On Fri, 12 Dec 2003 22:32:07 -0700, Wes Stewart
wrote:

On Sat, 13 Dec 2003 00:06:16 GMT, Roger Halstead
wrote:

|
|Every HF antenna here will go 1:1 "some where" ...

Not so.

I'd like to know how you can say that?

Have you measured all my antennas? You are welcome to come over and
check them out. Every one "according to my meter which is a Bird"
reaches 1:1 some where in the desired band. It may not be exactly the
frequency the formula predicted, but it'll be relatively close.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair?)
www.rogerhalstead.com
Return address modified due to dumb virus checkers

On Wed, 17 Dec 2003 06:44:06 GMT, Roger Halstead
wrote:

|On Fri, 12 Dec 2003 22:32:07 -0700, Wes Stewart
|wrote:
|
|On Sat, 13 Dec 2003 00:06:16 GMT, Roger Halstead
wrote:
|
||
||Every HF antenna here will go 1:1 "some where" ...
|
|Not so.
|
|I'd like to know how you can say that?

I can say it because it's true.
|
|Have you measured all my antennas?

No, but I've measured some of mine. Why just yesterday, I was out
measuring my vertical that started out as a Cushcraft AV-80. I'm
looking to use it on 40 meters. At resonance, at about 5.43 MHz, the
base impedance was 38.5 +j0. That's a 1.3:1 SWR.

And BTW that's a datum taken using a method described in HP
Application Note 77-3, "Measurement of Complex Impedance 1-1000 MHz."

You mistakenly believe that because an antenna *has a resonance* at
some frequency, its SWR is *1:1*. Not so, as shown above.

I have shown at least *one* example where you are wrong when you say
*every antenna*.

| You are welcome to come over and
|check them out.

No thanks. The weather here is much nicer for doing antenna work.

| Every one "according to my meter which is a Bird"
|reaches 1:1 some where in the desired band. It may not be exactly the
|frequency the formula predicted, but it'll be relatively close.
|
|Roger Halstead (K8RI & ARRL life member)
|(N833R, S# CD-2 Worlds oldest Debonair?)
|www.rogerhalstead.com
|Return address modified due to dumb virus checkers
|

On Wed, 17 Dec 2003 07:58:25 -0700, Wes Stewart
wrote:

On Wed, 17 Dec 2003 06:44:06 GMT, Roger Halstead
wrote:

|On Fri, 12 Dec 2003 22:32:07 -0700, Wes Stewart
|wrote:
|
|On Sat, 13 Dec 2003 00:06:16 GMT, Roger Halstead
wrote:
|
||
||Every HF antenna here will go 1:1 "some where" ...
|
|Not so.
|
|I'd like to know how you can say that?

I can say it because it's true.
|
|Have you measured all my antennas?

I think an important word has been missed. :-))


No, but I've measured some of mine. Why just yesterday, I was out
measuring my vertical that started out as a Cushcraft AV-80. I'm
looking to use it on 40 meters. At resonance, at about 5.43 MHz, the
base impedance was 38.5 +j0. That's a 1.3:1 SWR.

What do your antennas have to do with mine?


And BTW that's a datum taken using a method described in HP
Application Note 77-3, "Measurement of Complex Impedance 1-1000 MHz."

I understand that.

You mistakenly believe that because an antenna *has a resonance* at
some frequency, its SWR is *1:1*. Not so, as shown above.

I don't think I used the word resonance any where in my post although
at the end I did refer to the antennas being cut according to formula
and the 1:1 point not being where the formula said it should.


I have shown at least *one* example where you are wrong when you say
*every antenna*.

Ummm...no you haven't.

Nor did I say every antenna. I said "Every HF antenna here",
paraphrased, "Every HF antenna at this location does show a 1:1 some
where in the band for which it's used".

I am speaking solely about the HF antennas at this location and was
careful to point that out. All have been checked with a Bird 43 watt
meter and each one has a point where it shows no reflected power.
Their heights and angles are such that they are non reactive at those
points, or at least as near as I can tell on a Palomar bridge and are
so close to 50 ohms I can't measure the difference.

So as the question was asked and the thread titled. "Is it possible to
have a 1:1 SWR", the answer is yes. If I can do it, so can someone
else. I didn't give any probabilities, but the odds are relatively
slim that any one throwing up a wire is going to be lucky and find it
1:1 with J=0. However if some one reads 1:1 on their bridge it
doesn't mean the bridge is necessarily bad.
I should also point out that the wire antennas here are relatively
high at an 45 degrees to horizontal. Probably not a typical
installation.


| You are welcome to come over and
|check them out.

No thanks. The weather here is much nicer for doing antenna work.

Hey, it's nicer than when I put up the tribander. I think the chill
factor was 4 degrees that day.

Current conditions:
Temperature 29 °F / -2 °C
Windchill 17 °F / -8 °C
Humidity 69%
Dew Point 20 °F / -7 °C
Wind WNW at 17 mph / 27.4 km/h
Wind Gust -
Pressure 29.70 in / 1005 hPa (Steady)
Conditions Overcast
Visibility 10 miles / 16 kilometers
Clouds
(Above Ground Level) (FEW) : 2700 ft / 824 m
Overcast (OVC) : 6500 ft / 1983 m

It's a veritable heat wave. :-)) Although we did have nearly two
inches of snow today.



| Every one "according to my meter which is a Bird"
|reaches 1:1 some where in the desired band. It may not be exactly the
|frequency the formula predicted, but it'll be relatively close.

They are cut to formula plus a tad. Shortening equal amounts did not
put the 1:1 point at the same frequency on each of the 75 meter
antennas. However both do reach 1:1 with j=0 or as near as I can
measure. The Palomar bridge isn't exactly a precision instrument.

OTOH the AV-640 Hy-Gain multi band vertical reaches 1:1 (50 ohms and
J=0) at some point on every band 40 through 6. However I'm convinced
it's a perfectly matched dummy load on 20.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair?)
www.rogerhalstead.com
Return address modified due to dumb virus checkers
|
|Roger Halstead (K8RI & ARRL life member)
|(N833R, S# CD-2 Worlds oldest Debonair?)
|www.rogerhalstead.com
|Return address modified due to dumb virus checkers
|

Roger Halstead wrote:
Wes Stewart wrote:

On Sat, 13 Dec 2003 00:06:16 GMT, Roger Halstead
|Every HF antenna here will go 1:1 "some where" ...

Not so.

I'd like to know how you can say that?
Have you measured all my antennas?

Basic problem was the lack of a defined boundary for
"here". I figured it meant, "here in the US".
--
73, Cecil http://www.qsl.net/w5dxp



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On Wed, 17 Dec 2003 09:18:30 -0600, Cecil Moore
wrote:

|Roger Halstead wrote:
| Wes Stewart wrote:
|
|On Sat, 13 Dec 2003 00:06:16 GMT, Roger Halstead
||Every HF antenna here will go 1:1 "some where" ...
|
|Not so.
|
| I'd like to know how you can say that?
| Have you measured all my antennas?
|
|Basic problem was the lack of a defined boundary for
|"here". I figured it meant, "here in the US".

I don't know what "here" meant for sure, but he said, "although a
couple of them require a tuner to get there", even "there" his
statement is incorrect.

On Wed, 17 Dec 2003 09:18:30 -0600, Cecil Moore
wrote:

Roger Halstead wrote:
Wes Stewart wrote:

On Sat, 13 Dec 2003 00:06:16 GMT, Roger Halstead
|Every HF antenna here will go 1:1 "some where" ...

Not so.

I'd like to know how you can say that?
Have you measured all my antennas?

Basic problem was the lack of a defined boundary for
"here". I figured it meant, "here in the US".

Here as in http://www.rogerhalstead.com/ham_files/tower.htm which is
about 5 miles west of down town Midland MI. IE, my own installation.
:-))

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair?)
www.rogerhalstead.com
Return address modified due to dumb virus checkers