Meteor Scatter The Black Magic of David R. Kerl N9HF Linda H. Straubel N9LHS DBARA March, 2019

You’d be right! What is meteor scatter and what can hams do with it? Meteor scatter allows us a contact range of 500 to 1,400 miles on 28 MHz – 432 MHz. While millions of meteors soar over the earth every day, most are too small to use for meteor scatter. Usable meteors range in size from a grain of sand to a grain of rice. You might well think that bouncing a signal off such a tiny particle careening through space would be impossible. You’d be right!

What is the signal actually bouncing off? The term “meteor scatter” is a bit of a misnomer. We are actually bouncing signals off their ionized trails. These trails can be up to 30 km or 18 miles long.* Duration is anywhere from a fraction of a second to 45 minutes.** While longer durations are possible, 30 seconds is the longest usual duration before the trail dissipates. This is what we’re actually aiming for: Sources: https://ieeexplore.ieee.org/document/1144267; https://www.sciencedaily.com/terms/meteor.htm

Oops, let’s make the transmitter uni-directional, as well . . . 1,400 miles, max. In effect, we’re aiming the signals “over their heads,” giving them a lead to hit the trails and bounce our signals off them toward the receiving stations.

What equipment and software does meteor scatter require? SSB transceiver capable of 50-100 watts minimum, a Yagi antenna (e.g. 6m, 3 elements or more), a computer with Windows and WSJT-X installed, and a radio-to-computer interface. SOFTWARE: WSJT-X This is a suite of many weak-signal and EME programs, of which we are only interested in two, FT-8 and MSK-144. Example of an interface

MSK-144 is the program we will be using for meteor scatter. For those used to FT-8 for digital work, it is inadequate for meteor scatter. Here’s why: FT-8 requires approximately 6-7 seconds minimum of a solid signal to decode. MSK-144 will decode with a signal duration of fractions of a second. (Remember: that ionized trail may sometimes last only a fraction of a second.)

Here’s what my monitor looks like during meteor scatter:

Here’s a close-up of multiple pings:

Here’s a close-up of big, long-lasting ping:

A really long burn is nicknamed a “school bus.” Here, you can see why

* *This will indicate how visible they are . . . in case you are actually so foolish as to go out and look at them instead of using them for QSO’s.

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