From my understanding when you are checking SWR you should be 50ft away from
buildings etc. I'm just wondering how big an effect being close to a
building can have on SWR? If my SWR if around 2 (that'll do me) and I find
myself in a town near a building or in a jam with a big 18 wheeler alongside
could I find that my SWR could go from 2 to a damaging level due to the
closeness?


Cheers,

Dave

--
"Statistics are like a bikini. What they reveal is interesting. What they
conceal is vital. "

On Thu, 8 Feb 2007 10:10:33 -0000, "Dave P"
wrote in :

From my understanding when you are checking SWR you should be 50ft away from
buildings etc. I'm just wondering how big an effect being close to a
building can have on SWR? If my SWR if around 2 (that'll do me) and I find
myself in a town near a building or in a jam with a big 18 wheeler alongside
could I find that my SWR could go from 2 to a damaging level due to the
closeness?


Never heard of it happening or seen it happen myself. Objects like
buildings and the sheet metal on trucks will absorb far more RF than
they will reflect. Any -significant- reflection, enough to potentially
hurt your radio, requires a thin, straight conductor, parallel to your
antenna, with a specific length, and at a specific distance. Matter of
fact, some people who build their own antennas and -want- that kind of
reflection often find out that it's not easy -- certainly not as easy
as mounting a vertical next to a building or truck.

If you check SWR and it's over 3:1, most likely there's something
wrong other than just being close to a building or truck.

On Feb 8, 4:10 am, "Dave P" wrote:
From my understanding when you are checking SWR you should be 50ft away from
buildings etc. I'm just wondering how big an effect being close to a
building can have on SWR? If my SWR if around 2 (that'll do me) and I find
myself in a town near a building or in a jam with a big 18 wheeler alongside
could I find that my SWR could go from 2 to a damaging level due to the
closeness?


There is an effect like you mention... but nowhere near that severe.
Try and stay in the clear when making adjustments... but don't think
that parking next to another truck will change your match drastically.

www.telstar-electronics.com

From: (Dave*P)
From my understanding when you are checking SWR you should be 50ft away
from buildings etc. I'm just wondering how big an effect being close to
a building can have on SWR? If my SWR if around 2 (that'll do me) and I
find myself in a town near a building or in a jam with a big 18 wheeler
alongside could I find that my SWR could go from 2 to a damaging level
due to the closeness?
Cheers,
Dave
--
**"Statistics are like a bikini. What they reveal is interesting.
What they conceal is vital. "
-
The test range of a certain proven antenna manufacturer consists of an
open field and the surrounding area is free of objects.

On Thu, 8 Feb 2007 18:35:05 -0500, (I
AmnotGeorgeBush) wrote:

+++The test range of a certain proven antenna manufacturer consists of an
+++open field and the surrounding area is free of objects.
**************

Tha tis only necesary for making antenna pattern measurements. Also on
a certified range the ground is made of a consistant material so that
it is uniform over the entire distance between the transmit antenna
and the receiving antenna.

To do a certified range for 30 MHz the test antennae would need to be
separated by ten wavelengths and at least one quarter wavelength in
heigth, preferably higher.

james