[Skimmertalk] disabling USB connection

[Bob Wilson, N6TV]

On Sun, Jun 23, 2013 at 9:14 AM, Pete Smith N4ZR <n4zr at contesting.com>wrote:

> It occurs to me that one way to mute a QS1R, SDR-IQ or similar receiver
> might be to open one or the other (or both) data lines in the USB cable.
>  This probably is 'way too simple - does any of you know if the USB drivers
> used on motherboards would tolerate this without throwing an error?
>

It sounds like you want to mute the data to prevent "images" of your
transmitted signal from being spotted? It's probably much simpler to do
that in software (e.g. use a "reject" list to eliminate every variation of
your own callsign being spotted by the local skimmer).

The real need, of course, is to open or protect the front end of your SDR
whenever you transmit.  Opening or stopping the USB line will not protect
your SDR. :-)

Some RX antennas using remote Pre-Amps (e.g. active Rx Loops or short
vertical whips) provide a way to quickly remove pre-amp power using the PTT
line on the radio.  That's very effective, and much better than trying to
do it in software or via USB commands or tricks.

73,
Bob, N6TV