Propagation Talk by W1HIS, Andover, May 7

Tony Brock-Fisher, K1KP writes:

MIT Professor Chuck Counselman, W1HIS, will give a presentation on HF Propagation on May 7th, at 7 pm, at the Andover Safety Center in Andover, MA. Hosted by the Andover Emergency Management Group (AEMG) this talk is a general primer on HF propagation.

The talk will be oriented towards the ham who has a 100-W HF transceiver, no amp, and no tower, just a trapped multiband vertical on the ground or a wire 25 ft above ground, and who rarely (if ever) works CW or any of the so-called digital modes. The goal is to enable this ham to choose the best combination of time and frequency to work, say, parts of the USA 50, 150, 1500, and 3000 miles away, the Caribbean, and Europe, by SSB on HF.

The level of the presentation assumes that the intended audience has heard of ionospheric propagation but is fuzzy about how the maximum and minimum usable frequencies (MUF & LUF) vary with time of day, time of year, and solar activity; and what happens around the times of local sunrise and sunset.

The practical, how-to, mechanical aspects of HF ionospheric propagation will be emphasized while the theoretical aspects are minimized. Just enough of the science will be discussed to help the ham remember why and when things happen. Covered will be daytime D-region absorption; critical frequencies, such as foF2; NVIS; normal daytime E and F, and normal night-time F2 propagation; single and multiple F-hops. Little will be said about paths longer than about 5000 miles (8000 km).

Web sites will be listed where ready-made propagation predictions can be found, and where customized propagation predictions can be generated for the individual’s TX power, antenna, and mode (e.g., CW or SSB voice).

The Andover Safety Center is located at 32 North Main Street, Andover, MA 01810

Leave a Reply