Isolate An Auxiliary Receiver

[flintstone mop]

Hello
I would like to get any info to obtain better isolation of Auxiliary receivers in my shack. I was on the air using QRO on SSB on 17M and a small SDR receiver got severally confused after the QSO that it no longer operated. I would unplug the USB port and the computer thought it was still connected. RE-booting the computer; going into a Blue Screen Dump Crash. Computer restarted and everything was fine.
Past incidences have actually burned up the first coil for 160M on the RF deck of my R390A.

The present setup is a B&W switch for the AUX receivers ( the R390a, SDR receiver, and whatever transceiver is in use) that includes the ability to turn on a low noise pre-amp. This  is on the RX side of the station master T/R relay. My transceivers have their own T/R relays; the station also has it's master T/R relay.
Thanks for any thoughts.
Fred

[Pete, WA2CWA]

You at least need to ground the input side (wiper) of the B&W switch (for the AUX receivers)  when going into transmit. Most B&W switches also ground the connections that are not in active use. Have good ground on the switch housing. Don't rely on just the coax to provide a "good" ground.

[N2DTS]

For computers and sdr radios, you need to RF proof the computer and radio, lots and lots of snap on ferrites on every cable, every power supply, and I put them on all the coax where they enter and exit a cabinet.
You may need more then one, and to wrap the cable through a core a number of times.

For the antenna, I have a separate small TR relay at the sdr receiver. On TX its grounds the receiver antenna input, and opens and shorts the audio feed from the computer or sdr to the audio amp.

The main TR relay (giant contactor) grounds the receiver output during TX also.

I can run 3000 watts with the antenna's directly over the house without issues, and the sdr is always active so I can study my TX signal.

[Pete, WA2CWA]

I've been running my Flex 5000 barefoot and with the SB-200 linear and the only ferrites on cables I have are the ones that came with the Flex cables (power and Firewire). There are no additional ferrite things on anything else.

[N2DTS]

Much depends on the computer, where the antenna is, grounding, bands and swr.
I had some issues on higher bands with non resonant antenna's.

[WBear2GCR]

Something to clamp the voltage between the input of the receiver (or inside it) and the ant switch would provide some protection too. Of course that works only on a receiver, not a transceiver... thinking lower voltage transorb here... a few volts max is all that is needed.

               _-_-

[flintstone mop]

Thanks Brett and Pete.
The antennas are mostly 100 feet from the house. And the antennas are all resonant. The Magnetic loops are remotely tuned at the antenna. The tuner for the dipole using OWL is 25 feet from the shack. I have never had any RFI in the house or audio equipment in the shack.
The extra set of contacts going through another T/R relay might increase the attenuation needed. Maybe a clamp on ferrite on the coax bringing RX RF to the B&W switch ( a CSR-5G), might choke off any RF on the shield. and grounding the B&W switch.
Thanks again
Fred