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cathoderay57 · 17th Dec 2019, 6:01 pm

Re: higher than expected HT voltages, reading the Trader sheet again it says the voltage test results were taken with a mains voltage of 228v AC on the 224-255v mains transformer tapping. My mains is about 235v AC and there isn't a higher tapping to select. Also, doing some basic calcs shows the anode current of V2 is spot-on (3.4mA) and that of V4 very close (4.6mA vs 4.5mA). So I reckon unless I fit a stonkingly high wattage dropper resistor into the HT line I am stuck with the high voltages. Any comments welcome.

17th Dec 2019, 6:01 pm	#3
cathoderay57 Nonode Join Date: Oct 2017 Location: Bristol, UK. Posts: 2,384	Re: Marconiphone 538 Re: higher than expected HT voltages, reading the Trader sheet again it says the voltage test results were taken with a mains voltage of 228v AC on the 224-255v mains transformer tapping. My mains is about 235v AC and there isn't a higher tapping to select. Also, doing some basic calcs shows the anode current of V2 is spot-on (3.4mA) and that of V4 very close (4.6mA vs 4.5mA). So I reckon unless I fit a stonkingly high wattage dropper resistor into the HT line I am stuck with the high voltages. Any comments welcome.