Icom 7610 dual receiver with no RX antenna performance demonstration

I was setting up for a RX antenna video [coming] I noticed that I was receiving signals on the RX antenna port on the SUB receiver, although there was nothing connected to it. I investigated and called Icom and spoke with Rick. He stated this is normal. Anyways, enjoy the demonstration. DE W5DPH 73

[@g0fvt]

The leakage is many dBs down, not looked for the same issue with my FTDX101MP but it is likely to be similar.

[@PD0DH]

Same here on my 7610.. Sometimes S2-3 with strong(er) signals.

[@Stewart-HA5RV]

Disconnect the RX antenna coax at the back of the radio and see if it stops. You said that the RX antenna was grounded on that switch, I suspect the ground is picking up the signal now... I'm curious what the result is. 73.

[@HamRadio200]

Excellent point. When setting up for this video, I did just that. I was getting my radio setup to track frequencies and familiarizing myself with the main, sub and antenna switches. That's when I noticed the bleed over, with no antenna connected to the RX port. Coax hooked up and grounded seemed to make little if any difference. Once on my 7300, I listened to an 80m net without an antenna hooked up. Of course only stronger signals came through but that illustrates even further the sensitivity of these radio receivers.

[@Nobody-ld7mk]

Stray RF

[@timdbl7804]

looks like the isolation is only about 30 dB. Could be an issue if you are using a lossy rx antenna - which is an accebtable technique. Was the pre-amp off also on the RX antenna?

[@HamRadio200]

The pre-amp was off.

[@timdbl7804]

Try the RX antenna with the 7610 internal pre-amp ON on the RX antenna.... That might help, depending on where, in the 7610 front-end, the leak-across is happening.

[@timdbl7804]

Also try "IP+" on, on the main antenna, and/or reduce the RF receive-gain on the main antenna