Of course, one must not forget that, feedline notwithstanding, the antenna
Does radiate (we all hope). So I guess maybe 5kw 5 feet away from anything
whatsoever might be a problem.
Now on the other hand, sarcasm aside, a balanced feed (coax or open) as a
part of a balanced SYSTEM, will not radiate, while an unbalanced one will.
One can imagine that a knowledgeable old timer, knowing how poorly balanced
so many systems are in practice, might have sagely suggested that, if you
are going to use open feeders, you might well find some radiation from them,
and you had better count on that as part of the antenna.
Back in the day, when we might have had more room and fewer devices to
interfere with, this could even be thought of as a good thing, as the
radiation at odd angles might just net us a contact or two away from the
favored direction of whatever antenna was in use.
Of course, we also must remember that it was common to feed something like
an end fed zepp with home made open line, widely spaced, to match the
feedline to the very high impedance point at the end of the zepp. In this
case, that's a dramatically unbalanced system, and the feed would surely
radiate. I would say it would be fair to call that "part of the antenna",
but intentionally so.
In any case, this thread has gone far enough, in my humble view, and is
beginning to degenerate into sarcasm and away from physics, so I guess,
after this, I will decline to participate further in it. Thanks to all of
those who have contributed to the factual portions of the discussion.
73 de Gary, AA2IZ
----- Original Message -----
From: "Curt" <k3ey@yahoo.com>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Saturday, July 09, 2005 9:38 PM
Subject: Re: [TenTec] Yaesu FT9000 oversights in QST review
I remember an old timer telling me that on a ladder
line fed antenna the fed line was part of the
radiation system, but when reading all the worldly
knowledge on this reflector I see this Ot-er must have
been misinformed as I read a different story on how I
can operate 5KW at only 5 five away from my neighbors
TV and he will never know it, provided of course I
arrange and properly prune and tune and balance this
marvelous antenna that is better than sex with wide
eyed wild crazy women...thanks for the entertainment
guys. Guess I'll go join the wife and watch the big
flat 36 inch LCD screen with the DVR and forget about
ladder line for the day.
Love Curty
--- Tommy-W4BQF <aldermant@alltel.net> wrote:
> Curt,
>
> You may want to revisit your 'been there done that'
> thing. If you open wire
> feeder radiated, that was because you had an
> imbalance in your antenna some
> how. Two wires carrying V/I 180 degrees out of
> phase, does not radiate.
> Just make both sides of your antenna wire the same
> physical length and keep
> both sides away from anything that would unbalance
> the current in the
> antenna, and your open wire feed line will not
> radiate.
>
> Proof was when living in northern Virgania, I ran
> some 300' of open wire
> feeder to a sloping 80m dipole and fed it with 1.5
> KW during contest and
> chasing DX. Neighbors within 50' of each side of me
> had no TVI/RFI and my
> own home TV antenna used only rabbit ears, all with
> no problem for some 15
> years. A little patience in putting up your antenna
> and you won't have a
> problem.
>
> 73,
>
> Tommy - W4BQF
>
> ----- Original Message -----
> From: "Curt" <k3ey@yahoo.com>
> To: <wb2vuf@qsl.net>; "Discussion of Ten-Tec
> Equipment"
> <tentec@contesting.com>
> Sent: Friday, July 08, 2005 12:42 PM
> Subject: Re: [TenTec] Yaesu FT9000 oversights in QST
> review
>
>
> >
> > I agree! Ladder line works great, been there done
> that. It also radiates
> like crazy and if you are in close proximity to
> miserable neighbors, ladder
> line is not desirable fed line. If you live where
> even putting up a vertical
> is out and the only hope is that dreaded folded
> dipole, then I guess the
> folded dipole it is. To support that folded dipole I
> had to tie both ends
> off on two different neighbors property getting
> permission with the promise
> of absolutely no TVI. That dreaded folded dipole
> made working HF possible.
> All the nay saying who laugh to themselves watching
> what they perceive as
> fools work the world with their folded dipoles dummy
> loads I say: Give it a
> break guys. All you're doing is making yourselves
> look like old dried up men
> who despise anything that doesn't fit your perfect
> self perceived world
> view. Distain has become your mantra.
> >
> >
> > Bwana Bob <wb2vuf@qsl.net> wrote:Its a mystery to
> me why hams would go for
> a broadband antenna of any
> > kind, when a dipole fed with ladder line and used
> with a decent tuner
> > (auto or manual) is cheaper and more efficient.
> Yet, I constantly see
> > hams putting up T2FD resistive-loaded folded
> dipoles on emergency
> > operations centers. There is no deception here:
> the specs of these
> > antennas are published but not many hams read them
> and realize that such
> > antennas are only about 12% efficient on 80
> meters. Now the military
> > with frequency-hopping radios needs a broadband
> antenna because tuners
> > can't hop very fast and they add bulk to the
> portable kit. We change
> > bands, but its hardly a freq-hopping mode of
> operation.
> >
> > Years ago, I found myself in a city "somewhere in
> the Middle East".
> > There were many embassies within walking distance.
> I amused myself by
> > looking at the the HF antennas on the embassy
> rooftops. There were a
> > couple that used big log periodics, but the
> majority used simple dipoles
> > fed with 600 ohm ladder line- a design that goes
> back to the 30's and
> > 40's. Why argue with success?
> >
> >
> > 73,
> >
> > Bob WB2VUF
> >
> > Grant Youngman wrote:
> >
> > >
> > >
> > >>Maxcom later claimed that
> > >>the unit used in the QST rewiew was a display
> model that had
> > >>been "stolen".
> > >
> > >
> > > These guys are still very much in business,
> selling very expensive dummy
> > > loads -- uh -- ah -- sorry, "automatic" Antenna
> Tuners.
> > >
> > > The name has been changed to protect the
> innocent (or guilty, depending
> on
> > > how you look at it).
> > > http://www.maxx-com.com/
> > >
> > > Enjoy ..
> > >
> > > Grant/NQ5T
> > >
> > >
> > > _______________________________________________
> > > TenTec mailing list
> > > TenTec@contesting.com
> > >
> http://lists.contesting.com/mailman/listinfo/tentec
> > >
> >
> > _______________________________________________
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> >
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> >
> > _______________________________________________
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> >
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> >
>
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