Satellite Workshop 09
Up here in the Far North (just 550 miles south of John o' Groats)
we get some lah-di-dah types. This week I was being bothered by one
of the huntin', shootin', fishin' crowd who was definitely one of
those. He owns a large tract of land and he likes to lord it over
inferiors. Since I'm a "soldering iron plonker" (as a well-known
chairman of a well-known company once remarked) I clearly fell into
the inferior class.
His problem was that he had a local shop install in his mansion a
Pace MSS1000 together with a Churchill D2Mac decoder. It was fine for
a few months but at Christmas it had stopped working; that is to say,
the receiver still worked but the D2Mac pictures were not being
decoded.
The shop couldn't help so this was the gentleman's third visit to our
premises. On the first, he had brought the Churchill decoder. It
tested out OK. On the second visit he brought the decoder and the
MSS1000. They both worked perfectly for hours in our workshop. This
time he had brought them yet again. I watched him pull them out of
his Range Rover together with what looked like a gun bag. This time
he clearly meant business!
I backed away from him but he thrust the bag towards me, explaining
that it contained the handset and connecting leads and he wouldn't be
seen dead with a plastic carrier bag. He left the equipment on my
counter and hurried off to shoot some unsuspecting birds.
On test, the units worked perfectly with his card in the decoder
slot. I left them to warm up while I had a cup of tea. After that, I
rummaged in the bag to find the handset and came across a Scart lead.
Interestingly, this was definitely not the one the shop had supplied
when they installed the equipment. I know because they buy them from
me. I had a hunch and swapped leads. Sure enough, the picture
remained scrambled!
Just to be silly, I tried his Scart lead with a videocrypt decoder
instead. It worked perfectly. However, it simply would not work with
the D2Mac decoder. The cable was very large in diameter, which
suggested it was fully screened, and about one and a half metres in
length. The plug screen and pins were gold-plated. With my workshop
Scart lead, a short nine-wire cheap thing, the Churchill decoder
worked perfectly.
When his Lordship returned I asked him about the Scart lead. He
admitted rather sheepishly that he had treated himself to a new lead
for Christmas. In fact it was just about the time when the decoder
stopped working! I'm not sure if the light dawned but he turned a
little pink and left quite hurriedly.
This gold-plating of leads seems to be the "in" thing at present.
However, my understanding is that there's no advantage in putting
gold-plated pins into a socket which has tin-plated contacts. The
connection is no better and putting dissimilar metals together can
cause problems can't it? Any experts out there know about this?
Whilst browsing the USENET section of the INTERNET, I came across
some information from a young man called Mike Ginger. Now Mike seems
to spend a lot of time in experimenting with his Amstrad receiver. In
doing so he has discovered that more than 48 channels
are available with no modification at all! He writes:
"Selecting the extra 80 channels is simplicity itself. Go over to
your SRD400 and press PRESET then RECALL. Your display will show a
frequency, then the audio mode then 0 (Zero)! You can access the
extra channels only sequentially, by pressing the CHANNEL DOWN key to
scroll through them (but you can use TUNING UP or TUNING DOWN).
Whilst in this mode, which we will call Extended Mode, you can
return to Standard (48 channel) mode by pressing CHANNEL UP key,
or by directly accessing one of the normal, standard, 48
channels.
If you press CHANNEL DOWN you will notice the display changes
to channel 95. Pressing it again will show channel 94 and so on in
steps of -1 (minus one).
The first 80 of these channels, in Extended Mode, are extra
presets.
The next 48 are repeats of your Standard (48 channel) mode - so
changing any of these (in extended mode) will also change them in
Standard mode. The next 80 presets after this are repeats of the
first extra 80 presets in Extended mode, so I suggest that you do not
store anything whilst displaying these, or be aware
that any changes you make will also change the first 80 presets!
After you have scrolled through these you will return to Standard (48
channel) mode.
However, if you press CHANNEL DOWN until you come to channel 31, in
extended mode, you should see channels on Astra 1D but the Amstrad
SRD400 is picking them up (without an ADX!!). Pressing RECALL shows
the frequency to be around 6297 (or 16.297 GHz) which is incorrect.
Channels 31 through to 20 step -1 show these funny frequencies
together with Astra 1D channels 55 or 56. Have fun
experimenting."
Mike Ginger goes on to explain that a standard handset can be
modified to add the Preset and Recall functions. Thanks for
permission to publish this, Mike.
I was dragged all the way to Shrewsbury a few weeks ago by my wife
who wanted to shop and to visit the "Cadfael" centre. (This was
before the unfortunate news that the author of the Cadfael books,
Ellis Peters, had died.)
The centre itself was most interesting and my wife and children found
it all fascinating. However, the most interesting part of the trip
for me was the discovery of "Durrants" shop in the High Street. Here
are counters full of goodies for electronics enthusiasts. Not exactly
satellite TV but well worth a look. Oddly, my wife didn't find it at
all interesting and dragged me off before I had a chance to go
inside. I was forced to drive home without spending any money at
all!
An MSS500 came in with a very curious fault. It worked perfectly but
in one corner of the screen were some numbers which changed from time
to time. It was almost like a signal strength display. Assuming that
it was some sort of hidden test display, I rang Pace Technical help
line. The man from Pace was most helpful and explained that it was
indeed a factory test function which indicated correct AFC operation.
It was easily turned off by pressing "F" then "i" on the handset.
The customer couldn't understand how it had happened and was
extremely pleased that there was no repair charge (I'm a soft touch
but I've found that if you treat them right, customers often come
back and spend money later).
I've had three Philips-badged receivers with similar faults recently.
Usually no response to handset and sometimes no response to front
panel buttons. In addition, other odd occurrences such as no 13/18
switching because the receiver thinks it has skew control instead. In
each case, the Infra Red receiver had a dry joint, but soldering it
didn't cure all the problems.
Replacing the microprocessor had no effect. In desperation, convinced
that it was a microprocessor problem, I fitted a "1006"
version from a PRD900. The display showed "-E2", indicating that the
EEprom was being reprogrammed. The receiver then worked normally with
a PRD handset.
On replacing the original Philips microprocessor, I found that "-E2"
appeared again and then the receiver worked perfectly! I assume that
the original fault was corruption of the information stored in the
EEprom. Was it just coincidence that there was a dry joint on the
I.R. module or had this caused the corruption?
An old lady brought in an MSS1000. Apparently it had gone dead when
her son tried to tune in "Hot Bird" after fitting a second LNB to the
dish. On the bench, the set lit up and was clearly not dead. However
the screen flashed a warning message "LNB SHORT!" so I disconnected
the cable in a hurry. The warning continued to flash until I
disconnected then reconnected the mains supply. I checked the
installation menu. LNB input 2 was selected on channel one. When I
tried to change the setting to inputs "1 + 2" as it should be, I got
the warning message again. Before stripping the unit down, I decided
to try the factory reset. On the MSS1000, this is not such a problem
because it resets the Installation menu and channel one but leaves
the tuning of the other channels alone. As soon as I had punched in
the button sequence, the receiver worked perfectly. It seems that
some of these receivers don't like to have just one input selected.
Another fault I've come across is failure of the output I.C.s on the
Sound Board. This results in a ticking noise from the power supply.
Test by disconnecting the two-pin connector next to D54.