THeir monthly articles on how to build a dipole are usually factually
correct.
73s John NE0P
----- Original Message -----
From: "K4SAV" <RadioIR@charter.net>
To: <towertalk@contesting.com>
Sent: Friday, July 22, 2005 3:45 AM
Subject: Re: [TowerTalk] dumbing down
> Sic-em Tom! They deserve it!
>
> You are correct. I see this kind of stuff ocassionally appearing in QST
> and CQ. I'm sure it's in other magazines as well, but I only get those
> two. I also see it in the Antenna Compendiums as well.
>
> I guess you can't expect everyone to be technically educated. Some
> people just try various things, then make up some reasons why it is
> good, and write an article. (Radio is not the only place you see this
> occurring.) The editor of these magazines should be more responsible for
> reviewing this stuff, and kicking out articles that are technically
> wrong. I don't know how much of this is actually done, I have no way of
> knowing what has been thrown out, but sometimes an article will appear
> that is very obviously wrong. That really give the impression that
> things are not being reviewed at all.
>
> The really bad part is that some people are trying to learn from these
> articles.
>
> Jerry, K4SAV
>
> Tom Rauch wrote:
>
> >>At 02:44 PM 7/21/2005, SavageBR@aol.com wrote:
> >>
> >>
> >>>BTW we're not dumbing down TowerTalk.
> >>>
> >>>
> >
> >
> >
> >>>Indirectly Tower Talk and any other technical reflector
> >>>
> >>>
> >is being dumbed
> >
> >
> >>>down. Or, the need is being eliminated. As the
> >>>
> >>>
> >technically competent,
> >
> >
> >>>experienced, capable amateur dies off, so will the real
> >>>
> >>>
> >hobby of
> >
> >
> >>>amateur radio.
> >>>
> >>>
> >
> >
> >
> >>To relate it more to antennas.. I think that amateurs are,
> >>
> >>
> >in general, much
> >
> >
> >>more sophisticated when it comes to antennas these days.
> >>
> >>
> >Compare the
> >
> >
> >>antenna projects in ARRL handbooks over the years. Some
> >>
> >>
> >are perennial
> >
> >
> >>evergreens, but modern directive antennas are far better
> >>
> >>
> >than what was
> >
> >
> >>"state of the art" in 1960 or 1970.
> >>
> >>
> >
> >I almost hate to post this, but I seriously question the
> >direction our technical resources are heading.
> >I think peer review processes are slipping. Let me give an
> >example.
> >
> >August QST, page 35, has a very well written four page
> >antenna construction article. It unfortunately has a very
> >simple basic point wrong. The authors based the construction
> >on the incorrect assumption a small horizontal loop antenna
> >radiates a vertically polarized omni-directional signal. Of
> >course it doesn't have vertical polarization. It radiates an
> >omni-directional horizontally polarized signal!
> >
> >The article claims a comparison was made between the loop
> >and a J-pole. It said signals were "even". That can't be
> >true in line-of-sight communications unless the J-pole had
> >some very serious flaws or an esoteric effect like feedline
> >radiation or metallic structures nearby was affecting
> >antenna patterns.
> >
> >If you read the editor's note on page 35 it says: "While
> >horizontal loops do better in noisy situations because that
> >local noise tends to be mainly E-field oriented ....". What
> >does that mean? What is "mainly E-field oriented"?
> >
> >Now here's the real sad part. The antenna isn't good for the
> >original intent...efficient omni-directional vertically
> >polarized communications.....no matter how we position the
> >loop. Turn the loop on edge and it has a bi-directional
> >vertically polarized signal while wasting half of the
> >applied power as straight-up-and-down horizontally polarized
> >radiation. Lay it down flat and it is omni-directional, but
> >unfortunately it is also horizontally polarized.
> >
> >Articles like this embarrass and discourage everyone from
> >the authors to the editor to the poor fellow trying to learn
> >how to build something. They should be edited and corrected
> >before publication, not after.
> >
> >Now if you roll over to Technical Correspondence on page 60,
> >you find an opening letter about Packet, Pactor, and NVIS.
> >The letter writer wastes no time in being critical of an
> >older Elmer (he actually used those words) who thought the
> >idea of an 18 inch high dipole antenna for 80 or 40 was a
> >dumb idea.
> >
> >The writer uses some fantasy technorubbish about groundwave
> >and NVIS being "out of phase" and the 18 inch high antenna
> >curing a "phase distortion" problem.
> >
> >Well, I'm in full agreement with the older Elmer. The only
> >thing that happens when a horizontal dipole antenna is
> >installed significantly lower than 1/4 wl is the efficiency
> >drops, often like a rock!
> >
> >Thirty years ago people knew if we wanted a dynamite NVIS
> >signal we installed a dipole at 1/8 to 1/4 wl high and laid
> >a screen or grid of wires below the antenna to reduce earth
> >losses. Now we have people proclaiming in the best interests
> >of "Homeland Security" communications we need to use what
> >really amounts to a 10 dB or more attenuator on a 5 to 10
> >watt transmitter... rather than building a good system.
> >
> >This is probably why, when I listen to the GA ARES net, a
> >significant number of stations can't hear each other. Yet
> >with a dipole 35 feet high over a large ground screen I can
> >hear and work all the dog-gnat signals coming from grossly
> >inefficient antennas that are (no surprise) quiet. This is
> >where we are headed.
> >
> >How do we educate people and build reliable communications
> >networks when many technical concepts making it into what
> >once was our only peer reviewed reliable source of
> >information are getting so ridiculous?
> >
> >The CB'er down the road has metal pie pans with holes in the
> >center strung on his coax to "divert lightning" and an old
> >water cooler jug filled with pennies and saltwater for a
> >station ground. I fully expect to see that idea published
> >someday in a radio communication system handbook. After
> >all, steel wool baluns made it in, and we now have 18 inch
> >high dipoles that cancel phase distortion and horizontal
> >loops that radiate a vertically polarized omni-directional
> >signal. Pie pans seem the next logical progression.
> >
> >73 Tom
> >
> >_______________________________________________
> >
> >See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
> >
> >_______________________________________________
> >TowerTalk mailing list
> >TowerTalk@contesting.com
> >http://lists.contesting.com/mailman/listinfo/towertalk
> >
> >
> >
>
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|