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Old March 27th 05, 03:07 AM
Mike
 
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Belden 1505A is not overkill and is not allowed by DIRECTV or Dish for
installs, it’s an RG-59 type and not known for low loss. It’s bigger
brother, Belden 1694A is an RG-6 “type” and has a bit lower loss. Both
of these are precision 75 ohm cables intended for conveying 270mb
digital video inside a premises and not specifically for outdoor CATV or
Dish use. It also costs more than the lower loss RG-6 used for TV
antenna and Dish L-band, an installer would be wasting money using this
for his installs. You can buy Commscope (standard CATV stuff) RG-11 type
much cheaper than 1505 or 1694 and get half the loss at 1000MHz.
Mike


wrote:
A friend was contracted to do some wiring in a local hospital.
They were to order Belcon 1506A as part would run through an
air vent system. Some fool in purchasing decided to go with 1505A.
Same cable except it ain't plenium rated. The supplier wouldn't
take it back, and they had no storage space so he was given, as in
legal transferr with documentation.
The fool in purchasing lost his job.
Must be hard to be on the street when you are 58.

My friend had about as much use for this cable as I do a poke in the
eye. So he gave it to me. This is GOOD, very good cable loss at 1500MHz

is only 9.3dB/100'. Last weekend we helped a mutual handicaped friend
put up a better scanner and SW antenna. We used a laptop,my PRC1000 and
compared the 1506A with standard and low loss 50 Ohm coaxes. Pretty
day,
good fun. While we climbed like monkeys he fixed on hell of a supper.
First cookout of the new year and the food was GREAT!

With an NIB older radioshack diskcone, the one without the vertical
stinger, and a pasternack PL-259 to "F" female adaptor we tried some
tests. The 1505A was better, lower loss and greater noise rejection,
then any other cable we tried. Just for grins I used 50' of 50 Ohm
Heliax and while it was slightly better, heliax is are and expensive.
We also tried some of Beldons normal CATV coax and it was at least
as good as the 50 ohm and was a lot cheaper. His coax run is 50' from
the antenna to the ground (AKA "static" block. With a ~10 run to his
radio desk. He lives about 20 miles from Lexington KY, so we used
distant
(50 miles)NOAA stations and the UKPD/LFFFUCG fire trunking system.
This isn't a state of the art installation. My friend isn't interested
in trying to receive weak distant signals. HE just wants to keep up
with
his old comrades. We could listen to PD/FR and aero comms from a 50
mile
radius. He is tickled pink. Perhaps his ineterest will grow. And
perhaps not.

The foil and copper braid offer much better shielding, going from 96%
for braid, to to 100% for braid foil. This helps keep noise from your
computers from entering the signal path after the coax is in your radio

room. I have an older Contura 40MHz? laptop that the LCD screen is
NASTY.
I mainly use it for my DeLorme GPS but it will control my PRC1000 very
nicely. We learned that routing of coax can be more important then most

radio users think. By passing the recieve coax across the front of the
LCD screen , standard braid only coax started letting RF noise into the
receiver.
I used a "bunch"(10 on each side) of ferrite beads to keep the RF from
traveling up the braid's outer surface. Without the beads, even with
the
coax well away from the PC, we got a few slight birdies. This even
happened with the heliax.

For SW CATV worked as well as any other cable I have ever tried. Our
friend
is on a limited income, long term disability insurance, and it was nice
to be
able to do a first class install without breaking his piggy bank. While
1505A is clearly overkill it works very nice. This left more money for
his radios.
I have loaned him my PCR1000 untill his radios arrive. And it was nice
to use
a TV A/B switch to allow him to change from the diskcone to the 100'
longwire. And yea the 100' longwire overloads the PCR1000 on HF, but a
simple el-cheapo radioshack varaible attenuator, with F in and out
takes care of that. And yes
a 100' wire beats a diskcone for HF reception. Period!

I think the average SWL and scanner user is missing a bet by not
investigating
CATV coax and "F" fittings. There are good weather proof male "F"
fittings
that are much easier, and cheaper!, to make good connections with then
BNC.
Good CATV coax is much less expensive then similar 50 Ohm stuff because
they
make so much more of the CATV cable. Ground blocks are inexpensive and
will
allow one to easily meet the NEC requirement to ground the outer
conductor on
coax. And this stuff is made to stand up to bad weatehr. Cable TV
companies and
Direct TV want their installs to be as trouble free as they can make
them.
If you talk with your local cable installer you can often get odd
lengths of
CATV for the taking. I admit usng the 1505A was overkill , but why not,
we ahd it.
Terry