[ARC5] [Milsurplus] Low B+: The Genius of A.R.C.

[Bry Carling]

Great reading David - OTOH I think there may be a marker near the designer of the WS19 
that says Dunce.

On 11 Oct 2011 at 7:14, David Stinson wrote:

> Most of you know I've been for years working on ways 
> to use our rigs at low B+ to both preserve them and 
> to operate them without extensive parts replacement.
> Results with receivers have been good.  "ARC-5" receivers 
> work well all the way down to 24 volts with external amplifed
> speakers.  They have plenty of audio for earphones without the
> amplification.  This allows them to be operated with a single
> 24 volt, 2 amp power supply.  Over the years I've found no 
> down-side at all to this mode.  Despite dire warnings of 
> "cathode interface," I've had no trouble.
> 
> A few years ago, I moved on to working with the transmitters.
> I built a milli-watt drive 100 watt amplifier 
> and powered an "ARC-5" transmitter from only 24 volts.  
> The rig put out a good, stable signal of about 1/4 watt.
> 
> Now, since I'm building the 160 mtr AN/ARC-5 rig,
> I tried it with the MD-7 modulator.  I jumpered the 
> dynamotor connection pins, putting 24 volts B+ on all
> the modulator and transmitter stages.  Remarkably,
> the scope showed 1/4 watt output of nice, 100% modulated,
> good-sounding signal.  
> Way more than enough to drive my amplifier.
> 
> No way these modulation and transmitter stages continue
> to work as intended all the way down to their A+ voltage
> levels unless they were thoughtfully, ingeniusly designed 
> to do just that.  Try getting a DX-100 to do it ;-).
> 
> I think we should find the final resting places of the men
> who designed these sets and place a brass placard 
> next to their monument stone: "Unsung American Genius."
> 
> 73 DE Dave AB5S
> 
> 
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