[ARC5] "Curing Chirp in Command Transmitters" MO T-53, Vibration, AC Heater Power

[AKLDGUY .]

Mike Morrow KK5F wrote:

> If one is not operating his ham set in such a high-vibration environment,
> there will be no adverse effects from separating the heater circuit from
> the cathode, and eliminating T-53B from the circuit.

T-53B would then be connected to nothing, and that would be especially so
if the modifier decided to also disconnect the wires running to its
terminals
and the decoupling capacitor C61 at its "cold" end.

That loss of termination and possibly wiring would almost certainly lead to
an immediate shift in the oscillator frequency, which might be significantly
large and necessitate a retune to restore the dial calibration.

I think we've reached the point where the "twin" windings can be regarded
as bifilar wound, based on the patent, although the word bifilar doesn't
seem
to be used in the manual. Maybe at that point in time, the patent and the
adaptation of it in the Command transmitters was regarded as classified
information, so the word "twin" was used with no real explanation of how it
worked.

73 de Neil ZL1ANM