Want to get started in Digi modes

Discussion in 'Becoming an Amateur Radio Operator/Upgrading Privi' started by N5TDA, Oct 21, 2009.

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  1. N5TDA

    N5TDA Ham Member QRZ Page

    As the title implies I want to get started in the digi modes but I have no idea what I need to connect my radio,an IC-725, to my computer and what to do from there. Any help would be appreciated.

    Last edited: Oct 21, 2009
  2. KE7VLC

    KE7VLC Ham Member QRZ Page

    Well Rex your best bet is to Google the question. When I googled how to hook up digital modes to an IC-725 I found a few things of interest.



    The other thing you might want to do is seek out a local club, I would recommend looking for one that does digital modes or perhaps SSTV or PSK31, or just a regular club might work as well, and see if anyone there would be willing to show you their setup and perhaps help you out. I know that sometimes this is hard to do but the club I belong to had a demonstration of PSK31 last night as well as SSTV. They showed a few different ways to hook up a standard rig to a computer and it appeared that it was fairly easy to do.

    I would also do a google search for the digi modes you are looking to run....for example.....PSK31. I know that I run into tons of info doing it this way.

    Hope this helps at least get you started.
  3. KD0EAH

    KD0EAH Ham Member QRZ Page

    off the suggestion of a club member here...

    I simply downloaded the software and started to play with it.

    I also plugged in standard microphone to my computer (not a radio mic) I then simply put this in front of my speaker on the radio.

    Surprisingly, I was able to receive rather well this digital signals even from Italy, Peru, South Africa and other locations.

    I still need to get an interface of some sort to effectively transmit, but hey, it lit the spark to see what SSTV and PSK31 is about.

    Like true HAM fashion, just work with it till you figure it out.
  4. N5TDA

    N5TDA Ham Member QRZ Page

    Thanks for the info.
    I'll check around the local clubs and see what I can find.

    Thanks again
  5. K9ZMD

    K9ZMD Subscriber QRZ Page


    The same question came up in another forum last week, so I'll paste in the information I provided at that time.

    The basic starting point for sound card digital mode operation is a computer with a sound card and ports for LINE IN (or MIC) and LINE OUT. Next, you need some digital mode software. Many are available for free download, and you may have already found some with the links recommended to you. It won't take much searching to find others.

    Once you have the digital mode software installed and running, you are ready to try your hand at receiving digital signals. Some sort of "interface" is needed, and the very simplest would be acoustic coupling between the RCVR and your computer, i.e. just hold the computer microphone very close to the RCVR speaker and tune in a digital signal. Many web sites that discuss digimodes will also list popular frequencies for each mode. The web sites will also teach you about clicking on the digital signal trace to initiate decoding. I suggest starting with PSK31 because it is popular, easy to locate, and simple to tune in.

    You can also transmit digital modes by acoustic coupling between the computer output and the transmitter input, simply by holding the transceiver microphone very close to the computer speaker. You must also choose some method to trigger the transmitter into XMT. This can be by VOX or by PTT when using acoustic coupling.

    Although some operators claim to successfully use acoustic coupling for digimode operation all of the time, the concept brings to mind visions of 4-handed hams. It also requires a quiet radio shack to avoid unintended noise transmission (dogs barking, ringing telephone, XYL's voice, etc). There are other more convenient forms of interface, but regardless of the interface method, you will always find the basic elements that I've detailed here.

    Another simple method, but a step up in complexity, would be to use a simple audio cable between RCVR Phone jack and computer LINE IN. Expanding on that to add transmit capability would require another cable to connect between your computer LINE OUT and the XMTR audio in (the MIC jack is simplest). Triggering the rig into XMT can be done with a SPST switch or VOX. With this simple interface, the shack noises are no longer an issue. There are other issues, however, which include things like hum, ground loops, over-driving, and RFI. It is easy to home-build an interface that will avoid such issues, and you will be able to find instructions on the many digimode web sites. Note that they all include at least the basic elements that I've already detailed.

    Another element, but NOT ESSENTIAL, has already been mentioned to you. That is a CAT cable for controlling your transceiver by computer commands. I now use CAT control with my IC-746PRO, but I want to stress that you do not actually need it to begin digimode operation. I operated digimodes without CAT control for over 6 years before finally buying a CAT cable. Once you gain experience with digimodes, you will begin to see the many ways that computer control can be helpful; that is when you will feel the need for it.

    There are many commercial interface devices available, with many varying features. If you study the information available for each, you will see that they all include the same basic elements, usually combined with other convenient features. After 6 years using just a home brew interface (basically a couple of audio transformers for isolation) I bought a used SignaLink USB interface. It works fine, I like it, but I can't recommend it over any other because I have no experience with another commercial interface.

    I hope that I've provided a sort of "dummies guide" that will be useful to you for getting started. Armed with the basics and some internet searching, you will be able to begin digimode operation. There is an awfully lot more that can be (and has been) written about each basic element mentioned, and you can find all of that on the internet. As you read more technical discussions, you can at least relate those details to the one or more of the basic elements that I've described. 73

    Gary, K9ZMD/6
  6. KB2FCV

    KB2FCV Ham Member QRZ Page

    Another thing to keep in mind, you can start off by receiving by just connecting an audio cable from your speaker out to the line-in on your computer. You can then download the software/mode of your choosing and start decoding stuff right away!

    As for me, I run a rig blaster which does the job. It was easy to setup and use. There are also plans out there for building your own cable
  7. AE5JU

    AE5JU Ham Member QRZ Page

    Acoustic coupling mentioned above... I have used both the XGGCOMMS cable setup, and the Rigblaster Plug and Play, but I had an interesting QSO with Prof. Arnie Coro, host of the SW radio show DX'ers Unlimited. You may have seen some of Arnie's antenna plans for SWL'ers.

    Arnie described his acoustic coupling system. It is simply a microphone element floated in foam rubber stuffed in one end of a short piece of PVC pipe, and glued on the other end, a small 2" speaker. He has two of these, one from computer mic jack to radio speaker jack, and the other from radio mic jack jack to computer speaker jack. This plus a computer control cable.

    Total isolation from room noise. Can't get any simpler than that.

    BTW, the cable from XGGCOMMS works quite well.
  8. N5TDA

    N5TDA Ham Member QRZ Page

    Thanks for info guys you have all been a big help. Have purchased a control cable and d/l HRD. I think I'll get the SignaLinkUSB as soon as the funds are right or maybe just make a suggestion to the wife and kids for Christmas:D

    Thanks for the help

  9. VE3PP

    VE3PP XML Subscriber QRZ Page

    You will be happy with the SignaLink USB. I have used one for 1 1/2years and never had any problems with it while using it with various digital software.

    I now use HRD/DM780 all the time for digital and rig control. Works for me.

    EasyPal for digital slow scan tv.
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