Home cinema - Communal aerial woes

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Communal aerial woes - advice welcome!

Please excuse me if any of what follows is obvious - it's been 10 years
since I last
lived somewhere with a TV, and back then we got away with a pair of
rabbits' ears...

Anyway, we just splashed out and bought a Toshiba TV with built-in
freeview, and the
results aren't too spectacular (we're in London N7). The analogue
reception is fairly
dire on all channels, and the digital reception was non-existent until
I bought a
booster box from Argos. With that cranked up full, we get Multiplexes
1, B and D
(channels 25, 28 and 29) from Crystal Palace perfectly, Multiplex A
(channel 32) pretty
well, and Multiplexes 2 and C (channels 22 and 34) hardly at all (weak
and intermittent
signal strength and quality).

Our building is a four storey one recently converted into four flats.
We're on the ground floor, and talking to our neighbours upstairs, they
have the same problems, but
haven't got round to doing anything...

I have a sneaking suspicion that the developer who converted the
building into flats
might have cut a few corners on the communal aerial system. There is an
aerial on the
roof pointing in the same direction as the others in the neighbourhood,
towards Crystal
Palace. The cable from that comes down to the top floor of the communal
staircase, where
it runs into a splitter, which is a proSPL409P as seen on this page:

http://www.blake-uk.com/prod_product...n_protaps.aspx

The cables then run off to the four flats, and presumably divide
somewhere in the wall
cavities for each flat, since there is an aerial socket in every living
room and bedroom
in the building.

None of us is aware of having any power supply feeding an amplifier -
reading up on the
internet I get the impression the whole system should have one
somewhere.

I'd like to eliminate as many possiblities as I can before we call in
an aerial
installer,and if we do, I'd like to be well-informed anyway :-)
What I would like to ask the knowledgeable people on this group is:

1. Do the symptoms we're experiencing sound as if they could be caused
by the signal
being split too many times?
2. Should there be a powered amplifier somewhere in our aerial system?
3. If there is one we don't know about, is there any danger of me
damaging anyone's TV
(or myself) messing around with the splitter?
4. Can I test whether the signal from the aerial is good enough in the
first place by
directly connecting the aerial downlead to the cable that serves our
flat and bypassing
the splitter entirely?
5. If there is no amplifier in the system but there should be, what
sort of box could we
replace the splitter with to do that job?

Thanks in advance for any wisdom you can share.

Mark Cookson

Communal aerial woes - advice welcome!

"Mark C" wrote in message
ups.com...
Please excuse me if any of what follows is obvious - it's been 10 years
since I last
lived somewhere with a TV, and back then we got away with a pair of
rabbits' ears...

Anyway, we just splashed out and bought a Toshiba TV with built-in
freeview, and the
results aren't too spectacular (we're in London N7). The analogue
reception is fairly
dire on all channels, and the digital reception was non-existent until
I bought a
booster box from Argos. With that cranked up full, we get Multiplexes
1, B and D
(channels 25, 28 and 29) from Crystal Palace perfectly, Multiplex A
(channel 32) pretty
well, and Multiplexes 2 and C (channels 22 and 34) hardly at all (weak
and intermittent
signal strength and quality).

Our building is a four storey one recently converted into four flats.
We're on the ground floor, and talking to our neighbours upstairs, they
have the same problems, but
haven't got round to doing anything...

I have a sneaking suspicion that the developer who converted the
building into flats
might have cut a few corners on the communal aerial system. There is an
aerial on the
roof pointing in the same direction as the others in the neighbourhood,
towards Crystal
Palace. The cable from that comes down to the top floor of the communal
staircase, where
it runs into a splitter, which is a proSPL409P as seen on this page:

http://www.blake-uk.com/prod_product...n_protaps.aspx

The cables then run off to the four flats, and presumably divide
somewhere in the wall
cavities for each flat, since there is an aerial socket in every living
room and bedroom
in the building.

None of us is aware of having any power supply feeding an amplifier -
reading up on the
internet I get the impression the whole system should have one
somewhere.

I'd like to eliminate as many possiblities as I can before we call in
an aerial
installer,and if we do, I'd like to be well-informed anyway :-)
What I would like to ask the knowledgeable people on this group is:

1. Do the symptoms we're experiencing sound as if they could be caused
by the signal
being split too many times?
2. Should there be a powered amplifier somewhere in our aerial system?
3. If there is one we don't know about, is there any danger of me
damaging anyone's TV
(or myself) messing around with the splitter?
4. Can I test whether the signal from the aerial is good enough in the
first place by
directly connecting the aerial downlead to the cable that serves our
flat and bypassing
the splitter entirely?
5. If there is no amplifier in the system but there should be, what
sort of box could we
replace the splitter with to do that job?

Thanks in advance for any wisdom you can share.

Mark Cookson

Doesn't sound too promising. I see quite a lot of these conversions and most
of the time the aerial systems are a total mess.

You'll probably find the cables from the splitter feed to one socket in the
flats, then are daisy chained to the next one.

For some unknown reason most builders / electricians seem to think this is
the way to do it.

You'll also probably find that the cable is pretty cheap and nasty too, so
not worth rescuing. Sorry for being such a doom monger but cost usually
triumphs in these conversions and the aerial systems get bodged quite badly.

I did one today.........the (incorrectly mounted contract) aerial was
pointing directly into a huge thick tree........causing about 40db
attenuation on 2 channels and severe ghosting on the others. After sorting
that out I traced the wiring to see how it was split to the three flats and
then I found out how............here's a picture of it
http://server3.uploadit.org/files/daviduk1000-box.JPG. The box is
plastic....

Anyway, to try and answer your questions.

1. Well it certainly sounds like you've got a crap signal yes.
2. Not always necessary, but for a communal system serving 4 flats you'd
normally expect to find one.
3. Only danger here is neighbours fury as you cut them off while testing
4. Can do.....you'd gain about 8db
5. You could try fitting a 4 way amp but you might overload it with signal.
Get a branded 4 way amp (Antiference / Triax / Labgear) with the usual 8db
gain and see if it helps.

Don't forget to speak to other residents and get them to agree first before
you go tinkering.

Communal aerial woes - advice welcome!

-GB-Carpy wrote:

then I found out how............here's a picture of it
http://server3.uploadit.org/files/daviduk1000-box.JPG. The box is
plastic....

I nominate that for any prize going, the way they've saved that extra
bit of choc block by only connecting the core of the coaxial, classic,
mouth still slightly open....

Communal aerial woes - advice welcome!

In article . com, Mark
C writes
Please excuse me if any of what follows is obvious - it's been 10 years
since I last
lived somewhere with a TV, and back then we got away with a pair of
rabbits' ears...

Anyway, we just splashed out and bought a Toshiba TV with built-in
freeview, and the
results aren't too spectacular (we're in London N7). The analogue
reception is fairly
dire on all channels, and the digital reception was non-existent until
I bought a
booster box from Argos. With that cranked up full, we get Multiplexes
1, B and D
(channels 25, 28 and 29) from Crystal Palace perfectly, Multiplex A
(channel 32) pretty
well, and Multiplexes 2 and C (channels 22 and 34) hardly at all (weak
and intermittent
signal strength and quality).

Our building is a four storey one recently converted into four flats.
We're on the ground floor, and talking to our neighbours upstairs, they
have the same problems, but
haven't got round to doing anything...

I have a sneaking suspicion that the developer who converted the
building into flats
might have cut a few corners on the communal aerial system. There is an
aerial on the
roof pointing in the same direction as the others in the neighbourhood,
towards Crystal
Palace. The cable from that comes down to the top floor of the communal
staircase, where
it runs into a splitter, which is a proSPL409P as seen on this page:

http://www.blake-uk.com/prod_product...n_protaps.aspx

The cables then run off to the four flats, and presumably divide
somewhere in the wall
cavities for each flat, since there is an aerial socket in every living
room and bedroom
in the building.

None of us is aware of having any power supply feeding an amplifier -
reading up on the
internet I get the impression the whole system should have one
somewhere.

I'd like to eliminate as many possiblities as I can before we call in
an aerial
installer,and if we do, I'd like to be well-informed anyway :-)
What I would like to ask the knowledgeable people on this group is:

1. Do the symptoms we're experiencing sound as if they could be caused
by the signal
being split too many times?

Yes..

2. Should there be a powered amplifier somewhere in our aerial system?

Yes

3. If there is one we don't know about, is there any danger of me
damaging anyone's TV
(or myself) messing around with the splitter?

No, but best to ask them first to see how they feel about it.

4. Can I test whether the signal from the aerial is good enough in the
first place by
directly connecting the aerial downlead to the cable that serves our
flat and bypassing
the splitter entirely?

Yes you could, but there might be other nasties like more splitters or
other bodges and choccy block connectors..

5. If there is no amplifier in the system but there should be, what
sort of box could we
replace the splitter with to do that job?

Plenty around but best bet is to see if you can get a diagram together
of the whole shooting match and post it somewhere for further comment..

I'd suggest you complain to whom you bought the flat from if its a new
development.. But you'd be well advised to speak to the other occupants
before doing anything else you'll get the blame.. and you might get
congratulated if you sort the problem.

If all the cables are taken to the main splitter or there is a cable
from each outlet to a central point and the right aerial is there then
this shouldn't be that difficult to sort out.....

Thanks in advance for any wisdom you can share.

Mark Cookson

--
Tony Sayer

Communal aerial woes - advice welcome!

"-GB-Carpy" wrote in message
. uk...

"Mark C" wrote in message
ups.com...
The cables then run off to the four flats, and presumably divide
somewhere in the wall
cavities for each flat, since there is an aerial socket in every living
room and bedroom
in the building.
Are you sure there isn't a small amplifier next to the main consumer unit or
in a cupboard or somewhere in each flat? Or a splitter in the same sort of
location?

Carpy:
Doesn't sound too promising. I see quite a lot of these conversions and
most of the time the aerial systems are a total mess.
Ditto ditto ditto

You'll probably find the cables from the splitter feed to one socket in
the flats, then are daisy chained to the next one.
Or see above for a more helpful possibility.

You'll also probably find that the cable is pretty cheap and nasty too, so
not worth rescuing. Sorry for being such a doom monger but cost usually
triumphs in these conversions and the aerial systems get bodged quite
badly.
It's a fact that you might have to start from scratch and do the cabling
externally.

I did one today.........the (incorrectly mounted contract) aerial was
pointing directly into a huge thick tree........causing about 40db
attenuation on 2 channels and severe ghosting on the others. After sorting
that out I traced the wiring to see how it was split to the three flats
and then I found out how............here's a picture of it
http://server3.uploadit.org/files/daviduk1000-box.JPG.
By gum that's a cracker. I've nicked it of course for my site.

To the OP:
1. Talk to the neighbours before you do anything.
2. Is there a managing agent?
3. You might have to compromise. It would be cheap and easy to replace the
first splitter with an amplifier, or to put a one-output amp in front of it.
Far from ideal but it might be the best you can do in the circumstances,
especially if the splitters in the flats are inaccessible.
4. The outlet plates should all be isolating types. It's unlikely that they
will be. I should earth bond the first splitter and the possible new amp as
well.

Bill

Communal aerial woes - advice welcome!

Thanks for all the useful suggestions. I think I'll try joining the
aerial downlead directly with the lead running to our flat (after
checking with the neighbours, of course...) That might give us some
idea of whether it's worth trying an amplifier near the aerial, or
whether we need to pay someone to venture on to the roof and have a
look at the aerial itself.
On the bright side, I unscrewed one of the aerial sockets, and they do
at least seem to have used CT100 cable, which I gather from this group
is A Good Thing :-)

Many thanks

Mark