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STTS decoders


26 posts

Good Evening

Could anyone tell me if any of the TTS decoders are suitable for a Heljan class 26 (H2601) and Bachman Class 25 (32-402)

regards jsionyRN


208 posts

You can use any TTS decoder in any loco if it has an 8 pin socket.  Unfortunately none of the TTS decoders feature the Sulzer 6 cylinder 6LDA28 power units used in class 25 or 26.  The class 47 TTS decoder would not be suitable either as the class 47 was fitted with a Sulzer 12 cylinder 12LDA28-B pwer unit.  Have a look on YouTube for footage of full size class 25 and 26 locos. 




12053 posts

Community Moderator

The Bachmann is likely to have a MTC21 decoder interface [21 pin] whereas the TTS from Hornby are NEM652 interface [8 Pin]. Thus an adaptor cable would also be needed. No idea what decoder interface the Heljan has.


All the Bachmann's I own are MTC21.

Chris........ Making the wood in the trees visible.

Rog (RJ)

2216 posts

Many Heljan loco motors are known to draw a lot of current, so a TTS decoder which is only rated at 500mA could easily be destroyed by excessive current draw.  You need to check what the current draw is before installing a decoder.

Rog :-) I don't model anything in particular, I just play trains. Living on the South side of Nottingham. Keep taking the tablets. https://www.modelrailwayforum.co.uk/


1464 posts

I suppose it depends on the Heljan, my class 47 has an 8 pin socket with led lights. A lot of my others have 21 pin sockets and one of them actually has bulbs which I find amazing in this day and age (I only recently bought it new). So if it has bulbs, that definitely rules out TTS decoders. You have me worried now, I recently fitted a class 47 TTS to my Heljan class 47, I better check the current.

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