A1/A3 TTS decoder problem

[darren_mccoy]

Hi there, I installed a TTS decoder in my old early eighties Flying Scotsman.

Everything is almost working perfectly except it seems to get to its full speed half way up the speed scale, It then briefly stops and starts again, the sound is never interupted. It seems to forget where zero is on the speed scale after that.  

It's much easier to just watch this short video.

Any ideas or CV recommendations?

Initially the slow running was very jerky but I did some research and changed CV151 = 255 and CV152= 1. This sorted that and I now have very nice slow running.

Like butter!  

[Chrissaf]

Darren, as you are using a Dynamis, maybe your TTS decoder is affected by this issue.

.

https://www.hornby.com/uk-en/forum/hornby-tts-decoders-reported-problems/

 

[darren_mccoy]

The TTS decoder is very rough and ready, a good 5mm of bare wire coming out of each contact on the chip and the green wire came off after a couple of seconds. I had to splay the wires in oposite directions and insulate in between with sellotape.

 

/media/tinymce_upload/e347ad4357d5dfa54a60ec04903c044f.jpg

[96RAF]

In a situation like that I would resolder all the connections properly, but if they are all still attached firmly and its just a fear of wires shorting each other then I have used a hot glue gun to run a line of reinforcement and insulation along each side of the wire connections.

Rob

[Chrissaf]

I doubt very much indeed that that is factory wiring. Someone has had a good old go to create that mess. A classic example of applying too much heat (causing the insulation to run back up the wire) probably by using an inappropriate soldering iron, either too higher watt rating and/or a soldering bit that is physically too big.

.

The Hornby TTS instructions specifically state that soldering wires at the decoder end should not be attempted, for the very reason that the image above aptly demonstrates.

.

EDIT: If Rob's advice is followed and the wires are removed and reattached, then slip a short length of 1.2mm diameter heat shrink sleeving on the wire before soldering, so should the insulation run back again, the heat shrink can be pushed back over the bared wire and shrunk down to replace the insulation functionality. Far more effective than inappropriate Sellotape which will deteriorate over time.

.

PS - The URL link above is just an example.