[MarinTeams] Warming Brain Cells on a Cold Winter Night (Happy New Year!)

[Bill]

While struggling to keep warm this evening, I happened across an email in
the Radio Mobile support group.  Radio Mobile is a free VHF-UHF signal
coverage mapping program that is available to download.  The program
provides basic signal strength prediction information but unless you are
planning to put up a repeater, or work high-band DX, it takes a time
commitment and a cut of your life's pool of energy (e.g. frustration) to
acquire a useful familiarization of the software.

Moving on, the recent discussion (again, dismissing at peril God's story of
Adam and Eve and their loss of Paradise in pursuit of Knowledge) revolves
around an inquiry of similar signal prediction resourse for HF (High
Frequency, or what we know as short-wave).  To quote Joe in Missouri KDOZDM
who is looking for a frequency: 

"One is that it can be propagated by wave guide with no skip zones.   3 KHz
has a wave length of approx 55 miles which is the approx height of the E
layer and that may be why we get this unique wave guide propagation at those
frequencies.  It must work  -- as our nuclear subs are communicated with by
30 KHz wave guide transmissions."

He ruefully mentions the need of 200-foot towers that are apparently still a
compromise to couple radio energy at 30KHz.  If you have lived here for a
while, you may recall the giant towers, now gone, just off Highway 37.
Perhaps much of the development of VLF occurred in the Bay Area, as did the
earlier development in San Jose of superhetrodyne receiver technology and
many other fundamental radio technologies.  But I digress...

To quote a post from Ken, W7EKB who describes his use of VOCAP, a
HF-frequency propagation tool developed by Voice of America:

"I have found VOACAP to be extremely useful, for me, to choose most likely
times and frequencies to meet various radiogram traffic handlers.  It took
me about one year of "playing" with it to get the most reliable results from
it.  And if you think YOUR ground conductivity is bad, take a look at ours
here in Moscow, Idaho.

Anyway, I routinely use www.VOACAP.com/hf/
Greg Hand, who was the original developer for VOACAP has been very helpful
to me when I needed it.  YMMV."

Regardless of your desire or need to devote this much energy into mastering
these resources, a quick visit to their respective websites offer an
enjoyable slice of eye-candy, and I am sure you will find references in
various literature to results produced by these programs.  VOACAP was
developed to predict the signal reception of Voice of America world-wide
broadcasts and is now freely available for use by hams.  You might wish to
take a quick look at https://airwaves.social/@oh6bg for a teaser and
interesting graphics.  By the way, apparently we are at the peak of the
11-year sunspot cycle.   Good DX!

Oh, and we are sitting on a spot on the earth with some of the world's best
ground conductivity.  It is found here in the SFO Bay Area!
HAPPY NEW YEAR!

73 de Bill, AB6MT