Good advise so far.....a single antenna installation should use 50 ohm coax
to match the
output impedance of the radio to the input impedance of the antenna.
RG8/X is not suitable for VHF (very high freq.) or UHF (ultra high freq.)
because of
the inherent attenuation at thes freq.
The attenuation in db. could be so high with CB style coax as to completely
null a
weak or low powered signal at high freq.
Clean,soldered terminations are critical at VHF and UHF , the antenna should
be
grounded to the closest non-ferrous metal using copper braid, the reason
for braid is
that RF currents flow on the outside of a conductor (skin-effect) whereas
electrical
current flows on the inside or thru a conductor.
RF currents are tricky devils and care should be taken when dealing VHF and
UHF.
Also use chassis grounds on any type of transceiver and quality coax with
the antenna
mounted high and away from you as high levels of stray RF radiation will
cause
cataracts to form in your eyes.
--
KG4LBD
"Doug Dotson" wrote in message
...
Good advise! I'll check it out. What about their masthead antennas?
Doug
"Michael O'Dell" wrote in message
...
In article ,
(Larry W4CSC) wrote:
The PL-259 connector used to be called the "UHF connector" because it
came on UHF FM radios way back after WW2. I think RCA was to blame
for that one, but it might have been ol' Batwing.
There is only one SO-239 (female) and PL-259 (male) connector set.
The screw-in ferrules to shrink up the 3/4" coax hole to RG-58 and
RG-59 are different, though. None of them are "water proof",
unfortunately. None of them are a good match on any coax cable they
don't screw directly onto, either, like RG-8 or 213. They're
"acceptable" on RG 58 and 59 and 6 and 8X for our purposes and their
biggest benefit is anyone with simple soldering irons can put them
together with little skill, unlike proper 'N' or 'BNC' or 'SMA'
connectors we SHOULD be using.
On Sun, 21 Sep 2003 16:05:22 GMT, wrote:
Can someone tell me if there is a PL-259 connector for UHF and a
different one for VHF? I got a 259 from Radio Shack that was labeled
for UHF. It looked the same to me so I installed it, along with a
Shakespeare VHF antenna for a VHF marine band radio. Would not
transmit, but had a steady clicking from the speaker when mike was
open. I returned the radio to the factory for repair under warrenty,
and when returned was told the radio performed at factory specs, and
to check the installation. So, now I'm stumped, and hate to try
anything else without knowing what's going on. A SWR meter check
would
not help at this point. Thanks for any help.
Helmer
Larry W4CSC
3600 planes with transponders are burning 8-10 million
gallons of kerosene per hour over the USA. R-12 car air
conditioners are responsible for the ozone hole, right?
One Very Nice Feature(tm) of the Digital Antenna products
is that they provide cables pre-terminated with TNC connectors
which are only marginally larger than the quality marine 8X they
ship. they then provide a PL-259 "adapter" which the TNC
screws into to terminate in an SO-259. saves MUCH grief
fishing the cable and saves the work of terminating it
yourself. they claim providing pre-terminated cables
saves them lots of support time. a win all around as far
as i'm concerned.
I have no affiliation with Digital Antenna other than
as a satisfied owner of 4 of their antennas: 2x 8' Marine VHF,
an 8' cell stick, and their big SSB pole.
cheers,
-mo