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D O - I T - Y O R S E L F U P G R A D E S
A N D M A I N T E N A N C E
F O R T H E
A M S T R A D S R X 1 0 0 / 2 0 0 / S R D 4 0 0
S A T E L L I T E R E C E I V E R S
Compiled by:
Mike Ginger
Internet: mike.ginger@metricom.seuk.com
2nd Edition: 14 November 1995
1
I N D E X
=========
Subject Page
Contacting the Author . . . . . . . . . . . . . . . . . . . . 3
Extra Audio Sub-Carriers . . . . . . . . . . . . . . . . . . 4
Extra Remote Control Functions (SRX200/SRD400) . . . . . . . 11
Extra 'Free' PreSets (SRD400) . . . . . . . . . . . . . . . . 23
Optional VideoCrypt Decoder Selection (SRD400) . . . . . . . 28
Resetting the SRD400 if it Locks-Up in Standby mode . . . . . 33
2
C O N T A C T I N G T H E A U T H O R
=========================================
If you have any questions about these modifications, or would
like to share your own modifications/experiences with others,
then please contact me on one of the following electronic
networks:
Internet: Mike.Ginger@metricom.seuk.com
FidoNet: Mike Ginger, 2:251/21
I look forward to hearing from you!
3
*****************************************************************
* *
* EXTRA AUDIO SUB-CARRIERS FROM THE AMSTRAD SRX100/200 AND *
* SRD400 SATELLITE RECEIVERS *
* *
*****************************************************************
Introduction
============
As standard, the Amstrad SRX100/200/SRD400 family of satellite
receivers are only able to receive audio sub-carriers 7.02, 7.20,
7.38 and 7.56 MHz. For Astra satellite television viewing only,
this is fine. However, for those wanting extra radio stations (at
7.74 and 7.92 MHz) and/or to pick-up the sound carrier on the
Eutelsat and Intelsat satellites (6.50, 6.60 & 6.65 MHz), then
this limited selection of audio sub-carriers is somewhat
frustrating.
Various commercial audio upgrades have been available for these
receivers for some time - however their relatively high price has
made it difficult for most Amstrad owners to justify this
expense!
This article describes how to make such an upgrade, yourself, for
about 10 UKP, if you want to add subcarriers 6.50/6.60/6.65 and
7.74/7.92 MHz. If you want to add just 7.74/7.92 MHz then it will
only cost about 3 UKP. It should be of interest to Amstrad
owners, who want more than to just watch television from Astra,
and also anyone that might want to buy one of these receivers
secondhand (they are very cheap now to pick-up - the SRD400 is
usually a bargain as it has VideoCrypt built in) and upgrade it
cheaply.
This upgrade involves desoldering crystal(s) from your receiver,
placing them elsewhere on the main PCB board and connecting them
up to either a SPDT switch (by adding one additional crystal) or
a DPDT switch (by adding two additional crystals) - very easy!
Please note that the following upgrade has been successfully
performed on an Amstrad SRD400, but should be very similar for
the SRX100/200 family of receivers.
Components Required
===================
In order to perform the upgrade, the following components are
required. These are available from Maplins (and other component
suppliers like RS Components) and their order reference and price
(UKP) is also given, which are valid until 28 February 1996.
Continued on next page ...
4
Code Description Quantity Price Each
------ ---------------------- ----------- ----------
1) FY84F MP Crystal 18.432 MHz (see note 1) 1.29
2) FH98G SPDT Ultra Min Toggle (see note 2) 0.89
or FH99H DPDT Ultra Min Toggle (see note 2) 1.10
3) M10K 10Kohm 0.6W Resistor (see note 3) 0.04
4) XR88V Miniature Coax 1 (metre - see note 4) 0.39
Notes:
-----
1) This is a Series Resonant crystal, utilising Can Style HC-49U.
It will only be required if you want sub-carriers 7.74 & 7.92
MHz.
2) Order a Single Pole/Double Throw (SPDT) switch if you want to
fit ONLY ONE additional crystal, otherwise order the DPDT.
3) You will need one resistor for each additional crystal you are
fitting: order one, or two, as appropriate.
4) This is 75ohm miniature coax cable. If fitting two crystals
then you should have a bit left over from 1 metre.
All the components above are available from Maplins:
Tel. +44 (0) 1702 554161
Fax. +44 (0) 1702 553935
Please note that Maplin add a handling charge of 1.55 UKP per
per order.
In addition, if you require 6.50/6.60/6.65MHz audio sub-carriers
then you will need to order a 17.170 MHz Series Resonant crystal
(Can Style HC-49U) from QuartSLab Marketing Ltd. This firm can
make crystals up to any value (apparently). This cost me 6.50 UKP
inclusive of VAT and p&p in January 1995 - contact them first and
confirm details and prices (note they only take cheques/money
orders) before ordering. QuartSLab can be contacted at:
QuartSLab Marketing Ltd., PO Box 19, ERITH, Kent, DA8 1LH. UK
Tel. +44 (0) 1322 330830 Fax. +44 (0) 1322 334904
Please note that I have no connection, or interest, with these
companies whatsoever except as a satisfied customer.
Tools Required to perform the upgrade
=====================================
The following tools will be required to carry out the audio
upgrade:
1) Soldering Iron
2) Sharp Knife
3) Phillips (cross-head) screwdriver
4) Wide(ish) flat-head (normal) screwdriver
5
How is the UpGrade possible?
============================
The Amstrad SRX100/200 and SRD400 family of receivers use two IF
filters to derive the left channel (audio modes 3 and 5) and
right channel (audio modes 4 and 6). The values of these IF
filters are 10.70 MHz (left channel) and 10.52 MHz (right
channel).
Two crystals are also employed in deviring the subcarriers, one
is 17.72 MHz (audio modes 1 and 3/4) and 18.08 MHz (audio modes 2
and 5/6).
If you take the crystal value and subtract the IF filter value
the result is the subcarrier frequency that will be received, eg:
Crystal IF Filter Subcarrier Remarks
Value (MHz) (MHz) (MHz)
17.72 - 10.70 = 7.02 ) ie. audio modes
17.72 - 10.52 = 7.20 ) 1 and 3/4
18.08 - 10.70 = 7.38 ) ie. audio modes
18.08 - 10.52 = 7.56 ) 2 and 5/6
and if we add crystals 18.432 MHz and 17.17 Mhz:
18.432 - 10.70 = 7.732 or nearly 7.74 MHz
18.432 - 10.52 = 7.912 or nearly 7.92 MHz
17.17 - 10.70 = 6.47 or nearly 6.50 MHz
17.17 - 10.52 = 6.65 also picks-up 6.60 MHz
You might want to add subcarriers 8.10 and 8.28 MHz (with an
18.80 MHz crystal!):
18.80 - 10.70 = 8.10
18.80 - 10.52 = 8.28
In practise, the 18.432 MHz crystal gives excellent performance.
The 17.17 MHz crystal is satisfactory for subcarriers 6.50 MHz
and 6.65 MHz. A slight distortion is experienced on 6.60 MHz, the
distortion being worse on weak stations. This may, however, have
more to do with the de-emphasis system used on the Eutelsat
satellites (50 us) as the Amstrad receivers use 75 us.
Continued on next page ...
6
Performing the UpGrade
======================
When referring to top, bottom, left hand side, right hand side,
etc. please note that I am referring to the view of the receiver
when it is in its normal position with the control panel facing
you, as below:
Rear/back of the receiver
|\------------------------------------------\ Right
Left | \ \ Hand
Hand | \ Upper Tray \ side
side |\ \ \
\ \ \ \
\ \ \ \
Lower Tray > \ |-------------------------------------------
(underneath) \ \ | Front |
\ \| Panel (controls) |
\|-------------------------------------------
Figure 1: Amstrad SRX100/200/SRD400 satellite receiver
Once you have obtained the components, outlined above, proceed as
follows:
1) Disconnect your receiver from the electricity mains supply and
disconnect all leads going into the receiver (LNB, TV aerial,
RF out, etc.).
2) Place your receiver on a suitable workbench.
3) Switch on your soldering iron (to warm up!).
4) Turn the receiver over and undo the four screws underneath.
5) Remove the top cover (slide backwards and lift).
6) Remove the front (facia) cover - there are two plastic clips
holding this on underneath (unclip these first) and three on
the top (unclip these last).
7) Remove the VideoCrypt decoder board (SRD400):
Unclip the three leads - gently tease the leads out of their
sockets with a thin wide(ish) blade screwdriver. Remove the
two screws holding the board on. Lift out the Videocrypt board
by pushing the body lugs outwards.
8) Gain access to underneath of main PCB:
Remove the two screws holding the board to the lower tray.
Push lugs to left of receiver outwards and lift from left
hand side, pull slightly leftwards and then hinge on left
hand side. Their is no need to remove this board fully.
Continued on next page ...
7
The next thing to do is locate the original crystals supplied, on
the main board, which you will need to remove by desoldering one,
or two, as appropriate. The two crystals will be located together
on the board, one being marked 17.720 and the other marked
18.080.
Before removing the crystal(s) pause and think, at this stage,
how you want to be able to switch to your new selection of audio
sub-carriers. By keeping it simple, I'll assume that you wish to
fit only the 18.432 MHz (7.74/7.92) crystal. If you want to
select 7.74/7.92 on audio 1/3/4/7 then desolder crystal 17.720
otherwise desolder crystal 18.08 (audio 2/5/6). You will only
need to de-solder both if you are adding two (or more?) crystals.
If only adding one extra crystal, then the new circuit for
switching between the old and new crystals is given below:
----------------
| |
| (4) Crystal (6)----------------(9)
| | One | / \
- | ------------ \ \
| 10Kohm / \
| resistor \ (8)----------
| / SPDT |
- | ------------ \ Switch |
| | | / |
| (3) Crystal (5)----------------(7) |
| | Two | |
- | ------------ |
| |
(1) ---------- |
(Old crystal |
position) |
(2) ------------------------------------------------------------
Figure 2: Schematic diagram of adding one crystal.
If you wish to select your new crystal on setting audio 1/3/4/7
then 'Crystal One', in the diagram, would be the (desoldered)
17.720 crystal whilst 'Crystal Two' would be your new 18.432 MHz
crystal.
The connections, that will require soldering, are marked (1)
through to (9) above. These connections should be made by using
the inner strand of the miniature co-ax cable. Technically, the
outer strands should be earthed, to reduce any interference,
although I found that this was not necessary. Keep these
connections as short as possible.
Decide where, on the board, you wish to re-locate the crystals (I
turned mine upside down and glued them to the main PCB very near
to their original location) and do a quick 'dry-run' of cutting
the co-ax to its appropriate length before soldering anything.
8
You will need to locate your switch somewhere convenient. This is
best fitted after you have made your solder connections, (1) and
(2) in the diagram figure 2 above, to the main PCB and refitted
the main PCB back into the lower (cover) tray with the two screws
(solder these connections underneath the board).
I found an ideal place to house the SPDT (DPDT if adding two
crystals) switch was between the two lips that protrude slightly
inwards into the set on the right hand side of the lower tray
(immediately to the right of the crystals). You will find that
the switch will fit into the gap when the lever is facing either
towards the front of the set or to the rear of the set (not
facing up or down). You will need to make a small hole in the
right hand side of the lower tray so that the switch will fit
through. I found that I only needed one of the nuts supplied to
retain it in the tray. If you locate it here, you will also need
to remove, with a sharp knife, part of the lip on the upper
(cover) tray, or it will not fit back on!
Remember to connect a 10Kohm resistor to the throws of the
SPDT/DPDT switch (connections (7) and (9) in figure 2 above).
If you are adding two additional crystals then you need to just
'double-up' the schematic diagram in Figure 2 above.
Note that the connection of the crystal(s) is not polarity
dependant ie. they can be connected either way round.
Re-assembly is a direct reversal of dis-mantling the unit.
Some extra hints and tips
=========================
I've tried my crystals on different settings and found that the
following combination gave the best results:
With DPDT switch facing to the front of the receiver (I call this
TV mode):
Audios 3 and 4 give 6.50 MHz and 6.60/6.65 MHz respectively.
Audios 5 and 6 give 7.02 MHz and 7.20 MHz respectively.
With DPDT switch facing to the rear of the receiver (I call this
Radio mode):
Audios 3 and 4 give 7.74 MHz and 7.92 MHz respectively.
Audios 5 and 6 give 7.38 MHz and 7.56 MHz respectively.
The reason that I set them up in this sequence is the rationale
that I would either want to sit down and watch TV or just listen
to radio stations (the switch involves getting up and flicking
the switch over on the receiver, rather than in the armchair!).
Continued on next page ...
9
Also, most people are 'lazier' when watching TV than when
listening to the Radio. Thus the ability to select any TV sound
when the switch is in any one position.
I reset all channels 1 to 48 to Audio 2 (normal Astra TV sound).
I can now select most Astra radio stations just by flicking the
switch over (most are on 7.38/7.56 MHz).
Particularly for Eutelsat viewing, I can do all the TV sound
selecting from the armchair! (6.50/6.60/6.65 and 7.02/7.20).
I found better performance from the 6.50/6.60/6.65 MHz crystal by
running it through the audio 1 circuit (I did try the audio 2
circuit on my first attempt but experienced more distortion).
10
*****************************************************************
* *
* EXTRA REMOTE CONTROL FUNCTIONS ON THE AMSTRAD SRX200 AND *
* SRD400 SATELLITE RECEIVERS *
* *
*****************************************************************
Introduction
============
As standard, the Remote control unit on the Amstrad SRX200/SRD400
family of satellite receivers are not able to perform all
functions that are available on the front panel of the receiver.
The functions unavailable on the Remote Control are PRESET, H/V
select, TUNING DOWN, TUNING UP and AUTHORISE.
This is particularly frustrating to those users that want to make
use of the extended presets facility, outlined in the next
chapter, and those that want to scan the frequencies on other
satellites, like the Eutelsat family, without having to get out
of their armchair, kneel down perhaps, and press buttons on the
front panel of the receiver.
This article deals with upgrading the Remote Control to perform
all functions, except AUTHORISE.
This upgrade involves dismantling the Remote Control unit, making
up some connectors with tin-foil, perhaps soldering these
connections to make them more reliable, and making four buttons
out of any piece of spare rubber (black colour preferred!). You
will also need to cut out the new buttons positions on the
remote, with a sharp knife. This upgrade really is very easy and
virtually free.
Note that this upgrade has been successfully completed on an
Amstrad SRD400 remote. These notes can also be adapted to upgrade
the SRX200 Remote Control but the IC chip numbers, and Remote
Control layout, will be different on the SRX200 - experiment and
adapt!
For a more permanent fix, it may be better to purchase some
silver paint and use this instead of the silver foil. This will
prove more reliable in practise.
Components Required
===================
In order to perform the upgrade, the following components are
required. These are normal household items!
Continued on next page ...
11
1) Some silver foil, eg. Baking foil, Kit-Kat inner wrapper.
2) A small amount of glue.
OR
1) Small amout of Silver Paint. This is available from Car Spares
shops, eg. Comma Electrocure or from Maplins:
Code Description Quantity Price Each
------ ---------------------- ----------- ----------
1) FY72P Conductive Paint 1 6.79
Notes:
-----
The components above are available from Maplins:
Tel. +44 (0) 1702 554161
Fax. +44 (0) 1702 553935
Please note that Maplin add a handling charge of 1.55 UKP per
order.
These prices are valid until 28 February 1996.
Please note that I have no connection with the above named
companies, except as a satisfied customer.
Tools Required to perform the upgrade
=====================================
The following tools will be required to carry out the remote
control upgrade:
1) Soldering Iron (recommended - may not be necessary - will
not be necessary if using the Silver Paint method)
2) Sharp Knife
3) Small length of wire (for circuit testing)
4) Wide(ish) flat-head (normal) screwdriver
Continued on next page ...
12
How is the UpGrade possible?
============================
The IC (Integrated Circuit) chip inside the Remote Control of the
Amstrad SRX200/SRD400 is capable of performing all functions that
are available on the front panel, except AUTHORISE (SRD400 only).
Also, there are four more 'press key' contacts inside the SRD400
Remote (sorry, don't know about the SRX200) that are blanked off
- one of these is between the STANDBY and RECALL keys, the other
three being below the CHANNEL DOWN, CHANNEL UP and AUDIO keys -
all very convenient for the upgrade!
It would seem that Amstrad did consider providing these
functions, as standard, on the remote but decided at a later date
to blank them off. I can only think that they did this so that
users would not accidently lock themselves out of the receiver by
inadvertently enabling the parental lock (more of this later).
Performing the UpGrade
======================
In order to perform this upgrade, you will need to gain access to
the inside of your Remote Control unit.
To do this:
1) Slide off the battery compartment cover.
2) Remove the batteries.
3) You should see, inside the battery compartment, where the
upper cover (of the remote) meets the lower cover.
Insert a wide(ish) thin flat-headed screwdriver in here, as
indicated in figure 1 below.
Push the screwdriver in, and downwards (towards the upper
cover with the remote upside down) whilst pulling the upper
cover away from the lower. They should seperate. Repeat for
the other side of the remote.
Pull the lower cover slightly upwards whilst pushing in the
upper cover at the other two clip points (one in the middle
and the other at the end furthest from the battery
compartment).
With the lower cover removed access can now be gained to the PCB
of the remote.
Continued on next page ...
13
\
( \
\
) \
\
( \
\
) \
\
( \
\
) \
\
( \
\
) / | \ \
/ | \ \
( / /| |\ \ \
/ / | | \ \ \
) / | + | | \ \ \
/ | / / \ \ \ \
( / /| |/ / \ \ \ \
\ / / | / \ \ \ \
) / | - | / \ \< Insert Screwdriver
/ | / / \ \ here !
( \ \ |/ / \ \ \ \
\ \ / \ \ \ \
)\ \ \/ Inside of \ \ \ \
\ \ Battery \ \ \ \
( \ \ Compartment \ \ \ \
\ \ \ with cover slide off \ \ \ \
) \ \ \ \ \ / /|
\ \ \ \ / / |
) \ \ \ / / |
\ \ Lower \ \ / / |
\ \ Cover \ \ / / |
\ \ \ \ / / /|
\ \ \ \ / / / |
\ \ \ \ / / / |
\ Upper \ \ \ / / / |
\ Cover \ \ \ / / Lower / /
\ \ \ / Cover / /
\ \ \ / / /
\ \ | / /
\ \ | / /
\ \ | / /
\ \ | /Upper /
\ \|/ Cover /
\ | /
\ | /
\ | /
\|/
Figure 1: Amstrad SRD400 Remote Control, upside down viewed
from battery compartment end.
14
Remove the PCB from the upper cover, simply by lifting, and also
remove the rubber key selector (which is located underneath the
PCB with the Remote Control upside-down).
Now, replace the PCB in the upper cover, but the wrong way round
(so that the contacts face upwards, and towards you). At the
other end of the battery compartment, remove the battery
connector and replace the other way round. You can now replace
the batteries (the wrong way round) and lay the rubber key
selector on top of the PCB.
Pointing your remote at your receiver (with it switched ON) press
the key in the bottom right hand corner of the rubber key
selector (the key immediately below the AUDIO key - this key is
not full height). This should activate H/V select. No new
connection is necessary to enable this function (but you will
need to cut out the 'blank off' area and make a new key - more of
this later). Also note that this function is also available, at
this stage, by pressing the key to the left of it (immediately
below the CHANNEL UP key).
Whilst in this test mode you may like to test the different
selections possible, and check these with my results, by
connecting a short length of wire between the IC chip pins in all
the different permutations. The chip is located at the bottom of
the remote, or the point nearest the battery compartment.
Pin > 16 15 14 13 12 11 10 9
No's> | | | | | | | |
| | | | | | | |
-----------------------------
| Amstrad SRD400 |
IC > | Remote Control IC |
| (Integrated Circuit Chip) |
-----------------------------
| | | | | | | |
Pin > | | | | | | | |
No's> 1 2 3 4 5 6 7 8
Figure 2: The SRD400 Remote Control IC Chip and pin no's.
My testings have resulted in determining that the following
combinations are possible, as per the table in figure 3 below.
Note that some pin connection permutations do not activate
anything. SRX200 users will need to prepare their own table as it
may be different to the SRD400.
Continued on next page ...
15
IC Pin
Number 1 2 3 4 5 6 7
--------------------------------------------------------
8 | | | | 1 | 2 | 3 | 4 |
| | | | | | | |
--------------------------------------------------------
9 | | | | 5 | 6 | 7 | 8 |
| | | | | | | |
--------------------------------------------------------
10 | | | | 9 | 0 | 1* | 2* |
| | | | | | | |
--------------------------------------------------------
11 | | | | 3* | 4* |TV/SAT |CHANNEL|
| | | | | | | DOWN |
--------------------------------------------------------
12 | | | |STANBY |RECALL | AUDIO | H/V |
| | | | | | | |
--------------------------------------------------------
13 | | | |CHANNEL|PRESET |TUNING |TUNING |
| | | | UP | | UP | DOWN |
--------------------------------------------------------
14 | | | | | | | |
| | | | | | | |
--------------------------------------------------------
15 | | | | | | | |
| | | | | | | |
--------------------------------------------------------
16 | | | | | | | |
| | | | | | | |
--------------------------------------------------------
Figure 3: Table of possible Remote Control permutations.
In order to activate your new Remote Control selections you may
wish to solder small lengths of wire to the relevant IC chip pin
soldering the other end to your tin-foil, or whatever, button
switch.
I decided against this approach. The main reason being that the
pin connections are so close together on the chip that, I felt,
soldering direct to the pin(s) would have been too difficult.
Instead, I traced the relevant pin connections and translated
these into a map of the 'rubber-button' switch contacts. I
decided to solder to these contacts instead (much easier). At a
later date, I removed the silver foil contacts and replaced them
with new tracks painted with Silver Paint.
As standard, each switch contact appears as in figure 4 below.
Continued on next page ...
16
----------------------------
Contact furthest > | Top |
from batteries > | Contact |
----------------------------
| ---------------------- < keys actually
---------------------- | < contact here
---------------------------- when pressed.
Contact nearest > | Lower |
to batteries > | Contact |
----------------------------
Figure 4: Standard switch contact on Amstrad SRD400 remote.
Which, in the map in figures 6 and 7 below, are shown as in
figure 5 below.
STANDBY < Key/Switch function
Furthest > ----------
from batts. > | 12 | < Pin number connected to, on IC.
----------
Nearest to > | 4 | < Pin number connected to, on IC.
batteries > ----------
Figure 5: Interpretation of keypad map in figures 6 and
7 below.
Figure 6, below, is the map of the 'rubber-button' switch
contacts as standard, and before upgrading.
Continued on next page ...
17
unused key
STANDBY blanked off RECALL
---------- ---------- ----------
| 12 | | | | 12 |
---------- ---------- ----------
| 4 | | | | 5 |
---------- ---------- ----------
1 2 3
---------- ---------- ----------
| 8 | | 8 | | 8 |
---------- ---------- ----------
| 4 | | 5 | | 6 |
---------- ---------- ----------
4 5 6
---------- ---------- ----------
| 8 | | 4 | | 5 |
---------- ---------- ----------
| 7 | | 9 | | 9 |
---------- ---------- ----------
7 8 9
---------- ---------- ----------
| 9 | | 9 | | 4 |
---------- ---------- ----------
| 6 | | 7 | | 10 |
---------- ---------- ----------
0 1* 2*
---------- ---------- ----------
| 10 | | 10 | | 10 |
---------- ---------- ----------
| 5 | | 6 | | 7 |
---------- ---------- ----------
3* 4* TV/SAT
---------- ---------- ----------
| 4 | | 5 | | 6 |
---------- ---------- ----------
| 11 | | 11 | | 11 |
---------- ---------- ----------
CHANNEL
DOWN UP AUDIO
---------- ---------- ----------
| 11 | | 4 | | 6 |
---------- ---------- ----------
| 7 | | 13 | | 12 |
---------- ---------- ----------
unused key unused key unused key
blanked off blanked off blanked off
---------- ---------- ----------
| | | | | |
---------- ---------- ----------
| | | | | |
---------- ---------- ----------
Figure 6: Standard Amstrad SRD400 Remote Control layout
Now, lift off the rubber keypad selector, remove the batteries
from the battery compartment and remove the PCB.
18
You are now ready to make the new connectors with tin-foil (or
paint new tracks on the board with Silver Paint).
First, decide the layout of your upgraded remote. I decided that
the layout, for my remote, would follow that in figure 7 below.
STANDBY PRESET RECALL
---------- ---------- ----------
| 12 | | 13 | | 12 |
---------- ---------- ----------
| 4 | | 5 | | 5 |
---------- ---------- ----------
1 2 3
---------- ---------- ----------
| 8 | | 8 | | 8 |
---------- ---------- ----------
| 4 | | 5 | | 6 |
---------- ---------- ----------
4 5 6
---------- ---------- ----------
| 8 | | 4 | | 5 |
---------- ---------- ----------
| 7 | | 9 | | 9 |
---------- ---------- ----------
7 8 9
---------- ---------- ----------
| 9 | | 9 | | 4 |
---------- ---------- ----------
| 6 | | 7 | | 10 |
---------- ---------- ----------
0 1* 2*
---------- ---------- ----------
| 10 | | 10 | | 10 |
---------- ---------- ----------
| 5 | | 6 | | 7 |
---------- ---------- ----------
3* 4* TV/SAT
---------- ---------- ----------
| 4 | | 5 | | 6 |
---------- ---------- ----------
| 11 | | 11 | | 11 |
---------- ---------- ----------
CHANNEL
DOWN UP AUDIO
---------- ---------- ----------
| 11 | | 4 | | 6 |
---------- ---------- ----------
| 7 | | 13 | | 12 |
---------- ---------- ----------
TUNING
DOWN UP H/V
---------- ---------- ----------
| 7 | | 6 | | 12 |
---------- ---------- ----------
| 13 | | 13 | | 7 |
---------- ---------- ----------
19
Figure 7: Converted Amstrad SRD400 Remote Control layout
No further work was needed to enable H/V select. There are two,
exposed, connecting contacts that are, conveniently, located
beneath the button.
In order to enable TUNING UP (which at this time functioned as
H/V select) I masked off the existing connection with a piece of
self-advesive paper (like that used for envelope labels) so that
it would not activate H/V select. I then cut out a piece of tin
foil for one side of the 'switch' (IC pin contact 6 in figure 7
above). I cut-out a second, longer, strip for the IC no 13
connection part of the switch - this doubled as serving the
TUNING DOWN switch as well. Position the tin foil connectors as
close to centre, of where the button will press, as possible.
Also, leave as small a gap between the connectors, for each
switch, as possible. Same applies if you are using the Silver
Paint method.
A thin, tin-foil, connection was then made between IC pin
connector 6, on TUNING UP and IC pin connector 6 on AUDIO.
A thin, tin-foil, connection was then made between IC pin
connector 13, on TUNING UP and IC pin connector 13 on CHANNEL UP.
This was the TUNING UP key enabled!
Half of TUNING DOWN key was already prepared when making the
connections for TUNING UP (the IC pin 13 connection). A largeish
piece of tin-foil was cut to double as the second half of the
switch connection, connecting directly to IC pin connection 7 on
the CHANNEL DOWN switch above it.
This was TUNING DOWN key enabled!
Finally, PRESET needed to be enabled.
A largeish piece of tin-foil doubled as the IC pin 5 connection,
connecting directly to IC pin connection 5 on the RECALL button.
A piece of tin-foil was then cut for the IC 13 connection part of
the switch. A long, thin, piece of tin-foil was then cut to
connect this IC 13 connection, on PRESET to IC pin 13 connection
on the new TUNING DOWN switch. This was run down the left-hand
side and underneath the switch contact side of the PCB.
This was PRESET enabled!
Finally, all new contacts were soldered at their joins. I did not
do this on my first attempt and suffered unreliable operation, so
I recommend that you solder these joins. Solder as far away as
possible from where the rubber keys will make contact, otherwise
these joins will 'break' as soon as you start using your remote
again!
20
To avoid any problems in the future, it would be better to use
the Silver Paint method instead, as this is more robust.
In order to use these keys you will, of course, need to cut-out
the rectangular key holes, which are blanked off, in the upper
cover of the remote.
Use a very sharp knife to cut out these holes. Try and smooth the
edges of these new holes after they are cut out.
Finally, you will need to make some new rubber keys in order to
use your new functions.
I suggest that you make the keys just a bit too big to start with
and cut to size gradually until you get a good fit. Also I
suggest you leave a thin 'foot' on your new rubber switches (this
will stop them from falling out of the upper cover of the remote)
as in figure 8 below.
/ \
/ \
/ \
/ \ < 'Finger press' contact of new
/ \ rubber switch.
|\ \
| \ \
| \ \
| \ \
| \ \
| \ \
| \ \
| \ \
| \ / |
| \ / |
/\ \ / |
/ \ \ / |
\ \ \ / |
\ \ | |
\ \ | |
\ \ | |
\ \ | |
\ \ | |
\ \ | | \
\ \ | | /
Retaining > \ \ | |/
Foot of new > \ \ | /
rubber switch > \ \ | /
\ | /
This can be quite \ | /
thin and is just \ | /
to stop the key
falling out of
the remote.
Figure 8: Shape of new rubber switches.
21
If you prepare your new rubber switches in this way then you will
actually install them by inserting them from inside the Remote
Control unit. The retaining foot is to prevent them from
inadvertently 'popping-out'.
I did try and glue the new rubber switches on my first attempt
but rubber is not the easiest material to glue - and easily un-
sticks!
Now reassemble everything, except do not replace the upper cover
of the Remote Control at this stage (ie. insert your new rubber
keys in their respective housings, replace the rubber key
selector and replace the PCB and batteries).
Whilst supporting the PCB with one hand, turn your remote over so
that the keys are facing you and check that all your keys,
including the new ones, function as they should.
If one, or more, of the new keys do not function then remove the
batteries from the remote, turn the PCB and battery connector
over and replace the batteries. Use your test wire to check the
connections on the tin-foil, near to where the keys are touching.
If the function(s) fails then this would indicate that one of
your connections has come loose - re-solder! If these connections
are ok then it may be that the rubber key selectors are not
connecting over the gaps in your tin-foil - reposition the tin-
foil connections before the glue sets!
Some extra hints and tips
=========================
Try to avoid, at all times, hitting the H/V select key twice in
quick succession - if you then press AUDIO or RECALL you will
enter one of the (damned!) parental lock sequences. If this
happens (four dashes will appear on your display) the best thing
to do is remove the mains plug, wait 10 seconds, then plug back
in!
Credits
=======
Many thanks to Malik Dad, on the internet, for supplying
information on the Amstrad SRX200 remote control. This article
would not have come into existance without him.
22
*****************************************************************
* *
* EXTRA 'FREE' PRESETS FROM THE AMSTRAD SRD400 SATELLITE *
* RECEIVER *
* *
*****************************************************************
Introduction
============
As standard, the Amstrad SRD400 satellite receiver appears to be
capable of storing only 48 channels. For Astra satellite
television viewing only, this is fine. However, for those wanting
extra presets to store radio stations and/or to store the
different frequencies on the Eutelsat and Intelsat satellites,
then this limited selection of presets is somewhat frustrating.
Various commercial '99 channel' upgrades have been available for
these receivers for some time - however their relatively high
price has made it difficult for most Amstrad owners to justify
this expense!
This article describes how to access an extra 80 presets and the
good news is that this will not cost you a penny or involve any
modifications whatsover.
Accessing the Free Presets
==========================
Selecting the extra 80 presets is simplicity itself. Go over to
your SRD400 and press PRESET then press either one of TV/SAT or
RECALL.
If you pressed TV/SAT your display will now show channel 0
(Zero)!
If you pressed RECALL your display will show a frequency, then
the audio mode then 0 (Zero)!
I would recommend that you use the second method (PRESET then
RECALL) to access these extra presets, just in case you have an
ADX unit connected or intend to fit one at a later date.
The only drawback to these extra presets is that you can only
access them sequentially, by pressing the CHANNEL DOWN key to
scroll through them (you can press TUNING UP or TUNING DOWN
though).
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.
23
Do not store anything on these Extended Presets at this time -
read this article in full first!
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 presets, 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.
There does appear to be an exception to this rule though. If you
press CHANNEL DOWN until you come to channel 31, in extended
mode, you should see either a sparkly Teleclub or an Astra 1D
TestCard (at the time of writing) - these are two 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
(Teleclub) or 56 (Astra 1D TestCard). If possible, do not store
anything on these channel presets in case someone can shed some
more light on these. If you keep pressing CHANNEL DOWN until
channel 63 is displayed then theory dictates that channels 63 to
52 step -1 should be repeats of the first set of Extended presets
31 to 20 step -1, but this time no TV transmissions are received
and pressing RECALL displays a frequency of around 2106 (12.106
GHz).
Whilst exploring these extra presets you will notice some funny
channel numbers being displayed.
The following table, summarising the sequence of channels, should
be of use to you when using these extra (Extended) presets:
Column Column Column Column
(1) (2) (3) (4)
Number Remarks Number Remarks
Displayed Displayed
--------- ---------------------- --------- --------------------
0 ||8 Repeat of channel opposite
95 Can press CHANNEL UP for 0 ||7 Repeat of channel opposite
94 ||6 Repeat of channel opposite
93 ||5 Repeat of channel opposite
92 ||4 Repeat of channel opposite
91 ||3 Repeat of channel opposite
90 ||2 Repeat of channel opposite
Columns Continued on next page ...
24
Column Column Column Column
(1) (2) (3) (4)
Number Remarks Number Remarks
Displayed Displayed
--------- ---------------------- --------- --------------------
89 ||1 Repeat of channel opposite
88 ||0 Repeat of channel opposite
87 | 9 Repeat of channel opposite
86 | 8 Repeat of channel opposite
85 | 7 Repeat of channel opposite
84 | 6 Repeat of channel opposite
83 | 5 Repeat of channel opposite
82 | 4 Repeat of channel opposite
81 | 3 Repeat of channel opposite
80 | 2 Repeat of channel opposite
79 | 1 Repeat of channel opposite
78 | 0 Repeat of channel opposite
77 A9 Repeat of channel opposite
76 A8 Repeat of channel opposite
75 A7 Repeat of channel opposite
74 A6 Repeat of channel opposite
73 A5 Repeat of channel opposite
72 A4 Repeat of channel opposite
71 A3 Repeat of channel opposite
70 A2 Repeat of channel opposite
69 A1 Repeat of channel opposite
68 A0 Repeat of channel opposite
67 99 Repeat of channel opposite
66 98 Repeat of channel opposite
65 97 Repeat of channel opposite
64 96 Repeat of channel opposite
63 95 Repeat of channel opposite
62 94 Repeat of channel opposite
61 93 Repeat of channel opposite
60 92 Repeat of channel opposite
59 91 Repeat of channel opposite
58 90 Repeat of channel opposite
57 89 Repeat of channel opposite
56 88 Repeat of channel opposite
55 87 Repeat of channel opposite
54 86 Repeat of channel opposite
53 85 Repeat of channel opposite
52 84 Repeat of channel opposite
51 83 Repeat of channel opposite
50 82 Repeat of channel opposite
49 81 Repeat of channel opposite
48 80 Repeat of channel opposite
47 79 Repeat of channel opposite
46 78 Repeat of channel opposite
45 77 Repeat of channel opposite
44 76 Repeat of channel opposite
43 75 Repeat of channel opposite
Columns Continued on next page ...
25
Column Column Column Column
(1) (2) (3) (4)
Number Remarks Number Remarks
Displayed Displayed
--------- ---------------------- --------- --------------------
42 74 Repeat of channel opposite
41 73 Repeat of channel opposite
40 72 Repeat of channel opposite
39 71 Repeat of channel opposite
38 70 Repeat of channel opposite
37 69 Repeat of channel opposite
36 68 Repeat of channel opposite
35 67 Repeat of channel opposite
34 66 Repeat of channel opposite
33 65 Repeat of channel opposite
32 64 Repeat of channel opposite
31 ( Displays frequencies 63 ( Displays frequencies
30 ( in the range 6297 MHz 62 ( in the range 2106 MHz
29 ( (channel 31) to 6128 61 ( (channel 63) to 1953
28 ( MHz (channel 20). 60 ( MHz (channel 52).
27 ( Actual frequency must 59 ( Actual frequency could
26 ( be between 0818 and 58 ( not be determined as
25 ( 0803 as these would 57 ( no transmissions have
24 ( be the frequencies of 56 ( been received on these
23 ( transponders 56 and 55 ( presets!!! They are not
22 ( 55 on Astra 1D, which 54 ( repeats of channels 31
21 ( it displays!!! 53 ( to 20 step -1 in column
20 ( 52 ( (1) opposite !!!
19 51 Repeat of channel opposite
18 50 Repeat of channel opposite
17 49 Repeat of channel opposite
16 As Standard Mode channel 48
15 As Standard Mode Channel 47 And then back into Standard
14 As Standard Mode Channel 46 48 channel mode. Press PRESET
13 As Standard Mode Channel 45 and RECALL to re-enter extended
12 As Standard Mode Channel 44 mode at channel 0 in column (1).
11 As Standard Mode Channel 43
10 As Standard Mode Channel 42
09 As Standard Mode Channel 41
08 As Standard Mode Channel 40
07 As Standard Mode Channel 39
06 As Standard Mode Channel 38
05 As Standard Mode Channel 37
04 As Standard Mode Channel 36
03 As Standard Mode Channel 35
02 As Standard Mode Channel 34
01 As Standard Mode Channel 33
00 As Standard Mode Channel 32
9 As Standard Mode Channel 31
8 As Standard Mode Channel 30
7 As Standard Mode Channel 29
6 As Standard Mode Channel 28
Columns Continued on next page ...
26
Column Column Column Column
(1) (2) (3) (4)
Number Remarks Number Remarks
Displayed Displayed
--------- ---------------------- --------- --------------------
5 As Standard Mode Channel 27
4 As Standard Mode Channel 26
3 As Standard Mode Channel 25
2 As Standard Mode Channel 24
1 As Standard Mode Channel 23
0 As Standard Mode Channel 22
-9 As Standard Mode Channel 21
-8 As Standard Mode Channel 20
-7 As Standard Mode Channel 19
-6 As Standard Mode Channel 18
-5 As Standard Mode Channel 17
-4 As Standard Mode Channel 16
-3 As Standard Mode Channel 15
-2 As Standard Mode Channel 14
-1 As Standard Mode Channel 13
-0 As Standard Mode Channel 12
U9 As Standard Mode Channel 11
U8 As Standard Mode Channel 10
U7 As Standard Mode Channel 9
U6 As Standard Mode Channel 8
U5 As Standard Mode Channel 7
U4 As Standard Mode Channel 6
U3 As Standard Mode Channel 5
U2 As Standard Mode Channel 4
U1 As Standard Mode Channel 3
U0 As Standard Mode Channel 2
||9 As Standard Mode Channel 1
And then to channel ||8 at the
top of column (3) on page 24.
Some extra hints and tips
=========================
Avoid pressing the 'H/V SELECT' key twice, as this may initiate
the, damned, parental lock function. If you do press it twice
then the best thing to do is press CHANNEL UP or CHANNEL DOWN key
- this will cancel any parental lock sequence.
If you do, inadvertently, enter the parental lock feature then
you will need to reset the receiver by un-plugging it from the
mains, wait around 10 seconds, then plug back in.
27
*****************************************************************
* *
* RESETTING THE AMSTRAD SRD400 SATELLITE RECEIVER IF IT *
* LOCKS-UP IN STANDBY *
* *
*****************************************************************
Introduction
============
When new, one of the Amstrad SRD400's selling points was it's
built-in parental lock 'feature', which was included to allow
parents to prevent their children, etc., watching the erotic
offerings from the clear PAL channels of RTL, SAT 1 and PRO 7.
However, this feature can be more of a nuisance than a facility
and there may be times, for instance if you have 'freinds' round
that don't know what they're doing or just simply like pressing
buttons in all sorts of combinations, when the receiver will
suddenly 'lock-up'.
In times like these then you will not know how to unlock the
receiver if the PIN is unknown. In this situation you have two
choices. Either leave the unit on STANDBY for at least 48 hours
(2 days) or read this article and unlock it electronically!
Please note that the following upgrade has not been performed on
my Amstrad SRD400.
Components Required
===================
In order to perform the upgrade, the following components are
required. These are available from Maplins (and other component
suppliers like RS Components) and their order reference and price
(UKP) is also given, which are valid until 28 February 1996:
Code Description Quantity Price Each
------ ---------------------- ----------- ----------
M1K 1Kohm 0.6W Resistor 1 0.04
Notes:
-----
All the components above are available from Maplins:
Tel. +44 (0) 1702 554161
Fax. +44 (0) 1702 553935
Please note that Maplin add a handling charge of 1.55 UKP
per order.
Please note that I have no connection, or interest, with these
companies whatsoever except as a satisfied customer.
33
Tools Required to perform the upgrade
=====================================
The following tools will be required to carry out the upgrade:
1) Soldering Iron
2) Phillips (cross-head) screwdriver
3) Wide(ish) flat-head (normal) screwdriver
Performing the Repair
=====================
When referring to top, bottom, left hand side, right hand side, etc.
please note that I am referring to the view of the receiver when
it is in its normal position with the control panel facing you, as
below:
Rear/back of the receiver
|\------------------------------------------\
Left | \ \ Right Hand
Hand | \ Upper Tray \ side
side |\ \ \
\ \ \ \
\ \ \ \
Lower Tray > \ |-------------------------------------------
(underneath) \ \ | Front |
\ \| Panel (controls) |
\|-------------------------------------------
Figure 1: Amstrad SRD400 satellite receiver
Once you have obtained the components, outlined above, proceed
as follows:
1) Disconnect your receiver from the electricity mains supply
and disconnect all leads going into the receiver (LNB, TV
aerial, RF out, etc.).
2) Place your receiver on a suitable workbench.
3) Switch on your soldering iron (to warm up!).
4) Turn the receiver over and undo the four screws underneath.
5) Remove the top cover (slide backwards and lift).
6) Remove the front (facia) cover - there are two plastic clips
holding this on underneath (unclip these first) and three on
the top (unclip these last).
Continued on next page ...
34
7) Remove the VideoCrypt decoder board (SRD400):
Unclip the three leads - gently tease the leads out of their
sockets with a thin wide(ish) blade screwdriver.
Remove the two screws holding the board on.
Lift out the Videocrypt board by pushing the body lugs outwards.
Now, locate IC number IC104. This is located on the main
motherboard towards the rear/right-hand side of the receiver. It
is located just in front of the LNB input 'box'.
You will need to, temporarily, solder/connect one end of the 1K
resistor to pin 5 of IC104.
---------------------
| |
Pin 5 >>>>> [[| |]]
| |
[[| Chip |]]
| |
[[| IC104 |]]
| |
[[| |]]
| |
---------------------
Figure 1: Chip IC104
The other end of the resistor needs to be connected to 'ground'.
Do this by connecting it to any one of the 2 black leads which
you dis-connected from the rear of the VideoCrypt decoder (the
socket with two two white leads and two black leads).
Once you have connected the resistor up in this way, then re-
connect the LNB lead back into the receiver and plug back into
the mains (do not re-assemble the VideoCrypt decoder or replace
the receiver's cover at this time).
Do not touch anything inside the receiver (keep children/pets
well away) and press the following keys in the following
sequence:
Continued on next page ...
35
1) Press STANDBY on Receiver's Front Panel.
Display should show 8
2) Press H/V button twice.
3) Press AUDIO button once.
Display should show - - - -
4) Press 1234 on Remote Control.
Display should show ]] ]] ]] ]]
5) Remove resistor whilst the receiver is still switched on. do
this by dis-connecting the end from the VideoCrypt lead.
DANGER. MAINS VOLTAGE - DO NOT TOUCH ANYTHING ELSE INSIDE
THE RECEIVER WHILST IT IS STILL SWITCHED ON !
6) Press AUDIO button once.
7) Press STANDBY button once.
If the receiver still fails to respond then ic104 is probably
faulty.
If this was successful, then dis-connect the receiver from the
mains supply and dis-connect the LNB lead.
De-solder the other end of the resistor from chip IC104.
Re-assembly is a direct reversal of the dismantling instructions
above.
Some extra hints and tips
=========================
Although the voltage and current that will go through the
resistor is very low, and safe, do not touch anything else inside
the receiver whilst performing this repair. Some parts are live
mains, although these items tend to be on the left-hand side of
the receiver, where the transformer is located.
Credits
=======
This project would not have been possible without the help of:
Tony Theobald 2:250/220 (FidoNet)
36
--
Standard disclaimer: My views are strictly my own.