Ft-817 psk vox

Hello all,

Has anyone used the FT-817 to TX PSK31 via the Mic socket, rather than the data connector? Is there any reason why I shouldn’t do this?

The good weather is here again, and I want another bite of the PSK/SOTA cherry. This time I want to keep it as simple as possible. Mini-laptop, with freshly installed cut down version of XP, my usual FT-817 and linked dipole combo and a dead simple interface. I was thinking, two jack plugs, an RJ-45 plug and a dc blocking cap somewhere on the computer’s mic line, and that’s it. That way, I can use the 817’s VOX to key up and not have to carry my Rascal GLX and a RS232 adapter.

Any thoughts?

Dave M0MYA.

In reply to M0MYA:
Yes i have done PSK as well as SSTV via the mic and spkr on my FT817 then into a sound card however i didnt use VOX but instead had a toggle switch for the PTT. Sean M0GIA

In reply to M0GIA:

I used the back socket, my interface is 25X40X70mm, and the changeover is automatic in the PKT mode, the same setup was fine for SSTV - take a small digital camera and you could also do SSTV with photos of the summit!


Brian G8ADD

In reply to M0MYA:
You Could use a USB CAT interface for TX and then you can just have two wires to the data port on the radio. This is what I use on my TS-480 and it works very well and has the advantage that you don’t need an attenuator etc like you do with the mic socket.
Timothy 2E0KEA

In reply to M0MYA:

A lot of nonsense gets written about PSK interfacing. When I did Beinn Each SS-034 I used my teeny-tiny eeePC and a home made interface. The interface is a direct connection for the audio connections from the soundcard jack sockets to the 817 data socket. The PTT circuit is a transistor, resistor and two diodes that fits into a DB9 shell and normally connects to a COM port. On the eeePC I use a USB<>RS232 adaptor. The whole kit and kaboodle weighs 1.1kg, see http://www.flickr.com/photos/mm0fmf/2483108545/

VOX is naff compared to using the PTT output from the computer. You don’t need isolation rubbish (99.99999999999999999999% of people don’t need it even when at home using mains power supplies) and you don’t need attenuators (or DC blocking) that you probably will need if you use the mic socket. Also, soldering a 6-pin mini DIN is easier than trying to wire an RJ-45 style mic connector.


In reply to M0MYA:

I use the data socket of FT817ND, but the microphone socket should work too. My old FT840 does not have a data socket, so in that radio one needs to use the microphone connector.

73, Jaakko OH7BF/F5VGL

In reply to M0MYA:

If you use Ham Radio Deluxe it will key the PTT via a CAT command.

It means another wire between laptop & radio but no interface.

I hope to get some SOTA PSK in this year, maybe we’ll manage a summit to summit?


In reply to M0EIQ:

It means another wire between laptop & radio but no interface.

But you’ll still need an RS232<>USB adaptor for the laptop as few modern laptops have an RS232 port anymore. Then you’ll need some kind of level shifter to get the RS232 to TTL for the 817.

The level shifter will be of the same order of complexity as a PTT switch so you don’t gain anything. In fact it will be more complex. You do add the cost of another 8 pin mini-DIN connector on to the BOM.

Ham Radio Deluxe



You could try one like this although I don’t know about the quality.


In reply to 2E0KEA: Here’s another one that looks interesting: http://radioarena.co.uk/index.php?_a=viewProd&productId=2570 .

However, beware. I bought a cheap FT-817 interface a few months ago, don’t remember from where, but it looks like the picture of the Kenwood one on the site above. It wouldn’t TX at all. In the end I had to prise the case apart, trace the circuit and then rewire it because it was connected to all the wrong pins. It would have been quicker in the end to make one myself, which was what I was trying to save time by not doing.

I completely agree that the isolation is unnecessary. I had terrible 50Hz lines on this interface until I bridged across the screening from one side to the other. Many laptops such as the Eee PC have no ground connection through the power supply so they need to be grounded through the interface cable. Out on the hill, running from batteries, it probably makes no difference either way.

In reply to MM0FMF:

The level shifter will be of the same order of complexity as a PTT
switch so you don’t gain anything. In fact it will be more complex.

Actually, the whole process can be done with a couple of MOSFETs for switching and some resistors to set levels. See: http://www.botkin.org/dale/yaesu_if.htm

I’m not saying its good for the job being discussed in this thread, but if ever you need to shift RS232 to TTL cheaply and easily, it works. I use one to program my VX-6 on a regular basis (one set of freqs for homes in G and GW, another for visiting the YL’s folks in London).

Ham Radio Deluxe


Granted, the GUI is hideous by comparison to some products, but once you get your head around it, it is functional. I think the decoding is a work of art - it runs with very minimal overheads and will decode where other programs wont. Its also worked well where others (MixW in my case) could not figure out what to do with some dodgy on-board sound on certain laptops. Plus, the shareware version is very and indefinitely functional.

Hmmmm. I’ve just realised, I’m actually talking about MultiPSK, not Ham Radio Deluxe! I’ll leave the above bit of soapboxing in, just in case it causes someone to discover MultiPSK.

Back to the topic: I think I might just rob the PTT bit from this chaps interface: Alan Yates' Laboratory - PSK-31 Interface for the FT-817 and not bother with the isolation. Seems like it work for him.

Thanks for all the replies.

Dave M0MYA
[edit to make links work]