john stewart wrote:

(snip)

Hi Roger- I read your query along with John B's very good
description of some of these phase splitters. Here are two more
for you to ponder, as they were used in some 30's & 40's radios.

In this scheme there is no seperate phase inverter tube or transformer.
A resister of the proper value (about 2K) is inserted into the G2 lead
of the upper pentode of a PP pair. The resulting signal on that G2 is
capacitively coupled to the G1 of the lower member of the PP pair.
Of course there is some imbalance, but that is partially corrected by
the PP output transformer. This circuit was often seen using PP 6F6's
but could be applied to other pentodes or beam tetrodes as well.

John, the screen idea is what I came up with while trying to
figure out how to phase split without an extra tube - the
purpose of the original "kluge" - but I didn't calculate any
values. Done properly, it just might just work better than a
common cathode resistor - a good experiment for someone with
an old PP 6V6 amp to play with (I don't have one or I'd try
it!)

(snip)

Cheers, John Stewart

Cheers,

Roger

PS. Thanks to all for the great comments.

--
Roger Jones, P.Eng.
Thornhill, Ontario,
Canada.

"Friends don't let friends vote Liberal"