In the previous sections, we eavesdropped on a live conversation between two ham stations, one in Windsor Ontario and the other in Venezuela on the northern coast of South America. And I mentioned that while you’ll find hams of all ages working the bands at all hours of day or night, it’s also true that the majority of them tend to be older gentlemen.
In this third and final part, we will find out more about the special mode of communication I was using. It’s quite new.
This mode, called BSPK-31, is somewhat like the old Morse Code in that a little bit of power can go a very long way. But this new mode uses computers to do the work of coding and decoding so it’s actually extremely easy to use. If you can type, you can talk.
Hams use different modes of communication depending on conditions, personal interests, and budget. Morse code, normal voice with microphones, radio teletype (RTTY) and even amateur television (!) have all been around for many decades.
But the mode I’m using here is new as of about 1998. It pretty much requires a computer and also some sophisticated electronics in the transmitter and receiver. But that “sophistication” isn’t necessarily expensive. It’s just “special”.
What makes this particular mode called BPSK-31 interesting is that it 1) uses only a tiny sliver of radio space, 2) focuses all the transmitter’s energy into that tiny little area, and 3) because of that, on a good day the signal can go thousands of miles using almost no power at all.
It’s ideal for battery operation and, with a notebook computer running on its batteries on which to do the typing and display the results, this is the ideal mode for long-distance emergency communications.
My transmitter puts out 4.5 watts and I use not much more than a simple piece of wire thrown up in a tree for the antenna.
- If you have an old style night light, those are 7 watts.
- Or an old battery-operated flashlight, those use about 10 watts.
- The newer LED flashlights, if you get a crappy one, may use less than my radio. The better ones will use about the same or a little more. (And the LEDs rarely fail — you’ve replaced all your old incandescent flashlights with LED ones, right?)
But you won’t see any of these from more than a mile or two away. Too many things such as trees, houses, rain, fog and just plain dust in the air will stop that visible beam of light.
When the ionosphere is strongly reflective, my little 4.5 watts can easily go thousands of miles. Indeed, just after listening to these two gents talk about their antennas and radios, I called and “spoke” — in BPSK-31, everything is typed on the computer keyboard — with VE3NOO, Michael, in Bath Ontario. He was using 30 watts (that’s about what the light in your refrigerator uses) and was, as they say, blowing out my doors with a very strong signal.
The ionosphere is like a giant spherical ball encasing the Earth. On a good day, it’s an almost impenetrable mirror at the frequencies we use. Instead, radio signals inside that ball bounce up and down many times as they travel around the world. Single-bounce conversations are routine. Two- and three- bounces less so. But on very rare occasions, you can actually hear your own signal coming from behind you after it has made its way all the way around.
The antenna I use is a 33′ piece of wire run up with a pulley on the side of a palm tree in my front yard. Some hams have towers and large multi-element beam arrays to swing around way up and focus their signal in a specific direction but, on a good day, my simple vertical half-wave wire works just fine for me.
My call sign?
See you down the waterfall!