Inrad RX7300 Modification While Keeping The External Tuner Jack

How To Use The RX7300 For A Panadapter

One point of confusion may be the jacks on the rear and which one to use?

If you want to connect an RTL-SDR (or other) and use it as the sole receiver, while looking at the radio from the rear, connect the RTL-SDR to the RCA jack on the left leaving the RCA jack on the right open.

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If you want to connect a RX antenna (just for receiving), connect it to the RCA jack on the right and leave the one on the left open (or connect an SDR to the one on the left).

No RX antenna? Use a splitter, connect an SDR to it and have two receivers!

BTW, I have a cheap RTL-SDR and I tried a simple VGA splitter from Amazon and it did not work for me. There was too much noise and interference on mine. It may work for others and may be worth a try. The VGA splitter was only a few dollars and it might work better with a better SDR too.

Icom 7300, RX7300, RTL-SDR and Mini-Circuits Splitter

So I got the Inrad RX7300 installed easy enough and now I have a Mini-Circuits ZFSC-2-1 SMA Splitter attached to the Inrad RX7300.

With HDSDR and a cheap RTL-SDR dongle I have a panadapter going. The RTL-SDR receiver is not very good compared to the Icom 7300 receiver. Also, it picks up local AM and FM broadcast stations on the HF bands. That is the downside to the cheap RTL-SDR. If you don’t have strong local AM and/or FM broadcast stations close-by, it should work fine. There are filters you can buy or make for it too.

I have another SDR coming and I’m looking forward to trying it. I’ll post the rest of the installation and results when I have them, so there’s more to come.

Thanks for dropping by, please comment below. Have you tried this?

73 – Rich, K0PIR

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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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