Digital Novice, Chapter 2
Thursday, 03 January 2019 19:19

First things first.  There are a few things you need to keep in mind if you decide to try doing digital radio.

  • Digital radio is rarely a "plug and play" operation.
  • Every installation is a little different, and there is no one-size-fits-all guide for doing it.
  • Patience is a must.
  • If other hams made it work, you can make it work, too.

Probably the best approach for getting digital working is to keep your initial setup as simple as possible.  If you have a very modern radio, digital operation may be designed into your rig, and all you have to do is plug in a USB cable and get started.  If that's the case, hooray!  Get the cable, and go have fun.  If that's not the case, then there are five basic items you will need to get on the air with digital

  1. A radio
  2. An interface
  3. A computer (Mac or PC)
  4. Digital software
  5. Time sync program

Almost any radio can be used, but there may be trade-offs.  If you have a fairly current radio, one with lots of bells and whistles, you may have to get into programming some of the radio's menus to make it work.   I ran into that, and it turned out my mostly-modern radio couldn't be set to work efficiently with digital.  Fortunately, I had a late 1980's Icom IC-735 in the shack.  I bought it used at the Jackson Hamfest in 2011 for $300, and it's a very simple radio.   I have now turned it into my dedicated-digital radio.   It performs the needed tasks easily.  It receives a signal, stays on that frequency, and it has a data port (ACC12 on the IC-735) on the back.   Digital can be done without a data port, but it's not as simple.

The interface I am using is an MFJ-1204.  It's a USB cable on one side, and an 8 pin DIN cable (one that matches my radio data port) on the other.   The MFJ-1204 comes in a bunch of varieties, but those varieties just reflect which data cable comes with the interface.  All 1204 interfaces are the same box, just the data cable and the jumper settings inside are different.  This is a simple to use, easy to operate interface.  Two cables, two knobs, that's it.

My PC is a six-year-old Windows 7 desktop, and that's all I need.

You only have to have one piece of software, but no one piece of software does all digital modes.  For now, download two programs:  WSJT-X does FT-8, JY-65, and a few others.  FLDIGI does PSK-31 and maybe two dozen others.  Both are free to download.

What I'm going to describe is how I got going with FT-8, which is probably the most popular form of digital radio.  Most of what I describe is not the only way of getting the job done, but it will be a method I found to be easy and simple for me.

Getting Started

Download a program called Dimension 4 from Thinkman.Com. (Link: http://www.thinkman.com/dimension4/d4time531.msi)  This software will synchronize your computer's clock with the internet's clock.  Apparently, computer clocks tend to drift, and if your computer and the internet are out of sync by more than a few seconds, FT-8 probably won't work.  Download it, install it, and run it.

Next, find your radio's manual (or at least a downloaded pdf version of it) and keep it at hand.  You'll need it.

Buy a digital interface.  As an alternative, you can build one for cheap ($25 or thereabouts), and the internet is loaded with designs and plans and such. The interface is a little box that translates your radio audio into a digital signal your computer can understand.  Since I didn't want to spend months figuring out how to build one just to save $75, I bought an MFJ-1204 from Richard at MFJ.  The MFJ-1204 has a USB cable that goes to your computer and a data cable that goes to your radio. You'll need to tell MFJ what sort of data cable you need, so here is a chart of MFJ data cables: http://www.mfjenterprises.com/1204%20Cable%20Chart_web.pdf.  Your radio manual will have info on this which will help you select the cable you need.  If all else fails, call MFJ, give them your radio model,  and they can help you get the right cable.

Okay, so now you have a radio, a computer that is synced to internet time, and an interface that lets the radio and the computer talk to each other.  The only thing left now is to download some software that will translate what the computer hears into something you can understand.  Since we're setting up FT-8 first, download a program called WSJT-X from this link: https://sourceforge.net/projects/wsjt/    Once you've downloaded and installed the software, also download the WSJT-X manual, which will be helpful in understanding how the software works.

Link: http://physics.princeton.edu/pulsar/K1JT/wsjtx-doc/wsjtx-main-2.0.0.html

Great!  Now you've got all five pieces of the puzzle.  In the next article, we'll put these pieces together.

73,
AG5ND, Allen

 
 
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