[ARC5] Way OT -- SX-28

[Jim Haynes]

On Fri, 6 Aug 2021, Rich Post wrote:

> AFAIK, the move was less for cost-cutting but more for power consumption. 
> The FCC used a lot of these in portable application, run off vibrator
> packs.  A single-ended audio would significantly reduced B+ current demand.
> 
One could argue with that.  Loy Barton, who developed the idea of
amplitude modulating an RF amplifier using a Class B audio amplifier,
once advocated the use of a two-tube push-pull audio output stage in
battery operated radio receivers.  The reasoning was that a Class A
audio amplifier is pulling current all the time whereas a Class B
push-pull amplifier pulls current only when there is some audio present
to amplify.  So the Class B audio would give longer battery life.
(At least for the B-battery - more current would be needed from the
A-battery to power the filaments of the two tubes.)