Aerial advice - is it possible that a Police CB can interfere withreception?

Hi all,

I am in Wilsden, West Yorkshire and receive freeview from the Keighley
transmitter.

Around Christmas we had very poor reception of the ITV mux. I called
the aerial fitter that installed the original aerial and he said that
it was happening to many people in the Wilsden area, and that it would
probably come back by itself. However I also wanted the aerial mast
strengthening (it's windy up here!) and two more aerial points putting
into the house, so he came and did the work - also necessitating a
masthead amp, but after £200+ it was done.

He had inital problems getting the ITV channels to appear at all, but
after using an analyzer to get it "bang on" it did seem ok. However
we are still getting frequent break ups of the ITV mux - the freeview
box shows the signal yoyo-ing up and down in strength and quality.

I phoned them back and said if anything it was worse, and he said they
were doing work on the transmitter so I checked the BBC pages and
Keighley was having work done for a few weeks (although the stated mux
it affected wasn't ITV).

To cut a long story slightly shorter, I'm still getting poor reception
and feel pretty aggrieved that I paid a couple of hundred quid and
nothing improved (but now I have poor reception in 3 rooms instead of
1!)

I phoned them again and he got back to me with a story about a "Police
CB radio" in Keighley that was possibly in alignment with my aerial,
so it's signal was interfering with my TV signal.

Is this plausible? He said he could fit a special filter or choke and
would only charge me if it actually worked...! Is he talking about a
ferrite ring because I could buy one from Maplins myself and save some
money!

I'm contemplating checking this with another aerial installer but a) I
don't want any more expense (throwing good money after bad!), and b) I
don't want to string the second installer along with a job he might
never get.

Cheers

Neil

The fundamental question is, why is reception poor on the ITV mux? Is the
signal weak, or is there interference of some sort? Ask the installer, what
is the signal strength and BER as measured direct from the aerial without
any amplifiers involved? How does it compare with other muxes?

Bill

"Neil" wrote in message
...
Hi all,

I am in Wilsden, West Yorkshire and receive freeview from the Keighley
transmitter.

Around Christmas we had very poor reception of the ITV mux. I called
the aerial fitter that installed the original aerial and he said that
it was happening to many people in the Wilsden area, and that it would
probably come back by itself. However I also wanted the aerial mast
strengthening (it's windy up here!) and two more aerial points putting
into the house, so he came and did the work - also necessitating a
masthead amp, but after £200+ it was done.

He had inital problems getting the ITV channels to appear at all, but
after using an analyzer to get it "bang on" it did seem ok. However
we are still getting frequent break ups of the ITV mux - the freeview
box shows the signal yoyo-ing up and down in strength and quality.

I phoned them back and said if anything it was worse, and he said they
were doing work on the transmitter so I checked the BBC pages and
Keighley was having work done for a few weeks (although the stated mux
it affected wasn't ITV).

To cut a long story slightly shorter, I'm still getting poor reception
and feel pretty aggrieved that I paid a couple of hundred quid and
nothing improved (but now I have poor reception in 3 rooms instead of
1!)

I phoned them again and he got back to me with a story about a "Police
CB radio" in Keighley that was possibly in alignment with my aerial,
so it's signal was interfering with my TV signal.

Is this plausible? He said he could fit a special filter or choke and
would only charge me if it actually worked...! Is he talking about a
ferrite ring because I could buy one from Maplins myself and save some
money!

I'm contemplating checking this with another aerial installer but a) I
don't want any more expense (throwing good money after bad!), and b) I
don't want to string the second installer along with a job he might
never get.


Well you appear to have a rather strange company do your work.
Anyway not in Wilsden but within a few miles miles so know the area and I
guess all though several transmitters cover the area in general terms the
hills/valley will cause limitations. But is Keighley your only choice?
Do your neighbours use Keighley, do they have same problem, do they have
similar aerial, do they have mast head amplifiers?
If they OK call in their aerial firm and get what they have.

Back to your aerial man it is a shame customer satisfaction not the top of
his list of priorities.

--
Regards,
David

Please reply to News Group

On Feb 27, 2:51*pm, "David" wrote:

Well you appear to have a rather strange company do your work.
Anyway not in Wilsden but within a few miles miles so know the area and I
guess all though several transmitters cover the area in general terms the
hills/valley will cause limitations. *But is Keighley your only choice?
Do your neighbours use Keighley, do they have same problem, do they have
similar aerial, do they have mast head amplifiers?
If they OK call in their aerial firm and get what they have.

Back to your aerial man it is a shame customer satisfaction not the top of
his list of priorities.

--
Regards,
David

It's over a hill but previously reception was rock solid on all muxes
as soon as we got the wideband aerial. All the other local aerials
point to Keighley, though in slightly different directions! Installer
said ours was "spot on" and the others were all wrong...

I'll enquire as to whether any of the neighbours had to use
amplifiers, I suspect they don't (we never had to) - but they said
with 3 TV outputs we'd need it. At the very least I've got x pounds
worth of amplifier that can't even deliver what it's supposed to.

I will ask them what the signal strength and BER are when they visit.

Cheers

Neil
--
http://www.hencam.co.uk

In article
,
Neil wrote:


I'll enquire as to whether any of the neighbours had to use
amplifiers, I suspect they don't (we never had to) - but they said
with 3 TV outputs we'd need it. At the very least I've got x pounds
worth of amplifier that can't even deliver what it's supposed to.

I will ask them what the signal strength and BER are when they visit.

It may well be that the diagnosis of Police radio is correct. Your
amplifier is probably wideband and is 'unhappy' with a powerful out-of-band
signal. It is quite possible for a problem like this to happen on only one
channel. Why not try the filter, there are such things as "Tetra
filters"; Tetra being the acronym for the police radio system - it's not
CB, so fitting a CB filter won't help.

--
From KT24 - in "Leafy Surrey"

Using a RISC OS computer running v5.11

....snip...
It's over a hill but previously reception was rock solid on all muxes
as soon as we got the wideband aerial. All the other local aerials
point to Keighley, though in slightly different directions! Installer
said ours was "spot on" and the others were all wrong...

I'll enquire as to whether any of the neighbours had to use
amplifiers, I suspect they don't (we never had to) - but they said
with 3 TV outputs we'd need it. At the very least I've got x pounds
worth of amplifier that can't even deliver what it's supposed to.


Do you really mean a masthead amp? If the signal was (or should have been)
fine before, wouldn't a distribution amp. in the loft have been the correct
thing to fit? Please note this is a question and not a statement ;-).

And what do your neighbours say? Is ITV a problem on their sets?

Paul DS

....snip...
It may well be that the diagnosis of Police radio is correct. Your
amplifier is probably wideband and is 'unhappy' with a powerful
out-of-band
signal. It is quite possible for a problem like this to happen on only
one
channel. Why not try the filter, there are such things as "Tetra
filters"; Tetra being the acronym for the police radio system - it's not
CB, so fitting a CB filter won't help.

But didn't the OP say he had this problem before fitting the amp? I suppose
it's possible that the TV/Freeview box was also getting overwhelmed.

Paul DS

On Feb 27, 3:55*pm, "Paul D.Smith" wrote:

Do you really mean a masthead amp? *If the signal was (or should have been)
fine before, wouldn't a distribution amp. in the loft have been the correct
thing to fit? *Please note this is a question and not a statement ;-).

And what do your neighbours say? *Is ITV a problem on their sets?

Paul DS

Yes it was a masthead amp, was told we needed it to power the 3 TV
points.

Charles: I can't remember if he said it was a Tetra filter - but have
just googled and does seem to fit in with what he said.

Found this very helpful article, http://www.wrightsaerials.tv/Tetra.htm
so thank you for pointing me in the direction!

Cheers

Neil

In article , charles
scribeth thus
In article
,
Neil wrote:


I'll enquire as to whether any of the neighbours had to use
amplifiers, I suspect they don't (we never had to) - but they said
with 3 TV outputs we'd need it. At the very least I've got x pounds
worth of amplifier that can't even deliver what it's supposed to.

I will ask them what the signal strength and BER are when they visit.

It may well be that the diagnosis of Police radio is correct. Your
amplifier is probably wideband and is 'unhappy' with a powerful out-of-band
signal. It is quite possible for a problem like this to happen on only one
channel. Why not try the filter, there are such things as "Tetra
filters"; Tetra being the acronym for the police radio system - it's not
CB, so fitting a CB filter won't help.


Most all Police radio in the UK is now Tetra which is a constant carrier
system so its prolly Tetra interference if its anything..

A tetra filter would prove that or disprove it . A lot of Tetra bases
are on the Ofcom sitefinder page..
--
Tony Sayer

If you could get hold of a scanning radio which covers the frequencies in
question, you might get some answers. it certainly sounds like a cross mod
problem, and no, the filter would be a high pass or low pass depending on
the frequency of the offending transmitter. It would be needed before the
mast head amp in my opinion, as this is the most likely part to be affected.

Strange it is only one transmitter though, unless some mixing components
make it particularly bad there.

I can recall a similar problem when trying to get Hannington from
Chessington when ITV regions were actually different, a pager in the local
industrial park screwed reception up with patterning every time it came on.
We worked out the mixing components eventually and made a filter and it
almost, but not quite got rid off.

Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
"Neil" wrote in message
...
Hi all,

I am in Wilsden, West Yorkshire and receive freeview from the Keighley
transmitter.

Around Christmas we had very poor reception of the ITV mux. I called
the aerial fitter that installed the original aerial and he said that
it was happening to many people in the Wilsden area, and that it would
probably come back by itself. However I also wanted the aerial mast
strengthening (it's windy up here!) and two more aerial points putting
into the house, so he came and did the work - also necessitating a
masthead amp, but after £200+ it was done.

He had inital problems getting the ITV channels to appear at all, but
after using an analyzer to get it "bang on" it did seem ok. However
we are still getting frequent break ups of the ITV mux - the freeview
box shows the signal yoyo-ing up and down in strength and quality.

I phoned them back and said if anything it was worse, and he said they
were doing work on the transmitter so I checked the BBC pages and
Keighley was having work done for a few weeks (although the stated mux
it affected wasn't ITV).

To cut a long story slightly shorter, I'm still getting poor reception
and feel pretty aggrieved that I paid a couple of hundred quid and
nothing improved (but now I have poor reception in 3 rooms instead of
1!)

I phoned them again and he got back to me with a story about a "Police
CB radio" in Keighley that was possibly in alignment with my aerial,
so it's signal was interfering with my TV signal.

Is this plausible? He said he could fit a special filter or choke and
would only charge me if it actually worked...! Is he talking about a
ferrite ring because I could buy one from Maplins myself and save some
money!

I'm contemplating checking this with another aerial installer but a) I
don't want any more expense (throwing good money after bad!), and b) I
don't want to string the second installer along with a job he might
never get.

Cheers

Neil