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

[Fuqua, Bill L]

   The ARC-5 manuals states that if the 1626 or a 1625 is replaced the oscillator trimming capacitor may require
retuning using the crystal and 1629 as reference anyway. 
73
Bill wa4lav

________________________________________
From: ARC5 [arc5-bounces at mailman.qth.net] on behalf of AKLDGUY . [neilb0627 at gmail.com]
Sent: Tuesday, October 07, 2014 4:49 PM
To: ARC-5 List
Subject: Re: [ARC5] "Curing Chirp in Command Transmitters" MO T-53, Vibration, AC Heater Power

> 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 should have added that the linearity of the dial calibration might suffer
too, from one end of its range to the other.

73 de Neil ZL1ANM

On Tue, Oct 7, 2014 at 11:59 PM, AKLDGUY . <neilb0627 at gmail.com> wrote:

> 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
>
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