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.