On Wed, 26 Nov 2003 15:52:57 -0500, "Dave VanHorn"
wrote:


"lbbs" wrote in message
...
Can a handy man that has never install antennas, install a preamp. Or do
I
need
a professional?

It's basically common sense, but connections have to be clean and
water proofed.


The amplifier itself needs to mount at the antenna. That involves a ladder
usually, and some electrical tape for sealing the connections. Obvious

I use liquid electrical tape. Ace hardware carries it as well as
marine stores. "Coax Seal" is also good and can be covered with
regular electrical tape. Don't try to weather proof connectors just
using electrical tape.

Today's modern coax cables are long lived when installed properly. I
have some 20 years old doing as well as the day they were installed.
Older or inexpensive coax may not age as well. Twin lead, unless it's
of high quality does not usually age well. It also takes some
knowledge on routing and placement rather than put it where it's
convenient as with coax. Coax can be taped to the mast. Twin lead
needs to be held in insulated stand offs about 6 inches long. Never
use metal staples to hold twin lead in place as it's very sensitive to
nearby metallic objects.

I have two RG-6 cables that run underground through conduit for over
75 feet in a bundle of cables carrying control voltages as well as the
output from the ham station which is 1500 watts from 1.8 through 30
MHz, 100 watts on 50 MHz and 50 watts on 144 and 440 MHz. The overall
run is over 200 feet when you count the distance up the tower to the
antennas and from the conduit to the radio station and on to the TV
receivers. (bout 225 feet to the spitters, switches, and TV receivers
)

If water has gotten into the cable, you need to cut it back far enough
to find shiny braid. With older cables it's probably best to just
replace it.

I also find that I have to replace the "Balun" which is the device
that goes between the antenna connectors and the coax, about ever 2 to
4 years. It would be nice if some one made a good balun that could
stand up to the elements.

Then there are the RV antennas them selves.
Even to-of-the-line TV antennas are flimsy and of relatively cheap
construction (even if they are expensive). Most have hardware that
rusts out long before the antenna would cease being useful if they
used decent hardware (stainless steel). Elements are easily bent and
broke. They are made of cheap, thin sheet aluminum that is rolled into
a tube. The Aluminum is often anodized a gold color and it stands up
to weather quite well, even if the bolts rust off in a few years.

If you look closely there are two UHF TV antennas near the 90 foot
level on the tower in
http://www.rogerhalstead.com/ham_files/Tower30.htm
All the other leads run with the RG-6 from the TV antennas.

I did play around with this for a while when I first put up the tower.
http://www.rogerhalstead.com/ham_files/tower21.htm The gin pole is
still in place.

This http://www.rogerhalstead.com/ham_files/Tower29.htm is installing
the current array, but before the TV antennas were reinstalled just
below where my feet are anchored.



You'll have to fix the return add due to dumb virus checkers, not spam
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair?)
www.rogerhalstead.com

safety concerns apply. The rest is easy.