An easy one this...

I've installed a new tv socket - it was an MK one - looks lovely but was a
bit of a b***er to get the wire in. Anyway, it appears to be ok but I can't
help thinking that a spare bit of braiding might be touching the centre core
(it's very hard to see).

If it were so, what would the effect be - how can I tell?

TIA,

Daz

Kroma wrote:
An easy one this...

I've installed a new tv socket - it was an MK one - looks lovely but
was a bit of a b***er to get the wire in. Anyway, it appears to be
ok but I can't help thinking that a spare bit of braiding might be
touching the centre core (it's very hard to see).

If it were so, what would the effect be - how can I tell?

TIA,

Daz

If your picture is pretty good then you have done the job.

normally you cant go wrong wiring a TV outlet the braid is folded back over
the sheathing and then clamped in a brass/metal retainer.

--
Sir Benjamin Middlethwaite

"The3rd Earl Of Derby" wrote in message
.uk...

If your picture is pretty good then you have done the job.

normally you cant go wrong wiring a TV outlet the braid is folded back
over
the sheathing and then clamped in a brass/metal retainer.

Getting the braided part (already folded back) and the sheathing underneath
the clamp was the hard bit - it moved the braiding around - dangerously
close to the core!

I'm quite sure it's ok - if it wasn't would there be a risk of damage to my
new shiny tv?

Daz

"Kroma" wrote in message
...

"The3rd Earl Of Derby" wrote in message
.uk...

If your picture is pretty good then you have done the job.

normally you cant go wrong wiring a TV outlet the braid is folded back
over
the sheathing and then clamped in a brass/metal retainer.

Getting the braided part (already folded back) and the sheathing
underneath the clamp was the hard bit - it moved the braiding around -
dangerously close to the core!

I'm quite sure it's ok - if it wasn't would there be a risk of damage to
my new shiny tv?

Daz

Nope, just a ****e picture!

Sparks...

On Sat, 29 Oct 2005 00:23:02 +0100, "Kroma"
wrote:

| An easy one this...
|
| I've installed a new tv socket - it was an MK one - looks lovely but was a
| bit of a b***er to get the wire in. Anyway, it appears to be ok but I can't
| help thinking that a spare bit of braiding might be touching the centre core
| (it's very hard to see).
|
| If it were so, what would the effect be - how can I tell?

You would lose signal which would be shorted out. If it works you are OK if
not re-do the job.
--
Dave Fawthrop dave hyphenologist co uk
Help make Usenet a better place: English is read downwards,
please don't top post. Trim replies to quote only relevant text.
Check groups.google.com before asking an obvious question.

Kroma wrote:
"The3rd Earl Of Derby" wrote in message
.uk...


If your picture is pretty good then you have done the job.

normally you cant go wrong wiring a TV outlet the braid is folded
back over the sheathing and then clamped in a brass/metal retainer.

Getting the braided part (already folded back) and the sheathing
underneath the clamp was the hard bit - it moved the braiding around
- dangerously close to the core!

I'm quite sure it's ok - if it wasn't would there be a risk of damage
to my new shiny tv?

Never having known anything much about TV aerials or the theory thereof,
I was surprised once when up a ladder reattaching one to the aerial
mast, to find that at the aerial end of the cable, the braid and core
were each connected to different parts of the aerial; ie they are
connected electrically anyway.

So that would be a 'no' to your question!

David

I was surprised once when up a ladder reattaching one to the aerial
mast, to find that at the aerial end of the cable, the braid and core
were each connected to different parts of the aerial; ie they are
connected electrically anyway.

Yes, and no!

Electricity isn't as simple as it first looks! The two wires are
connected in a DC sense, but you also need to consider AC. When the
signal in a wire is alternating, the wire and anything else conducting
that it passes through, will provide different "resistence" to flow.
What is simply a metal loop at DC is a small coil at AC, and the higher
the frequency the more significant this is. If you look at a
transformer it is just a long length of wire wound into a coil - but at
50Hz it behaves very differently to at DC. When you get up to 500MHz or
so that simple bent bit of metal behaves nothing like a length of wire.

Ever wondered why TV aerials use coax cable? Because at UHF frequencies
other sorts of cable would behave so differently than they do at DC
that they would be no good.

"Kroma" wrote in message
...

"The3rd Earl Of Derby" wrote in message
.uk...

If your picture is pretty good then you have done the job.

normally you cant go wrong wiring a TV outlet the braid is folded
back
over
the sheathing and then clamped in a brass/metal retainer.

Getting the braided part (already folded back) and the sheathing
underneath
the clamp was the hard bit - it moved the braiding around -
dangerously
close to the core!

The MK unit in front of me has a 2 mmm gap between the centre pin and
braid clamp, on that account I would make sure the braid was well
under the clamp and not protruding from the pin side at all. Make
sure you don't kink the cable when fitting the outlet to the wall box.

I'm quite sure it's ok - if it wasn't would there be a risk of
damage to my
new shiny tv?

There is no voltage on an 'ordinary' TV aerial, so no chance of damage
to your set, but if one of the hairs of the braid were to touch the
centre pin your picture would be made much worse, if any at all.

A satellite TV aerial does have a voltage on the centre pin and the
receiver might be damaged by a hair of the braid touching the centre
pin.

Roger

"Kroma" wrote in message
...

"The3rd Earl Of Derby" wrote in message
.uk...

If your picture is pretty good then you have done the job.

normally you cant go wrong wiring a TV outlet the braid is folded
back over
the sheathing and then clamped in a brass/metal retainer.

Getting the braided part (already folded back) and the sheathing
underneath the clamp was the hard bit - it moved the braiding around -
dangerously close to the core!

I'm quite sure it's ok - if it wasn't would there be a risk of damage
to my new shiny tv?

A handy tip I was told by an aerial installer is when fitting a standard
aerial wall plate remove the metal clamping bits from the plate and
instead connect an F plug to RF Out socket and glue that into the hole
where the existing wall plate bits were. He said apart from being a
much secure connection it also helps to eliminate the possibility of
interference picked up on the unshielded part of the cable held by the
clamp & screw

Huge wrote:

Lobster writes:

[17 lines snipped]


Never having known anything much about TV aerials or the theory thereof,
I was surprised once when up a ladder reattaching one to the aerial
mast, to find that at the aerial end of the cable, the braid and core
were each connected to different parts of the aerial; ie they are
connected electrically anyway.


We-e-e-e-e-e-e-ll. They're a short at DC, anyway. The miracle of AC
'leccy, eh?


they are 75 ohms at 400Mhz though :-)

they are 75 ohms at 400Mhz though :-)

The good ones are - how about the run-of-the-mill sort though?

There is no voltage on an 'ordinary' TV aerial

Really? I bet you anything that there is at least some voltage...

On 29 Oct 2005 05:35:00 -0700, "Matt Beard" wrote:

| There is no voltage on an 'ordinary' TV aerial
|
| Really? I bet you anything that there is at least some voltage...

Two thirds of knack all, usually micro volts.
--
Dave Fawthrop dave hyphenologist co uk
Help make Usenet a better place: English is read downwards,
please don't top post. Trim replies to quote only relevant text.
Check groups.google.com before asking an obvious question.

Dave Fawthrop wrote:
On 29 Oct 2005 05:35:00 -0700, "Matt Beard" wrote:

There is no voltage on an 'ordinary' TV aerial

Really? I bet you anything that there is at least some voltage...

Two thirds of knack all, usually micro volts.
1 volt there abouts
--
Sir Benjamin Middlethwaite

In article ,
John wrote:
A handy tip I was told by an aerial installer is when fitting a standard
aerial wall plate remove the metal clamping bits from the plate and
instead connect an F plug to RF Out socket and glue that into the hole
where the existing wall plate bits were. He said apart from being a
much secure connection it also helps to eliminate the possibility of
interference picked up on the unshielded part of the cable held by the
clamp & screw

You can buy screened outlets these days.

--
*I wish the buck stopped here. I could use a few.

Dave Plowman London SW
To e-mail, change noise into sound.

In article , The3rd
Earl Of Derby writes
Dave Fawthrop wrote:
On 29 Oct 2005 05:35:00 -0700, "Matt Beard" wrote:

There is no voltage on an 'ordinary' TV aerial

Really? I bet you anything that there is at least some voltage...

Two thirds of knack all, usually micro volts.
1 volt there abouts
--
Sir Benjamin Middlethwaite



Might have that very, very, close to a high power TX, but the microvolt
to millivolt region is nearer the mark.

As to the braid short, it can have varying results and possibly
frequency dependent ones as well. Just make sure it isn't
happening....
--
Tony Sayer

In article ,
tony sayer wrote:
As to the braid short, it can have varying results and possibly
frequency dependent ones as well. Just make sure it isn't
happening....

Yup - it's possible a shorted cable might improve the signal at certain
frequencies...

--
*A picture may be worth a thousand words, but it uses up a thousand times more memory.

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Fawthrop wrote:

On 29 Oct 2005 05:35:00 -0700, "Matt Beard" wrote:

| There is no voltage on an 'ordinary' TV aerial
|
| Really? I bet you anything that there is at least some voltage...

Two thirds of knack all, usually micro volts.

Referenced to what?

All voltages are relative...

On Sun, 30 Oct 2005 09:28:22 +0000, The Natural Philosopher wrote:

| Dave Fawthrop wrote:
|
| On 29 Oct 2005 05:35:00 -0700, "Matt Beard" wrote:
|
| | There is no voltage on an 'ordinary' TV aerial
| |
| | Really? I bet you anything that there is at least some voltage...
|
| Two thirds of knack all, usually micro volts.
|
| Referenced to what?
|
| All voltages are relative...

Between the core and braid of the coax.

--
Dave Fawthrop dave hyphenologist co uk
Help make Usenet a better place: English is read downwards,
please don't top post. Trim replies to quote only relevant text.
Check groups.google.com before asking an obvious question.