[ARC5] AN/ARC-3 ?

[Michael Clarson]

Jim: I have to disagree about the transmitter.It really did tune itself --
no presets like the SCR-522. See the manual, Page 58 of the PDF referenced
for a description. Nice manual, lots of pictures.

http://www.w7ekb.com/glowbugs/Military/PDF%20files/ARC3/AN_ARC-3,36,49.pdf

I had one of these in the early 1970s, and was absolutely amazed how it
actually tuned itself up. It really sensed resonance. There were some one
time tracking adjustments to make sure all the variables tracked each other
-- no simple feat to design since stages operated at different frequencies.
Once tracking was set, it tuned to the 18th harmonic of whatever in range
(100 to 156 Mc) crystal was selected. --Mike, WV2ZOW

On Fri, Jan 22, 2016 at 1:49 PM, Jim Haynes <jhhaynes at earthlink.net> wrote:

> On Fri, 22 Jan 2016, Michael Clarson wrote:
>
> Yes, it was an autotune system.  Which means it was preset by a technician
> rather than automatically finding resonance like Really Modern stuff.
> There were only 8 channels of the autotune in all the models.  The
> models having more channels simply had the ability to switch between
> 2 or 3 or 4 crystals for each of the original 8 channels.  So the
> frequencies in any one of the 8 channels had to be close enough together
> that the equipment was not seriously out of tune whichever crystal was
> selected.  Each of the 8 channels had to be pre tuned to a compromise
> among the several crystals which could be selected for that channel.
>
>
> Jim: I don't know about the ARC-3 rcvr, but the transmitter autotune would
>> retune the entire transmitter. All stages were ganged together, motor
>> driven
>> and tracked, and there was a relay that sensed a TUNED condition. --Mike,
>> WV2ZOW
>>
>>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/arc5/attachments/20160122/7a550f16/attachment.html>