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Grex > Radio > #57: Help with CB Transmissions. | |
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| Author |
Message |
manthac
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Help with CB Transmissions.
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Feb 2 20:19 UTC 2006 |
Is there anyway to legally make my cb transmissions get out better? Some
places I can transmit 30+ miles and other times I only get out about .5 miles.
I am a SWR meter hookup and the SWR reading is always low 1.5 or less on
channel 17. I can talk 30 - 45 miles away from my house and sometimes just
.5 mile away on the road. The power output and input into the cb is always
the same. I have been looking at some preamps, and was wondering if one of
those may help?
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| 9 responses total. |
gull
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response 1 of 9:
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Feb 2 21:05 UTC 2006 |
The only legal way is to improve your antenna. This can be difficult
in a mobile installation because short antennas are very inefficient on
the CB band. What are you using now?
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eprom
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response 2 of 9:
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Feb 3 18:19 UTC 2006 |
is using a CB yagi legal?
I'm not exactly sure, but I thought you are limited to an elevation of 60 ft
above the surface it's mounted on....so an antenna on a 1000 ft building can
have a total height of 1060 ft(?). correct me if i'm wrong.
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gull
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response 3 of 9:
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Feb 3 19:33 UTC 2006 |
As far as I know directional antennas are legal. A Yagi might be
impractical in a mobile installation, though. ;)
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rcurl
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response 4 of 9:
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Feb 3 19:36 UTC 2006 |
A *rotateable* Yagi - with a compass for automatic orientation. Hams do think
of such things....
(Come to think of it, you might was a bus for carrying a CB Yagi...)
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gull
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response 5 of 9:
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Feb 3 19:55 UTC 2006 |
I've seen mobile 2m and 70cm Yagis, but they were used for "fox hunts."
The best mobile antenna for CB that's at all practical is a 1/4-wave
whip. It has no gain, but that still makes it better than the
shortened antennas with loading coils most people use -- there are
significant losses in those coils. Unfortunately, at a little over 8
feet long, it's still impractical on most vehicles, especially if you
drive in town. But basically, the longer the antenna, the better off
you are.
There's a good introduction to CB antennas here:
http://www.signalengineering.com/ultimate/mobile_antennas.html
It'll help you cut through the hype. Most CBers don't understand
antenna theory, and the antenna manufacturers know it!
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springne
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response 6 of 9:
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Feb 3 20:14 UTC 2006 |
Get a copy of the "Big Dummies Guide to CB Radio"; it's excellent.
Has quite a bit on antennas including a home brew one made out of just coax
that you can throw up in a tree.
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krokus
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response 7 of 9:
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Feb 19 04:38 UTC 2006 |
Yes, directional antennas are legal on Class D radios. But while
that will help greatly, I'd also suggest operating SSB for covering
the distance. (Most SSB work is done on Channels 36 through 40.)
What is the application you're trying to use this in?
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gull
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response 8 of 9:
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Feb 23 03:08 UTC 2006 |
I thought about suggesting that, but I wasn't sure if there were many
people using SSB on CB.
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krokus
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response 9 of 9:
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Feb 26 18:07 UTC 2006 |
Yes, SSB is used often on CB. There are even ways to get callsigns
for doing that, and exchanging QSL cards. (Many people chase DX on
CB, despite it being illegal to do so in the US.)
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