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

[J. Forster]

Will your marker say clueless?

The WS19 did what it was supposed to do, very well. It was a breakthrough
design.

-John

===============


> 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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>
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