Satellite Workshop 14
Some questions arise time and time again. A favourite seems to be
"when I connect my satellite receiver to my Nicam stereo video
recorder with the RF cable, I don't get stereo sound." The answer is
to connect the left and right audio connections via Scart or Phono
sockets (whichever is provided). Even then, the "Nicam" light will
not be displayed on the video recorder because "Nicam" stereo is not
available via satellite. However, Dolby Pro-Logic is used on many
films and a suitable receiver and amplifier combination (or MSS1000)
will provide amazing sound effects.
This receiver seems to have received a new lease of life as it
appears on the second-hand market at ridiculously low prices.
However, it is invariably sold without a User Handbook and this
produces the same question (even from dealers): "How do I get the
on-screen menu?" Well, you don't because this model does not produce
one. It is limited to the front panel display only. Since the display
does not show frequency, you can't easily tell what program you are
watching.
However, the receiver is actually more versatile than it appears.
Channels 01 to 16 cover Astra 1A, 17 to 32 cover 1B, 33 to 48 cover
1C and 49 to 54 cover Telecom 1C. Channels 55 to 99 cover the range
950 to 1710 MHz in 20 MHz steps. These are factory-set to horizontal
so you will need a remote control handset to change the polarisation
to vertical for some of them. Channels 55 to 99 are ideal for "Hot
Bird" or for radio programmes.
Note that ALL channels are fixed (pre-tuned) and only fine-tuning is
possible. Channels P1 to P8 are "favourites" and you can set these to
mirror any of the other 99 channels. The programming is not very
straightforward but a User Guide is (was) available ( 6.95) from
SatCure. This comprehensive booklet includes channel frequency
listings for both standard (10.0 GHz) LNB and Enhanced (9.75GHz) LNB
as well as channel settings when an ADX Plus is used. In addition, a
special 2-LNB switching box " VH7" is available. The RD480 sends a
special pulsed code up the LNB cable for each channel. The switching
box recognises the code and selects the appropriate LNB of the pair.
Cambridge developed this system long before 22kHz tone switching was
considered and it works very well.
Having just attended the dealer training course at Pace's factory in
Shipley, I should now be expert at repairing this model. However, I
simply haven't had many to repair. Early problems seem to have been
solved during the warranty period and the ones I see are those which
have suffered from animal urine or mains surge due to lightning.
The latter seems to destroy the switching transistor without
otherwise doing much damage. I recommend that you always replace the
47uF/400v capacitor since I've seen a few which had failed.
Pace's training courses, by the way, are really excellent. Whereas
other manufacturers in the past have charged 99 and thrown in a
buffet lunch, Pace gave the course and provided a full works
restaurant meal plus Service Manual and updates free of charge. Since
spaces are limited, the training is limited to dealers and you should
book early. I don't know what future courses are planned but you
should be able to find out from Tricia Payter on 01274 532000.
Talking about Service Manuals reminds me that I've just received one
for the following models: GRD100/150/200/250/280/300, JVC TU-C200,
Matsui RD600, Philips STU3301/3501/3601. The price was 14.95 plus 1
postage from: Grove Farm Publications, Grove Farm, Long Lane, Barnby
in The Willows, Newark, Notts, NG24 2SG. The manual is excellent and
comprehensive. Circuits and circuit descriptions plus parts lists are
included.
This receiver forms the basis for a budget cost motorised system.
There are plenty of them in use and they are generally quite
reliable. When a fault does occur, however, life becomes difficult
without Service information. The manual ( 10) and spare parts are now
available from Satellite Surplus (Telford). Give Frank Martin a ring
on 01952 598173 for more details. Frank is well known on the Radio
Rally circuit and has all sorts of satellite equipment bargains.
This receiver has been mentioned previously as being susceptible to
some sort of microprocessor "lock-up" which prevents it from
responding to the remote control. Apart from the obvious need to
press "SAT" on the Remote, instead of "TV", various solutions have
been found to work some of the time: Replace the
microcontroller with one from a PRDxxx then put the original back
(or, as one enterprising dealer told me, leave the Pace micro in,
supply a Pace Remote and sell the Philips remote at a profit!)
Alternatively, fit a new, blank EEprom.
You will be interested to know that a secret button sequence was
written into the firmware in order to force the receiver to ignore
the Remote (don't ask me why). Hold "Standby" and "+" while applying
mains power. You will see "P10" in the display. The Remote will now
be ignored. To reverse the process hold "Standby and "-" while
applying mains power. You will see "P8" in the display. The remote
will now work again. Obvious, really!
Although this model is not Astra 1D compatible, a lot of people still
use it and are happy to pay for repair when it goes wrong. A fault
which is becoming increasingly prevalent is the demise of C21 and C25
at the front of the power supply. Amongst other things, C25 failure
causes streaks on decoded pictures and C21 causes the 5 volt rail to
decrease in voltage. A common symptom is that the receiver will
remain in standby until it has warmed up, after which it may work but
the pictures will be sparkly and tuning drift occurs. I replace these
capacitors, now, as a matter of routine.
Dry solder joints on the transformer pins, T2, is also quite common.
The symptoms usually include factory reset occurring at power-on or
intermittent loss of picture. I've even seen one which would flash
its LEDs in a random sequence before going off completely. The
customer's fault description often includes the words "when tapped"
or "loses memory" so look out for this.
In its day this was a wonderful machine and nothing has changed apart
from the public's perception. It has 999 tunable channels with
polariser control and a superb picture quality. The drawback is that
the tuning range is limited so you must use an ADX to receive Astra
1D. It has no built-in decoder and needed a simple wiring
modification to allow it to use an external one. It makes an
excellent basis for a motorised system and can be acquired for a
song. Remote controls are not available but you don't really need
one.
Reliability of the receiver is generally good but a few faults appear
on a regular basis: No LNB voltage--check the switch position!
Measure the fuses and replace as necessary. Remove the base plate and
resolder all the connector pins beneath the rectifier board. Picture
problems: Replace the electrolytic capacitors inside the tuner. Make
a note of their orientation because it's not marked in the tuner!
There are two 1 F electrolytics situated towards the rear, left side
of the board, one on each side of an I.C. I forget their designations
but find them and replace if necessary. They cause low video
level.
The tracks around the Scart socket are very fragile and intermittent
connections to the decoder are common. Bear in mind that the wiring
modification allows an external decoder to be plugged into the "VCR"
socket and the decoded picture appears at the RF modulator output but
not at the TV Scart socket!
Several of these have arrived for repair, recently. The latest
belonged to a "couch potato" who required me to collect the unit from
his house because he wanted to remain at home to watch the football
on terrestrial TV. As is often the case, the unit was showing "hum
bars" on the screen. I replaced the 150 F "Gloria" capacitor in the
power supply and all was well. If you catch this problem too late,
"Gloria" tends to expire and can often melt the copper tracks below
her. In this case, track repair and replacement of the UC3844 will be
required. The capacitor and occasionally the BUZ80A will have to be
renewed. Often the damage is so extensive that repair is not
viable.
Echostar's apparent reluctance to provide parts and service
information even to its service agents does not make repairing these
units any easier. JD Electronics in Sudbury used to be an appointed
agent but now work as independent repairers. Express TV in London
seem to be the only "class A" authorised service agent. Protel have
been appointed as "class B" service agent but had not, when I spoke
to them, received the service manuals or parts! Nor had another
"class B" agent, GT Satellites in Swansea.
Sometimes I wonder about hygiene when I lift the cover off a receiver
and look inside. This particular one appeared to have been used as a
vacuum cleaner! The fault symptom was "audio but no picture." Not
surprising since everything inside looked black. Having cleaned out
the dust, fluff and dog hairs, I scraped away the black carbon which
had once been glue then replaced C54 and R80 which invariably fail.
This didn't make any difference so I resorted to using my
oscilloscope. Sometimes it's quicker than guessing! The baseband
signal from the tuner was reaching the C-Band switch but going no
further.
Failure of this slide-switch is very unusual. I shorted out the
switch and traced the signal as far as R9 where, again, it stopped.
(Sometimes C1 and C6 also fail but, in this case, they were all
right). Replacing R9 (470 ) got the signal to TR1 and no further. The
signal coming out of TR1 emitter and going into the decoder was very
weak. The voltage on R4/R5 junction should have been 2 volts but was
zero. Replacing R5 (12k ) finally produced a picture from the decoder
Scart but not from the TV Scart or RF output. A dry joint on C55 was
the final culprit and, with this repaired, the receiver worked
perfectly. I just can't believe that all these faults occurred
simultaneously!
The power supply components looked very blackened and I wondered if
it would last the guarantee period before failing. In the end my
conscience won and I replaced the suspect components before returning
the unit to the customer.
Based on the Winersat, this receiver with built-in positioner was
developed by the Eurosat group a couple of years ago. The owner had
disconnected his receiver and brought it to my workshop on a wet and
windy day following a thunderstorm.
"I've checked the fuse" he informed me, "so it's going to be
expensive; but let me have an estimate if it's more than fifty
pounds."
He left the unit with me and, having nothing better to do on this
particular day, I removed the cover and rummaged inside. The receiver
was in good condition; it had not become obviously hot and nobody
else had been inside it. In fact I suspected that the fuse which the
owner had checked had been the one in his mains plug because there
are several inside the Manhattan 9000. I measured each fuse in turn
and found that E301, a 630mA fuse, was open circuit. With a new one
fitted, I stood well back and switched on the mains power. The
receiver lit up and subsequent tests showed that it now worked
perfectly.
The customer was delighted when I told him that the cost was within
budget and I had no pangs of conscience: I have to make a living.
When working, these receivers give a good picture and a lot of owners
are still happy to have them repaired, even though they are not "1D
compatible." When a lady telephoned and asked me to collect and
repair her SRD4, therefore, I didn't argue but simply emphasised my
standard charge. She thought this was reasonable since it included
collection and delivery so the job went ahead. The receiver had,
apparently, suffered very poor pictures for a few weeks before
finally giving up in a thunderstorm (I love lightning, don't you? I
stand at the window and count my bank balance rising with each
flash.)
A repair kit from Economic Devices soon had the power supply working
but the pictures were tremendously sparkly. It was not difficult to
pinpoint the tuner module as the culprit. Sometimes the cause is dry
joints inside but not in this instance. A tuner module lifted from an
old SRB1 receiver did the trick and, since I'd had this BSB receiver
given to me for nothing, I could justify charging only my standard
rate for what would otherwise have been an uneconomical repair.