wrote:
On Oct 26, 1:20 pm, Michael Coslo wrote:

I've considered putting a tuner on my Bugcatcher for 80 meters, but
haven't. The thing is so narrow there that the alternative is two taps
for the phone portion of the band.

That would more more for impedance matching rather than the
loading coil itself. I have no real problem with that. I've often used
simple L network tuners for matching mobile antennas.
The system I have a problem with is using the tuner as the
loading coil itself. It's usually a disaster as far as efficiency.

Okay, I got it, it makes sense that "tuning the coathanger" approach
would be bad.

Maximum current is at the coil, and often that coil will be
surrounded by body metal. Not good.. Poor current distribution
through the whip, and low overall efficiency. Not good..
If they left out bugcatchers in the test, no wonder all those
tuner fed things looked so good...
If your antenna acts very "high Q", that's actually good.
It means it's probably a pretty decent radiator.
I'd be more worried if it acted overly broadbanded, or low Q.
You won't lose much if you use a tuner for Z matching in your
case.

I've been pleased so far. I worked some CA QSO party from the middle of
PA on 20 meters with it, and all I could hear I could work (100 watts)
Florida, the midwest, and all the typical 20 meter paths from here too.

40 meters received good signal reports. I worked South Carolina, the
Outer Banks, Virginia. Maine Not enough to make a definitive statement,
but it doesn't not work. No QSO's on 80 yet, but the next evening I take
it out, I'm giving it a try.

It is narrow, but that's only been a big problem on 80.

"Michael Coslo" wrote in message I've been pleased so far.
I worked some CA QSO party from the middle of
PA on 20 meters with it, and all I could hear I could work (100 watts)

While you can not work a station if you can not hear it, that is no way to
compair an antenna. I have an off center fed antenna up 45 feet and a
tribander up 57 feet. I can hear more on the beam than I can on the OCF .
I can probably work all I can hear on either antenna. It is I just hear
beter on the beam on the bands it is cut for.

On Oct 29, 11:51 am, Michael Coslo wrote:


It is narrow, but that's only been a big problem on 80.

I've seen some on 80 where the people would tune them
at driving speeds because the leaning back of the antenna
would detune far enough to be a problem. :/
They didn't have a wide enough bandwidth to really get
both positions with a good match. Good performing
antenna though.
How well mine does depends on the path, distance, etc..
On 40m, mine will beat my dipole which is at 35-40 ft
on paths over about 1000 miles or so late at night.
IE: Houston to Florida.
We tested that many times to make sure it was not
a fluke. I have no trouble on 80, but it also varies with
time of day, distance. It's probably at it's worst real early
in the evening to close NVIS range stations. But as it gets
later, it will usually get better and better once the band gets
stable and stretches out a bit. As usual, the longer the path,
the better it might do vs a med height dipole.
But I'm often pretty strong even to NVIS range stations.
Not uncommon to be over S 9.. Sometimes 10-20 over..
Course, all the guys on dipoles might be hitting them at
30-40 over.. :/ But no problem talking. And I've never run
an amp mobile.. Just 100w..
MK

Art Clemons wrote:
"I don`t expect too."

Why all the Andy Rooney crap here?

No problem with a tuner. "The input power was the same on each antenna."

No problem with 360 feet. Received carrier power is proportional to
radiated power at that distance along the horiaontal path.

Best regards, Richard Harrison, KB5WZI

Didn't SGC have a version of a tuner that sort of clamped on an outside car
window and had an 8 foot vertical rising from it ?

Did anyone here ever use one and what were the results ?

Nick

(in UK - don't see QST)

Richard Harrison wrote:

No problem with a tuner. "The input power was the same on each antenna."

How can the input power be the same if it's going through the tuner? The
input power is the same at the input of the tuner, but we have absolutely
no idea what the output power from the tuner is. Isn't that a problem for
a fair test? Would not a more reasonable approach be to use something like
Wattmeter and get the antenna resonant? I've seen folks who used antenna
tuners find out the tuner can get really hot into some loads? If the tuner
is consuming some of the RF as heat, that's power not reaching the antenna
ergo not a fair test.


No problem with 360 feet. Received carrier power is proportional to
radiated power at that distance along the horiaontal path.



Isn't 360 feet within the near RF field at most HF frequencies?

On Oct 26, 5:53 pm, Art Clemons wrote:
Richard Harrison wrote:
No problem with a tuner. "The input power was the same on each antenna."

How can the input power be the same if it's going through the tuner? The
input power is the same at the input of the tuner, but we have absolutely
no idea what the output power from the tuner is. Isn't that a problem for
a fair test? Would not a more reasonable approach be to use something like
Wattmeter and get the antenna resonant? I've seen folks who used antenna
tuners find out the tuner can get really hot into some loads? If the tuner
is consuming some of the RF as heat, that's power not reaching the antenna
ergo not a fair test.

I may be missing the story...Is he feeding all these whips with the
tuner
alone, with no loading coil, or he feeding coil loaded antennas with
a
tuner for impedance matching?
I got the impression he was using the tuner alone, with no other
loading
coils on the whips.
I have no real problem with using a tuner for impedance matching
as long as it's not the actual loading coil.
I guess without seeing the article, it's hard to tell what his point
is.
MK

Art Clemons wrote:
"Would not a more reasonable approach be to use something like a
Wattmeter and get the antenna resonant?"

You have a point. The wattmeter was on the input to the tuner and we
don`t know what the tuner`s loss is. If the loss is negligible,
everything should be OK, and "the input power was the same on each
antenna."

Best regards, Richard Harrison, KB5WZI

On Oct 27, 12:15 am, (Richard Harrison)
wrote:
Art Clemons wrote:

"Would not a more reasonable approach be to use something like a
Wattmeter and get the antenna resonant?"

You have a point. The wattmeter was on the input to the tuner and we
don`t know what the tuner`s loss is. If the loss is negligible,
everything should be OK, and "the input power was the same on each
antenna."

Best regards, Richard Harrison, KB5WZI

I received back a fairly detailed email from the QST editor
involved... I will reply to him next week... I will incorporate some
of the comments on here - with attribution to the author(s)..
Everything (except private comments) will be shared here...
Right now, back to the inhumane QRN on 80 meter cqww...

denny / k8do

On Thu, 25 Oct 2007 23:02:12 -0400, Art Clemons
wrote:

I almost could not believe that an article that starts out with using an
antenna tuner to deliver all possible power to mobile HF antennas got
published.

I also noted that the testing antenna was 360 feet away.

I'm waiting to read on here that I've mis-understood a great method of
measuring HF mobile antennas, but absent a troll or two, I don't expect
too.

As a Student of the Art of Amateur Radio with a special fondness for
antennas I found the article useful and interesting. At least as far
as it went!

Last year I purchased a radio especially to go mobile. I have yet to
find an acceptable mobile HF antenna to use on my Chrysler Minivan. I
am beginning to believe that there are no acceptable solutions to the
problem as I define it.

Further, I have concluded that ALL MOBILE HF installations are poor
compared to a dipole five feet off the ground, some are just worse
than others.

The article simply sheds some light on the practical issues one
encounters with popular alternatives.

I think an auto tuner with whatever whip length one can tolerate is
the best one can do with a Chrysler Minivan.

Modeling programs do not consider the radiation from the loading coils
but field measurements do.

Tuner losses can be estimated from the software in the Arrl Antenna
Books.

If you can write a better article for QST, please do so. But please
remember, most of us don't choose the ethical we drive because of its
ability to carry a less bad radio antenna!

John Ferrell W8CCW
"Life is easier if you learn to
plow around the stumps"