I'm a big fan of the bucket variometer and if you take the time to
wind it with taps every other turn minimum, you can resonant a 30 foot
capacitively top loaded vertical in about 2 minutes just by checking
each tap and watching what X is doing with your on your analyzer. No
calculations required to do that.
Then is just a matter or matching to the feed line and there are a
bunch of options there and minimal math required.
John Molnar, WA3ETD, wrote a great article for CQ a few years ago that
is more of less on his website with details for how he winds buckets:
https://wg2xka.wordpress.com/the-variometer/So there are easy options for resonating and matching existing
vertical antennas on 472 for someone willing to put in a little elbow
grease.
73!
John..
On 1/11/22, Dwight Blevins via 600MRG <
[email protected]> wrote:
Greg,
You asked about "something equivalent." There definitely is and it will cost
you maybe $125.00 max (if that). The equivalent is a 5 gallon plastic
bucket, a cheap 25' aluminum vertical and a roll of solid core insulated
wire (16 or 18 gauge). Add a 3-wire top hat to the vertical and ground mount
the thing with the big bucket loading coil, feed point taped up from ground.
I'm 75 years old and easily picked up the whole apparatus and had it up and
tied off in less than an hour, once everything else was assembled.
It works great on receive and my little 5 watt one tube 630m exciter loads
up with ease. I can copy KB5NJD Q5 most any time he is on the air, CW. All I
have for a counterpoise is that the mounting mast goes in the ground maybe
40 inches and I have that tied off to a nearby chain link fence. Again, tip
of the antenna is maybe 25' up. For the top section I bought a 60 inch whip
which attaches to the top of the vertical where the top hat wires are
connected. They go down at a 45 angle, tied off with insulators to stakes on
the ground. So the 3 top hat sloper wires serve to support the slender
vertical when the wind comes.
I don't know what the radiation resistance is, but the thing works great,
low background noise, no BCI garbage, etc! I'm not saying don't buy the
commercial antenna, but on my budget I have to make my own stuff, which is
the fun part of the hobby :)
73'sKW7TColorado
On Tuesday, January 11, 2022, 06:38:03 AM MST, Greg KF5N
<[email protected]> wrote:
I like the design as I could use it even in my relatively small back yard.
The availability of a turnkey antenna and other gear is good, but I'm not
even sure there is that much easily available reference material if you want
to build your own.
I recently ordered the 2022 ARRL Handbook, and found only one page on LF
propagation. Did I miss something, or is there no other information on the
ham LF allocations in the latest handbook?
Let's say I was a newbie interested in trying out 630 meters. Where would I
go to find construction details for an antenna equivalent to this commercial
offering?
Long ago (1980s) I built and operated a Lowfer Beacon. There was the series
of books by Ken Cornell, and a couple of enthusiast periodicals on Lowfer
and other LF topics.
Lots of antenna topics and construction articles in those publications.
Is there something equivalent to this today for 630 meters?
73 Greg KF5N
On Tue, Jan 11, 2022 at 8:03 AM John Langridge <[email protected]> wrote:
Good morning,
Jamie, N2VJ, reported this morning on SLACK that a US-based company is
producing a portable, turnkey 630-meter vertical antenna system.
Originally developed for BC medium wave AM as an emergency continuity
system, this model has been modified for 472-479 kHz. You can see the
specs here: https://theradiosource.com/products/antenna-630pd.htm
Jamie indicated that the company is probably testing the market and
the price may be somewhere in the $890 USD range. While that may seem
pricey to some, there are a lot of people out there still waiting for
a turnkey option and engineering and materials are expensive these
days. Yes you can build this stuff for a LOT cheaper but there are a
lot of hams today that can't or won't so here is an option to fill the
void.
Have a look and show some interest as doing so often drives product
development and innovation.
Jamie explicitly noted that he is not endorsing this product and he
has no financial interest.
73,
John KB5NJD
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