Icom 7300 RTTY FSK with MMTTY and N1MM Logger

Icom 7300 RTTY FSKI'm operating the Icom 7300 RTTY FSK. Wow, I have wanted to try RTTY (FSK) for years. This is the first radio I could get it setup on without having to buy external equipment.

I've used AFSK in the past and it's fine, but there's always the adjustment of the soundcard involved and if it gets knocked around the signal is lousy. I feel like I have to continuously monitor it.

I have FSK setup now using MMTTY which of course is used by N1MM Logger. N1MM is my favorite logging program for contests. I'm not a serious contester, more of a casual contester. Can't wait to try it in a contest.

Why FSK? Well there's the sound card issue with AFSK and I noticed after setting up AFSK on the 7300 that the signal on the spectrum scope is not aligned with the signal on MMTTY (N1MM Logger). In other words when I use the 7300's spectrum scope to tune to a signal and line it up, it's not in the band scope of MMTTY. It's completely outside the band scope and I have to go searching for it. Using FSK, when I tune to a signal using the Icom 7300 spectrum scope, it aligns perfectly in MMTTY's band scope.

icom 7300 rtty fskThere are other advantages with FSK, but I won't go into a lot of detail. AA5AU explains it pretty well. The article is here. I want to show how it's setup.

Icom 7300 RTTY FSK

I'm using two cables. One CI-V for rig control and the USB for digital modes including FSK and CW! (I am assuming that you have already downloaded the USB driver from Icom for the 7300 and have installed it. Then you can connect the USB cable.)

In the radio there are a few settings to be made. Go to Menu>Set>Connectors. I changed DATA MOD to USB because I've been operating PSK31 with the sound card. USB SEND is set to RTS. USB Keying (CW) is set to DTR and USB Keying (RTTY) is set to DTR. This works for me, so try it this way. I'll post a video clip in a week or so bringing this all together, ie., PSK31, CW and RTTY (FSK).

To see how N1MM is setup take a look at this post: ICOM 7300 N1MM LOGGER PLUS SETUP (different video than below)


The key here is the plugin. If you don't already have MMTTY installed go ahead and do that. Download it here. Then get the plugin here. (UPDATE 7/10/17: The EXTFSK v2.0e looks to be included with MMTTY, so there's no need for the extra download. Try MMTTY first, and if you don't see EXTFSK when setting up MMTTY, you can download EXTFSK from here) If needed, install the plugin following the directions on the page.

Open MMTTY go to Options>Setup MMTTY. Go to the TX tab. The Port for PTT & FSK should be set to EXTFSK64. That will bring up the  plugin window. Select your COM Port for the USB cable. FSK output = DTR, and PTT output I have set to RTS. Next go to the Misc tab. Under Tx Port select COM-TxD(FSK). Click the USB Port button and select A:Normal. The next tab you go to is the Soundcard tab. Under Reception select the USB Audio CODEC for the Icom 7300. (This is installed before you connect the USB cable and it's the driver you downloaded from Icom.) Under Transmission nothing is selected, because we are not using the soundcard. We are sending on/off keying. You'll see that in the plugin window when you transmit.

YouTube player


There you have it, the Icom 7300 RTTY FSK. To see how N1MM is setup take a look at this post: ICOM 7300 N1MM LOGGER PLUS SETUP (different video than above)

Thanks for coming by. If you have any suggestions please comment below. How do you like your Icom 7300 and have you used it for RTTY? Best 73 and good DX. - 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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Dave W8EIR
8 years ago

Rich, you’re the man! Thanks for your great post!

Timothy ORourke
7 years ago

I did not see where you used the CI-V cable ?

7 years ago

I’ve been watching your channel and your hanging out on your blog a lot lately. I’ve had my 7300 for over a year and was running it with a Tigertronics SignalLink USB. I decided, after chatting with a fellow in my DX club, to use the internal sound card. Well that led me to your page and I’ve been working through the videos. Just got FSK working! Thanks for the great videos. 73 and good DX OM. -jim KE4GVO

Declan Craig
7 years ago

Hi Rich, set up as per your video and blog, works 100% on my PC but on my Laptop a slight issue. When I click a macro the rig TX’s a carrier for approx 5 secs before sending the characters. Wonder if you have come across this ? maybe it’s peculiar to my laptop


7 years ago

How to make it done on IC-7410?

6 years ago

Hi Robby,
I setup RTTY with Log N1MM and I used one cable USB.

Denny Thompson
6 years ago

Regarding your Topic “MMTTY Icom 7300 RTTY FSK”. Using your link,
“(UPDATE 7/10/17: The EXTFSK v2.0e looks to be included with MMTTY, so there’s no need for the extra download. ” I went to their site but could not find any link to EXTFSK v2.0e. Can you please direct me to this link?
Thanks for this and your great videos.
Denny, KR7SWA

Chris (2E0XRD)
5 years ago

Hi thanks for the great videos I have FSK working but trouble is when i shut the program down and turn my radio back on ,it goes into a transmission loop where i have to turn off the radio with the power button? any ideas I’ve followed everything but this is a real problem ..am i missing something?
thanks again for all the great videos.

Chris Darby
5 years ago
Reply to  K0PIR

Hi Rich tried what you said but i think it was something to do with omni rig from another program.
One other thing i found was that i was unable to send CW as well, the setting that was the problem was in the radio set section after the cw drop down box i changed the setting to ptt instead of rts always off.
Now i have a fully working FSK /CW set up on the 7300 with just USB.
Thanks again for all the time and effort you put into the videos they really do help!
Chris 2E0XRD

Jim W
5 years ago
Reply to  Chris (2E0XRD)

Excellent article! I can transmit and receive, but it would seem that people have to go looking for me and that I am off freq when transmitting to them.
Any ideas?
Thanks – Jim K9IDX

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