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October 3rd 03, 12:29 AM

On 2 Oct 2003 10:24:25 -0700, (Brian) wrote:

Dan Richardson wrote in message . ..
On 30 Sep 2003 09:11:02 -0700, (Brian) wrote:

Danny, can you give us a match/swr for each band? The antenna is
supposed to not need matching.

Brian

Brain,

According to the manual the antenna uses a 50 to 800 Ohm broadband
matching transformer at the feed point. Assuming then that the
antenna's feed point should be near the 800-Ohm figure I ran a sweep
for 3.5, 7, 10.1, 14.2 and 28.5 MHz referencing a 800-Ohm impedance to
calculate the SWR. I got the following results:

3.5 1.40:1
7.0 1.88:1
10.1 1.92:1
14.2 1.96:1
21.2 2.37:1
28.5 2.41:1

Those figures appear to be in close agreement with the manufacture's
claim.

That said I feel that worrying about the SWR's effects on antenna
operation is somewhat like worrying how well a car will run based on
the amount of air pressure in the tires.

73
Danny, K6MHE

Danny, thanks for running the numbers. I appreciate it.

And feel free to drive your car w/o air pressure in your tires. Maybe
you've got the Presedential and Armored Car series tires. Since I
don't, I prefer air in my tires, and in my antennas, I prefer an SWR
somewhat below my transmitter's SWR protection circuit's limit.

73, BrIan/N0IMD

I guess I choose a poor analogy regarding SWR. On my list SWR is the
least of my worries as it is one of the easiest to fix. I would be
much more interested in the antenna's pattern (launching the signal in
a direction and angle I wish), what amount of gain it has at that
direction/angle and what efficiency it operated at.

Back to the analogy of a car. I would be more interested in how the
engine ran, transmission worked and so forth. A flat tire (read
excessive SWR) is easy to fix but rebuilding an engine is another
matter.

73 Danny

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