ColinB

Sorry Chrissaf I thought it was you, somebody definitely said that. As for getting slated for not supplying a speaker, virtually every other sound manufacturer I have bought a unit from, requires you buy the speaker separate. I think the system for the Thumper, I bought off Howes might have come with a speaker, but all the rest I have had to buy a separate speaker. I assume Hornby as it mass produces these, adds the speaker to make end of line testing easier. The more expensive units are generally loaded with the right sound data, on a one off basis, basically as they are ordered so they can easily test with their own speaker. The other thing is Hornby TTS decoders are sold by any Hornby approved Model Shop, whereas the more expensive ones are sold by specialist Model Shops, so a wired on speaker makes it easier to test.

These are what you want https://www.petersspares.com/peters-spares-ps84-141mm-disc-coach-wheels-one-wheel-live-to-axle-x1-pair.ir . I gather he had then specially made. Then all you need are some pickups. Actually a better way would be to feed power through from the driver carriage, then you don't need the wheels. On some of the early Brittanias Hornby used a 2 pin plug and socket between loco and tender, with the socket on a PCB, these would have been ideal, but they don't sell the PCB as a spare. There is a big opportunity for someone out there with PCB design skills.

I agree with all the comments, Chrissaf mentioned ages ago that Hornby found it cheaper to include the speaker. It is useful to check that it all works before you change the speaker. On some of the Bachmann models it does mention how to fit the speaker, but half the time the speakers you can buy don't quite fit in the space. In Hornby's case, there are no instructions, but have obviously gone to a lot of effort to put a mounting point in the tender. If it is any consolation, I fitted sound to a Bachmann DMU, the instructions told me to virtually take the loco apart to fit the speaker at the bottom behind the front bogie. I tried several speakers and found the position suggested was difficult to get to and fouled the motor drive. Eventually, I bought an iphone speaker off EBay, it fitted at the top above the PCB without the need to take anything apart, which meant I had wasted several hours taking it apart. I have got to admit though the Hornby TTS decoders are really good value for the money, ok they are not as good as the expensive ones, but if you just want some sound they are perfect. I have many of my locos fitted with them, I only wish Hornby would do more, but I can see why. They are not that much more than a decent decoder.

On mine I used silicon spray that seemed to work well. I build classic motorcycles as a hobby so I buy cans of silican lubricant round auto jumbles. I also bought some of that ptfe grease from Peters Spares that also works well. As I said before, check the valve gear runs freely, that was an issue on one of mine.

Have you seen how much they are? Looking at the well known spares supplier, they are about £22.50 each. I was thinking of doing it, but that is a bit over the top. They do make the insulated wheels though. I think you can get a kit for less than the price of a bogie.

Having looked at the photos, I am sure that they weren't there when I first replied, it must have been the A4 where I had to file a slot. I think with the Duchess I took the sugar cube speaker approach. I have complained about this before, why put in all that design effort to achieve something that doesn't fit, but then I do get the thing that electronics are not really Hornby's thing. I suppose it could be that they designed the enclosure and then further down the line someone specified a different speaker, where I worked a buyer changed the plastic for a fuel tank and forgot to ask if it was petrol resistant.. A sugar cube will fit in the same hole and probably be less likely to short out against the weight (terminals are smaller).

Either buy a sugar cube one from YouChoos or similar supplier, or go on to EBAY and there is someone selling iphone speakers which are small and very good. I am surprised the original speaker doesn't fit though, surely they are using the same tender as the Duchess class, which although you have to cut a slot (speaker fits but no room to pass through the wires) will actually accept the round speaker. Chrissaf has the better idea though, get a smaller and better speaker.

I have had the same issue with two modules, usually an issue with one side of the H bridge stage going wrong. On both occasions got the module changed. On one of my locos it happened when the track voltage accidently touched one of the motor feeds, so check the loco wheels aren't accidentally touching one of the bits of uninsulated wire that goes to the motor, or a slight short on the 8 pin DCC socket in the loco, between pins 1 and 8 or 4 and 5. I forgot before you do anything, do as jane2 said, reset the module, this happened on a LaisDCC module to me and resetting it, cured it.

The first thing to do is to figure out if there is something wrong with the decoder. If it is easy, take the decoder out of the GWR HST and try it in the class 47. If it works in the class 47, then there is something wrong with the GWR HST. What you can also do if you have a multimeter is check the resistance between the pins on the 8 pin connector in the GWR HST. THey should all read high resistance except between pins 1 and 5. Whatever you do don't try the class 47 decoder in the GWR HST, just in case it is damaging them. Other than wrong wiring of the 8 pin socket, the only other thing I can think of is the capacitor across the motor causing issues. I have had "run away" with some LaisDCC modules with bad track (sometimes the loco even goes backwards), but Hornby ones are usually ok. I fitted the HST TTS decoder to my ringfield based HST with no issues, generally if it is dirty track the decoder sound usually just keeps resetting.

I changed mine recently on HST intercity, that dates back to 80's/ 90's as Chris says they just clip in. In my case I wanted to replace the original plastic ones for newer metal ones to give better running. Looking at my EBay history I am pretty sure I used Hornby R8096.

I am going to add tram tracks to my layout. I worked out flexitrack was the best solution, its cheap and you can bend it to any shape you want. In the towns it will be encased in a road so it won't move. There were some youtube videos around on how to do it. I was originally worried about the tight curves but trams have a very short wheelbase. Flexitrack is ok, just make sure you pin or screw it down. Buy yourself a decent pair of track cutters with the money you save on the track or use a Dremel and you will be ok.

Reading yor post again, I would say there is a short between one of the loco pickups and the motor wires, or a motor wire occasionally touches chassis, that is the only way I can see that you would melt a wire.

First thing to do is to run the chassis with decoder and speaker alone without the body and see if it still works. From your description it sounds like you may have damaged the decoder, generally when they die, they work for a little bit either losing sound or forward/backward direction and then become a permanent short circuit. Probably and this is no insult to your abilities you shorted something out when trying to squeeze all of it into the smokebox. I did the same thing quite recently with a type 66 loco. I know people tell you not to, but put the decoder in a heat shrink sleeve, but don't heat shrink it, or heat shrink it enough to stop it falling off, but not enough that isn't any air around it. The good news is, if it is less than a year old Hornby will replace it, probably not at the moment with all the restrictions but eventually they will. If you think that the space is too small, then buy a tender bottom from a later Tornedo, Peters Spares was doing them. The tender top will still fit. Also buy the 4 pin socket to go on the tender and the corresponding 4 pin plug with lead, and put it all in the tender. Whilst you are doing all that you can also add some pickups in the tender, I bought another tender bottom from an A1 or A4 and ripped out the pickups, suprisingly the tender bottom with pickups was about £2.00. I did it to mine to give better running and surprisingly not too expensive. The replacement tender bottom I am sure wasn't that expensive around £5.00, the most expensive bits were the lead and socket. Actually, to be quite honest the speaker connections on the decoder pcb are quite big, so the biggest worries when soldering to it are lifting the pcb tracks if you have too hot an iron, or leaving it on too long. You also have to be careful not to create shorts by letting solder drip onto the rest of the pcb. The worst bit is if you create a short between the two speaker connections, this will definitely kill the decoder, but you can also easily do this by shorting out the wires. You wll find that the speaker leads are the first to fall of the decoder if you are not very carefull handling the weight of the speaker.

I initially thought that there wouldn't be enough energy stored in the capacitor on the "stay alive" to drive the motor but I was wrong. I bought a DCC concepts decoder which came with one, so I used it and yes they definitely work. I even fitted them to some of my old Ringfied based locos, Lima and Hornby and they make a substantial difference, previously they stopped on pieces of dirty track but with the "stay alive" they didn't. YouChoos do a sophisticated board that if you use Chrissaf's data on connections, works well with Hornby TTS decoders. If you are using DCC it is an easier fix than adding extra pickups.

This is the one you want : https://www.ebay.co.uk/itm/DCC-MTC-21-pin-female-to-21-wire-adaptor-PCB-New-UK-Stock-Seller-/202458411536?hash=item2f23763210

I have found depending on the make of the 21 pin to 8 pin converter, there may be up to a difference of 1 to 2 mm between the different makes. It doesn't sound a lot, but it certainly makes a difference. If you are going to remove the 8 pin socket from the 21 pin to 8 pin converter, you are probably better off buying a LaisDCC 21 pin breakout header (brings the 21 pins out to solder pads). Unless you are reasonably skilled at getting an 8 pin socket out of the PCB, the socket pulls out the plated through holes as it is removed, damaging the PCB. What we used to do to get them off was to basically cut the plastic away and then unsolder the pins individually.

Hornby don't make an TTS decoder for any electrical loco, unless I missed something. I have one of these models and I think there was quite a lot of room to fit the decoder. If not, do what I did with my class 37 (see post). I did think about buying a sound decoder for my EMU and then thought "but EMUs don't really make any noise" so why bother, unless you are thinking of fitting it into a "Thumper", and you wrongly called it an EMU.

Yes, I did think about it. You could take the 8 pin socket out of the 21 pin to 8 pin converter and replace it with 8 way ribbon cable, then terminate it with the 8 way socket. I stick with rewiring it, it is much neater and takes up less space. Trouble with flying leads it is one more place to short out the module especially when trying to fit it in a small space.

Yes that is exactly the sort of thing. Rewiring the 8 pin is a pain, but on a Bachmann diesel is does make the speaker connections tidier, which is good as normally they are the first wires to fall off.

The easiest way to tell is on the tender the wheels with the traction tyres are the insulated ones, so on the loco, the insulated ones will be on the opposite side to the tender traction tyre side, or alternatively the uninsulated loco wheels will be on the same side as the traction tyres. If you have a multimeter check that the wire from the motor to the pin on tender is connected, this is a crimp connection and it might have high resistance.

What you might have done wrong is oiling the axles, did you put a minute amount of oil on. If you put too much on, it acts as an insulator. This loco picks up one side of the supply from the loco the other from the tender, so the connection between loco and tender via the pin is critical. I have recently been upgrading my ringfield based A4, so I know a lot about these. The other thing to check, is the loco's valve gear, it has got to be totally free otherwise the tender has difficulty pushing it along. Peters Spares does enhanced motor housings for this model which means you can convert the tender to pick up from both wheels if you interested. Also check that all the armature windindings are connected together, on one of mine, it was one of the windings that was broken. I suspect the washer that fell out is a spacer for the pony truck.

I don't know if this is useful to anyone, but I recently decided to add a TTS sound decoder to my Bachmann class 37. I did the usual, like buying a 21 to 8 pin converter, only to find the body wouldn't fit. The combined height of the 8 pin socket and the 8 pin header of the TTS decoder was greater than the space available. Anyway, eventually I bought one of those 21 pin adapters that bring the pins out to PCB solderable holes. So all I had to do was solder the 8 wires of the TTS to their equivalent pins on the 21 pin socket. The other advanvange is pins 9 and 10 connect to the speaker connections on the Bachmann PCB, so you can wire the speaker wires to them and use the speaker connections Bachmann supply. So what you end up with is a TTS decoder on a 21 pin header that you can easily replace it with a DC header, or ordinary decoder. The only issue is if it goes wrong and you have to send it back to Hornby, but hopefully that does not happen, as it is a good idea to test it on an 8 pin rig before you do the conversion. It might be an improvement if someone made a 21 pin to 8 pin converter that used a 8 pin socket on a flying lead, that way it would get over the issue of height.

Don't use the plural, it doesn't find anything.

It is OK I found it on the supplimentary sheet. I was fitting it to a Bachmann and had the same issue with the 21 pin to 8 pin adapters, it made it too high so I was having difficulties getting the body on. I thing I might look into putting the 8 pin socket on a flying lead to reduce the height.

Does anyone know if Hornby have stopped their unconditional replacement of TTS decoders, I cannot find it in their latest data that comes with the module. Why is it they work perfectly OK until you put the loco body on. I assume as I pushed the body down something touched, although I had insulated everything.