Subj : Antenna
To   : BEN RITCHEY
From : MIKE ROSS
Date : Thu Jul 07 2005 11:50 pm

"BEN RITCHEY" bravely wrote to "ALL" (07 Jul 05  16:12:41)
 --- on the heady topic of "Antenna"

 BR> Ok, it's up, and MUCH better reception. I got the NWS weekly test
 BR> yesterday around 11 Am which I had not heard in months. Luckily Cindy
 BR> missed us though Dennis is on it's way. FYI, I live about 30 minutes
 BR> from salt water (Lafayette, LA) so hurricanes are an ever present
 BR> threat.
 BR> Oh yeah, the antenna <g> I just ran the entire length of #12 copper
 BR> wire I had until I ran out (almost out of roof, too), which gives me a
 BR> 1.5' horizontal (thru the wall), a 5.5' vertical (high as I can go)
 BR> then about 10 feet horizontal. Works great, so thanks for *ALL* the
 BR> ideas.
 BR> I'm guessing the horizontal span isn't doing much, though, as the
 BR> original antenna is vertical <g>. BTW, is there a way to tune the
 BR> antenna, or do I need to? I have a Field Strength/SWR tester from Radio
 BR> shack I never used, if needed (?). At one time I was going to play with
 BR> short range (100') transmit/receive but the transmitter kit never
 BR> worked right. :(


With a vertical antenna the angle of incidence should point towards
the horizon or as low as possible for best reception. This angle
depends on the antenna length and quality of the ground. With the
long-wire antenna the lobes are concentrated by each wavelength
increasing the gain and the antenna becomes directional away from the
end of the wire being fed. Your horizontal span would likely be doing
the most if properly oriented. That is with the end pointing at the
emitter.

Tuning a random length wire antenna is not easy. I would require a
generator/transmitter/noise-source, an impedance bridge to measure the
radio's input characteristics, and a matching network to connect
eveything together. Are you starting to think it is more trouble than
the possible marginal improvement is worth?

 M*i*k*e

.... Real programmers scratch bits into their EPROMS using a lens and pin.
--- Blue Wave/DOS v2.30
 * Origin: Juxtaposition BBS, Telnet:juxtaposition.dynip.com (1:167/133)

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