[Milsurplus] AN/ARC-65 (was: RE: AN/ARC-8 questions)

[Jim Haynes]

On Mon, 7 Sep 2009, D C *Mac* Macdonald wrote:

> was cumbersome, to say the least.  If I recall, they
> had 20 channels that had to be pre-programmed.  To set
> the frequency for channel 1, you had to select channel
> 11 to bring the selector drum for channel 1 into view
> for programming.  To program any other channel you
> would select the channel that was PLUS or MINUS 10
> channels of desired to bring the selector drum into
> view.
Yes, instead of having direct frequency input they had that
master control box with 20 preset channels chosen by moving
sliders on a rotating drum.  And the sliders for the current
channel were on the back of the drum, so you had to rotate
it 180 degrees to get to them.  Then there were slave control
boxes that could only select one of the 20 preset channels.

Then the frequency setting from the drum was not sent to the
radio as a binary code, but rather was sent as a variable resistance.
The thing inside the radio would balance a Wheatstone bridge to
determine which frequency was selected.