Yaesu FT-897D home-brew digital interface

I am looking to build an interface for my Yaesu FT-897D to do digital modes. Can someone point me to a good design/schematic that I can use to build my own?

I have a 6-pin mini-din cable.

Thanks & 73,
Vince - K9NIB

 

google this "psk31 homebrew "

then see this
http://forums.qrz.com/archive/index.php/t-263328.html?

 

I did this with the Buxcomm Rascal rather than homebrew my own mainly because the kit of parts was cheaper than ordering them discretely - and there was a circuit board included, too. Mine was installed on a Yaesu 857, which uses the same interface mechanism as you. Word from one who's been there: Pay attention to your grounding scheme and make sure your computer's power supply is clean of RFI hash.

Cheers,

David/KG6IRW

 

The Rascal is a good , one but here's a simpler one:
http://www.eham.net/reviews/detail/9543

This one was in last month's QST. The good point is that it uses the sound from the soundcard to do the push to talk keying. It also comes with a mini-DIN cable if you order the kit. I have two of these waiting to be built sometime in the next few days.

 

I bought one of these kits from Unified Microsystems. It works nicely.

http://www.unifiedmicro.com/sci6.htm

Like the others, unless you already have the little transformers it's probably cheaper to get a kit which includes a nice case etc.

You'll have to build or buy cables to go to your radio. The interface has RCA sockets.

You might have to fiddle with the audio levels. I had to add two resistors as a voltage divider for the audio going to the computer. My TS430S only has a speaker output and my Sony Vaio laptop only has a microphone input so the levels were far too high.

It has an opto coupler for PTT which I'm not using because I don't have a serial port on the computer. VOX works well but you need to be careful to turn off other things on your computer that might make sounds and trigger the VOX. Turn the VOX off when you're not actively using it. Someone pointed out that if your radio has an axillary audio input on the back then use that but disconnect the microphone. There's a good chance that the microphone is still connected when you're using the axillary input.

 

The 897 does have the 'digital VOX' function - when it's in 'DIG' mode, you can still use the VOX to key the transmitter. Don't forget to set the DIG mode in the menus - I think it's menu 38.

At the simplest, you could just use a direct connection between the computer soundcard and the mini-DIN plug. I prefer to at least have some isolation between the computer and the radio - mostly to prevent the injection of hum to the signal from outside AC sources and potential ground loops, but also to protect both the radio and the computer from accidental overloads, shorts, etc.. You could simply use two 1:1 audio isolation transformers like SKip's interface does. This will provide DC isolation between the units.

 

Have you made your cable yet? I just did this myself for my 897D to Acer laptop. I used a PS2 extender cable (6pin mini din) and cut off one end. I spliced in two headphone jacks. One for tx and one for rx. Microphone input and headset jack. I am currently having issues with the rx portion (bad solder connection) and am running a cable from the radio's speaker jack to the microphone jack. the set up seems to be working ok. I have made about 20 psk31 contacts with good comments on signal quality. I do adjust the sound card level for no ALC ever time I move frequencies. If you have any questions feel free to contact me.

73,
John

ps. I am also running the CAT cable using HRD V5.

 

Let me see if I can find the schematics for my interface. Pretty much works with all newer yaesu's. (817,857,897,950). I key through the cat.

 

This is the simplest way to do it.
I use an FT-897D.

A spare PC keyboard cable and 2 mini-plugs to match
the speaker and microphone jacks on your computer.

One plug soldered to the Data-In wires, one plug soldered to
the Data-Out wires. (The manual has the pinout of the 6 pin-DIN.)
Use your ohmmeter to determine which wires go to which pin.

I use this lash up and it works flawlessly.

I am am avid contester, both RTTY, PSK, MSFK and other digi modes,
and have had great success with this set-up.

Old PC Keyboard cable...FREE
2 mini-plugs...about 75 cents each.

5 minutes construction time and you are in business.

Use the DigiVOX feature on the FT-897/857.
No external PTT required.