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MULTI-SAT
ARMS
INTRO
Forty eight channels not enough? No room to put up a steerable dish?
Fancy another 100 TV channels? No problem, and you won’t have to take out a
second mortgage. In addition to the 48 TV channels your dish is picking up now,
it’s also receiving signals from half a dozen other satellites close to Astra
1A, 1B and 1C, but those transmissions hit the dish at an oblique angle and
bounce off back into space again.
However, they needn’t get away,
a second LNB (the gizmo on the arm in front of the dish), mounted next
to the existing one, can be used to intercept them. We’ve collected together a
selection of gadgets that will enable you to do just that. They range in
complexity from simple bolt-on brackets for a second LNB, to motorised arms
that allow a fixed dish to pick up signals from several different satellites,
at the touch of a button.
Fixed or adjustable brackets are most suitable for those who only want
to receive one extra satellite; obviously they’re a lot cheaper than motorised
arms, but you have to add on the cost of a second LNB and the extra cabling or
a dish-mounted switch-box. Motorised
arms cost more but they give true multi-satellite access, and you won’t
necessarily have to buy a second LNB, though older LNBs might not work very
well as the signals from the other satellites are usually much weaker than
Astra. Motor arms are also worth considering if you’ve only got one LNB input
on your receiver, though that needn’t preclude you from buying a fixed bracket,
it just means you’ll have to buy a switcher box, or swap the cables when you
want to change satellites.
In both cases installation can be quite tricky, and unless you feel
comfortable working up a ladder with small, fiddly components and tools, and
possibly re-aligning your dish, it’s prudent to have the work carried out by an
engineer. Needless to say this will also add to the overall cost. By the way,
prices vary enormously, those we have given are fairly typical, but the best
advice is to shop around.
IRTE
MULTISAT typically £130
On paper
this is the most expensive of the two motorised LNB arms, though the street
prices are often a lot closer together. It’s the most sophisticated of the two
systems, and a little easier to install as it uses the existing LNB downlead,
to carry power and control signals to the arm. Several versions are available,
to fit most popular dishes, up to 80cm in diameter. Installation is reasonably straightforward and could be carried
out by most competent DIYers in an hour or two. The kit includes a set of
universal mounting brackets for most common types of LNB.
The control
unit connects between the LNB cable and the receiver, and is operated by IR
remote control. Once it has been connected and powered up the set-up routine is
fully automatic. The LNB moves from side to side, storing satellite positions
in its memory as it goes. The system is optimised to receive Astra, Eutelsat
F1, F2, F3 and Kopernicus; other combinations are possible, though this would
involve re-aligning the dish.
Multisat is
well designed, easy to use and capable of good results, though it obviously
works best with newer, low noise LNBs, unless the dish is re-aligned.
Recommended.
Contact:
ELECTROTECH DISTRIBUTION, Unit 6, Drury Way Industrial Estate,
Laxcon
Close, Neasden, London NW10 OTG. Telephone 081-451 6766
Quality of
construction 9
Ease of
installation 8
Value for
money 9
Overall 95%
LENSON
HEATH MULTI LNB HOLDER typically £12
Superbly
well made LNB bracket, primarily for Lenson Heath dishes with
rectangular-section boom arms. It enables two (or more) LNBs to see satellites
up to 5 degrees either side of the dish’s focal point. The kit comprises two
slotted arms, with calibration marks stamped into the metal; one arm can be
used if required. The arms bolt in place of the existing LNB holder, all
necessary nuts, bolts washers and moulded fittings are supplied. Two LNB
saddles, made from ABS plastic, with a 40mm throat, and 23mm collar adapters
are included in the outfit. Once assembled there is plenty of adjustment for
each LNB, for focus, skew angle and lateral position.
It’s
advisable to pre-assemble the unit as it can be quite tricky juggling with the
numerous small parts, whilst clinging on to a ladder. With so many variables to
contend with alignment can be quite awkward as well, especially for novices;
the instructions are very brief and assume a degree of prior knowledge.
An obvious
choice for owners of suitable Lenson Heath dishes. Possibly a bit ambitious for
nervous beginners but it’s very flexible and -- depending on the performance of
the dish and LNB -- capable of excellent results.
Contact:
LENSON HEATH Ltd., Thames Industrial Estate, Marlow, Bucks SL7 1TB. Telephone
(0628) 890820
Quality of
construction 9
Ease of
installation 5
Value for
money 8
Overall 90%
LENSON
HEATH DUAL BRACKET KITS typically £6
Simple
no-fuss fixed brackets for Lenson Heath dishes, available in two versions
(right or left-handed) for mounting either side of the original LNB. The
brackets are formed from shaped metal plates, with holes and slots for mounting
the plate to the dishes boom arm, and the supplied LNB support bracket. This is
made of ABS plastic and has a 40mm throat. The bracket has a fixed angle, enabling
the second LNB to see Eutelsats F3 or F5, with the dish aimed at Astra.
Installation
is easy, the bracket is held in place by the existing LNB bolts, which may need
to be replaced if they’re too short. The slotted holes on the bracket allow a
small amount of adjustment but this shouldn’t take more than a minute or two.
It’s
difficult to imagine how it could be made any simpler, there’s nothing to go
wrong, making it a logical choice for those with suitable dishes, who just want
to watch one extra Eutelsat satellite.
Contact:
LENSON HEATH Ltd., Thames Industrial Estate, Marlow, Bucks SL7 1TB. Telephone
(0628) 890820
Quality of
construction 9
Ease of
installation 9
Value for
money 9
Overall 95%
LITTLEXTRA
POLAR ARM typically £17
Littlextra
is designed to enable a fixed dish to see both Astra at 19.5 degrees East of
South, and Telecom 1C, way over at 5 degrees West, (or anything in between).
Incidentally, Telecom 1C carries the Irish channel Setanta Sports and Canal
Course French horse-racing channel; be warned both are encrypted and cannot be
viewed without specialised equipment or viewing cards.
The arm
consists of a curved ‘polar bar’ supported by a pair of clamps on the centre
bracket, which fits on to the dish arm. The supplied bracket is designed to fit
tubular section arm booms. Two LNB saddles with 23-40mm throat adapters bolt to
the arm and slide freely from side to side. Moderately easy to assemble and
align (do a dry run first, the threads are very tight), and it requires that
the dish is re-aimed, at a point between the two satellites, a signal strength
meter is recommended. The instructions are a little brief but there’s
sufficient information for most competent DIYers. In spite of looking rather
flimsy the structure is quite rigid. The wide span means most 60cm dishes will
be working at full stretch, so low noise LNBs are essential, and an 80cm dish
is preferred.
A fairly
specialised design, mainly of interest to those wanting to receive both Astra
and Telecom 1C, otherwise there are cheaper and simpler ways of picking up the
more interesting satellites in between.
Contact D-MAC INTERNATIONAL, Unit 26 Burnham Road,
Glasgow G14 OXB. Telephone (041) 954 8737
Quality of
construction 8
Ease of
installation 7
Value for
money 8
Overall 80%
LITTLEXTRA
3 DEGREE ARM typically £
The same
basic LNB mounting components as Little Wizard and Littextra, this time
configured to pick up two adjacent satellites, typically Astra and Eutelsat F3,
at 16 degrees East of South. Very simple, all ABS plastic construction,
comprising two LNB saddles with 23-40mm LNB throat rings, bolted to a short
base plate, giving the two LNBs roughly 3-5 degrees viewing angle. This in turn
bolts to a bracket, designed to fit models with tubular-section boom arms; the design
is slightly crude at this point, with much of the bracket’s free-movement
fouled by the end boss. Sturdily made though, and there’s very little to go
wrong, but there is another potential problem. In common with the Little Wizard
and Littlextra Polar arm the LNB saddle top sections are held in place by a
pair of self-tapping screws, which are devilishly tight; so tight in fact that
it takes an unreasonable amount of pressure to tighten the screws first time,
enough to upset the alignment of the dish. It’s a good idea to free up the
threads on the ground beforehand; trying to screw the things up at the top of a
ladder would be very dangerous.
Generally
well designed, the components are strong and well made, but the limited range
of adjustment means it’s only suitable for receiving Astra and F3.
Contact
Quality of
construction 8
Ease of
installation 9
Value for
money
Overall 85%
LITTLE
WIZARD typically £15
Cheap,
simple and to the point. Little Wizard is configured for Eutelsat F1 at 13
degrees. It is made of tough ABS plastic and comprises a shaped base plate with
two LNB saddles. The outfit also includes a set of dish arm mounting hardware,
adapters are available to fit square or round section dish arms. The LNB
supports have throat rings with diameters from 40mm to 23mm. The instruction
sheet is reasonably clear and easy to follow. Assembly takes just a few
minutes, the threads on the LNB clamps are very stiff first time they’re used,
too stiff in fact to tighten one-handed up a ladder, so it’s advisable to
pre-assemble on the ground. The arm fitting brackets might also be a snug fit
on some dishes, so don’t forget to take a soft mallet up the ladder when you
go.
Installation
is reasonably simple, there’s a fair amount of travel in the bracket. The
instructions show two alignment methods; the simplest is to leave the dish
pointing at Astra and adjust the second LNB for Eutelsat; however, for those
who enjoy a challenge, and a better picture (with average quality LNBs) realign
the dish onto Eutelsat, with the second LNB picking up Astra. The whole business shouldn’t take more than
half an hour or so, providing there’s no problems dismantling the old LNB
assembly. Worth considering, if all you’re after is a way to pick up Eutelsat
F1.
Contact
Quality of
construction 8
Ease of
installation 8
Value for
money 8
Overall 85%
TRANSARM
PRO-FIT LW08 ‘Little Witch’ £16.50
Substantial
all metal arm, designed to clamp onto dishes with rectangular-section boom
arms. It’s quite easy to fit, and the existing LNB doesn’t have to be removed,
which makes it an attractive proposition for those of a nervous disposition!
There’s only a couple of bolts to tighten once it’s up, so alignment is pretty
straightforward as well. The range of angular adjustment is limited but with
the dish aimed at Astra it’s capable of seeing Eutelsats F1 and F2. The LNB
bracket is supplied as an extra, (we’ve included it in the price), the used
with our sample was made out of ABS plastic, it was a standard configuration
with a 40mm throat.
The
instructions we’ve seen are scant, they’re just about adequate for experienced
installers but we fear they would leave most DIYers high and dry. Construction
is strong and it feels very solid, if anything it’s over-engineered for the job
it has to do, and there are far simpler alternatives, nevertheless ease of installation, and the fact that you
don’t have to disturb the dish or LNB are major plus points.
Contact:
PHOENIX, Hampton House Trading Estate, School Road, Evesham, Worcs WR11 6PR. Telephone
(0836) 443339
Quality of
construction 9
Ease of
installation 9
Value for
money 8
Overall 90%
TRANSARM
PRO-FIT (Amstrad fit) £9.50
This one is
designed specifically as a replacement arm for 60 and 80cm Amstrad
(Communicado) dishes, to enable them to pick up the most popular ‘alternative’
satellite Eutelsat F1 at 13 degrees. The arm is just over a metre long, with a
second shorter arm welded on to form a Y-shape. A support bracket to hold the second LNB fits over the end, this
is normally supplied as an extra but we’ve included it in the price shown. Fitting is very simple, just remove the
existing arm, replace it with the Transarm, re-fit the original LNB, and clamp
on the second LNB and holder. There are no adjustments, apart from the skew
angle of the LNBs in their brackets. It’s cheap and almost foolproof and the
simplest method yet of upgrading an Astra dish for Eutelsat. The only problem
is deciding what to do with the old arm...
Contact :
Phoenix, Hampton House Trading Estate, School Road, Evesham, Worcs WR11 6PR.
Telephone (0836) 443339.
Quality of
construction 9
Ease of
installation 8
Value for
money 9
Overall 90%
MSA ADAPTER
typically £16
Crude but
reasonably effective bolt-on adapter arm for a second LNB, enabling it to see
Eutelsat’s F1, 2 and 3 and Kopernicus if fixed on Astra. All metal construction
which includes a 32mm U-bolt clamp. This fits on to a pair of jointed plates,
one of which has a short section of tube welded to it. This acts as the
mounting point for a standard LNB bracket.
The instructions state that the U-bolt clamp can be used with
rectangular or tubular section arms, that’s true, but we feel the fit may not
be very satisfactory in case of a square-section boom arm, and could possibly
lead to deformation, if the clamp bolts were over tightened.
It’s fairly
simple to fit but alignment can be quite tricky as it’s difficult to tighten
the hinge bolt without upsetting the aim. It’s also mechanically suspect with
single bolt and lock washer holding the whole thing together.
Contact SPECTRUMVISION, 61 Brantwood Drive,
Heaton, Bradford BD9 6QR. Telephone (0274) 548988
Quality of
construction 8
Ease of
installation 8
Value for
money 8
Overall 80%
SELECT-A-SAT
typical price £130
The second
of the two motorised LNB arms. It’s simpler than the IRTE arm, but it requires
a second 4-core cable from the control box up to the dish, to carry power and
control signals to the servo motor. Constructed mostly from transparent
plastic it’s also a little bulkier than
the IRTE design. Installation is straightforward; at the receiver end a small
control/IR receiver box plugs in between the LNB downlead and tuner (leads
supplied).
It’s
designed to work with 60 and 80cm dished. Fitting the unit to the dish arm is
reasonably simple but alignment is somewhat involved, and depends on the dish
being re-positioned, so that the stronger Astra signals are received
off-centre, leaving the more sensitive centre portion of the dish for the other
lower-power satellites. Satellite locations for Astra, Eutelsats F1, F2, F3 and
F4 are stored in the control box, and selected from a rather chunky infra-red
remote handset.
It works
well enough -- possibly better than the IRTE unit if the dish is re-aligned as
suggested -- but given the choice we’d plump for Multisat which is better
designed, simpler to install and operate.
Contact SELECT-A-SAT, Pearcroft Road,
Stonehouse, Gloucester GL10 2JY. Telephone (0453) 827378
Quality of
construction 7
Ease of
installation 7
Value for
money 7
Overall 85%
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2. LNBS
INTRO
Low-noise block converters --
LNBs to their friends -- are the unsung heroes of satellite television, quite
simply it couldn’t exist without them! They have an incredibly difficult job to
do, namely picking out the unimaginably weak signals coming from TV satellites
36,000 km away in space. It’s difficult to appreciate just how feeble those
signals are; by the time they’ve travelled through thousands of kilometres of
space and the Earth’s atmosphere to reach your dish power levels are down from
45 watts per channel at the satellite, to just a few hundredths of a billionth
of a watt, barely perceptible against the roar of natural and man-made noise.
LNBs have three specific tasks, firstly they have to be able to tune in
to the narrow band of microwave frequencies used for satellite TV
transmissions; secondly, they have to amplify the signals; and lastly, the
signals have to be converted to lower, more manageable frequencies, so they can
be sent by cable to the set-top satellite receiver.
Price and performance go hand in hand and whilst a £25 LNB on a 60cm
dish is perfectly adequate for reception of Astra in the South of England, it
will be struggling to produce a clear picture on the same sized dish further
north than Birmingham, say, and picture quality from any of the other TV
satellites is likely to be poor, wherever it’s used. Performance is defined by
the LNBs noise figure, expressed in decibels. It denotes the difference in the
signal to noise (S/N) ratios of the signal before and after it has passed
through the LNB, so the lower the number the better. Most general purpose Astra
LNBs have noise figures between 1.2 and 1.8dB; higher performance models have
noise figures of 1.2dB or less, increasingly under 1.0db.
There’s now another factor in the equation, Astra 1D, due to be
launched later this year. This new satellite, which will be co-located with
Astra’s 1A, 1B and 1C will be broadcasting on a different set of frequencies,
between 10.70 to 10.95 gigahertz, that’s below the FSS band (10.95 to 11.70GHz)
used by the other three satellites. Older LNBs can usually cover part of the
new band but we suspect many existing STV viewers may need to upgrade their LNB
and possibly their receiver as well, if they want to watch all the new
channels. There’s now a growing number of Astra 1D compatible or ‘enhanced’
LNBs, with wider frequency coverage (10.70-11.70 GHz) and to ensure they work
with the greatest number of receivers, local oscillators running at 9.75GHz
(normal LNBs have an LO frequency of 10GHz). They’re now in the same sort of
price range as conventional FSS LNBs, so to give you an idea of what’s
available we’ve been giving some of them the once-over, though for obvious
reasons you’ll have to wait until Astra 1D is up and running for full-blown
performance test reports.
CAMBRIDGE
JUNO AE6
Solid all
metal construction, familiar in-line layout with electronics compartment behind
the feedhorn. Full wideband capability with 9.75 GHz local oscillator. It has a
40mm waveguide throat, so it will fit most dishes without any problems. Stated
noise figure 1.0db, performance good on existing Astra channels with
sparklie-free reception of normally troublesome UK Gold.
Contact:
CAMBRIDGE INDUSTRIES Cambridge House, Crompton Way, Irvine, Ayrshire KA11 4HU.
Telephone (0294) 222100
BS Rating 95%
CONTINENTAL
MICROWAVE 0.8dB
Popular,
top-performing British-made LNB, this version with a 9.75GHz local oscillator
and an impressive noise figure of just 0.8dB. Rugged construction, 40mm
fitting, small and light, ideal for compact steerable dishes. Outstanding
performance on current Astra channels, but it really comes into its own on
multi-satellite systems where the lower noise figure makes all the difference
on weaker signals.
Contact: CONTINENTAL MICROWAVE TECHNOLOGY Ltd., 171
Camford Way, Sundon Park, Luton, Beds LU3 3AN. Telephone (0582) 491149
BS Rating 98%
CONTINENTAL
MICROWAVE 1.2dB
Identical
in shape and general specification to the 0.8dB model, but this time with a
noise figure of 1.2dB. Better suited to Astra-centred applications, though
still capable of producing a reasonable picture from nearby Eutelsat
satellites.
Contact: CONTINENTAL MICROWAVE TECHNOLOGY Ltd., 171
Camford Way, Sundon Park, Luton, Beds LU3 3AN. Telephone (0582) 491149
BS Rating 90%
MARCONI SOLO E
Astra 1D
compatible version of the very popular Solo, with 9.75GHz local oscillator.
Tough all metal construction with 40mm fitting. Noise figure below 1dB,
certainly consistent with results obtained from previous standard spec Solo.
Excellent Astra performance and worth considering for multi-satellite
installations.
MARCONI
ELECTRONICS Ltd. Elstree Way, Borehamwood, Herts WD6 1RX. Telephone 081-953
2030.
BS Rating
95%
MICROELECTRONICS
TECHNOLOGY GP235F
The odd one
out in this roundup with coverage extending from 10.70 right up to 12.75GHz.
Local oscillator running at 9.75GHz, so suitable for Astra 1D applications,
with wideband receivers with tone-switching facilities. Cylindrical
construction, no waveguide but standard C120 fitting. Noise figure of 1.3dB
gives reasonable Astra picture on 60cm dish but better suited to a large (1
metre plus) steerable antenna, with a advanced multi-satellite receiver.
Contact:
PROTEL DISTRIBUTION Ltd., Communication House, 879 High Road, London N12 8QA.
Telephone 081-445 4441
BS Rating 88%
PROTEL
MP6-A
Similar in
design and construction to Continental Microwave LNBs but of Taiwanese origin.
Fully configured for Astra 1D with a 9.75GHz local oscillator and frequency coverage
extending from 10.70 to 11.80GHz. High quality construction with all-metal
components and 40mm waveguide fitting. Quoted noise figure of 1.0dB born out by
good Astra performance and better than average picture quality on adjacent
Eutelsat satellites. Worth considering for undemanding multi-satellite
operation.
Contact:
PROTEL DISTRIBUTION Ltd., Communication House, 879 High Road, London N12 8QA.
Telephone 081-445 4441
BS Rating 98%
SHARP
BSCS86M00 1.2dB
All plastic
construction, it feels resilient but only time will tell if the snap-fit
construction is as robust, and impervious to the British climate as metal-clad
designs. Standard 40mm diameter fitting, noise figure rating 1.2dB. Astra performance is fine on a small dish, a
few sparklies on UK Gold but nothing to worry about South of Watford.
Contact ELECTROTECH, Unit 6, Drury Way
Industrial Estate,
Laxcon
Close, Neasden, London NW10 OTG. Telephone 081-451 6766
BS Rating
80%
NORTHERN
TELECOM UCJ-6551
One of the
most recent arrivals, similar in shape, though not construction to their range
of LNBs supplied to the likes Nokia and Pace, now with metalised plastic
instead of metal casing. Designed to fit 40mm brackets; it has a full Astra 1D
spec with 9.75GHz local oscillator, and a noise figure of 0.9dB. Astra
performance very good and better than average picture from adjacent Eutelsats.
Worth considering for multi satellite applications.
Contact:
NORTHERN TELECOM EUROPE Ltd., Aspen Wat 2, Yalberton Industrial Estate,
Painton, Devon TQ4 7QU. Telephone (0803) 667003
BS Rating
95%
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Ó R. Maybury 1994 0208
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