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ASTRA UPGRADE
INTRO
Are you stuck on Astra, or can your satellite receiver be
used as part of a multi-satellite system? We've been looking at ways of
upgrading three popular Astra tuners
COPY
When you brought your present satellite
receiver were you impressed by claims of 'future-proof' technology? Probably
not, we've become pretty cynical lately, with good reason, and there's quite a few people out there,
stuck with decoderless, 16-channel satellite receivers to prove it. The once
thing we can be sure of is a steady increase in the number of Astra channels
and the writing is already on the wall for any receiver with less than 64
channels, but enlightened STV systems manufacturers dare not stop there, which
is why most new receivers have a minimum of presettable 99 channels, even ones
ostensibly designed for fixed-dish operation.
Such a large number of channels may seem
irrelevant, even with the prospect of yet more Astra satellites but these days
an increasing number of manufacturers have at least half an eye on
upgradability and several now market compatible positioner units, for
multi-satellite operation. A positioner is an electronic box of tricks that
controls a motorised actuator arm, which tracks the dish along the Clarke Belt,
along which all of the TV broadcast satellites are situated. The positioner has
three jobs, first and foremost it must know precisely where the dish is at any
given point on its travel; secondly it must be able to memorise the positions
of all the satellites that can be 'seen' by the dish, and thirdly it should be
able to interface with the receiver, so that selecting a channel number
automatically steers the dish to the appropriate satellite.
PROBLEMS?
If you plan to upgrade be warned that a
positioner box is only the beginning. In addition you will need an actuator arm
and a suitable polar or horizon mount for your present dish, providing of
course it has an unobstructed view of the Southern sky, if not it may be
necessary to move it. In fact, if you've only got a bog-standard 60cm Astra
dish you might as well replace that as well because most of the other
satellites you'll be watching put out much weaker signals, and you'd do well to
consider a dish at least 1-metre in diameter, though check local planning
regulations first. You might as well replace the LNB too, whilst you're at it,
if you're serious about multi-satellite operation you should use a dual or
triple band type, that will enable you to pick up those elusive transmissions.
Now we come to the big question, does your receiver need replacing?
This is beginning to sound like the story
of the hundred year-old broom, who's head and handle have only been replaced
half a dozen times... By now you're thinking it would be far easier to start
from scratch with a motorised dish system, and you would probably be right,
but if your receiver is a comparatively
recent IRD with plenty of life left in it might make more sense to go the
upgrade route, especially if you're prepared to shop around for the necessary
components. Positioner boxes sell from £100 upwards, depending on the make and
model; an actuator and polar mount will add a further £60 or so to the bill,
and a 1-metre dish and LNB another
£120, say. With all the bits and bobs, extra cable etc. that comes to around
£300 to £350, a possible saving of several hundred pounds over the cost of a
motorised dish system, some of which sell for well over £1,000, so you see, it
can be worth the time and effort.
But where do you start? The first place
is your receiver. Has it got enough spare channels to make the exercise
worthwhile, and is there a compatible positioner? You might find the answer in
the instruction book, otherwise contact your dealer. If there isn't one don't give up just yet, it's
not essential for the positioner to connect up to the receiver, it just means
you'll have to press a couple of extra buttons on the positioner's own remote
handset to manually select each satellite. The next, and by far the most crucial
step is to check whether or not your present dish position is suitable, and
this is where you might need professional help. The dish should have a clear
view South; if it's 'looking' at Astra through a gap in adjoining houses then
there's not much point motorising your present dish because all you will get is
one or two extra satellites, if you're lucky. Assuming you have a suitable
location you will need to make sure it can bear the extra weight of a larger
dish, mount and actuator arm; now you can start looking around for the extra
parts.
To help you on your way, and to show you
just how easy or difficult it can be we've been trying out three systems that,
amongst other things, are sold on the basis that they can be easily upgraded to
multi-satellite operation. Here's what we found.
NOKIA SAT 1700 AND 262-5152 POSITIONER
The 5152 positioner has been designed
specifically to work with Nokia's 5900-series of receivers, which includes the
SAT's 1100, 1200, 1700, 2100 and 2200 models. It will not easily integrate with
other systems and it can only control actuators with pulse or reed-relay
feedback systems. The unit can store positional details of up to 40 satellites
and it can be controlled either from the receiver, or by suitable IR handsets
supplied with Nokia, Luxor and Salora TVs, though the last two brands have not
been available in the UK for several years. A remote control handset is
available as an optional extra.
The 5152 shares the same cabinet design
as the SAT 1700 and its immediate predecessors; it connects to the host receiver
by a single phono lead, which carries remote control data between the two
units. Front-panel controls are hidden behind the central hinged flap, they
comprise five buttons for East/West tracking, satellite position up/down, and
memory. A three-digit front-panel display shows relative antenna position (000
to 999), satellite position plus various mode and status indications.
The installation and set-up routines are
fairly convoluted, best carried out by an engineer unless you're reasonably
confident or experienced in these matters. The antenna alignment procedures are
reasonably straightforward but some of the programming routines are
long-winded. Satellite position numbers will also have to be programmed into
the receiver, so that selecting a channel automatically steers the dish to the
correct satellite.
Once installed the 5152 behaves
impeccably. Not, perhaps, the ideal system for enthusiasts or dedictated
button-pushers, there's very little to play with, but definite appeal to Nokia
SAT system owners, already hooked on fuss-free STV and looking for a painless
way to expand their viewing choice,
FACT FILE
Address: NOKIA CONSUMER
ELECTRONICS Bridgemead Close
Westmead, Swindon SN5 7YG
Tel: (0793) 644223
VERDICT
Build/styling 8
Compatibility 9
Features 7
Ease of use 7
Buying Satellite rating
85%
Effortless channel
expansion for Nokia owners
System: basic antenna control unit
Satellite memory: 40 positions
Full/partial remote: full with compatible receiver
Dimensions: 360 x 268 x 60mm
PACE PRD-900 AND MSP-991 POSITIONER
The MSP-991 is the companion positioner
for Pace series 700,800, 900 receivers, though it will also work with 9000,
9200 and MRD920 receivers. It can also
operate as a stand-alone unit with other systems, and it comes with its own
remote handset. The 991 will work with both of the most common types of
actuator, i.e. those with pulse
(reed-relay) or photo-sensor feedback systems.
Cosmetically it follows the same theme of
the 700/800/900 series, with the controls (four buttons for on/standby, mode,
East and West) hidden behind a hinged flap. The front panel display comprises a
three-digit readout showing dish position,
programme number (when used with 9000,9200 and MDR920 receivers) and
status. Connection to a compatible receiver is via a SCART lead, which plugs
into the 'decoder' socket, there's a
loop-through to a second SCART on the back of the positioner box, which can be
used if the receiver's decoder socket is occupied.
Installation follows the usual routine of
setting the East and West limits on the dish, then programming in the position
of each satellite in turn. On 700/800 and 900 series receivers dish position is
stored along with the channel number in the in the receiver's memory. It works
the other way around on 9000/9200 and MDR920 receivers with the channel number
and satellite position held in the 991's memory. In both cases the dish will
track to a selected satellite, simply by pressing the appropriate channel
number on the receiver's remote handset. There are a couple of provisos, some
early 9000 and 9200 series receivers which cannot store more than 28 and 64
satellite positions, though that's unlikely to be a major problem for most
users.
A smooth and sophisticated positioner,
mainly of interest to Pace owners but versatile enough to operate with any
other make or type of system, and capable of controlling a wide range of
actuators.
FACT FILE
Address: PACE Victoria Road, Saltaire, Shipley BD18 3LF
Tel: (0274) 532000
VERDICT
Build/styling 9
Compatibility 9
Features 9
Ease of use 8
Buying Satellite rating
95%
Versatile multi-system
design and a first choice for Pace owners
System: multi-role
antenna positioner
Satellite memory: 128
Full/partial remote: full, via SCART lead
Dimensions: 66 x 360
x 210mm
PALCOM SL-650IRD AND SL-650P POSITIONER
Skip this one unless you have Palcom 650
receiver, or plan to get one, because the SL-650P positioner will only work
with that receiver. It's fairly obvious from the styling that they're a matched
pair, and very smart they look too, discreet and businesslike. The two units
connect together via an 8-pin DIN lead and the receiver's remote control
handset operates both units. The positioner will work with most types of
actuator, including those with the less common Hall-effect magnetic sensors, as
well as reed-relay and opto-couplers.
Positioners are often an afterthought but
in this case the receiver and positioner appear to have been designed to work
together from the outset and function more like a single-box multi-satellite
receiver. The high level of integration between these two units is illustrated
by a complete lack of ifs, buts and maybes in the instructions, and facilities
like 'autofocus' which corrects for any small positional errors. These can
be caused by slippage or unintentional
movements of the dish or mount etc., the system monitors the signal strength of
the selected channel, and adjusts dish position accordingly. Autofocus can be
adjusted to compensate for satellites which are close together, or switched off
altogether, if needed. Installation and set-up procedures are easy to follow,
thanks to a very informative and simple to follow on-screen display system
which includes dish position as just one more pre-settable parameter in the
programming menu.
A smart and sophisticated system which
trades versatility and cross-brand compatibility for total system integration.
It's fairly expensive but it's the one and only choice if you have a Palcom
650IRD.
FACT FILE
Address: STRONG, 3/16
Chelsea Garden Market, Chelsea Harbour,
London SW10 OXE
Tel: 071-352 0600
VERDICT
Build/styling
9
Compatibility
10
Features
9
Ease of use
8
Buying Satellite rating
98%
The only choice if you
have a Palcom 650IRD
System: dedicated
positioner for the 650IRD receiver
Satellite memory: 50
Full/partial remote: full
Dimensions: 62 x 430 x 250mm
VERDICT
Build and styling
In all three cases the positioners are
housed in matching cabinets, so as far as looks are concerned it's a matter of
personal taste. The plain, simple and functional Palcom units will probably age
better than the more contemporary-looking Pace and Nokia systems. Build quality
is good on all three though the Pace and Palcom positioners use heavier-duty
components and look, as well as feel more robust.
Features
The Pace and Nokia positioners share a
similar set of features; the Pace unit has a larger memory capacity, though
it's questionable whether there will ever be an need to store the positions of
more than twenty or thirty satellites. The Palcom positioner's 'autofocus'
facility could be worth having, especially when used with larger dishes in
windy locations, which can be prone to positioning errors.
Ease of use
Once these systems have been correctly
installed and programmed they're all extremely easy to use; moving the dish to
a new satellite is no more complicated than selecting a channel number. When it
comes to manually steering the dish the Pace and Palcom positioners offer
marginally more scope for exploration as they can both be remotely controlled
from their infra-red handsets
Value for money
Prices vary but a trawl through the
advertisements in Buying Satellite puts the three positioners at between £100
and £160, with the Pace unit generally towards the lower end of the range, and
the Palcom usually the dearest. The Palcom receiver is the the most expensive
of the three and with its positioner comes closest to the cost of a
purpose-designed multi-satellite receiver.
Compatibility
As far as system compatibility goes the
Palcom unit wins hands down. The Pace and Nokia units integrate easily with
their companion receivers but they still feel a little like an afterthought.The
Pace unit was the only one that could be easily used with other makes of
receiver, the Nokia positioner could, at a pinch, but there's no chance with
the Palcom unit.
TECHNICAL TIPS -- a brief guide to multi-satellite jargon
Actuator
Motorised servo mechanism with an
extending arm that moves the dish on its polar mount.
Clarke Belt
Ring of
geosynchronous satellites encircling the Earth 36,000km above the
equator, named after Arthur C. who first proposed the idea back in 1945. From
the UK it appear as an arc, low in the Southern sky
Declination
The offset angle of a dish on a polar
mount, in relation to its own horizontal plane. One of the parameters used to
align a multi-satellite dish.
Dish limiting
Means of preventing the dish from
travelling beyond pre-set limits at either end of its travel. Dish limits are
set in software, ie by the positioner, and by mechanical switches on the
actuator gearbox.
Feedback systems
The way the actuator tells the positioner
where the dish is, along it's arc of travel. The three most common systems
generate a stream of pulses as the actuator moves, either using a mechanical
switch, reed-relay, 'Hall' effect sensor (both switched by a rotating magnet),
or opto-coupler, whereby a roatating disc with holes around its edge interrupts
a beam of light focused on a photosensor.
Horizon or Polar mount
Specially designed dish mounting system
that tracks precisely across the Clarke Belt
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© R.Maybury 1993 2209
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