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-   -   TV distribution around the house - again (http://www.homecinemabanter.com/showthread.php?t=65592)

Dave[_19_] January 25th 10 02:04 PM

TV distribution around the house - again
 
Couple of months ago we moved into this house and, against all the odds, we
actually like all the decor as it is and will not be looking to redecorate
anywhere for a good long while yet, so running new coax around the place is
a no-no for now.

Previous owners used (and left in place, so we now use) a 'behind-the-set'
aerial distribution amplifier that basically looks like a 13A plug with an
aerial input and two outputs. The current setup is a terrestrial aerial
feeds into our Sky+ box, RF1 is taken to an adjascent DVD recorder and on to
the TV, RF2 is taken to the input of the amp and then a single coax goes
around the house to feed an aerial socket in every room.

It seems to work alright except that it won't pass the signal for a Sky
"magic eye" thingy, meaning that we have to go downstairs to change the Sky
channel. Anyone recommend a replacement that will allow us to use a magic
eye and second remote upstairs?

Thanks



[email protected] January 25th 10 02:52 PM

TV distribution around the house - again
 
On Jan 25, 1:04*pm, "Dave" wrote:
Couple of months ago we moved into this house and, against all the odds, we
actually like all the decor as it is and will not be looking to redecorate
anywhere for a good long while yet, so running new coax around the place is
a no-no for now.

Previous owners used (and left in place, so we now use) a 'behind-the-set'
aerial distribution amplifier that basically looks like a 13A plug with an
aerial input and two outputs. The current setup is a terrestrial aerial
feeds into our Sky+ box, RF1 is taken to an adjascent DVD recorder and on to
the TV, RF2 is taken to the input of the amp and then a single coax goes
around the house to feed an aerial socket in every room.

It seems to work alright except that it won't pass the signal for a Sky
"magic eye" thingy, meaning that we have to go downstairs to change the Sky
channel. Anyone recommend a replacement that will allow us to use a magic
eye and second remote upstairs?

Thanks


It would be interesting -- nay essential -- to know how the one cable
going 'all round the house' is connected to all the rooms.

Bill

Ivan[_2_] January 25th 10 03:14 PM

TV distribution around the house - again
 


" wrote in message
...
On Jan 25, 1:04 pm, "Dave" wrote:
Couple of months ago we moved into this house and, against all the odds,
we
actually like all the decor as it is and will not be looking to
redecorate
anywhere for a good long while yet, so running new coax around the place
is
a no-no for now.

Previous owners used (and left in place, so we now use) a
'behind-the-set'
aerial distribution amplifier that basically looks like a 13A plug with
an
aerial input and two outputs. The current setup is a terrestrial aerial
feeds into our Sky+ box, RF1 is taken to an adjascent DVD recorder and on
to
the TV, RF2 is taken to the input of the amp and then a single coax goes
around the house to feed an aerial socket in every room.

It seems to work alright except that it won't pass the signal for a Sky
"magic eye" thingy, meaning that we have to go downstairs to change the
Sky
channel. Anyone recommend a replacement that will allow us to use a magic
eye and second remote upstairs?

Thanks


It would be interesting -- nay essential -- to know how the one cable
going 'all round the house' is connected to all the rooms.



The old ring main technique, much used by electricians and would be aerial
system installers!





Dave[_19_] January 25th 10 03:29 PM

TV distribution around the house - again
 
wrote:
On Jan 25, 1:04 pm, "Dave" wrote:
Couple of months ago we moved into this house and, against all the
odds, we actually like all the decor as it is and will not be
looking to redecorate anywhere for a good long while yet, so running
new coax around the place is a no-no for now.

Previous owners used (and left in place, so we now use) a
'behind-the-set' aerial distribution amplifier that basically looks
like a 13A plug with an aerial input and two outputs. The current
setup is a terrestrial aerial feeds into our Sky+ box, RF1 is taken
to an adjascent DVD recorder and on to the TV, RF2 is taken to the
input of the amp and then a single coax goes around the house to
feed an aerial socket in every room.

It seems to work alright except that it won't pass the signal for a
Sky "magic eye" thingy, meaning that we have to go downstairs to
change the Sky channel. Anyone recommend a replacement that will
allow us to use a magic eye and second remote upstairs?

Thanks


It would be interesting -- nay essential -- to know how the one cable
going 'all round the house' is connected to all the rooms.

Bill


Hi Bill and thanks for your interest. A quick furtle about with a
screwdriver and continuity tester shows me that a coax leaves the
distribution amp, goes out through the wall and up, to re-enter the house
under the floorboards in the front bedroom and then goes to a flush mounted
socket on the far wall. A second piece of coax leaves from that socket and
goes into the back bedroom socket, and from there a third piece of coax
dives down into the kitchen etc., etc.

All in all, there's seven TV aerial sockets around the house that seem to be
wired in a radial fashion, ie, from one to another, to another, to another,
ending at the seventh. We've got three TVs (lounge, kitchen and bedroom) and
two DVD/HDD recorders (lounge and bedroom).

Hope that helps, and thanks again.

Dave



Bob Lucas January 25th 10 07:18 PM

TV distribution around the house - again
 
I don't intend to comment upon the suitability of your RF
distribution system, except to say that you should be using an
aerial distribution amplifier with multiple outlets, to provide a
separate feed to every RF socket in the house.

If you connect multiple RF sockets to a single output from the
amplifier, you will dilute the signal that each TV receives.
That will affect picture quality. Furthermore, TV-Link magic
eyes are temperamental, and require a good and unbroken
connection, all the way back to the satellite receiver. I doubt
whether a "shared" RF cable would meet the criteria.

Having made those points, the TV-Link magic eye will not work
until you turn on the RF Outlet Power Supply to RF2 of your Sky
receiver (unless you are using a new-type distribution amplifier
with its own power supply). You will find full instructions with
the TV Link magic eye. Have you enabled the Power Supply on your
Sky receiver?

Then, there are two other things that will almost certainly
prevent the output voltage from reaching the TV Link magic eye -
and can block the return signal to your Sky receiver.

1. Your existing RF amplifier / distributor. You must either
replace that amplifier with a different model that is compatible
with TV Link - or purchase and fit a "bypass kit", which fits on
each side of the amplifier (such as the one at
www.tvlink.co.uk/bypass.htm).

2. If the aerial face-plates in your other rooms have separate
VHF/UHF sockets that are fed from a single RF lead, then they
will probably be incompatible with TV Link. Remove each one and
check for electronic components behind the face-plate. If you
see resistors or capacitors, then the socket will almost
certainly obstruct the output voltage from the Sky receiver (and
the red neon indicator on the TV Link will not come on). One
solution is to replace those sockets that you intend to use with
a magic eye. You could use basic sockets (with no electronic
components) or a compatible type, such as the one at
www.tvlink.co.uk/wallplate.htm.



"Dave" wrote in message
...
Couple of months ago we moved into this house and, against all
the odds, we actually like all the decor as it is and will not
be looking to redecorate anywhere for a good long while yet, so
running new coax around the place is a no-no for now.

Previous owners used (and left in place, so we now use) a
'behind-the-set' aerial distribution amplifier that basically
looks like a 13A plug with an aerial input and two outputs. The
current setup is a terrestrial aerial feeds into our Sky+ box,
RF1 is taken to an adjascent DVD recorder and on to the TV, RF2
is taken to the input of the amp and then a single coax goes
around the house to feed an aerial socket in every room.

It seems to work alright except that it won't pass the signal
for a Sky "magic eye" thingy, meaning that we have to go
downstairs to change the Sky channel. Anyone recommend a
replacement that will allow us to use a magic eye and second
remote upstairs?

Thanks


[email protected] January 25th 10 07:51 PM

TV distribution around the house - again
 
On Jan 25, 2:29*pm, "Dave" wrote:
wrote:
Hi Bill and thanks for your interest. A quick furtle about with a
screwdriver and continuity tester shows me that a coax leaves the
distribution amp, goes out through the wall and up, to re-enter the house
under the floorboards in the front bedroom and then goes to a flush mounted
socket on the far wall. A second piece of coax leaves from that socket and
goes into the back bedroom socket, and from there a third piece of coax
dives down into the kitchen etc., etc.

All in all, there's seven TV aerial sockets around the house that seem to be
wired in a radial fashion, ie, from one to another, to another, to another,
ending at the seventh. We've got three TVs (lounge, kitchen and bedroom) and
two DVD/HDD recorders (lounge and bedroom).

Hope that helps, and thanks again.


This isn't radial, it's 'daisy-chain'. Just a semantic point! The
arrangement is so far away from any correct way of doing it that I
can't really advise you. It's very surprising if it works from the
point of view of decent picture quality, and there are lots of
possible reasons why a Sky remote eye wouldn't work -- too numerous
for me to list. If you called any decent installer out to this he
would say that the only thing to do would be to start again and run
separate cables from each TV outlet to a common point. At that point
an amplifier with 'remote eye passthough' would be fitted.

Others will no doubt suggest a various measures which might the remote
eyes work, but the thing will always be unreliable and unpredictable,
so personally if I were you I wouldn't waste my time -- I'd start from
scratch and install a proper system.

Bill

Graham.[_2_] January 25th 10 08:03 PM

TV distribution around the house - again
 


"Ivan" wrote in message om...


" wrote in message
...
On Jan 25, 1:04 pm, "Dave" wrote:
Couple of months ago we moved into this house and, against all the odds, we
actually like all the decor as it is and will not be looking to redecorate
anywhere for a good long while yet, so running new coax around the place is
a no-no for now.

Previous owners used (and left in place, so we now use) a 'behind-the-set'
aerial distribution amplifier that basically looks like a 13A plug with an
aerial input and two outputs. The current setup is a terrestrial aerial
feeds into our Sky+ box, RF1 is taken to an adjascent DVD recorder and on to
the TV, RF2 is taken to the input of the amp and then a single coax goes
around the house to feed an aerial socket in every room.

It seems to work alright except that it won't pass the signal for a Sky
"magic eye" thingy, meaning that we have to go downstairs to change the Sky
channel. Anyone recommend a replacement that will allow us to use a magic
eye and second remote upstairs?

Thanks


It would be interesting -- nay essential -- to know how the one cable
going 'all round the house' is connected to all the rooms.



The old ring main technique, much used by electricians and would be aerial system installers!


Don't forget there is (or was) a legitimate version of this technique using faceplates
with built in attenuated tap-offs.

Don't forget to wire a 75R resistor across the last one.

--
Graham.

%Profound_observation%



Dave[_19_] January 25th 10 08:22 PM

TV distribution around the house - again
 
wrote:
On Jan 25, 2:29 pm, "Dave" wrote:
wrote:
Hi Bill and thanks for your interest. A quick furtle about with a
screwdriver and continuity tester shows me that a coax leaves the
distribution amp, goes out through the wall and up, to re-enter the
house under the floorboards in the front bedroom and then goes to a
flush mounted socket on the far wall. A second piece of coax leaves
from that socket and goes into the back bedroom socket, and from
there a third piece of coax dives down into the kitchen etc., etc.

All in all, there's seven TV aerial sockets around the house that
seem to be wired in a radial fashion, ie, from one to another, to
another, to another, ending at the seventh. We've got three TVs
(lounge, kitchen and bedroom) and two DVD/HDD recorders (lounge and
bedroom).

Hope that helps, and thanks again.


This isn't radial, it's 'daisy-chain'. Just a semantic point! The
arrangement is so far away from any correct way of doing it that I
can't really advise you. It's very surprising if it works from the
point of view of decent picture quality, and there are lots of
possible reasons why a Sky remote eye wouldn't work -- too numerous
for me to list. If you called any decent installer out to this he
would say that the only thing to do would be to start again and run
separate cables from each TV outlet to a common point. At that point
an amplifier with 'remote eye passthough' would be fitted.

Others will no doubt suggest a various measures which might the remote
eyes work, but the thing will always be unreliable and unpredictable,
so personally if I were you I wouldn't waste my time -- I'd start from
scratch and install a proper system.


Thanks for that Bill. Unfortunately (as far as this is concerned anyway)
it's going to be at least a couple of years before any redecorating needs to
be done, so no chance of taking a hammer and chisel to anything yet.
Picture-quality-wise, worst case scenario is/was two TVs on and the two
DVD/HDD recorders actually recording - and everything seems to be fine, no
problems at all. Maybe it shouldn't work, but it is - except for the sky
remote eye :-)

Cheers anyway mate.



Dave[_19_] January 25th 10 08:40 PM

TV distribution around the house - again
 
Bob Lucas wrote:
I don't intend to comment upon the suitability of your RF
distribution system, except to say that you should be using an
aerial distribution amplifier with multiple outlets, to provide a
separate feed to every RF socket in the house.


That's what I'll eventually do Bob but as I said, the decor is actually
really good and to our taste so it'll be at least a couple of years (if not
longer) before I can start running new coax everywhere.

If you connect multiple RF sockets to a single output from the
amplifier, you will dilute the signal that each TV receives.
That will affect picture quality.


We've had two TVs on and the two DVD/HDD recorders actually recording, all
at the same time, and see no change in picture quality from just a single TV
on its own. We're honestly happy with it all apart from having to go
downstairs to change the Sky channel. The distribution amp is, according to
the previous owners of the house, about 10 or 12 years old and is not marked
as "suitable for use with Sky remote eyes", which I believe some modern ones
are.

Furthermore, TV-Link magic
eyes are temperamental, and require a good and unbroken
connection, all the way back to the satellite receiver. I doubt
whether a "shared" RF cable would meet the criteria.


You may well be right there Bob but, if a suitable new amp can be had for
about, say, 20 quid, I'd have a punt on it.

Having made those points, the TV-Link magic eye will not work
until you turn on the RF Outlet Power Supply to RF2 of your Sky
receiver (unless you are using a new-type distribution amplifier
with its own power supply). You will find full instructions with
the TV Link magic eye. Have you enabled the Power Supply on your
Sky receiver?


Yes

Then, there are two other things that will almost certainly
prevent the output voltage from reaching the TV Link magic eye -
and can block the return signal to your Sky receiver.

1. Your existing RF amplifier / distributor. You must either
replace that amplifier with a different model that is compatible
with TV Link


Which is why I was asking for recommendations. I'm willing to throw about 20
quid at it as an experiment

- or purchase and fit a "bypass kit", which fits on
each side of the amplifier (such as the one at
www.tvlink.co.uk/bypass.htm).


Ah, that may well be worth a go :-)

2. If the aerial face-plates in your other rooms have separate
VHF/UHF sockets


No, they're just a single faceplate with a single coax socket

that are fed from a single RF lead, then they
will probably be incompatible with TV Link. Remove each one and
check for electronic components behind the face-plate.


No caps/resistors or components of any kind on any of them.

If you
see resistors or capacitors, then the socket will almost
certainly obstruct the output voltage from the Sky receiver (and
the red neon indicator on the TV Link will not come on). One
solution is to replace those sockets that you intend to use with
a magic eye. You could use basic sockets (with no electronic
components) or a compatible type, such as the one at
www.tvlink.co.uk/wallplate.htm.


Thanks for your reply Bob.

"Dave" wrote in message
...
Couple of months ago we moved into this house and, against all
the odds, we actually like all the decor as it is and will not
be looking to redecorate anywhere for a good long while yet, so
running new coax around the place is a no-no for now.

Previous owners used (and left in place, so we now use) a
'behind-the-set' aerial distribution amplifier that basically
looks like a 13A plug with an aerial input and two outputs. The
current setup is a terrestrial aerial feeds into our Sky+ box,
RF1 is taken to an adjascent DVD recorder and on to the TV, RF2
is taken to the input of the amp and then a single coax goes
around the house to feed an aerial socket in every room.

It seems to work alright except that it won't pass the signal
for a Sky "magic eye" thingy, meaning that we have to go
downstairs to change the Sky channel. Anyone recommend a
replacement that will allow us to use a magic eye and second
remote upstairs?

Thanks




Ivan[_2_] January 25th 10 08:51 PM

TV distribution around the house - again
 


"Dave" wrote in message
...
Bob Lucas wrote:
I don't intend to comment upon the suitability of your RF
distribution system, except to say that you should be using an
aerial distribution amplifier with multiple outlets, to provide a
separate feed to every RF socket in the house.


That's what I'll eventually do Bob but as I said, the decor is actually
really good and to our taste so it'll be at least a couple of years (if
not longer) before I can start running new coax everywhere.

If you connect multiple RF sockets to a single output from the
amplifier, you will dilute the signal that each TV receives.
That will affect picture quality.


We've had two TVs on and the two DVD/HDD recorders actually recording, all
at the same time, and see no change in picture quality from just a single
TV on its own. We're honestly happy with it all apart from having to go
downstairs to change the Sky channel. The distribution amp is, according
to the previous owners of the house, about 10 or 12 years old and is not
marked as "suitable for use with Sky remote eyes", which I believe some
modern ones are.

Furthermore, TV-Link magic
eyes are temperamental, and require a good and unbroken
connection, all the way back to the satellite receiver. I doubt
whether a "shared" RF cable would meet the criteria.


You may well be right there Bob but, if a suitable new amp can be had for
about, say, 20 quid, I'd have a punt on it.

Having made those points, the TV-Link magic eye will not work
until you turn on the RF Outlet Power Supply to RF2 of your Sky
receiver (unless you are using a new-type distribution amplifier
with its own power supply). You will find full instructions with
the TV Link magic eye. Have you enabled the Power Supply on your
Sky receiver?


Yes

Then, there are two other things that will almost certainly
prevent the output voltage from reaching the TV Link magic eye -
and can block the return signal to your Sky receiver.

1. Your existing RF amplifier / distributor. You must either
replace that amplifier with a different model that is compatible
with TV Link


Which is why I was asking for recommendations. I'm willing to throw about
20 quid at it as an experiment

- or purchase and fit a "bypass kit", which fits on
each side of the amplifier (such as the one at
www.tvlink.co.uk/bypass.htm).


Ah, that may well be worth a go :-)

2. If the aerial face-plates in your other rooms have separate
VHF/UHF sockets


No, they're just a single faceplate with a single coax socket

that are fed from a single RF lead, then they
will probably be incompatible with TV Link. Remove each one and
check for electronic components behind the face-plate.


No caps/resistors or components of any kind on any of them.

If you
see resistors or capacitors, then the socket will almost
certainly obstruct the output voltage from the Sky receiver (and
the red neon indicator on the TV Link will not come on). One
solution is to replace those sockets that you intend to use with
a magic eye. You could use basic sockets (with no electronic
components) or a compatible type, such as the one at
www.tvlink.co.uk/wallplate.htm.


Thanks for your reply Bob.

"Dave" wrote in message
...
Couple of months ago we moved into this house and, against all
the odds, we actually like all the decor as it is and will not
be looking to redecorate anywhere for a good long while yet, so
running new coax around the place is a no-no for now.

Previous owners used (and left in place, so we now use) a
'behind-the-set' aerial distribution amplifier that basically
looks like a 13A plug with an aerial input and two outputs. The
current setup is a terrestrial aerial feeds into our Sky+ box,
RF1 is taken to an adjascent DVD recorder and on to the TV, RF2
is taken to the input of the amp and then a single coax goes
around the house to feed an aerial socket in every room.

It seems to work alright except that it won't pass the signal
for a Sky "magic eye" thingy, meaning that we have to go
downstairs to change the Sky channel. Anyone recommend a
replacement that will allow us to use a magic eye and second
remote upstairs?


You obviously know what you're doing, but it's maybe worth a mention, you
have got the power to RF2 switched on in the engineers menu have you? an
easy way to check is to plug the eye into the RF 2 outlet and the led should
illuminate, if it does then maybe you can try it in wall outlet 1,2,3 etc
and figure out where the break is.






Ian Jackson[_2_] January 25th 10 09:11 PM

TV distribution around the house - again
 
In message , Graham.
writes


"Ivan" wrote in message
. com...


" wrote in message
...
On Jan 25, 1:04 pm, "Dave" wrote:
Couple of months ago we moved into this house and, against all the odds, we
actually like all the decor as it is and will not be looking to redecorate
anywhere for a good long while yet, so running new coax around the place is
a no-no for now.

Previous owners used (and left in place, so we now use) a 'behind-the-set'
aerial distribution amplifier that basically looks like a 13A plug with an
aerial input and two outputs. The current setup is a terrestrial aerial
feeds into our Sky+ box, RF1 is taken to an adjascent DVD recorder
and on to
the TV, RF2 is taken to the input of the amp and then a single coax goes
around the house to feed an aerial socket in every room.

It seems to work alright except that it won't pass the signal for a Sky
"magic eye" thingy, meaning that we have to go downstairs to change the Sky
channel. Anyone recommend a replacement that will allow us to use a magic
eye and second remote upstairs?

Thanks

It would be interesting -- nay essential -- to know how the one cable
going 'all round the house' is connected to all the rooms.



The old ring main technique, much used by electricians and would be
aerial system installers!


Don't forget there is (or was) a legitimate version of this technique
using faceplates
with built in attenuated tap-offs.

Don't forget to wire a 75R resistor across the last one.

That certainly was one way of doing it. Each faceplate contained a
directional coupler, with the 'tap' port of the coupler feeding the
faceplate TV socket, and the 'out' port connected to the ongoing cable.
[In some, the tap was diplexed to provide separate TV and FM outputs.]
However, this was really only a 'specialised version' of the traditional
'old way' of distributing TV via a string of cascaded tap units.

Even though it appears to work OK (for the TV signals), it might be
fairly easy (and less hassle) to 'sanitize' the existing system by doing
something similar. The existing cable could be retained, but connected
to a string of single, separate in-line taps (under the floorboards),
located at (or close to) the first six of the aerial sockets.

Three taps with values of (say) 16dB followed by three more of 10dB
might do the job. [The different values are suggested simply to help to
equalise the signal levels at the TV sockets.] The 'tap port' of each
would be connected to the existing wallplate TV socket. The 'out port'
would be connected to the ongoing cable. To provide a permanent (and
adequate) RF termination on the end of the cable, the last TV socket
would be connected to the cable via a 10dB attenuator. [Or via another
10dB tap, with its out port terminated.]

Obviously, in addition to the existing losses in the cable, there would
also be an additional (non-cumulative) loss of 10 or 16dB at the tap,
and there would also be the cumulative insertion loss of each tap (say
1dB for a 16dB and 1.5dB for a 10dB). The distribution amplifier would
have to have enough gain in hand to make up for these extra losses. The
amplifier would have to be of the type designed to pass the magic eye
signal (reverse direction). [This could be the problem with the existing
one] Note that the remote eye signal would suffer a 10 or 16dB loss back
through the tap. [I don't know what is permissible reverse loss is with
the Sky equipment.]
--
Ian

Brian Gaff January 25th 10 09:36 PM

TV distribution around the house - again
 
Maybe you have moved to under the transmitter mast? On the other hand it may
well work if the amp in the lounge is giving a very big output and the
serious mismatches and loading are just about coped with. I guess you would
need a pass through amp instead of the one in the lounge, but the chances of
finding one that will perform the current miracle are quite remote... pun
intended.

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!
"Dave" wrote in message
...
wrote:
On Jan 25, 2:29 pm, "Dave" wrote:
wrote:
Hi Bill and thanks for your interest. A quick furtle about with a
screwdriver and continuity tester shows me that a coax leaves the
distribution amp, goes out through the wall and up, to re-enter the
house under the floorboards in the front bedroom and then goes to a
flush mounted socket on the far wall. A second piece of coax leaves
from that socket and goes into the back bedroom socket, and from
there a third piece of coax dives down into the kitchen etc., etc.

All in all, there's seven TV aerial sockets around the house that
seem to be wired in a radial fashion, ie, from one to another, to
another, to another, ending at the seventh. We've got three TVs
(lounge, kitchen and bedroom) and two DVD/HDD recorders (lounge and
bedroom).

Hope that helps, and thanks again.


This isn't radial, it's 'daisy-chain'. Just a semantic point! The
arrangement is so far away from any correct way of doing it that I
can't really advise you. It's very surprising if it works from the
point of view of decent picture quality, and there are lots of
possible reasons why a Sky remote eye wouldn't work -- too numerous
for me to list. If you called any decent installer out to this he
would say that the only thing to do would be to start again and run
separate cables from each TV outlet to a common point. At that point
an amplifier with 'remote eye passthough' would be fitted.

Others will no doubt suggest a various measures which might the remote
eyes work, but the thing will always be unreliable and unpredictable,
so personally if I were you I wouldn't waste my time -- I'd start from
scratch and install a proper system.


Thanks for that Bill. Unfortunately (as far as this is concerned anyway)
it's going to be at least a couple of years before any redecorating needs
to be done, so no chance of taking a hammer and chisel to anything yet.
Picture-quality-wise, worst case scenario is/was two TVs on and the two
DVD/HDD recorders actually recording - and everything seems to be fine, no
problems at all. Maybe it shouldn't work, but it is - except for the sky
remote eye :-)

Cheers anyway mate.




widgitt January 26th 10 01:47 AM

TV distribution around the house - again
 
I suppose if it works, I can't argue....but daisy chaining of sockets
is usually a total desaster and the first thing to do, as everyone
says, is to pull it all out and do it properly, a seperate feed from
the amp for each socket.
However...if the pictures are ok, it is unlikely that a bipass amp
made for magic eye use will work. It would be much easier and cheaper
to use a "Radio Remote" sender to operate the Sky box from other rooms
if they are not too far away. No connections, just a sender and a
receiver. (Not a video sender, just a remote sender)

http://cpc.farnell.com/remote-control-extenders



There are two small blocks of flats nearby, about 12 each block. There
is a master aerial for each block and the electricians saw fit to run
one cable to each flat from the loft amp and then chain onto three
more sockets in each flat. The whole thing has been a desaster from
the time they were built and the developer refused to take any
responsibility for the first couple of years until the residents had
called in various aerial installers and each one had passed the same
judgement.
I wrote a detailed report and quoted for the job of correction but it
was not accepted. Eventually somebody shouted loud enough and
something was done.....
The next time I was called privately by a resident to sort out their
TV, which had virtually no channel 4, I was able to investigate:

The firm "correcting" the situation had drilled a hole in each
faceplate and managed (just) to pull enough of the outgoing cable from
each socket through the hole and then to plug in a cheap "Y" splitter,
one output for the set in that room and one for the ongoing cable. The
last socket in the chain had 3 splitters before it so you can guess
how well it worked !

Further complaints went from the residents to the landlords but with
no effect so eventually my customer, who was on the top floor with
their own loft, got us to fit a loft aerial, a remotely powered amp
and a drop to each room which was easy due to convenient fitted
cupboards. Problem solved but I suspect other residents struggle on. A
couple of satellite dishes have appeared.

[email protected] January 26th 10 02:00 AM

TV distribution around the house - again
 
On Jan 25, 7:03*pm, "Graham." wrote:
"Ivan" wrote in media.com...

" wrote in message
....
On Jan 25, 1:04 pm, "Dave" wrote:
Couple of months ago we moved into this house and, against all the odds, we
actually like all the decor as it is and will not be looking to redecorate
anywhere for a good long while yet, so running new coax around the place is
a no-no for now.


Previous owners used (and left in place, so we now use) a 'behind-the-set'
aerial distribution amplifier that basically looks like a 13A plug with an
aerial input and two outputs. The current setup is a terrestrial aerial
feeds into our Sky+ box, RF1 is taken to an adjascent DVD recorder and on to
the TV, RF2 is taken to the input of the amp and then a single coax goes
around the house to feed an aerial socket in every room.


It seems to work alright except that it won't pass the signal for a Sky
"magic eye" thingy, meaning that we have to go downstairs to change the Sky
channel. Anyone recommend a replacement that will allow us to use a magic
eye and second remote upstairs?


Thanks


It would be interesting -- nay essential -- to know how the one cable
going 'all round the house' is connected to all the rooms.


The old ring main technique, much used by electricians and would be aerial system installers!


Don't forget there is (or was) a legitimate version of this technique using faceplates
with built in attenuated tap-offs.

Yes and it was crap. Believe it or not we still maintain such a
system. The skinflints there won't pay for a proper upgrade. It costs
them a fortune in call-outs though. Every time a new resident moves in
the first thing he does is remove the wallplate and fit a brass one,
leaving the outgoing cable disconnected.


Don't forget to wire a 75R resistor across the last one.

The last one is normally a 12dB tap and the termination is built in.
But yes, any value can terminate the line.

Bill

[email protected] January 26th 10 02:08 AM

TV distribution around the house - again
 
On Jan 25, 7:22*pm, "Dave" wrote:
wrote:
On Jan 25, 2:29 pm, "Dave" wrote:
wrote:
Hi Bill and thanks for your interest. A quick furtle about with a
screwdriver and continuity tester shows me that a coax leaves the
distribution amp, goes out through the wall and up, to re-enter the
house under the floorboards in the front bedroom and then goes to a
flush mounted socket on the far wall. A second piece of coax leaves
from that socket and goes into the back bedroom socket, and from
there a third piece of coax dives down into the kitchen etc., etc.


All in all, there's seven TV aerial sockets around the house that
seem to be wired in a radial fashion, ie, from one to another, to
another, to another, ending at the seventh. We've got three TVs
(lounge, kitchen and bedroom) and two DVD/HDD recorders (lounge and
bedroom).


Hope that helps, and thanks again.


This isn't radial, it's 'daisy-chain'. Just a semantic point! The
arrangement is so far away from any correct way of doing it that I
can't really advise you. It's very surprising if it works from the
point of view of decent picture quality, and there are lots of
possible reasons why a Sky remote eye wouldn't work -- too numerous
for me to list. If you called any decent installer out to this he
would say that the only thing to do would be to start again and run
separate cables from each TV outlet to a common point. At that point
an amplifier with 'remote eye passthough' would be fitted.


Others will no doubt suggest a various measures which might the remote
eyes work, but the thing will always be unreliable and unpredictable,
so personally if I were you I wouldn't waste my time -- I'd start from
scratch and install a proper system.


Thanks for that Bill. Unfortunately (as far as this is concerned anyway)
it's going to be at least a couple of years before any redecorating needs to
be done, so no chance of taking a hammer and chisel to anything yet.
Picture-quality-wise, worst case scenario is/was two TVs on and the two
DVD/HDD recorders actually recording - and everything seems to be fine, no
problems at all. Maybe it shouldn't work, but it is - except for the sky
remote eye *:-)

Cheers anyway mate.-


Sorry to be a bore, but the fact is, if you put 9V on the daisy chain
to power the remote eye it will appear across all the outlets, and
there's a good chance a telly or something will short it out. The
phenonomal amount of mismatch will make it unlikely that the remote
eye return signal will get back to the Sky box. The whole thing will
be inherently unreliable.

Bill

Bill

[email protected] January 26th 10 02:15 AM

TV distribution around the house - again
 
On Jan 26, 12:47*am, widgitt wrote:
There are two small blocks of flats nearby, about 12 each block. There
is a master aerial for each block and the electricians saw fit to run
one cable to each flat from the loft amp and then chain onto three
more sockets in each flat. The whole thing has been a desaster from
the time they were built and the developer refused to take any
responsibility for the first couple of years until the residents had
called in various aerial installers and each one had passed the same
judgement.


I recently had cause to write the following email:

Hello xxxxx,

I’ve done my best with this, and the residents I dealt with are happy,
but there are problems that couldn’t be fixed today.

1. In the flats I visited the installers have connected the cable from
the head-end to the bedrooms only. The only TV cable running to the
living room is an extension from the bedroom. This makes it difficult/
impossible to get everything working in both rooms. Botched attempts
had been made to feed signals to both rooms from one cable. I guess
the same thing has been done in some or all of the other flats.
2. The cable used is not TV cable; it is CCTV cable. This cable is not
suitable for terrestrial TV and is very unsuitable for satellite use.
The cable loses a very large proportion of the signal. This makes it
very difficult to provide adequate signal levels in the flats, and
exacerbates the problems caused by the fact that the only cable from
the head end goes to the bedroom instead of the living room. It isn’t
even good quality CCTV cable; really weird stuff that won’t strip
properly.
3. The (cheap and nasty) aerial is tied to a pipe and I cannot make it
secure. The aerial can move in the wind because the pipe twists round.
4. In an attempt to compensate for the cable being the wrong type the
head end signal levels are excessively high, causing some distortion.
5. Because the local relay transmitter is close signals arrive at the
TV sets without passing though the TV system. Since the signals from
the system are weak these ‘direct’ signals cause interference.

There isn’t much that can be done about (1) and (2) except respond to
any individual complaints and just try in each case to find a solution
that works well enough for the resident to accept. It will be a fudge
every time, but there’s not much else we can do.

Regarding the aerial, if this was closer to home I would automatically
go back with a ground stand (etc) and put a new aerial up on the high
flat roof. Not a cheap job and at this distance the cost would be even
higher, so I’ll do nothing until and unless instructed by you.

Incidentally, this system uses the local relay transmitter. At digital
switchover this relay will replace the analogue signals with digital
ones, using three of the same channels. Therefore no alterations to
the system will be necessary as a direct consequence of digital
switchover.

Attached are a few pictures for your delectation and delight.

Bill

[email protected] January 26th 10 02:34 AM

TV distribution around the house - again
 
On Jan 26, 12:47*am, widgitt wrote:
The firm "correcting" the situation had drilled a hole in each
faceplate and managed (just) to pull enough of the outgoing cable from
each socket through the hole and then to plug in a cheap "Y" splitter,
one output for the set in that room and one for the ongoing cable. The
last socket in the chain had 3 splitters before it so you can guess
how well it worked !


In 2005 I was called to an 11 storey block that had four flats on each
floor (except the ground floor which had three). I was met by the
caretaker who was an old man (about my age). He explained that the TV
reception problems had been gradually getting worse for many years,
and were now particularly acute on the lower floors. He told me with
some pride that he had 'kept the aerial working' by responding to
individual complaints. In most cases he had found that the replacement
of the wallplate brought about a big improvement. However, he warned
me, it was important to connect both cables to the new wallplate or
people in the flats below lost their reception. For twenty years he
had been gradually removing the padded outlets and replacing them with
ones from the local DIY shop. These were non-isolated and non-padded.
The lower floors had very poor reception indeed. I spoke to the
chairman of the residents' association over a cuppa and explained that
a proper job would involve running new cables externally. But a quick
fix was needed, because a new system wasn't going to happen overnight.
OK, well if a botch is justifed I can be a super botcher! I went into
every flat on Level 8 and fitted an amp with 30dB gain and high output
capability, between the incoming and outgoing cables. The amps were
just loose on the floor in corner of the room. I then gave the
caretaker a bag of 12dB attenuators and brief instructions as to how
to respond to complaints. This works embarrassingly well, and it was
hard to get the residents' assn to understand that further repairs
were necessary. In the end a new system went in, but without Sky+,
which they couldn't 'see the point of'.

Bill

[email protected] January 26th 10 07:54 PM

TV distribution around the house - again
 
On Jan 26, 1:21*pm, Paul Martin wrote:
In article ,
* * * * wrote:

Don't forget to wire a 75R resistor across the last one.

The last one is normally a 12dB tap and the termination is built in.
But yes, any value can terminate the line.


Being pedantic: how about 0R or 10M?

--
Paul Martin


Sorry, what I wrote was ambiguous. No, I'll come clean. It was
downright misleading. By' terminate the line' I meant 'be the last tap
on the line'. The impedence matching terminator would normally be 75
ohm, but of course in theory for a very low value tap it should be a
slightly higher value. Actually, these padded outlet lines are a total
mess in terms of matching. Not so bad if the linking cables are long
because (since the cable used was often a lossy type) the reflections
'got lost' to some extent. But a system with CT125 links and only 3m
between outlets (a drop down a stack of flats) can be just a nightmare
really.

Bill

widgitt January 27th 10 02:22 AM

TV distribution around the house - again
 
Another interesting set-up in our area is the set of newly converted
barns. About 6 of them. Nice buildings, split level and 4 or 5
bedrooms each and about 8 aerial sockets per house.
One of my existing customers bought one and called me when they moved
in, to set up the tvs etc.
I got very poor results so I assumed, as usual for a new house, that
there was no aerial. However the owner told me that the builder had
stated that there was an aerial and distribution provided..he knew as
he had done that part himself ! I was now suspicious. I checked a few
of the other sockets and the signals were different in each room, some
channels high and some low but overall very poor.
I decided to check the aerial first and, having discovered three
diferent lofts, I found it eventually in one of them. A perfectly good
Antiference XG lying on the floor.
I couldnt see the rest of the set-up as the cable disappeared through
a wall.
Obviously the first thing was to see if it was able to work in the
loft and then set it up correctly.
I mounted it high up and aligned it with the analyser and the signal
was very good and well balanced across the channels (just analogue at
the time).
Downstairs it was another matter entirely. The signals still varied
widely from room to room and channel to channel although they were
overall a bit better.
Back to the loft I traced the cable to the next roofspace. It went to
a masthead amp then a power supply about 6 inches away and then to a
two way set-back amplifier. Two cheap cables came from it and
disappeared into the rest of the house.
To cut an even longer story short, the builder had wired the whole
thing as a ring circuit. Starting at the amp, running round the house
to each of about 8 sockets and back to the amp !

The customer phoned the builder there and then, had a rather forceful
conversation with him, and handed the phone to me to explain. I would
rather have written a report, to be honest, but it was too late for
that. I explained exactly what was wrong and received a torrent of
abuse for not knowing what I was talking about and was told that he
had wired all of the houses he had built in the same way. It was
perfectly good and there had never been any problems!

The whole story carried on for some time as different people moved
into their new houses and found poor results.. After a lot of fuss the
builder agreed to get us to correct things as well as we could and he
paid up but the systems are still a problem.


[email protected] January 27th 10 02:56 AM

TV distribution around the house - again
 
On Jan 27, 1:22*am, widgitt wrote:
To cut an even longer story short, the builder had wired the whole
thing as a ring circuit. Starting at the amp, running round the house
to each of about 8 sockets and back to the amp !


Years ago I was asked to fit an aerial in the loft of a large house
that had been converted into a 32 room old people's home. In the loft
the builder proudly showed me two coaxes, saying, "I've brought both
ends up to the loft so you can connect the aerial to both." I said,
"Yer wot?" and he expanded his explanation. The TV sockets in all 32
rooms and two lounges were in one loop. The eventual outcome was that
an external surface fixed system was installed, but was only after a
prolonged period of poor reception/no reception for the residents.

Bill

Steve Terry[_2_] January 27th 10 04:23 AM

TV distribution around the house - again
 
"Java Jive" wrote in message
...
This is astonishing to me. I literally can not remember how young I
was when I first learnt that an aerial is connected to the TV via a
single lead! Have these people never noticed that in old houses where
only one room is wired, the TV coax goes straight down to that room
and not back up to the aerial again?

snip top post


A Sparks understanding rarely goes beyond ring mains

Steve Terry
--
Get a free Three 3pay Sim with £2 bonus after £10 top up
http://freeagent.three.co.uk/stand/view/id/5276



Max Demian January 27th 10 10:43 AM

TV distribution around the house - again
 
"Java Jive" wrote in message
...
This is astonishing to me. I literally can not remember how young I
was when I first learnt that an aerial is connected to the TV via a
single lead! Have these people never noticed that in old houses where
only one room is wired, the TV coax goes straight down to that room
and not back up to the aerial again?


Well you wouldn't use a ring main for a single socket, would you?

--
Max Demian



charles January 27th 10 11:12 AM

TV distribution around the house - again
 
In article
,
wrote:
On Jan 27, 1:22 am, widgitt wrote:
To cut an even longer story short, the builder had wired the whole
thing as a ring circuit. Starting at the amp, running round the house
to each of about 8 sockets and back to the amp !


Years ago I was asked to fit an aerial in the loft of a large house
that had been converted into a 32 room old people's home. In the loft
the builder proudly showed me two coaxes, saying, "I've brought both
ends up to the loft so you can connect the aerial to both." I said,
"Yer wot?" and he expanded his explanation. The TV sockets in all 32
rooms and two lounges were in one loop. The eventual outcome was that
an external surface fixed system was installed, but was only after a
prolonged period of poor reception/no reception for the residents.


I met a very similar set up at the BBC pavilion at the Royal Welsh
Showground at Builth Wells. Here the two ends of the ring had been
connected to the outputs of a 2 output preamp.

Of course the architect was the brother-in-law of one of the BBC Welsh
Governors and the electrician was a relation. nuff said.

--
From KT24

Using a RISC OS computer running v5.16


[email protected] January 27th 10 11:40 AM

TV distribution around the house - again
 
On Jan 27, 2:22*am, Java Jive wrote:
This is astonishing to me. *I literally can not remember how young I
was when I first learnt that an aerial is connected to the TV via a
single lead! *Have these people never noticed that in old houses where
only one room is wired, the TV coax goes straight down to that room
and not back up to the aerial again?


Don't forget that people become electricians almost by chance
sometimes. The candidates don't necessarily have any special aptitude,
and to be honest I find some site electricians (employees) to be of
only average intelligence at best. They learn their own jobs monkey-
fashion and that's the end of it. I very often have to liaise with
these people because they often install our cables, and believe me, if
a thing can be done wrong they'll do it wrong. I'll quote one example
from many. Last year I found a gang of four busy installing in a large
building, called Building 'A'. They were puzzled by a few anomalies
and I had to point out that they were following the plans for Building
'B'. The two buildings were very similar but had slightly different
shapes.

Let's be fair, the rate of pay is pretty abysmal, and anyone with
anything about them either gets promoted or becomes self-employed.

Of course, I must say that I shouldn't tar them all with the same
brush. I have encountered clever, thoughtful, intuitive site
electricians as well as those discussed above. Many times I have
completed my part of the work and I've been able to say to the
electricans, "Well thanks guys, you've done a superb job for me." An
example again from last year, when the sparks installed the whole TV
network to our drawings, with 720 connections, and only made four
mistakes.

Bill

Doctor D January 27th 10 06:31 PM

TV distribution around the house - again
 

I met a very similar set up at the BBC pavilion at the Royal Welsh
Showground at Builth Wells. Here the two ends of the ring had been
connected to the outputs of a 2 output preamp.

Of course the architect was the brother-in-law of one of the BBC Welsh
Governors and the electrician was a relation. nuff said.



Did it work?
I always recall a plethora of aerials at the RWS pointing almost upwards at
the Builth Wells relay about 1 mile above it. I'm sure the BBC pavilion had
something "quirky" like a colour king or an XG8A in contrast to a sea of
contract 10A and 18A aerials elsewhere on the site.


charles January 27th 10 06:56 PM

TV distribution around the house - again
 
In article ,
Doctor D wrote:

I met a very similar set up at the BBC pavilion at the Royal Welsh
Showground at Builth Wells. Here the two ends of the ring had been
connected to the outputs of a 2 output preamp.

Of course the architect was the brother-in-law of one of the BBC Welsh
Governors and the electrician was a relation. nuff said.



Did it work? I always recall a plethora of aerials at the RWS pointing
almost upwards at the Builth Wells relay about 1 mile above it. I'm sure
the BBC pavilion had something "quirky" like a colour king or an XG8A in
contrast to a sea of contract 10A and 18A aerials elsewhere on the site.


I never saw what they finally fitted. Certainly, when I was there the
aerial was a contract 10 ele. I suspect I specified ine with a balun,
since there was a requirement for Ceefax reception.

But it was all a long time ago.

--
From KT24

Using a RISC OS computer running v5.16



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