Re: Best brand coax and F connector for HD cable?

[Roger <GetValidAddress@xxxxxx>]

On Tue, 02 Jan 2007 06:40:42 GMT, lnh <lnoh@xxxxxxxxxxxx> wrote:

>In article <lkgep2dlnti1q6o350m8oak0pegt1in6m2@xxxxxxx>,
> Roger <GetValidAddress@xxxxxx> wrote:
>
>> On Fri, 29 Dec 2006 16:49:59 -0500, "Robert L Bass"
>> <robertbass1@xxxxxxxxxxx> wrote:
>>
>> >> Belden RG-6 is what you want...
>> >
>> >*Any* RG6 Quad Shielded cable will do fine.  Belden, like Monster, has
>> >marketed their name very well.
>
>Wrong. Belden tests their cables. Monster is hype.
>
>> With today's cables using a 100% foil shield, plus a braid there is
>> little to gained by more layers of braid. Just stick with a name
>> brand.
>Wrong. Here in Houston if you dont use Quad shield you WILL see the
>leakage

How can you get better than 100% shielding?  The only time *heavier*
shielding would be of help is when there is *substantial* current
flowing in the shield.  OTOH if there is substantial current flowing
in the receiving antenna shield something else is seriously wrong.
>
>>   I use both Greenlee and the
>> Snap n Seal connectors.  They cost a bit more, but are both
>> mechanically sound and water proof.  The old hex crimp are easy to
>> pull apart.  One of these can hold my weight on the cable and in work
>> clothes I go over 180#.
>Well, my hex crimps will hang a TV, so they are fine. I seen enough bad
>Snap and Seal connectors that I automatically cut them off and
>reterminate.

That certainly has not been my experience.
>
>> As to how well  the foil and braid works; I run the cable through
>> conduit with the cables for my ham station. They will be running as
>> much as 1500 watts 1.8 through 50 MHz, a couple hundred watts on 144
>> MHz and up to 50 watts on the 440 MHz band.  I have two cables that
>> run to remote preamps on UHF antennas at roughly 90 feet and two that
>> run to the satellite dish at roughly 15 feet.  There is no interaction
>> of leakage between systems.
>
>That's just bad practice. Is that measured, or just observed?

In reverse order:  Part measured with an HP spectrum analyzer,
observing measured data rates, and listening with very sensitive
receivers.  In addition I've seen no observable interference on the TV
or heard any on the radio during checks.

As to practice: They are all signal leads (with the exception of the
rotator and remote antenna switch control leads and both are low
voltage) and are according to code. All shields are grounded at the
base of the tower and they are grounded to the tower  at the top, or
where the cable starts down the tower in the case of the TV, Dish, and
side mounted antennas. Those shields are again grounded at a bulkhead
where the cables enter the house. Also at that point are a number of
Polyphasers
So to recap, the coax shields are grounded at the top of the tower,
bottom of the tower, and where they enter the house. All leads are the
same length from the tower to the house which minimizes the likelihood
of a voltage build up between them during a lightning strike.

One additional note: All of the radio station coax is 100% foil shield
plus braid as well. All runs are either Times Wire LMR 400 or LMR 600


This is the antenna  setup.
http://www.rogerhalstead.com/ham_files/Tower29.htm
The TV antennas do not show in this photo, but are about where you see
the plate in the tower below my feet. That is shown in the following
photo.  The bottom antenna at 100 feet runs about 15,000 watts
effective radiated power on 14, 21, and 28 MHz. Those bands have
harmonics in the low and high VHF TV channels.  The long antenna above
that one at 115 feet is for 50 through 54 MHZ which is directly
adjacent to channel 2 with the second harmonic in the 100 to 108 MHz
 range. At the top, which is 130 feet are two sets of antennas. The
longer, outside pair run 144 to 148 MHz which is between the low and
high band VHF TV channels.  The shorter pair inside those runs on the
440 MHz band.  The flexible pig-tails to all these antennas have their
shields grounded about 8 to 10 inches below the top of the tower.

http://www.rogerhalstead.com/ham_files/Tower30.htm
My two TV antennas can be seen under the large ham antenna in this
shot. (The one to the NW stands out, you have to really look to see
the one pointed South) Both have remote preamps within about 2 feet of
the antennas. These antennas, with 20 db preamps are in the near field
of all of the ham antennas. This does necessitate filtering the 144 to
148 MHz range as those signals can saturate the preamps when the
antennas are pointed in the same direction as TV antenna pointing to
the left.
The white vertical that is side mounted on the tower (South side) runs
both the 144 and 440 MHz bands. That antenna runs about 6 db gain or
an effective radiated power on the 144 MHz band of about 200 watts.
The top of said antenna is about 20 feet below the TV antennas.
Another vertical like the one shown is going to be mounted, upside
down directly under the one in the photo. They will be end to end with
the second one being used for data and a link through the Internet to
other ham gateways.

The satellite dish does not show in either photo, but is on the same
side of the tower as the white vertical and about level with the roof
line. I'll eventually get this photo updated.

Behind the black C-band dish is a smaller tower with a 7 through 50
MHz vertical on the West end of the shop.  There is a crossed, folded
dipole (which doesn't show) right at the base of the vertical for the
HD TV tuner in the shop computer.

http://www.rogerhalstead.com/ham_files/boat6.htm

This station, computer, and amplifier have been completely reorganized
since the photo was shot.  All of the cables with the exception of the
CAT5e run through the conduit shown.  The CAT5e runs through the wall
behind the equipment at floor level and then underground through
conduit.

The old antique station has been rebuilt with the exception of the
transmitter. It is capable of running the legal power limit.  There is
a much smaller transceiver that drives an old Henry 2K4 amp (not
shown) that I normally use.

Although the station sounds elaborate, most of the equipment was
purchased used (some like the 2K4 had to be rebuilt to work) and I did
all of the tower work myself.

There is a substantial buried ground system that has 32 or 33 (lost
count) ground rods CadWelded(TM) to the cables tying everything
together into what is called a single point ground system or as near
so as possible.
.
>
>> In addition I run a CAT5e cable with a gigabit network between 5 and
>> 10 feet from and parallel to those cables
>
>That's not good practice, either.

It meets code and works well.  Besides to get that 130 foot run from
the house to the shop leaves little in the way of alternatives.  My
only real concern for the Gigabit network is lightning as the tower
has taken an average of 3 visually confirmed direct hits a year since
it was installed. It took five hits this past summer  I'd go wireless
but it's just too slow for the amount of traffic I put on the network.
I was operating this computer when the last strike occurred (Wireless
keyboard and mouse).  All 4 computers on the network were up and
running and I had a large file transfer going between the computer to
my right and the one in the shop.  When the lightning hit the lights
blinked, the UPSs squealed, the network went down, right back up, and
continued the file transfer.

BTW with that many visually confirmed hits I wonder how many times it
actually gets hit.

The point behind all of his is: Proper termination and grounding along
with good coax allow this system to work well in an environment far
more severe/hostile than most will ever experience.

>
>> Roger Halstead (K8RI & ARRL life member)
>> (N833R, S# CD-2 Worlds oldest Debonair)
>> www.rogerhalstead.com
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com