F6. .7A. 6.3v. 4.41W
6A8. .3A. 6.3v. 1.89W
6Q7G. .3A. 6.3v. 1.89W
5Y4G. 2.0A. 5.0v. 10.0W
Total -->. 21.97W. Round to 22W

Thus the total power minus what is used by the heaters is: 65 - 22 = 43W. This is the power consumed by the circuitry connected to the high voltage winding.

The highest voltage I see is 250V at the plate of the 6F6. Using I =P/V the high voltage current should then be 43/250= .172A.

I believe that essentially all of this current flows through the candohm, so using
P = I*I*R, I get the following power numbers :
Resistor. Power. Resistor rating needed
202 ohm. 5.97W. 20W
8 ohm. 0.23W. 2W
35 ohm. 1W. 5W

Sorry for the long post, but do these numbers make sense?

Thanks in advance,
Jon