[MrFixr55]

Hi MRM,

It depends on the wattage of heat dissipation required. For your radio:
Per the RCA Receiving Tube Manual, (RC14) the maximum output current of a 5Y4 is 125mA. Lets say 150 mA to build a little safety into it. Let's also say that the total B+ Load is 150 mA. Your Candohm, #43 is between Chassis Ground (Common) and the center tap pf the HV secondary feeding the rectifier plates, therefore the total 150mA B Current passes through this resistor.

The purpose of this resistor is to develop a negative bias voltage for various tubes, the highest voltage being for the 6F6 Output tube. Per the same RCA Receiving Tube Manual, the grid bias required for a 6F6 at 285V is -20V.

The total resistance of the Candohm is 245 Ohm. The total voltage drop across the resistor is 20V. Since current is constant through a series circuit, and Power (in Watts) = V X A, the power dissipated is 20V X 0.150A = 3W. So 3W flameproof metal film resistors would do the trick. 5W Wirewounds provide a higher margin of safety.

Now, in actuality, the total current load on the power supply is likely a lot lower than what I stated here before. If we look at actual tube load instead of maximum current capacity of the rectifier, the total cathode current(in mA) of all tubes added up is:

14 (6A8) + 8.7 (6K7) + 1 (6J5) + 1 (6F5) + 51(6F6) = 76mA. Since the 8uf cap also goes to chassis ground instead of to the center tap like the 25uF cap does, its ripple current has to be accounted for. Per the internet, the ripple is about 20mA. So we are at about 96mA. So round to 100 mA and the actual wattage dissipation is 2W.

On top pf that, note that the majority of the dissipation is across the 202 Ohm portion of the Candohm. The dissipation across the 8 Ohm and 35 Ohm resistors is much less than 3 watts.

So bottom line, use a 3W or 5W 200 Ohm resistor and at least a 1/2 Watt for the other two.

So it's your choice.

Did I overengineer this answer? Probably.