Digital Modes 101

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I must check this wire.....

Do that. From a tactical perspective, though, it's bright yellow. If you don't want anyone to know you're using an antenna, use black wire. And don't transmit. Ever.

If you want to do this professionally (and I mean, professionally), the best receive antenna you can have is to run black wire across your rooftop (along the peak), from end to end. Run the wire off the roof, and connect it to your coax under the soffit. Preferably, you will run the wire *from* the far end of the roof, *to* close to where your power meter is. This will allow you to run another wire from the ground braid of the coax to the grounding rod, so that if lighting strikes, your radio has a fighting chance for survival. It also keeps static electricity from building up on your radio.

From there, you will run the coax into the soffit, which will allow you to run it through the attic. Once in the attic, you can run it down any wall you like, and out of the wall of whichever room you choose. Home Depot sells wall fish rods for fairly cheap. Or, you can do a "closet drop". Go into the closet, poke a hole in the corner closest to the door (inside the closet), and run your cable from the attic, through that hole, out of the closet, and out to your radio.

Bear in mind, although it's stealthy, it's a receive-only antenna. If you try to transmit with it, the RF going to the grounding rod will enter the house's electrical system, which would be a catastrophe.
 
Digital Modes 101

(NOTICE: This is mostly used on HF, that being, 30MHz and below. To receive communications from other people, you will need a scanner or a radio which covers 30MHz or below. Otherwise, you can use anything to communicate with your friends and family digitally, as long as it's legal.)


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So today I'll be discussing the other part of the radio world that a lot of people aren't even aware of, that being, digital modes. This involves connecting your radio (or scanner) to a computer. Why the hell would you do that? Well, we will get to that in a minute. First, here's what you need to know about this immediately:

  • If you don't have a ham license, it's still okay to receive digital information (but not send any out). For this you would use a scanner.
  • Digital information can travel much farther than voice communications. Beeps and blips seem to cut through static a lot better than the human voice does.
  • You can receive text, faxes, and even imagery.
  • Hooking it all up is ridiculously easy to do. You probably already have what you need.
  • Yes, you can even decode Morse Code, and read what is being sent out.
  • With some simple microphone mods, you can use any radio to both send and receive digital communications.

We will first get this all hooked up, and then I will walk you through the world of digital modes.

Step 1: What You Need / Hooking it Up.
  • a radio or scanner
  • a 3.5mm headphone cable (male on both sides)
  • a computer
  • free software (FLDIGI is my favorite - you can get it here.)
Download and install the software, plug one end of the headphone cable into your scanner or radio external speaker jack, and plug the other end into the microphone jack on your computer. You are in business. It's really that easy.

(For ham operators, it's a little more complicated than that, because we also want to transmit digital information as well. Since most of us are not hams, I will leave this part out for now. If any of you hams who have never used digital modes need help, just message me below and I will explain what you need to do. It's not that bad.)

Step 2: Configuring the Program

Chances are, there's nothing for you to configure. Just dial-in a frequency where digital information is being passed, on your radio or scanner. I'll elaborate on that in a bit as well, and give you a frequency list which should get you rocking.

Dial in a frequency (try 14.070). You should see a "waterfall" like this:

psk31_Waterfall.gif

Pictured here are PSK31 signals

Each one of those "strips" is a different conversation. Click on one of them, and the text should pop up in your window so you can read it. Anyhow, if you see this (or something like it), you are good to go. If not, then you need to tell the program to use your computer sound card. If you need help with that, message me below.

What the Hell is This all About?

The thing is, once the SHTF, this is where (and how) you'll find most of the useful information that is being passed over the air. Satellites will likely be knocked right out of the sky, and with them, television, internet, and so on. From that point, you can expect nothing but propaganda on your FM stereo system, not unlike the 1940s. Yeah - "Fireside Chats". We're partying now!

So, I will break down the different digital modes and purposes as easy and basic as I can. Once you really get to playing with this, you'll be able to look at and hear a signal, and know which kind of digital signal it is. Being able to do that makes things easier, but hey, we all have to start somewhere.

The Main 4 Digital Modes:

For now, we will start you off on just 3 of the many different modes ("Op Mode", in the upper left-hand corner of FLDIGI):

WEFAX.jpg

A satellite weather image, intercepted by radio and FLDIGI.
  • PSK - This is for "beginners", and you will find this mostly on the ham bands. Here you will find conversations taking place. These are usually just boring exchanges of information about where the stations are and which equipment they are using. Bear in mind, they are simply testing their equipment and trying to get as many contacts as they can.

    Some PSK signals will be "fatter" than others. For that, you will need to figure out which PSK they are using. The skinniest (and slowest) ones are PSK31. PSK63 is the next step up. And you might even see PSK125 from time to time, but that's rare. And while your program can handle much more PSK modes than that, you will probably never see it.

    A list of PSK frequencies can be found here: http://www.qsl.net/darn/PSK31.htm
  • RTTY - This is another "beginner" type signal. It's a lot slower than PSK, but, it can travel much longer distances. You will find this to be a pattern throughout all of the digital world. Slower = longer distance. It looks like two strips, and sounds like two tones alternating back and forth. Hint: take a look at the first image in this tutorial. That is what a RTTY signal looks like. The most common is RTTY 45.

  • HF FAX - This is the one that got me hooked. You can download weather maps directly from radio signals. Here is a nice NOAA .pdf with every frequency, world wide: http://www.nws.noaa.gov/os/marine/rfax.pdf
  • CW - Don't know Morse Code? No problem! Select "CW", and click on the stream of beeping, and the program will translate it into text for you!
Oh, and here's a little tid-bit: If you are a ham operator, there is an HF email service available (called Winlink 2000) which is a separate program. This means that even once internet is wiped out completely, you still have the ability to send emails (or at least, to other people who have the same capability).

Yes, things have changed over the years. Having the ability to operate digitally will really expand your possibilities for information gathering and sharing. Needless to say, the ones who will be the most informed, will be the ones who can communicate the most.

Get a ham license now and train yourself. This tutorial won't be here once the SHTF.
I finally got my s**t together and started working PSK31. I am using my portable radio at the moment, that being the Icom IC-7200. The nice thing about this radio is the sound card is built in. This eliminates the need for buying extra equipment to interface with the computer. I am currently using Ham Radio Deluxe software, but I am trying to switch to FLDIGI. My next leap into digital modes will be JT-65.

Great thing about the digital modes is you don't need a lot of power, and since they use less bandwidth than does voice on SSB you can get your signal out further even during these crapy band times.....
 
Welcome to the dark side!

Your next move is to open an eQSL account, because you're going to be getting way more international traffic than you're used to.

I could never warm up to RTTY or those JT- modes. Too slow, abbreviated, blah. Also, here's my favorite digital modes page, in case you haven't already found it:

http://hfradio.org.uk/html/digital_modes.html
Thanks for the link! I have heard RTTY is prone to errors. It isn't something I am looking into doing anytime soon.
I have heard JT-65 is good for EMCOMM. Right now PSK31 is perfect for me.
What software do you use? I am currently using Ham Radio Deluxe (HRD). I have also been trying to get FLDIGI and DIGIPAN working.
The radio I use is the Icom IC-7200. It has a built in soundcard.
 
Welcome to the dark side!

Your next move is to open an eQSL account, because you're going to be getting way more international traffic than you're used to.

I could never warm up to RTTY or those JT- modes. Too slow, abbreviated, blah. Also, here's my favorite digital modes page, in case you haven't already found it:

http://hfradio.org.uk/html/digital_modes.html

 
Thanks for the link! I have heard RTTY is prone to errors. It isn't something I am looking into doing anytime soon.
I have heard JT-65 is good for EMCOMM. Right now PSK31 is perfect for me.
What software do you use? I am currently using Ham Radio Deluxe (HRD). I have also been trying to get FLDIGI and DIGIPAN working.
The radio I use is the Icom IC-7200. It has a built in soundcard.


Well, if PSK31 is your favorite (mine too), then Fldigi is the best of what's out there. You can customize the appearance of the interface (which is already by far, the best of what's out there), and customize what the buttons do. A lot of people on PSK will send the same messages simply by clicking different buttons. No need for typing. That makes things a lot easier. The bitch is, configuring it.

With your 7200, that should be very easy to do. Just pull up your Windows Control Panel, then Device Manager and look at your COM ports (expand the view). There should be two in use, with identical names. Take note of which port numbers they have. On paper! Then:
  • In Fldigi, go to "Configure" at the top, and then to "Rig Control".
  • Click on the "Hamlib" tab.
  • Check the "Use Hamlib" box.
  • In the dropdown menu, find your radio. There's a beta version of it, but it should work fine.
  • Set your COM port number and click "Initialize". It's 50/50. If that one doesn't work, then try the other one that you remember. The frequency in the Fldigi frequency display should change to whatever frequency your radio is on. That's your confirmation that you did it right!

You should be set! You will also need to configure your soundcard settings next. The Capture and Playback settings should be obvious - it's not your computer soundcard that you are selecting - it's your radio's soundcard. That gets the sound over the USB, instead of having to plug in an audio cable like the rest of us have to do. Click "Save" and look at your waterfall. You should see traffic if you are tuned in to the right frequency.



Now. If you want to get into seeking out weird signals and trying to decode them (VERY DIFFICULT), then MultiPSK is what you want to use. That one has a few more data modes to choose from. The interface sucks, but the data modes that it has are pretty awesome. I'm doing that because I want to have the ability to hear a signal, and know what data mode it is, so I can decode it.
 
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