[600MRG] Hamcom redux - MF and LF

[John Langridge]

Good afternoon all....

It was a very good weekend at Hamcom here in the DFW area.  Both of my
sessions ( 2 hours each, officially) were very well attended and there
were numerous questions with lots of interest.  Friday and Saturday
presentations were largely very different presentations, however.

Friday I started by recounting some of the highlights from 630 and
2200m from the past year and spent about 45 -50 minutes on this topic.
There was a lot to say as it was a very solid season, particularly at
the beginning in the Fall and early Winter but in hindsight I wish I
had saved more time for transmit antenna discussions than just an
hour.  At the half way mark I transitioned to discussing transmit
antennas that are in use by the active core group of stations - most
verticals and their various loading configurations and small loops. We
performed a few calculations and the variometer resonating  and
matching demo went off without any problems.  I sold two of the three
variometers that I had built on the first day and there were a lot of
"tire kickers" for the third one.  I fully expect there will be new
blood on the air in my area this coming season.  One operator
purchased a coil and replaced his existing coil Friday night, noting
today that the new one gave him about an amp more antenna current than
his previous vintage so it was worth the effort to build them.  I'll
probably make a few more next year if the market remains ripe.


Because I wanted to focus more on transmit antennas, which is where
the bulk of the questions are, I started in the middle of my agenda on
Saturday, leaving the rehash of the 2018-2019 season for any left over
time at the end. We ran a LOT of calculations using a number of
different methods to prove the viability of the various approaches and
talked about strategies for implementing antennas in restricted
environments.  Once again the variometer demo went off without any
problems and I found a buyer for the third variometer so I didn't have
to haul it home.

So there are a couple of things that were obvious this year that were
not as obvious in previous year's presentations:

1)  Many operators are very close to "being there" but its little
things like winding matching transformers or procedures for resonating
an antenna that elude some of them.  The vario approach was easy
because calculations are not required with a bucket vario in most
cases and a given size vertical /  top loading config (between 25 foot
and about 120 foot tall with a variety of top loading wire
configurations) and they only have to be able to take square roots
when winding matching transformers (when not using an auto transformer
or  L-network approach).  Most of the print resources out there assume
too much prior knowledge and guys bog down on the math, where
applicable.  Even with all of the resources that we make available,
some guys simply don't know where to start or how to start looking.
Several ops said this independently.  That's surprisingly common in
society today in a number of disciplines.



2)  A commercial source of loading devices would be helpful.  MFJ was
working on some items in their engineering group a few years ago but
they have a lot of things on their plate that don't actually make it
to production.  There is an opportunity here for a would-be
entrepreneur that can exercise good quality control while not losing
their mind as they remove insulation from tap points on a coil.  The
visual appearance of a bucket varios doesn't seem to be a detractor
for anyone that I've spoken to this weekend (or even, for that
matter).  Most people realize that Calvin Kline or Gucci are not
stamped on the coils...


3)  There are a lot of operators are genuinely interested in this
stuff.  That's encouraging.  Sometimes its tough to tell when
presenting whether or not people are listening or thinking about
lunch.  It was obvious from the questions, comments, interaction and
seeing many people take notes that we are really headed in the right
direction.


If you have an opportunity to work on a station this Summer for the
2019 / 2020 season (which begins September 1!), please spend some time
preparing now.  This really is a "more then merrier" type thing and
you will be surprised what you can do with a simple station.  There
are more than enough people to help if help is requested.  And
besides, K0KE is going to activate Wyoming this Fall so you want to be
ready for that if you are collecting states.

I'll be presenting again, remotely, next month at the Oklahoma Ham
Holiday and will probably present an updated survey of these bands.
Not as comprehensive as what was presented this weekend but a bit of a
way to introduce those who have never been exposed to any of this.

73 and thanks for letting me ramble for a bit...If you were in
attendance this weekend, thanks for spending a few hours talking about
MF and LF with me...

John KB5NJD



PS:  Im catching up on reports for the weekend now... those will be
published at the end of the Saturday night / Sunday morning report
that will publish Sunday morning near 1730z.