[ARC5] Why an UNUN?

[Mike Morrow]

>> I didn't express myself as clearly as I should have, and meant that
>> somewhere I've seen 5 ohms as the impedance that the transmitter
>> is designed to work into.
>
> That seems as good a design center as anything, Neil.  My only point was 
> that it had to tune a range around that point, so it's hard to say 
> precisely what center point the ARC engineers chose.  I seem to recall a 
> 5 ohm figure as well, but I couldn't find it during a lineup of the 
> usual suspects.

I think the electrical characteristics of the A-61-A dummy load would be
a good indication of the "nominal" design goal for "command set" MF/HF
transmitters.  The transmitter testing set-up from the SCR-274-N manuals
show the transmitter connected to A-61-A terminal A, which is a 5 ohm
resistor in series with a 100 uuF capacitor in series with the RF ammeter.

73,
Mike / KK5F