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The Rebirth of HF

posted Oct 23, 2020, 7:05 PM by Charles Boling   [ updated Oct 23, 2020, 7:06 PM ]
Attached is a reprint of an article that gives a nice overview of HF propagation modes, the ionosphere & solar weather, MUF/LUF, etc.

Though it's sort of focused on the public sector, it's informative for all.  As it mentions, hams have been some of the biggest users of HF these days, with commercial/military use dropping. As with the specific cases of LORAN, WWV, etc., the general abandonment of HF for newer technologies makes financial sense as long as things operate the way they should, but the lack of a robust backup for some of those technologies should give one pause, as many hams have pointed out to officials over the years. The article talks about an increasing awareness of this, and steps to use newer developments to make better use of this venerable part of the spectrum.

This state of affairs regarding HF, and this renaissance, is something I've seen through my involvement in the Civil Air Patrol. CAP could be considered to be between "professional" (military) and "amateurs" (hams). A volunteer force, CAP, like SAR, ARES, and other volunteer organizations, is the "cheap" alternative to paying the "regulars" for exceptional activities. (A Cessna 182 being piloted by a volunteer is hundreds of times cheaper than an F15 and all its support crew, even if you're paying the gas -- even if you bought the plane!  Same goes for radio operations. Almost all of CAP's radio gear is paid for by USAF funds, and is much more expensive than equivalent ham gear because it's required to meet tighter NTIA emmission specs as well as be rugged. Some of CAP's radio operators are very "appliance" oriented; they use the radios as needed for their job and don't care how they work; others are dedicated to communications but still don't get into the science much. On the other hand, there are a lot of hams in CAP, too, and they tend to be more creative and helpful in making communications work under tough circumstances. Anyway, CAP has largely maintained its HF and VHF voice and data networks and operated on the air even as the main forces' radios have been collecting dust. Like hams, CAP's [slowly] trying out new things and figuring out ways to make better use of what they have (sometimes repeating lessons learned and forgotten). The feds are starting to see some of the potential value in it, and if we're willing to do the "dirty" work for them instead of them trying to figure out, they're happy to throw a little money our way.

I've been trying to write this during a long, drawn-out remote computer support session, and I don't even know if what I wrote makes sense. Ignore me and just read the article. :-)

Charles Boling,
Oct 23, 2020, 7:06 PM