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Old October 26th 04, 11:25 PM
Alex Clayton
 
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"asym" wrote in message
news
On Tue, 26 Oct 2004 18:25:35 GMT, "Alex Clayton"
wrote:

[snip]

works. Is the longer antenna supposed to work better with other bands or
something? I would like to lop off a little more if it has no ill effect.
I


The longer the antenna, the lower the frequency.

There are many resources out there that will show you how to use an
SWR to tune your antenna to the proper frequency, for stuff around
850MHz, 3.3 inches is the resonant length for 1/4 wavelength.. a
little bit shorter to account for the velocity in the material.

Be careful, get a good SWR if you can and use that. If not, I'd move
down to 1/8 to 1/4 inch snips at a time, not a full inch. As soon as
it starts to get worse, stop cutting, because you're at the low end of
the length.

Going below 1/4 wavelength you can't get any shorter and have it get
better. If you were going for 1/2 (6.6 inches @ 850mhz) and cut too
far, you could "start over" and keep cutting it down to 1/4, but
you're well past that if you're down to 4" already.


How much do they cost? Looking over e-bay it looks like there is no shortage
of replacement antennas if I screw one up. If I buy an SWR (what the hell is
this?) I don't know what I would do with it after? I took another inch off
it, and it still works great for the 800 and 400. The police here are
switching over to the new 800 trunked system so they are broadcasting on
both the old 450's and new at the same time. Switching back and forth
between the two reception is still as far as I can tell, the same as it was.
The county and State Patrol here use 150's. I normally don't bother with
them but to test it I turned them on and they are working fine with the 3
inches too. Wish I had known this long ago it would have been nice not to
have the longer antenna getting in the damn way.