UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

cathoderay57 · 15th Oct 2020, 9:27 pm

What rectifier are you using?The specified U12 is directly heated but if you have replaced it with an indirectly heated valve that might explain why the HT is significantly higher than expected, on account of its lower series resistance (even allowing for the use of a high impedance DVM). Might not be helping things.

15th Oct 2020, 9:27 pm	#21
cathoderay57 Nonode Join Date: Oct 2017 Location: Bristol, UK. Posts: 2,387	Re: Marconi 346 Radio What rectifier are you using?The specified U12 is directly heated but if you have replaced it with an indirectly heated valve that might explain why the HT is significantly higher than expected, on account of its lower series resistance (even allowing for the use of a high impedance DVM). Might not be helping things.