On Sun, 12 Feb 2006 13:25:44 GMT, "Ralph Mowery"
wrote:


"Tony Hwang" wrote in message
news:meBHf.602959$ki.30465@pd7tw2no...
jg wrote:


Hi,
Twin lead also has better quality foam ones not the skinny twirly kind.
Coiling up extra coax is not a good idea it can act like RF choke and
could lower signal level.
Tony

Coiling up extra coax wil not make it like a RF choke and will not lower the
signal level. As long as the coil diameter is large enough that the center
conductor does not cut into the iner insulation and short to the shield,
nothing on the outside of the coax will affect the strength of the signal.
The signal is carried on the inside of the outer shield. Coil up all the
extra you want. One thing that will affect the signal is if you have way
too much coiled up (like 20 or more feet) is the extra loss in the length of
coax. YOu will get the same ammount of loss if it is coiled or just ran in
a line.

If you are transmitting , coiling up the coax may have a benifit as it will
act as a choke and keep the transmitted rf that is coupled from the antenna

You sound like you know what you're talking about, but one thing gets
me. Here you say it will act as a choke and at the start of the
previous paragraph you say it won't. Why does transmission have a
different result from reception, or is there some other difference?

from getting back to the transmitter. Discussion on this is beyond the TV
application and not needed here.




Remove NOPSAM to email me. Please let
me know if you have posted also.

That's it.
http://salestores.com/chma428bouhf.html

"mm" wrote in message
...
On Sun, 12 Feb 2006 13:25:44 GMT, "Ralph Mowery"
wrote:


"Tony Hwang" wrote in message
news:meBHf.602959$ki.30465@pd7tw2no...
jg wrote:


Hi,
Twin lead also has better quality foam ones not the skinny twirly kind.
Coiling up extra coax is not a good idea it can act like RF choke and
could lower signal level.
Tony

Coiling up extra coax wil not make it like a RF choke and will not lower
the
signal level. As long as the coil diameter is large enough that the
center
conductor does not cut into the iner insulation and short to the shield,
nothing on the outside of the coax will affect the strength of the
signal.
The signal is carried on the inside of the outer shield. Coil up all the
extra you want. One thing that will affect the signal is if you have way
too much coiled up (like 20 or more feet) is the extra loss in the length
of
coax. YOu will get the same ammount of loss if it is coiled or just ran
in
a line.

If you are transmitting , coiling up the coax may have a benifit as it
will
act as a choke and keep the transmitted rf that is coupled from the
antenna

You sound like you know what you're talking about, but one thing gets
me. Here you say it will act as a choke and at the start of the
previous paragraph you say it won't. Why does transmission have a
different result from reception, or is there some other difference?

from getting back to the transmitter. Discussion on this is beyond the
TV
application and not needed here.


I have been a ham radio operator for over 30 years and at one time held a
first class phone license that was good for the comercial radio repair.

When receiving the signal comes from the antenna it comes down on the
outside of the inner wire and the inside of the outer sheild. Unlike
Direct current which uses all the wire area, as the frequency goes up, the
signal only uses part of the area. That is a copper tube can carry just as
much signal as a solid wire the same diameter. Large coax (usually called
hardline) is often made this way. There is nothing useful on the outside of
the shield of the coax. In otherwords everything from the receiving
antenna is on the inside of the coax and coiling it up has no effect .

When transmiting it is possiable that some of the signal from the antenna
will couple or be introduced on the outside of the coax. This unwanted
signal will come back down the coax on the outside of the shield and can
cause problems with the transmitter and other electronics in the house. If
the coax is wound in a coil it may choke off this unwanted signal. The coil
is usually placed outside the house .

Ok, so is it possible to have both my current antenna pointed in one
direction (minus the UHF section) and use this new antenna pointed in a
different direction? Then just combine the signal? This would give me
the best of both world w/o the need for a rotor.

You seem to know a lot. Here's a question, if my mast is well grounded
(buried a few feet) do I still need to ground the coax before it enters
the house? The way I see it, the mast will dissipate any charge on the
antenna? Yes?

jg wrote:
You seem to know a lot. Here's a question, if my mast is well grounded
(buried a few feet) do I still need to ground the coax before it enters
the house? The way I see it, the mast will dissipate any charge on the
antenna? Yes?

Not sure who you are addressing, but the shield of the coax does need to
be grounded before entering the house. This is regardless of whether the
antenna mast is grounded, but it should be. I would run a copper ground
wire, at least 12-gauge, from a clamp on the antenna mast to a good
copper clad ground rod. Connect the shield of the coax to this ground
wire too. You can use a coax grounding 'block' to make the shield
connection to the ground wire. This block is the kind that cable TV
companies use to ground their coax before it enters the house. You can
buy one at Radio Shack or hardware stores with coax parts.

In article .com,
jg wrote:
Ok, so is it possible to have both my current antenna pointed in one
direction (minus the UHF section) and use this new antenna pointed in a
different direction? Then just combine the signal? This would give me
the best of both world w/o the need for a rotor.

Sure. Back in the dark ages, when the UHF channels went up to Channel
83, TV sets didn't have a combined antenna input, instead they had
two (usually 300 ohm) inputs, one for each band. To save cable,
VHF/UHF splitter/combiners were used if you had an all band antenna.
They're bidirectional, the same unit can be used either way. So you
can run two antennas into the one cable.

Mark Zenier
Googleproofaddress(account:mzenier provider:eskimo domain:com)

Thanx to all who replied and helped out. I've installed a balun
tranformer at the antenna and I've replaced the entire run with RJ6
coax cable. Picture quality increased drastically on all channels.
I've got my antenna pointing 206 degrees yet I can still pick up
channels 29 (103 degrees) and 19 (143 degrees.) (My antenna's fault
I'm sure.) At any rate the local stations (Sacramento) all come in
super clear, so I'll leave it as it is.

Thanx again.

"jg" wrote in message
oups.com...

You seem to know a lot. Here's a question, if my mast is well grounded
(buried a few feet) do I still need to ground the coax before it enters
the house? The way I see it, the mast will dissipate any charge on the
antenna? Yes?


I try not to give advice on lightning protection. For about 25 years I had
a tower up about 40 feet and never took a hit of any kind. The tower was
not very well grounded and there were about 6 coax cables from various ham
antennas coming into the radio room. None were grounded . There was also a
wire about 130 feet long split in the middle and coax comming into the radio
room. It was up about 30 feet and not grounded in any way. Only damage I
ever took was a couple of telephones over the phone line. The installation
was done by the phone company and I never looked at it to see how well it
was done. Others I have know had well grounded systems and still had their
equipment wiped out by lightning.

"jg" wrote in message
oups.com...
Thanx to all who replied and helped out. I've installed a balun
tranformer at the antenna and I've replaced the entire run with RJ6
coax cable. Picture quality increased drastically on all channels.
I've got my antenna pointing 206 degrees yet I can still pick up
channels 29 (103 degrees) and 19 (143 degrees.) (My antenna's fault
I'm sure.) At any rate the local stations (Sacramento) all come in
super clear, so I'll leave it as it is.

Thanx again.

If you ever get the urge, buy a good long distance antenna and put a rotor
on it and see what you get!
B