Howbi

Have you tried re-setting the decoder Barry? Might just be a glitch due to old age; (I usually get one every week nowadaysthinking_face)......HB

If you are looking to open it up to fit a decoder then you will find the answer on the instruction sheet that comes with the loco.

I was just about to post a meaningful reply when I noticed that this thread is eight years old so I held myself back.......flushed

The 3 start-up options are perfectly reasonable, you choose which one you prefer at the time. As for the sound of the diesel engine revving up; this is to try and emulate the real thing. These locomotives are driven by Electric traction motors so the diesel engine is often heard revving up to drive the generators up to the required current output. So the speed of the diesel engine does not match the speed of the loco. I doubt there is any fault with yours.

@Olly.........check the value of CV443 which is the steam hiss sound, default is 100. This is the continuous sound I hear on my Loksound steamer when stationary......HB

I'm surprised there have been no replies thus far so maybe this will help. In the Dec 2019 Hornby magazine test of the 48 DS I quote " we connected Bachmann and Gaugemaster decoders to the sample all of which fitted happily inside. The three pole motor ran perfectly with both". No mention of the Hornby 6 pin version. The deciding factor is the decoder's length; I used a Lais 6 pin which was a tad too long so I had to resort to the Dremel to remove some metal in the cab to enable a fit (not recommended).

@Sarah.......you will find these old HD catalogues interesting........ http://img.chem.ucl.ac.uk/dublo/catalog.htm

Change CV29 to a value of 2. This stops DC runaway.

Sorry to learn of your ill health S.O.T. and hope you can enjoy a Happy Christmas.......HB

I don't see the point of 6 pin decoders, they have 2 redundant pins which can't be used without an additional PCB to provide the positive feed for the functions to work.

@81F.......I simply use Bread Board link wires to plug into the 4 pin socket as shown....

Assuming your decoder is a Hornby TTS.......... Regarding the sound you have a choice, if you wish to reduce the overall sounds then CV178 should be changed, range 0- 8. If it is just the chuffing sound to reduce then CV161 is the one, range 0 - 8. Running too fast is usually down to the controller setting.

If you are thinking of using a sound equipped decoder then obviously you would choose one that is specifically produced with the Mallard steam sounds but if you just need a motor decoder then there is no difference between steam and diesel. You will need to establish what type, ie, Direct fit or Harness fitted, 8 pin or 21 pin etc. Which make and model is your Mallard?

So much detail appearing, great progress Rob........H

Definitely a Hornby standard 8 pin decoder R8249.

DCCconcepts have some working loco lamps in stock..........HB

Well, apart from all the negativity, I thought the Program was in part entertaining, informative and interesting showing ordinary folk doing what they do in various aspects of modelling. It is what it is and I, like thousands of others, look forward to the upcoming episodes.....thinking_face.......HB

Not a problem, Fishy. sunglasses......HB

Sounds like DC runaway where the decoder thinks it is getting a constant DC voltage instead of the DCC command. You will need to put the controller into programming mode and change CV29 to a value of 2. This will prevent DC running. Which controller are you using?.

@Second time around.........if you scroll down to the bottom of this page you can type your reply in the Reply box.........no need to use the blue box button.

If you are relying on a single power feed to the outer loop I would suggest a second power feed to the inner loop just to ensure a more reliable supply to all four sides of the crossover.(observing matched polarity).....HB

You need to change CV150 to a value of 1, this has solved the jerky running many times......HB

This archive is very comprehensive............https://www.meccanoindex.co.uk/Mecmag/MM-Mag-UK.php?id=1634545678

@Stephen.........it is prudent to affix the points to the baseboard either by screw or nail to ensure a level surface for the traversing rolling stock. It has been found that a set of points can have a concave curvature in the Frog area which results in the derailment of many lightweight vehicles.......HB

Flying Scotsman with a decoder fitted..........