Inrad RX7300 Modification While Keeping The External Tuner Jack

Finally the Inrad RX7300 modification! I’m in the process of adding a panadapter to my Icom 7300. The Inrad RX7300 is installed and I managed to keep the external antenna tuner jack on the rear of the IC-7300. All I did was let it dangle from the rear of the radio. This is temporary and I make no guarantees about this.

The alternative is to provide power to the external tuner and use the tuner button on it. That has it’s drawbacks. For one, I won’t be able to use software (HRD) to start the autotuner.

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I have an LDG AT-600ProII Autotuner connected to the Icom 7300 and I use it with my amplifier.

In a few months when I move the radio into my camper, I’ll keep the Inrad RX7300 and do away with the external tuner jack altogether. I won’t need the external tuner in the camper.

Inrad RX7300 Modification

Installation of the Inrad RX7300 is a breeze. Another Ham (Steve Ellington) has a YouTube video on the installation, so I won’t be making one. I have some photos on the next page.

What is different from mine is the external antenna tuner jack.

The instructions included with the Inrad RX7300 are well written. However, the black and white photos in the instructions are tough to make out. Go to page 2.

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I'm an Amateur Radio enthusiast. I love the hobby and experimenting with radios, antennas and software. On my YouTube channel I upload videos on the Icom 7300 and Icom 7610 along with Ham radio software programs. I hope to inspire people to try new things in Amateur Radio.

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4 years ago

Very nice video!

Omar Paredes
4 years ago

Very interesting and use-full add-on circuit hook-up for the IC7300.
Good videos, living a clear idea of the enhanced operation of the IC7300 with SDR programs.

brian gallear g8vpr
4 years ago

nice videos bt on the 7300 how do yo get it to go to and display 11500 as the baud rate

thanks brian..

brian gallear g8vpr
4 years ago


I CANT GET IT TO SHOW any where, i need to set port baud rate to set up N1MM spectrum analyser
in his logger program i wish to use that program to display waterfall from 7300

many thanks rich
brian g8vpr

Daniel Trainor
3 years ago

Hi Rich, I am contemplating getting the new Icom 7610. I was just reading the Manual and notice it has more TX/RX antenna connections and options than the 7300. I see two main Ant 1 and 2 connections and also a RX (in/out). One thing I wish to do is use my SDRPlay SDR RX with SDRuno as a seperate RX and panadapter with OMNIRig Control. But, with all the new flexibility of 7610 ant port options, I am not sure which ant jack to hook up the SDRPlay RX to. I am thinking it would be to the RX (out) – but there may be some other interesting options. Have you experimented with the 7610 Ant TX and RX configurations yet? PS. I am liking your channel. 73, Dan

Daniel Trainor
3 years ago

Thanks Rich! Yeah maybe just RX out for SDRPlay. And IF through USB would possibly be yet another option. So much more flexibility as compared to 7300 with Inrad RX7300 mod. Should be fun experimenting with all these ant in/out options. Love your channel, keep the videos coming! 🙂 – dan

3 years ago

Hi Rich. I just installed the RX7300 mod. Can I use the RX7300 for the receive antenna for the ICOM 7300 and also for my SDRPlay? I know I can just install the SDRPlay using the transmitting antenna, but I would prefer to use my receive antenna if possible. Does the RX7300 2nd RCA jack (the one on the right side (looking from the back) forward the receive signal coming in from the left RCA jack? Thank you. 73, Gary WD9HDM

Jeff Hochberg
2 years ago

Hi Rich,

I ended up buying a device very similar to the Inrad RX7300 off eBay. I was thinking that this would basically be plug-and-play and that I would be able to connect my SDRPlay to the output jack of the mod. I thought that the mod simply split the RX output so I could have a second receiver connected – that being the SDRplay.

Obviously not that simple! When I watched the video you created (, I noticed that your notes say you also using Mini Circuits ZFSC-2-1 Splitter/Combiner.

Would you mind sharing how you have everything connected?


Atlanta, GA

Mel Ming
1 year ago

Do you have a photo showing the install with the tuner jack coming out the back?

1 month ago

The RX7300 has been discontinued.

Richard Donahue
24 days ago
Reply to  Steve

There is another out on eBay. Just search for RX7300.

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