[ARC5] Netting Switch

[Jack Antonio]

On 5/26/2013 1:10 AM, Mike Morrow wrote:

> A simple netting switch can be added to an otherwise stock
> command set system by installing a SPST switch that opens
> the keying line from pin 5 of modulator connector J-52 to
> the receiver rack.

I did this on an SCR-274N set I built up. And it worked, sort
of.  The problem was that even though the receive antenna line
is grounded by the antenna relay, there was still enough
signal picked up by the antenna wiring, to overload the
receiver.  The antenna wire needed to be disconnected from
the receiver to reduce the signal to the point a good
zero beat could be obtained.

I now use a spotting oscillator, using the circuit from
the TBX calibrator. But, it needs a crystal on the frequency
of interest. (Thanks to Dave Stinson for the tip).

Built it into an old BC-357 marker beacon receiver
so that at least it sort of looks like it should be there.

Jack Antonio WA7DIA/4