THE TASTE OF D...
Satellite TV is a fast-moving technology but are you aware
that your present system -- even if its only a few months old -- could soon be
obsolete and is almost certainly incapable of picking up the new channels from
Astra 1D, which will be launched in just a few months time?
Whenever you hear the words
'future-proof' and 'satellite TV' mentioned in the same breath, run for cover!
The only thing you can be certain about is that any satellite system brought
today will be obsolete well before its guarantee has expired. It's not a new
phenomenon, premature obsolescence has been a fact of life in satellite
television technology since the earliest days. Ten years ago, when the first
domestic STV systems went on sale in the UK, receiver design changed even
faster than it does today. If you need proof that it is still happening just
ask anyone who got lumbered with a BSB system. Ask anyone who brought an early
16-channel Astra receiver, or one without a Videocrypt decoder. Ask anyone
who's receiver has mono sound or fewer than 50 channels, and this time next year,
ask anyone -- and that will be most of us -- unable to receive the new channels
broadcast from the Astra 1D satellite.
So can you ever get ahead
of the game? Sorry, the simple answer is no. STV technology is changing far too
quickly for that, and there's no sign of a let-up. Astras 1E and 1F are already
under construction and due to be launched in 1995 and 1996, there's even plans
for Astra 1G. None of today's satellite receivers will be able to pick them up
or decode the digitally formatted signals, let alone many of the other
satellites and transmission systems planned over the next five years. The best
you can hope for is that your next satellite receiver will get you through the
next year or two, before it too is past its sell-by date...
Don't be disheartened, the
trick is to regard satellite TV as a transient medium, never rush into
anything, and don't expect any of it to last, then you won't feel let down.
Over the past 50 years we've become accustomed to the slow pace of change of land-based broadcasting systems;
satellite TV is a very different animal, and altogether more fragile, as we
have already seen. Apart from the high mortality rate amongst broadcasters the
satellites themselves have a limited life expectancy of around ten years, maybe
a little longer if the operators are careful with the finite supply of fuel
that keeps them in their carefully controlled orbital position; and that's
providing nothing else goes wrong in the meantime. Terrestrial TV transmitters
can be maintained and upgraded almost indefinitely, and easily fixed if a fault
develops. One tiny piece of space junk could destroy a TV satellite in an
instant, a meteorite shower could wipe out all three Astra birds! Of course
that's a highly unlikely scenario, but it illustrates just how uncertain the
future of satellite television is, you never know what's going to happen!
On that cheerful note we
come at last to Astra 1D, the new kid on the block, due to go aloft on an
Arianne rocket later this year. At least that's the theory. Earlier this year,
on January 24th to be precise, an Arianne rocket carrying Eutelsat II F5 and
Turksat 1 fell into the Atlantic ocean after a third-stage fuel pump failed.
See what we mean about it being a fragile business? Subsequent launches have
been put on hold until late Spring, by which time Ariannespace hope they'll
have figured out what caused the failure, and that has meant all future launch
dates have had to be re-scheduled.
Even supposing Astra 1D
gets into orbit more or less on time, it still has to get through the crucial
start-of-life and shakedown programmes, before it can be fully commissioned;
the broadcasters -- and no-one is officially saying who they are yet -- won't
take up their options and sign on the dotted line until the satellite is seen
to be up and running, by which time we'll probably be well into the first
quarter of 1995. So there's no need to panic, once we know more about the
channel line-up you can decide for yourself whether or not there's enough
interesting new programming to watch, to justify buying new equipment.
However, there's no harm in
thinking ahead, about what is to come, so let's be optimistic and anticipate
that everything goes according to plan. We'll start by taking a closer look at
the new satellite, and consider why you probably won't be able to receive the
new channels on your present set up.
When the Astra system was
conceived, back in the early 1980's, it was envisaged there would be three or
four co-located satellites broadcasting on the Fixed Satellite Services (FSS)
band. This is a band of frequencies which extends from 10.950 to11.700
gigahertz (GHz). To briefly recap, these incredibly high frequency microwave
signals are beamed from space, picked up by the dish, which focuses the signal
on to the low-noise block-converter. The LNB amplifies and changes the signal
to a more manageable form, to what's known as the IF or intermediate frequency.
For the record, on Astra systems the IF frequency is between 950 and 1700 MHz
(i.e. transmission frequency minus 10GHz). The signals are then carried by
cable to a set-top receiver, which works like the tuner in a TV, selecting or
tuning specific channels across the IF band,
which, as we've already said, is from 950 to 1700MHz. Remember those
numbers, we'll be returning to them shortly!
So far so good? As we now
know Astra has been a big success, but more importantly the technology has
advanced at an unexpected rate and SES, the Luxembourg consortium which owns
and operates the system, have grasped the opportunity to increase the number of
satellites and channels, to meet the expected demand for multi-channel
television across Europe. There's no room left on the FSS band so Astra 1D will
broadcast on a previously unoccupied set of frequencies immediately below the
FSS band, between 10.700 and 10.950 GHz.
standard Astra LNBs were not designed to operate on the new frequencies,
(though in practice quite a few will, more about that in a moment). No problem,
just swap the LNB for one with extended coverage? If only it were that simple,
such devices do exist but think back to what we said a few moments ago about
receiver tuning range. The 10GHz shift in IF frequency would take Astra 1D
signals beyond the coverage of most receivers. So why not change the LNBs IF frequency?
Again, good idea and that has been thought of too, but bringing the lower Astra
1D frequencies within range of a receiver means the upper end of the band, i.e.
channels on Astra 1B, will then be outside the receiver's tuning range, you
can't win. Okay, broaden the receiver's tuning range and use a wide-band LNB?
Yes, that's possible too, but now we're talking about renewing the whole system
-- apart from the dish -- there has to
be a cheaper and simpler way?
There's a couple of possible solutions that would enable most
current Astra receivers to pick up some or all Astra 1D channels, including a
couple of channels on Astra 1C that are outside the range of many of today's
receivers. The first one is a widget called a converter, they're already available
for those who want to catch RTL 5, which is one of the two 'missing' Astra 1C
channels; Global Communications are the first to market one in the UK and it
sells for £33. The Global Converter connects between the LNB and the receiver;
basically it shifts the IF frequency up by 500MHz, so that the lower
frequencies picked up by the LNB come within the receivers tuning range.
Now you may have spotted a
flaw in this argument, if the LNB's frequency coverage doesn't extend down far
enough, it won't pick up all of the new channels. In fact, as we hinted earlier
quite a few standard Astra FSS LNBs will cover at least some, if not all of the
new channels. Global reckon most recent LNBs should be able to pick up around
half of the new channels without too many problems, though other factors, such
as latitude will have an effect, and the further North you go the fewer 1D
channels you can expect to receive.
Global have told us they're compiling a list of LNBs that they know will give
full coverage, this they hope to have ready by the Summer.
As it stands Global's
converter box is not really a plug-in-and-go upgrade, some provision has to be
made for switching between the bands otherwise Astra 1B channels become
unavailable when watching 1D. Some receivers already have external switching
facilities but for most STV viewers it will have to be fitted by a competent
dish installer. Incidentally, Global will also be marketing another converter,
to re-enable the lost Astra 1B channels, and there's talk of fitting both units
in one box, hopefully we'll have news of a more DIY friendly product closer to
Dual-band or 'Astra Lo'
LNBs as they have become known are a real possibility, they will be designed to
cover both the existing FSS band, and the lower frequencies used by Astra 1D.
The problem here is how to switch between the two bands. The cable which
connects the receiver to the LNB already carries a switching voltage, to change
polarity, so some other method will have to be used. There are two
alternatives, another wire going up to the dish or, more likely, a switching
tone, generated by the receiver and sent down the LNB cable. The current
proposal, backed by SES, is for a 22kHz tone; several manufacturers have
already adopted the idea, but once again we're talking about buying a whole lot
of new equipment. We're fairly hopeful that someone will come up with an
external switchbox and LNB upgrade kit for existing receivers, well before the
Astra 1D service begins
There's little much doubt
that the new service, when it begins, will be seen by comparatively few people,
so if they want to widen the audience, the channels are going to have to be damn
good, good enough in fact to persuade people to go out and spend their
hard-earned money on new equipment!
SIDEBAR ONE -- RECEIVERS AND LNBS
If you're in the market for
a new satellite system our advice is to hang on. Over the next few months we
expect to see a growing number of 'Astra 1D compatible' IRDs (integrated
receiver-decoder) and LNBs coming on to the market. Don't be hurried into
buying equipment, there's nothing much to see at the moment, and there's bound
to be a price premium at first. Bear in mind also that the satellite could fall
into the sea, you could be run over by a bus, and who knows, this time next
year they might be giving Astra 1D upgrade kits away in packets of
If you simply have to be
the first kid on the block then one of the first receivers to be marketed as
Astra 1D compatible will be the Mark II version of the ever-popular Nokia SAT
1700. It will have increased channel coverage, and 16 of its 320 factory
programmed channels have been set aside for the new satellite. No price as yet
but it should be reaching the shops by the time you read this. The other
receiver to look out for is the Pace MSS500 which will also be Astra 1D ready,
this is due to be launched in the next few weeks, the price is expected to be
If you're planning to buy a
new IRD right now then it makes sense to put the ones that have at least some
chance of picking up the new channels at the top of your list. Four models, the
Amstrad SRD550, Cambridge ARD200, Pace
PRD800 and PRD900 have either extended IF coverage and/or switchable LNB IF
offset frequency facilities, which should be a big help if and when you come to
upgrade. In fact the choice is wider than you might expect, the Cambridge and
Pace receivers are both heavily cloned. The ARD200 is also available as the
Akai SX1000, Alba ISR7000, BT SVS-200 and JVC TU-AD1000; the Pace-based models to
look out for are Ferguson SRD16, Grundig STR-1, Hitachi SR1050, Nokia SAT 1602
and Panasonic TUS-D200.
SIDEBAR 2 -- WHAT'S ON 1D?
So far details of Astra
1D's channel line-up are very sketchy, and clearly SES -- the satellite
operators -- will be playing their cards very close to their chest until much
closer to the launch. However, the indications are that options on all of the transponders
have now been taken up. Thus far only a couple of organisations have publicly
declared an interest, they are the China News Europe and The Family Channel,
who are currently broadcasting from Astra 1C. Other names to watch out for in
the run-up to launch day include The Sci-Fi Channel, The Travel Channel and the
Afro Caribbean Channel.
SIDEBAR 3 -- ASTRA E,F and G
Looking even further into
the future at least three more Astra satellites are planned before the end of
the decade. Astra's 1E and 1F are due to be launched in 1995 and 1996
respectively, with 1G as an in-orbit backup, that's planned for 1997. No, before
you ask, you won't be able to receive any of them on current or future Astra 1D
receivers. That's mostly because they'll be broadcasting on yet another band of
frequencies, this time above the FSS band. However, the most important
difference between the new satellites and the present generation of Astra birds
will be the transmission format, Astra 1E will be the first high-power TV
satellite dedicated to digital TV, and that's when it really gets interesting.
Digital TV is the television of the future; it will mean hugely increased
channel capacity, greater security for subscription and pay-to-view services,
and the first step towards global digital high-definition TV. One of the most intriguing
possibilities is 'video on demand' or VOD, a facility that will enable
subscribers to dial up a movie, and watch it when they want to, not when the
schedules dictate. It works like this: a digital transponder can theoretically
carry dozens of channels, so the same movie could be shown many times over, but
the start times would be staggered so that a subscriber would never have to
wait more than a few minutes for the beginning to come around. Widescreen, high
definition and interactive digital TV systems have already been developed and
the promise of a world-wide standard will break down the remaining barriers to
the much talked about global village. To repeat that very well used phrase, that's
the theory... Stay tuned, it sounds interesting!
© R.Maybury 1994 3103