At 07:55 PM 7/21/2005, Tom Rauch wrote:
>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.
Depends on which resources you're talking about.
>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!
I think that that specific example is more a case of poor editing. I read
it as meaning that the radiation pattern (ignoring polarization) of the
loop is basically the same as a dipole (i.e. that symmetric
donut). Technically it isn't.. a small loop has the same radiation pattern
as a "small dipole", which is slightly different than the radiation pattern
of a resonant dipole, but that's a pretty esoteric difference, and in all
cases, we're still talking about a donut shaped pattern.
I agree that the polarization issue should have been discussed, inasmuch as
HTs and mobile operators have nominally vertically polarized antennas. As
to what the actual polarization characteristics of this proposed antenna
might be (there is, after all, a fair amount of metal around it) it's
anyone's guess.
>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.
I suspect that this is a qualitative statement. I decry the lack of rigor,
or, more to the point, the fact that they're missing a suitable disclaimer
of rigor. It's ok to make qualitative statements (e.g. "works about as
well in our limited test"), as long as you don't imply that they're not.
It's hard for QST to get decent construction articles that are interesting,
accurate, etc.
>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"?
This is the part I have the biggest gripe on. Particularly since it's
theoretically by someone who should know better.
>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.
The other original intent, though, is that it would pass HOA inspection
muster. Oddly, I suspect a better overall solution would have been
something like a 1/4 wave ground plane, using that loop as the counterpoise
and the vertical mast as the radiator.
>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.
I agree..
I had a bit of a discussion with the editors of QST about a HV power supply
article last year that displayed some serious safety and general HV design
practice shortcomings. It seemed obvious that the author didn't have a lot
of HV design experience. The editors forwarded my comments to the author,
who wrote back with some rationalizations and some statements that appear
to be outright untruths. Is it worth it to fight the battle? Do I really
want to get into a slanging match about whether wires in a photograph are
radioshack style clipleads or HV wire? Nope. Such is life.
QST is a consumer grade magazine, with consumer grade review standards. It
is not a technical journal, nor can ARRL practically vet all the articles
to that level of expertise. Sure, they could probably come up with a list
of people to review papers on a regular basis, but I've been in that
situation. As an editor, it's hard to extract the reviews out of the
reviewers, and then to manage the needed interaction with the author. [You
get the reviews, you summarize them, you send the summary to the author for
comments, the author sends back their responses, you shoot the responses
back to the reviewers, they come back with yet another set of responses,
etc. It's tedious and time consuming and a heck of a lot of work.]
As a reviewer, it's hard to get the review done on a reasonable time
schedule for publication. Very few of us have the luxury of a job where
you get paid to do reviewing, and doing a good job is time
consuming. Hmm.. do I spend four or five hours of my leisure time
reviewing an article for QST that has some errors, writing up explanations
that will make sense to the author. This is no easy feat.. if they were
already experts, they wouldn't have made the mistake in the first place,
right? We're not talking about "in equation 12, shouldn't the minus sign
be an addition" kinds of commments. You don't want to wind up just
rewriting the article (in which case the original author is justly offended
and probably won't write any more articles, nor will he encourage his
friends to do so).. Or, do I spend that four or five hours of my time
doing something that "I" want to do, building antennas, playing with the
kids, talking on the radio.
This problem is NOT unique to QST. All magazines with technical content
(including IEEE peer-reviewed journals) face exactly the same
problems. You want a free pass to a big conference? Volunteer to be a
session leader: you'll have to find reviewers, coordinate the reviews, etc.
_______________________________________________
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
|