We had no idea when we wrote the past two parts of this article on radio gear for when TSHTF, that they were going to be so very popular. Most peoples’ concerns are based in the fear that they will loose all contact with loved ones, as well as how to get first hand, unfiltered news. Having good communication equipment – and knowing how to use it – can put those fears to rest. Let’s continue to learn how to communicate after chaos has hit, the Internet (and maybe the entire power grid) is down and you want to know what’s going on.
NOTE: This article is going to be a little more technical than past ones, but if anyone has any questions, please drop us a line at email@example.com – we’d love to help if we can.
First, let’s define CW, RTTY and SSTV as they apply to radio signals:
CW, is Constant Wave Mode, the radio mode that is used to send Morse code.
RTTY (radioteletype) is a way of sending text files via the radio to others. You would create a text document using any word processor, then save the file in .txt format.
SSTV (Slow Scan TV) is a bit of a misnomer. It is more like sending and receiving a fax. You would send a .jpg or .bmp file.
Now we’re going to talk about how to transform a Freeband radio (this can be a 10 meter converted rig or an HF Ham radio) into a simple modem through which you can send text messages or images. These are some of the things you’re going to need to get started experimenting with radio facsimiles and packet radio transmissions.
- A Ham Radio or any radio transceiver (listening and talking) with CW (Constant Wave) mode. If you just want to receive (listen, not talk) any Short Wave receiver that can tune to the frequencies you’ll need is good enough.
- A cable to connect the radio to the computer (via the audio output) to the radio’s CW input for sending RTTY messages. For receiving RTTY messages, the cable goes from the mic/audio input to the radio’s CW output. Most often this is 1/8th inch stereo plug, like those found on headphones and ear buds.
- HamFax software, available here for free: http://sourceforge.net/projects/hamfax/ . There are many other programs that can do RTTY or Slow Scan TV but we have found the HamFax software to be easy to use and works with Windows, Linux and Apple.
- The program GMFSK, available at: http://sourceforge.net/projects/gmfsk/?source=directory. With this software you will be able to make .txt documents into packets that you can send to anyone listening.
- Either a photo or text file to send or receive.
- A net work of others equally equipped at various long distances with whom to experiment.
After you’ve installed hamfax, you can run the application, choose a photo that you want to send, and in the tool-bar, you will click transmit, transmit to file. Hamfax will have a set of questions for you to answer to set up the transmission to best fit the hardware.
Now, let’s get into packet radio. Packet radio uses the CW mode and is faster, more practical, and more intelligible – and like the old HAMs say, “when nothing else can get out CW will get though.” This process uses a faster audio transmission and translates text. The packet is a text file of your choosing.
To test your receiving capabilities, most Slow Scan TV pictures can be found on the 20 meter band, beginning around 14 Mhz. Just scan up the bands until you hear the sound of fax machines on the air waves and you’re there. With either software booted and the radio’s audio output (also known as external speaker jack) connected to your computers microphone input, you can begin receiving faxes/photos or text files.
And all this can be done with 12 volts of DC solar power!
To conclude, this simple option is the first thing we need to consider when we look at rebuilding electronic communications. Imagine a valuable tool like the Internet, available to anyone who can pick up and translate a radio transmission. Imagine if that independent link to the rest of the world could be a fountain for knowledge, not adulterated by the need to make monetary profit. Think about this Internet and think of the extent to which you really have free speech. Then think about the same power of technologically used in a manner free from the bias of advertisers.
This may only be simple communications technology – just the basics. The important fact is that the information to be published through that bandwidth will be free and uncensored. This will remind us and motivate us to keep working together to improve this technology as we keep it free.
Dan & Sheila are the authors of Surviving Survivalism – How to Avoid Survivalism Culture Shock, and hosts of the podcast, Still Surviving with Dan & Sheila. For questions about space in their Intentional Survivalist Community or other survivalist issues, they can be reached at firstname.lastname@example.org.