Hello:
I have a tube radio to repair. It's output valve is an ELL80 (two EL95 in one tube) and was broken at the base and the socket showed signs of overheat and cold solder joints. I have the valve on order but when checking the output transformers (it has 2) onde of them has a primary resistance of ~900ohm and the other ~4000 ohm. I measured the turns ratio using a signal generator at 1khz and got 45,6 and 46,0 which squared and multiplied by the speakers output impedance (5ohm) gives ~10kohms which is the expected impedance for the ELL80. Given all this info how can i check which transformer is bad? they both drive an speaker just fine using the Sig. Gen. but i can't believe they can have such different dc resistance.
Thank you in advance
Best Regards
Steve Sousa