Stuttering on start with tts but not with non-tts

[Will Hay]

Hmm, so I've just had a Class 37 tts delivered, which is faulty so will be returned.

 

I noticed that the vitrains I fitted it to stutters on start and slow down, and is fine once up to speed.

I assumed as a resultbof the faulty chip but having tried my vitrains class 47 it does exactly the same wirh a different tts chip and, when I remove the tts chip and put a standard, non-sound hornby decoder in the stutter disappears.

[96RAF]

You often have to set TTS decoders up to match a particular make of loco. This is usually by way of altering the motor algorithm. All explained in the famous manual.

[Will Hay]

Oh my god, CV150 is now '1'.

What a change.

I can't believe I've suffered it as long as I did.

[ColinB]

I think someone on here mentioned it when the class 37 TTS decoder got released. I have to do it for all diesel locos except for some reason class 66 ones, even some of the Bachmann ones.

[Will Hay]

Hi Colin.

Why for the Bachmann, is it because you fit a hornby decoder to them because, like me, you don't wanna spend three figures on sound?

[ColinB]

Yes exactly, I normally change the connector to 21 pin, I don't use adapters as they usually foul the roof ( I think class 66 is the only one where is doesn't). Some of my models do have the expensive ones and yes they are good but even though I complain about them, TTS decoders are really good value for money. With a decent speaker they sound OK. On the Hattons class 66 you have to fit the expensive ones to get all the light functions.

[96RAF]

If you read the TTS leaflet it used to say motor algorithm 2 (i.e. CV150 value = 1) was specifically for Baccy locos, now it says it is a linear curve suited to some Lenz decoders. Algorithm 1 is a non linear curve more suited to Hornby R8249 and similar decoders, hence TTS.

[ColinB]

Weird, on the latest Bachmann class 66 I bought (the one in BR blue), I didn't have to change CV150. I have had to do it on virtually every other one.