>
>
> Can someone tell how 43ft can be claimed as an optimized height on 160M?
>
How can it be claimed as multiband?
Look, the 43 foot vertical craze is a bunch of BS, and there are no
manufacturers, in my opinion, who are innocent of putting marketing above
good antenna engineering with respect to their version of this antenna.
It works OK for hundreds and hundreds and hundreds of people, probably even
on 160m. Some bands have very low losses and so the antenna works as well
as a resonant or base- tuned vertical, because the feedline and UNUN loss is
negligible. On the bands above 80m, it's probably going to clock in pretty
favorably to some other choices, maybe 3dB or 5dB down on a couple bands,
and neck-and-neck on other bands.
But an antenna that "works OK" in a subjective test just has to be better
than 15 or 20dB down from some other antenna, and there aren't a whole lot
of people putting the 43 footers to a test vs. a properly loaded antenna on
160m.
Let me just put it this way.
My best guess based on comparison with model of *my* 160m antenna (base
loaded 60 footer with a big coil) is that it's somewhere in the vicinity of
6dB to 8dB down from a full size quarter wave. Let's call it 6dB. That
makes it 25% efficient. If it is more lossy, it strengthens my point.
I can get on 160m and make lots of contacts with 5W applied to the antenna.
That's 1.25W effective radiated power (in reality, it might be less). I can
work anyone at all (on CW at least) within about 800 -900 miles and on good
nights I can eke out DX contacts with Europe's superstar Topband ears.
So if I decided to put up an antenna system that had 30dB worth of feedline
and ground system losses, and I ran 1500W to that system, I would get 1.5W
ERP. That 1.5W ERP would be enough to work anyone at all within about
800-900 miles and eke out DX contacts with Europe occasionally. If it had a
mere 18dB of feedline and ground system loss, you'd be radiating more than
20W. I've run 100W to my base loaded vertical, let's call that 25W ERP, and
I've worked 108 countries on Topband,
In my opinion, "optimized height" means "it's 43 feet, the magic number that
makes you want to buy it"
On Topband, in particular, I think the antenna gets a perceptual boost
because everyone assumes you have to run high power to make any contacts on
160m. While it may be true that you need to radiate 1kW to 1500W in order
to work Southeast Asia from W3 on Topband, all you have to do is get 20 or
25W radiated in order to work DXCC on 160m, and then you even get some good
real signal reports and answers to your CQ calls.
So maybe people feed 1500W to the antenna system, radiate 15W, and assume
everything is working great because they get a "599 nice signal" from DF2PY
and S59A and worked VP6DX. That's enough for some people to consider it a
"working" antenna on 160m.
73
Dan
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