I've been considering adding an external RTL-SDR panadapter setup to my IC-7300 to expand the waterfall view beyond the built-in 30kHz bandwidth. A panadapter allows you to see all of the radio stations currently transmitting across an entire band. When working HF, this is very useful as it allows you to quickly home in on CQ calls and other activity. The 7300's scope is decent but limited for contesting when I need to see wider band activity. Has anyone done the SDR and transceiver sharing antenna mod on this particular rig? I'm planning to use a DXE-RTR-2 for TX/RX switching to protect the dongle.

I did this exact mod on my IC-7300 last year using an RTL-SDR V3 and DXE-RTR-2. The DXE RTR-2 is a high-grade relay box which can do much more than discussed here. I'm very pleased that I have chosen this option for my shack, this panadapter setup will be hard to beat. The wider spectrum view during contests is a game changer - you can spot pile-ups and clear frequencies instantly.

Be careful with antenna sharing on the 7300. SDR radios can be damaged by transmitter power when an SDR and transceiver share the same antenna. Make sure your switching circuit is bulletproof - I've seen guys fry dongles when their T/R switching failed. Test it thoroughly at low power first.

Worth mentioning that the SDR radio will require a good USB supply, this can be an issue if you already have lots of other devices connected to your PC. I had to add a powered USB hub because my laptop couldn't handle the RTL-SDR plus all my logging software and rig control simultaneously.