19-11-2016, 05:41 PM
I did consider putting a mains PSU inside it for the variable screen voltage, but decided against it in favour of a variable supply of 0 - 250 Volts DC going into the unit, the anode voltage being selected from the variac, and using the same voltage with the coarse and fine screen dropper from the same supply. A 12 variable 12 Volt battery grid bias appeals to me mainly because of its simplicity. A battery, switch and pot. cost less than a pot, transformer, rectifier and smoothing! I do have all those items, but putting a 12V transformer in it would be one less transformer for other projects!
I will be starting by building the box first of all!
Bob
I will be starting by building the box first of all!
Bob
