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
|