[Lowfer] [EXTERNAL] station on 13450khz

[John Hamer]

You've convinced me. That will definitely be my next project. I'm trying to
design a hifer transmitter right now. Experimenting with capacitor values
with crystals. I finally have enough equipment and understanding to know
what my transmitters frequency actually is. Its pretty cool what you can do
with a nice receiver and a waterfall display.

My background is in microcontroller software and pcb design. This stuff is
a completely different game. I have a lot to learn.
On Jun 2, 2016 8:15 PM, "JD" <listread at lwca.org> wrote:

> Excillent! I figured the frequency was too high for a beverage. I will
>>>> have to check that out!
>>>>
>>>
> It's actually easier to make a true Beverage at upper MF through at least
> mid-HF than it is at LF.  Most antennas being called Beverages at LF don't
> come close to being a wavelength long, and basically amount to grounded,
> terminated loops...which will certainly receive OK, but  without most of
> the directivity of a true wave antenna.
>
> At HF, one advantage of a Beverage is that it doesn't have to be terribly
> long or even very tall.  Bob Sutton in NZ uses the short fiberglass posts
> that you poke into the ground to set up temporary electric fence runs, for
> instance, and that's what I've got laid out on my farm right now too.
> Certainly works for him!  (Actually, he designed the array as two parallel
> 2-wavelength runs spaced half a wavelength apart for the 30 meter band, run
> into a combiner to maximize rejection right off the sides. At 22m, they are
> nearly 3 wavelengths long and spaced at 0.75 lambda, which doesn't suppress
> as strongly at 90 degrees off-axis, but that's not much of an issue with
> Beverages. What the extra relative separation at 22m does is to narrow up
> the main lobe and make the back lobes distinctly skinnier, which are
> advantages in their own right.) Taller supports are OK to an extent, but
> you start to run into impedance transformation issues and other concerns if
> the vertical height becomes more than a few percent of the wavelength.
>
> Some of the best antenna resources online are the Web pages of Charles
> W8JI in west Georgia, and he happens to have quite a bit of practical
> experience with Beverages at HF. (Caution, though--if you believe in magic
> antennas, or explanations of operation based on "pop science" principles
> rather than real physics, expect him to deflate your balloon.) His
> Beverages tend to run a bit taller than Bob's or mine, up into tree branch
> level, which is fine given that his primary interests lie from 160 to 40
> meters...but you probably won't need or want that much height at 22m. The
> W8JI Beverage page is at: http://www.w8ji.com/beverages.htm
>
> John
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