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

"Neil" wrote in message
...
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!

I don't think you should jump to the conclusion that the problem is caused
by TETRA. It's a very unscientific way to go about it! It probably is, but
really any half decent installer should be able to identify the problem
positively by the use of test equipment. Note that I said 'identify' -- not
'cure'.

Regarding the possibility that the problem is caused by a strong local
transmission -- TETRA or other -- there are many different techniques for
providing a cure. A simple TETRA filter is not a guaranteed answer.

Bill

On Feb 27, 8:11*pm, "Bill Wright"
wrote:

Regarding the possibility that the problem is caused by a strong local
transmission -- TETRA or other -- *there are many different techniques for
providing a cure. A simple TETRA filter is not a guaranteed answer.

Bill

The installer came on Friday, had a quick look on an analyser, said
the signal was fine (not surprising since the interference is
sporadic) and fit the tetra filter.

Signal strength went down slightly, but everything still worked. He
said we have to wait a while as there is still work on the Keighley
transmitter been performed. (It's true, there was work on the
transmitter listed in the BBC pages but it was scheduled to finish on
the 29th last month, and the mux listed as been affected wasn't the
one we have problems with).

Anyway, of course the interference is still happening, and tonight ITV
started breaking up at about 9:30pm and is now unwatchable.

The installer said if the tetra filter didn't help, then there was
nothing else he could do for us, and we'd have to write a letter to
his boss to discuss all the money we've spent on trying to get digital
tv reception.

The only thing that I just remembered was ages ago, I had some
interference in the sound on the live webcam feed at my website
http://www.hencam.co.uk - every now and again it sounded like a taxi
cab came through the audio feed - I fixed it by sticking a ferrite
ring on the audio cable.

So I'm completely ****ed off with everything now, and the other half
has said "why the hell didn't we just get Sky"...

If I get another installer out, will they be in a better position to
actually try and pinpoint the problem rather than **** me about
wasting money I don't have? If the interference only happens
sporadically then how the hell can I demonstrate it to the installer?

Cheers

Neil

"Neil" wrote in message
...
If I get another installer out, will they be in a better position to
actually try and pinpoint the problem rather than **** me about
wasting money I don't have? If the interference only happens
sporadically then how the hell can I demonstrate it to the installer?

Of course I sympathise with you but it's a bit of a bugger for the installer
as well. I mean, in all honesty what can he do if the fault won't appear
when he's there? These situations can be a nightmare really. How long does
the interference last? Would it be feasible to ring the installer during the
day when it starts in the hope that he gets there whilst it's happening? If
so he would be able to check that the signal strength remained normal, and
if he found that was the case, coupled with a worse than normal BER, and if
there was no obvious interference across the UHF band, you'd know that it
was co-channel (or within the channel) interference.

Bill

In article
s.com, Neil scribeth thus
On Feb 27, 8:11*pm, "Bill Wright"
wrote:

Regarding the possibility that the problem is caused by a strong local
transmission -- TETRA or other -- *there are many different techniques for
providing a cure. A simple TETRA filter is not a guaranteed answer.

Bill

The installer came on Friday, had a quick look on an analyser, said
the signal was fine (not surprising since the interference is
sporadic) and fit the tetra filter.

Signal strength went down slightly, but everything still worked. He
said we have to wait a while as there is still work on the Keighley
transmitter been performed. (It's true, there was work on the
transmitter listed in the BBC pages but it was scheduled to finish on
the 29th last month, and the mux listed as been affected wasn't the
one we have problems with).

Anyway, of course the interference is still happening, and tonight ITV
started breaking up at about 9:30pm and is now unwatchable.

The installer said if the tetra filter didn't help, then there was
nothing else he could do for us, and we'd have to write a letter to
his boss to discuss all the money we've spent on trying to get digital
tv reception.

The only thing that I just remembered was ages ago, I had some
interference in the sound on the live webcam feed at my website
http://www.hencam.co.uk - every now and again it sounded like a taxi
cab came through the audio feed - I fixed it by sticking a ferrite
ring on the audio cable.

So I'm completely ****ed off with everything now, and the other half
has said "why the hell didn't we just get Sky"...

If I get another installer out, will they be in a better position to
actually try and pinpoint the problem rather than **** me about
wasting money I don't have? If the interference only happens
sporadically then how the hell can I demonstrate it to the installer?

Cheers

Neil

Checked with any neighbours to see if their thus affected as yet?..
--
Tony Sayer

Neil wrote:

I am in Wilsden, West Yorkshire and receive freeview from the Keighley
transmitter.
Around Christmas we had very poor reception of the ITV mux.
snip

Wilsden is 2 miles from the Cullingsworth transmitter right? So your
mux2 from Keighley is probably being stomped on by analogue Channel 4
from Cullingsworth, also on UHF channel 68, and probably in almost in the
same direction.

Try tuning an analogue channel into channel 68, and you'll probably see a
noisy Channel 4 there.

Which means that the best place to situate that tetra filter is up the
rigger's arse.

--
Dave Farrance

On 3 Mar, 14:55, Dave Farrance
wrote:
Neil wrote:
I am in Wilsden, West Yorkshire and receive freeview from the Keighley
transmitter.
Around Christmas we had very poor reception of the ITV mux.

snip

Wilsden is 2 miles from the Cullingsworth transmitter right? So your
mux2 from Keighley is probably being stomped on by analogue Channel 4
from Cullingsworth, also on UHF channel 68, and probably in almost in the
same direction.

Try tuning an analogue channel into channel 68, and you'll probably see a
noisy Channel 4 there.

Which means that the best place to situate that tetra filter is up the
rigger's arse.


That's an interesting point, I'd forgotten about that relay. It's
actually not in Cullingworth, but in nearby Ryecroft and is about 30
degrees to the west of the Keighley transmitter from Wilsden. It's
just a few aerials on a telegraph pole, radiating a measly 13W in
total (analogue only). Keighley radiates each digital mux at 100W,
however it is behind a hill. I will get my dad to try tuning to 68 and
see what he gets. Not sure what he can do about it if it is that,
looks like after digital switchover this clash will disappear (plus
Keighley goes up to 2KW per mux).

Tim Mitchell

wrote in message
...
That's an interesting point, I'd forgotten about that relay. It's
actually not in Cullingworth, but in nearby Ryecroft and is about 30
degrees to the west of the Keighley transmitter from Wilsden. It's
just a few aerials on a telegraph pole, radiating a measly 13W in
total (analogue only). Keighley radiates each digital mux at 100W,
however it is behind a hill. I will get my dad to try tuning to 68 and
see what he gets. Not sure what he can do about it if it is that,
looks like after digital switchover this clash will disappear (plus
Keighley goes up to 2KW per mux).

If you've identified the source of the interference you might have some
chance of avoiding it.

Bill