Mills MRA-5 resistors in tube circuits

[dodo]

Hi

Does someone used mills MRA-5 ww resistors as cathode resistors or high voltage resistors in psu with voltage range 200 - 350 V ?

I'm asking because there is difference in voltage range showed in the the data sheet of the MRA - 5 - 400 V max 😕 and the voltage range showed in Percy catalog 200 V 😕 :

"* MRA-5 (5watt) non-inductively wound, very compact size for its power rating, copper leads
200V Maximum, 1% tolerance, 50ppm TCR <10Ω, 20ppm >10Ω, .167" Diameter x .650" Long

Thank you in advance for the feedback

 

[Eli Duttman]

P = V²R The largest MRA-5 value Percy shows is 20,000 Ω. Applying the formula yields 316 V. Given that bit of arithmetic, I'd say Percy is correct in 200 V. max. for MRA-5s and 400 V. max. for MRA-12s.