watch satellite TV in bed? Rick Maybury has some ideas that could help you
watch multi-channel TV and video in every room of your house...
According to a recent market survey the average British household now
has 2.5 television sets. We’re not sure where people keep their point-five of a
TV, but of the other two, one is usually in the main living room, the other is
in a bedroom or the kitchen. That’s all well and good if you live in a good
reception area and you’re happy with just four terrestrial TV channels on the
second set, but what if the signal isn’t strong enough for a basic set-top
aerial, or you want to watch satellite channels, or a video as well?
Anything is possible, of course, but unfortunately there are no cheap, simple
or instant solutions to these problems. We’ll take a look at some of the more
obvious low-tech options first.
The simplest method is to split the aerial feed as it emerges from the aerial
(or VCR or STV receiver’s RF output, if you want to watch those as well), just
before it goes to the main TV, and run an extra aerial cable to the room or
rooms, where you’re going to use another TV. There’s a couple of points to bear
in mind. The first one concerns the weakening of the signals when more than one
set is connected. Picture quality will suffer, possibly to the point where you might
not get a satisfactory picture on either TV. The answer is to use a properly
designed aerial splitter, preferably one with an built-in signal booster or
amplifier, with two or more outputs, so you can run separate feeds to several
rooms at once. Needless to say that even if your second TV is a stereo model,
you won’t get stereo sound from either the VCR or satellite channels with this
kind of basic RF distribution system.
The most obvious problem with this type of set-up is that there is no
means of controlling the source component (VCR or satellite tuner), so you
would have to keep going back to the living room, to work the VCR, or change
satellite channels. We’ll come to ways of overcoming this in a moment.
If picture and sound quality are important, and your second TV has
stereo sound then you might want to consider a custom hard-wired or AV
distribution system, installed in your home by a specialist firm. However, apart
from being horribly expensive -- you won’t see much change from a couple of
thousand pounds for a basic system -- it can entail a great deal of upheaval; it’s probably worth
thinking about if you’re having a lot of decorating or renovation work carried
out, or -- if you have the foresight and good fortune to own a new house -- having
a system fitted whilst it is being built..
Another possibility is to buy all of your video and audio components
from one of the very few top-end manufacturers who have developed ‘multi-room’
systems. They include companies like Bang and Olufsen who have an integrated
distribution control system, called Beolink. It uses a combination of cables,
RF and infra-red links to send video, audio and control signals to other
components around the house. In fact several manufacturers have developed
similar technologies at one time or another, though only a tiny handful ever made
it past the drawing board.
Five years ago Philips boldly tried to persuade the consumer electronic
industry to adopt a common standard for this kind of technology. They devised a
system called D2B or the domestic digital bus, which would enable all manner of domestic appliances to share common control
protocols, it even had a facility whereby VCR timers could be remotely
programmed over the phone. A small number of products (TVs and VCRs) appeared fitted with the necessary control
electronics and sockets, however, the Japanese majors gave it the thumbs down,
several of them had systems of their of own -- Home Bus, CE Bus and Esprit to
name just a few -- and as far as we’re aware they’ve all been put on hold.
Someone someday will do it, but don’t hold your breath...
Whilst we’re on the subject of what was, or may have been, does anyone
remember the Rabbit? Rabbit was an ingenious AV distribution system sold in the
UK about four or five years ago. It sent video, audio and control signals down
a thin two-core wire. When it worked it worked brilliantly, unfortunately it
was prone to interference if the cable ran too close to mains wiring, and the wire
was extremely vulnerable to damage. There’s probably still a few kicking around,
gathering dust in dealers stockrooms, if you come across one at a reasonable
price (less than £30 say) it might be worth a gamble.
The big drawback with virtually all
distribution systems is the need to run cables all over the house, wouldn’t it
be great if someone came up with a way of sending signals, without wires? Well,
they have and you can, the only trouble is it’s illegal in this country, or not
yet available. The commonest of these gadgets are known generically as video senders.
They’re basically miniature TV transmitters, that re-broadcast the aerial output
signals from a satellite receiver or VCR, so they can be picked up nearby on a
TV. The TV has to be tuned to a spare channel, usually the same one as the VCR
or satellite receivers RF output frequency. It’s fairly obvious why they’re
illegal, even though the output power is very low, in the order of a few
milliwats, and can only travel a few metres; nevertheless there’s still a
chance that the transmissions will interfere with a neighbours TVs or other more
important items of radio equipment. For the record it’s not actually illegal to
sell or buy video senders, and typically they cost between £30 to £50, but be
warned the authorities have no difficulty tracking them down if they receive any
complaints, and at least one offender was speedily identified and apprehended after
using a video sender to watch his own home-made naughty videos!
Several companies have come up with ways
of using household mains wiring to distribute AV and control signals. The way
it works is similar in principle to those cordless baby alarms and intercoms
that were popular a while ago, audio and video signals are modulated on to a
high frequency FM carrier which rides ‘piggy-back’ on the mains cables, and as
most homes have ring-mains systems, the signals are available at every wall outlet.
Prototype systems we have seen in the past few years appear to work very well
indeed. In principle they’re very easy to install with simple plug-in adaptor modules sited next to
the TV. The adaptor has AV sockets that connect directly to the TV, and in some
cases a small infra-red receiver that relays control signals back to a
transmitter unit next to the source components.
It sounds like an ideal solution, so why
can’t we go out and buy one? Well, once again there’s a problem with the
legality of these devices. There are quite complex rules about what you can and
cannot do with the mains supply. The electricity generating authorities
variously maintain only they are allowed to squirt signals down the mains, and
in any case they have their own plans for using the National Grid for
distributing everything from telephone calls to TV and video on demand.
So far the methods we’ve described have been expensive, inconvenient or
illegal, but here’s an idea that gets around pretty well all of the problems.
Buy a second satellite tuner and VCR. It’s not nearly as expensive as it
sounds. You can pick up second-hand STV receivers and VHS video recorders quite
cheaply nowadays -- typically £50 to £100 -- you might even have one or both
devices going spare if you’ve upgraded recently. The only minor difficulty
would be supplying a feed from the dish to the second satellite box, though it
needn’t be a problem, splitter boxes for satellite dish down-leads are readily
available for just a few pounds. The only other slight drawback is that the two
receivers would have to share the single Videocrypt smart-card. There are
devices that allow two receivers to operate from one card, but the wiring would
be quite complex, particularly if the two receivers were some distance apart.
In any case the small-print in the BSKYB subscription agreement has been
changed recently, to preclude their use, and they may not be available for very
much longer, and may even have disappeared by the time you read this. By rights
you should take out another subscription if you’ve got a second receiver but
unless you tell them about it seems highly unlikely they’ll ever find out, and
we won’t let on...
We’ve looked at the various ways of distributing the signals around the
home, but there’s still the problem of remotely controlling the distant VCR or
satellite receiver. In the case of integrated one-make multi-room systems that
shouldn’t be a problem, but for those with AV and RF installations based around
a hotchpotch of components, from various different manufacturers, this next
batch of products might prove interesting.
A company called Radio Remote have developed a range of wireless remote
control systems, that will allow you to control a satellite receiver or VCR
from almost anywhere in the house, without wires. They’re based on the Fox
universal remote control handsets which have been fitted with miniature radio
transmitters, (that’s in addition to the existing infra-red emitter, so they
still work as normal). The handset is programmed with a library of command
codes covering a wide range of TVs, video and audio equipment, from most of the
major manufacturers. The transmitted radio signals are picked up by a small
receiver module, placed close to the equipment to be controlled. The receiver
converts the radio signals into infra-red pulses that reproduce the commands
needed to operate the relevant device. The range between the handset and the
receiver is around 25 metres -- more than enough for most houses -- and it
costs around £80. For more details
contact Radio Remote on (01903) 700714
Powermid is one of the easiest ways of
remotely controlling distant devices, but unlike the Radio Remote it
relies on the equipment’s original handsets. Powermid consists of two wacky-looking
black pyramid-shaped units. The transmitter is sited alongside the second TV,
whilst the receiver is placed in line of sight of the devices you wish to
control. The transmitter has an IR receptor which picks up commands beamed from
the remote handset. These are converted into radio signals, they are picked up
by the receiver which changes them back into infra-red pulses. Once again the
range is in the order of 25 to 30 metres and it sells for around £50. Powermid
is distributed by Celtel and they can reached on (01256) 64324.
Powerlink is very similar to Powermid. It’s another two-piece system
with the transmitter unit picking up infra-red remote commands from existing
handsets. The signals are re-broadcast by radio to the receiver, which translates
them back into infra-red pulses, beamed at the equipment to be controlled. It’s
also compatible with Radio Remote handsets and it costs around £60. Radio
Remote are on (01903) 700714.
BOX COPY 1
There are basically two types of aerial splitter, passive ones which
simply divide the signal from a TV aerial, (or the output from a VCR and
satellite receiver) into two paths; and active splitters, or distribution
amplifiers, which can have two or more outputs and boost the strength of the
signals so they can be sent along longer cable runs. Passive splitters are generally
quite cheap, usually costing between two to five pounds. Most of them are have
an input plug, and two output sockets, they’re simple to install and there’s
not a lot that can go wrong. The only points to be aware of are the length of
the cables, especially if you live in a weak signal area, and it’s important to
use a good quality, low-loss co-axial lead, to connect the splitter’s output to
the second TV. Make sure you use the
right type of cable, it should be designed for the job and have a 75 ohm
impedance; prices vary but expect to pay between 40 to 75 pence per metre.
Active splitters start at around £15 for basic one-in, two-out models.
The internal amplifier is normally powered by a plug-in mains adaptor, or the power
supply is built-in and everything is housed inside a plug-in module; they
consume very little power and be safely left switched on all the time. Boosters
with more than two outputs cost a little more, typically £18 plus for a three
output design, and £20 to £30 for one with four outputs. Splitters, boosters and coaxial cable are all
widely available from TV and video dealers. The two leading companies in this
market are Antiference and Maxview, they can be reached on (01296) 82511 and (01553)
BOX COPY 2
AV OR ‘HARD-WIRE’
a hard-wire AV distribution system is not for the feint-hearted, and only
really sensible if you’re absolutely committed to the best AV performance, with
the equipment and bank-balance to match. Line-level stereo audio and composite
video signals do not travel especially well, there’s a limit to how far they
can go before noise and interference knock picture and sound quality on the
head. There are no simple off-the-shelf solutions either, the longest SCART to
SCART extension leads we’ve come across are only five metres long; you would
need half a dozen or more for a simple living room to bedroom hook-up, moreover
they look untidy are difficult to conceal, and we wouldn’t even want to guess
what the picture and sound would be
like with that type of hook-up.
need to be kept as short as possible and routed well away from potential
sources of interference. Ideally the signals will sent via a distribution amplifier,
and they’re not cheap. Multi-core screened cable is bulky and can be rather
expensive, and it’s important to fit specially designed and correctly
terminated wall sockets at each remote location. From that you may rightly
conclude that it’s not really a DIY sort of job. However, there are plenty of
companies willing to carry out this kind of work for you, but they should be chosen
with great care. When phoning around for quotes always ask if they can provide
references for at least one other similar installation, if they can’t, it
suggests they might not have done this kind of work before -- you will be their
first attempt -- so give them a miss. In the end, however, the cost of a
hard-wire installation is difficulty to justify, simply to feed a second small
screen set in the bedroom, it would almost certainly be far cheaper to buy a
second satellite system or VCR.
Ó R. Maybury 1995 1603