[AMRadio] Protecting receiver (was WTB: Coax relay, 110VAC, aux contacts)

[Rob Atkinson]

Hi Bernie thanks for this information on switching with a QRO rig.

73

Rob
K5UJ

On Sat, Nov 19, 2011 at 11:32 AM, Bernie Doran
<qedconsultants at embarqmail.com> wrote:
> yep:   On closing the xmit switch, a DPDT, the plate relays are grounded
> through the second pole. The first control relays are tripped grounding rx,
> operating mute circuits, shorting speaker, turning on the driver stage,
> transfering the antenna, starting the Hamsters running on the wheel,
> etc,etc.   and also sending a signal to the plate relays to start them,
> after a very short delay, first plate relay applies 240 through dropping
> resistor  then second relay closes appling full 240 to the plate xformer.
> On receive the plate relays drop almost immeadiatly, as does the plate
> voltage as there is still drive applied because of a small delay in the
> control relays, they have  a nice fat capacator across the coils.     The
> Hamsters head to the water for a drink!!   There could also be a set of
> contacts on the antenna relay in series with the second pole of the DPDT
> switch to prevent plate operation if the antenna relay did not operate.  I
> have not found that necessary as the xmter shuts down on more safetys than I
> can count. It is a Gates BC1G.
>
>