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Katar83 · 2nd Feb 2023, 12:42 am

Yes, both resistors are ok and within spec and cathode voltage follows socket where ac4/pen is plugged in.
I've ordered some 82uF caps just in case but good to know that slightly lower voltage is fine.
HT voltage is 373V so a bit high, should I slightly increase value of the resistor?
Also might be slight measurement error, my analogue Simson multimeter shows just over 360V.
I'll have to get a heatsink for that resistor anyway, after 10minutes it's boiling hot.
Not checked other valves just yet, will do tomorrow.

2nd Feb 2023, 12:42 am	#67
Katar83 Pentode Join Date: Feb 2021 Location: Thetford, Norfolk, UK. Posts: 130	Re: What did I get myself into? Murphy A40C. Yes, both resistors are ok and within spec and cathode voltage follows socket where ac4/pen is plugged in. I've ordered some 82uF caps just in case but good to know that slightly lower voltage is fine. HT voltage is 373V so a bit high, should I slightly increase value of the resistor? Also might be slight measurement error, my analogue Simson multimeter shows just over 360V. I'll have to get a heatsink for that resistor anyway, after 10minutes it's boiling hot. Not checked other valves just yet, will do tomorrow.