[Arran]

http://www.nostalgiaair.org/pagesbymodel...017623.pdf

I'm still figuring out the math involved in calculating wattage on power resistors, so please bear with me. The schematic shows the voltage going into R14 is 250v. The voltage going out is 210v, so that's a voltage drop of 40v. The resistance of R14 is 1500 ohms, so amperage is V/R=.02666?

P=R(I squared), so P=1.06? Wattage should be three times the calculated value, so I need at least a 1500 ohm 3 watt resistor? Closest I have to that is a 1200 ohm 5 watt, so I guess a visit to the electronics store is in order.

Am I even close to correct here? What is currently in the radio looks to be a 1000 ohm wire-wound (possibly 10 watt) resistor?

Somebody with some math tutoring patience want to straighten me out here?

Also, what is the wattage on flex-ohm resistors? Or is that a function of length?

 Is the resistor in question a flexible resistor or are you asking about another you have found? I don't know what the maximum wattage is for flexable resistors but in my experience they are not usually more then 2 or 3 Watts, so maybe not more then 5 Watts at the most.
 I looked at the schematic you linked to, and I would say that it would be highly unlikely that they would use anything like a 10 watt resistor in there originally, though there is nothing stopping you from using one as a replacement other then physical limitations, so clearly this 1000 Ohm job is a replacement. You could use a 1200 Ohm 5W in there in a pinch, it's acting mostly as a choke resistor in a Pi filter circuit not as a voltage dropper, the difference would be negligible. I'm not sure about the Rider manual they lifted this from but most Silvertone schematics usually have a parts list, perhaps whomever scanned and uploaded this to Nostalgia Air omitted it.
Regards
Arran