[Heathkit] Filament Voltage Regulation

[Eddy Swynar]

Hi Guys,

Can anyone reading this recall a brief article that described REGULATING the 6.3-VAC filament voltage to the SB-300 receiver...?

Apparently the author of the write-up was experiencing "thermal drift" in his 300, that was attributed to the filament voltage LOWERING in his PTO oscillator tube whenever another heavy load came on-line to the AC mains. If I recall correctly, he used a voltage doubler / zener diode combination to hold filament voltage steady at 6.2 VDC just for the oscillator tube...

Does anyone recall the source of this, or am I simply having "...a senior moment"...?!   : >)

~73~ de Eddy VE3CUI - VE3XZ