FSK RTTY and CW keying using G3LIV Isoterm Multimode

After years of operating mostly on SSB and CW, I caught the digital bug in 2005, initially using PSK31 but subsequently RTTY, which has since become my favourite operating mode on HF. There's something captivating about those diddle-diddle sounds and watching text appear on the screen from stations halfway across the world. But getting everything set up properly can be a bit of a headache, so I wanted to share details of my setup.

I'd had a Yaesu FT-950 for a while and to my mind, it's a fantastic rig. Connecting it to the computer for audio digital modes (PSK31 and AKSK RTTY) was relatively easy but for FSK RTTY I needed something more sophisticated. 

Enter the G3LIV ISOTERM MULTIMODE interface (which I believe is no longer in production since Johnny G3LIV retired). Getting everything connected was straightforward having purchased the correct cable set for for 950. 

The interface sat between my FT-950 and the computer, handling all the audio routing for PSK31, PTT switching, and FSK keying for RTTY. 

I used MMTTY for RTTY operation ( I still do), and it worked flawlessly. The waterfall display was clean, and decoding was spot-on (benefiting also from the audio peaking on the Mark & Space frequencies when using the FT-950's FSK RTTY mode).

But here's the really cool part – The Isoterm Multimode also lets you use the same setup for CW as well! This capability allowed me to use the CWType software from Sergei UA9OSV, for rapid-fire contest and DXpedition CW exchanges, with great success. 

The best part? No more worries about accidentally transmitting garbage or overdriving my audio levels. The isolation provided by the ISOTERM means I can experiment with settings without fear of causing interference or damaging anything.

If you're looking to dive into the digital modes with your FT-950 (or really, any modern rig), I can't recommend this setup enough if you have or can find one of these units. It opened up a whole new world of operating for me.