On Aug 14, 4:43 pm, John Byrns wrote:
In article om,
Andre Jute wrote:
And, since I would have the guy pinned down, still trying to close his
mouth, I'd impress on him the necessity of a new rectifier, twin GZ37
in one tube, i.e. a complete one-tube high voltage high current bridge
rectifier). The reason I don't choose the venerated GZ34 is that the
-37 is a better rectifier in every respect and anyway its size and
shape match the 300B bulb I've already specified above. All that heat
may need the bigger tube too than the GZ34.
Wouldn't it take something more like a triple GZ37 to make "a complete
one-tube high voltage high current bridge rectifier"? At least three
independent cathodes would be required, along with three rectifier
heater windings on the Power Transformer.
Yes, you're right. This was pointed out to me by Mr Williamson, my
correspondence tube electronics tutor with whom I had been studying
Kondo's Ongaku, when I just naturally put four GZ37 on my first
kilovolt supply. But a decade and more has passed since then, and I
still use four full wave GZ37 per bridge (God bless Billington for
supply, and for 5R4GWY -- the ones with ceramic bowl base -- that
actually do the HV business unlike some probably Russian-made rubbish
I also had) and my trannies have four filament supplies... I just
forgot.
But even if we take up Max's idea, of a second GZ37 in the same
envelope with an independent filament for each plate, that's too many
connectors to fit into my other parameter of a standard octal base.
(Four plates and 6 filament/cathode connectors add up to 10.)
I'll have to amend that to a GZ37 with separate cathodes/fils per
plate separately brought out. Still, that's only two tubes for a
bridge, rather than three, so there's a saving of one tube, and other
convenience too. (Though, on the whole, I am not impressed with
crosstalk through the filaments, which once exercised the obsessives
on the Joenet. I remember mentioning it to Simon S, the British amp
and tranny designer, and he burst out laughing.)
Regards,
John Byrns
--
Surf my web pages at, http://fmamradios.com/
Thanks for bringing Mr Williamson to my mind. I haven't thought of him
recently, and he deserves to be remembered for everything he taught
me.
Andre Jute
Now let us praise famous men -- Ecclesiastes
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