[ARC5] Shunt vs. Parallel

[AKLDGUY .]

After several interesting replies, I figure it like this, which may be
wrong:

Plate modulation (AN/ARC-5):
With no modulation, the peak plate voltage swings between near zero and
twice the applied B+.
With 100% modulation, the peak audio voltage from the secondary of the
modulation transformer
adds to the B+ and doubles it, with the result that the peak plate voltage
is now 4x the applied B+.

Screen modulation (ATA, SCR-274N):
I couldn't figure this, but on thinking it over, I think that screen mod is
the same when no audio is
applied (ie. peak plate voltage is 2x). With full modulation, it's the
screen voltage that is approximately
doubled, from about half the normal to normal. This cannot add to the plate
voltage, which stays
at the former excursion of 2x the applied B+.

So we're talking about 4 x 550, or 2200 volts peak for AN/ARC-5 plate
modulation, and 1100 for ATA
and SCR-274N screen modulation.

As well as that, the voltage at the rear connector rises from 550 VDC
(steady) in the ATA and
SCR-274N to 1100 V peak in the AN/ARC-5, due to the impressed audio,
necessitating the larger
spacing on the pins.

73 de Neil ZL1ANM
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/arc5/attachments/20170716/8f942888/attachment.html>