While it's old and lacks some of the refinement of newer rigs, I find that my IC-735 makes a great PSK31 rig. The thing that particularly impresses me is the stability; while I'm sure that it must drift some, I can't detect *any* drift when I turn it on from a cold start. So if your IC-735 is in decent shape, no worries there.
Here's what else you'll need:
- A computer. It need not be a super-fast machine, by any means. I use an old machine with a 1 GHz Pentium III processor, far slower than just about anything you'd buy today, and it works just fine. I'm using Windows (2000, in my case), which allows me to choose among a fairly vast array of software, but you can find Linux programs, too, if you prefer to run some form of Linux O/S.
- Software. The good news is, there's lots of high-quality software for PSK31. Two of my favorites are:
Digipan, an older program that is no longer under development, but which is very easy to use and does a great job. You can find it at http://www.digipan.net/
DM780, which is part of the Ham Radio Deluxe suite. This is a highly-polished program that supports lots of digital modes, and while it's somewhat harder to learn than Digipan, it's worth the extra time spent. You can find it at http://www.ham-radio-deluxe.com/
These are by no means the only choices; there are *lots* of programs out there.
- An interface between your computer and your IC-735. You need something that will route (a) rx audio from the receiver to the computer, (b) tx audio from the computer to the transmitter, and (c) something to enable transmit mode. Some people go with extremely simple interfaces, like a couple of audio cables and a way of keying the transmitter off the serial port. I'd recommend using an interface that provides DC isolation between the computer and your IC-735. I use a Donner Digital interface that plugs into one of the IC-735 accessory connectors. It's cheap and works well, and you can find it at http://home.att.net/~n8st/DDI-index.html
If you're looking for something a more sophisticated, you might try one of the SignaLink devices, available from Tigertronics, at http://www.tigertronics.com/
You can also roll your own interface, if you want, with not much more than a couple of audio transformers and an optoisolator. For an example, go to http://www.geocities.com/n2uhc/interface.html
Hope you have fun on PSK31!