GWR HST SET

[Chris1970]

I’ve recently purchased the Hornby GWR HST set. Have now fitted a TTS chip to the powered end and it starts fine all singing and dancing etc ... gets to a curve and loses all control. Sound still working, horns and other bits not working can’t slow it down or speed it up! 

anyone else found this at all. I’ve heard people mention the front pick ups are quite loose on the front bogie with this set could this be the problem

Many thanks Chris

[Chrissaf]

The key word in your question that may be a significant clue is the word "set" as in GWR HST set which I assume to be the R1230 DC Analogue set. Assuming my deduction to be correct, then this set includes a DC Analogue R8206 power track to connect the controller to the track.

What controller by the way? The R1230 set comes with a R7229 DC Analogue controller, so I assume that as well as a TTS decoder you have added a Digital DCC Controller, but which one?

Anyway, back to the plot. The R8206 analogue power track is not suitable for DCC layouts, it either needs to be modified for DCC use or replaced with the Digital R8241 power track. The Analogue versions include a capacitor wired across the rails which corrupts and distorts DCC signals and the TTS decoders are particularly susceptible to this signal distortion resulting in odd loss of control behaviour such as you have described.

The image below shows how to modify the R8206 for DCC working. Note also that R8201 link wire connectors [if used - left hand side image] also contain this capacitor and need modification.

If you don't mean the R1230 DC Analogue set and you are referring to a HST train pack [not set]. Then please advise which one by R number.

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[Chris1970]

Hi 

thank you for reply 

it’s the R 1230. I’ve wired straight to the track without using the power clip provided. It’s a TTS mtu chip using a prodigy express handset, have set up using a sprog and runs fine on a 6 foot long test track ( straight )

but moment hits a curve on the main layout it loses response. The contacts are touching the wheels it seems at the front. 

Many thanks chris

[Chrissaf]

Then it seems to be a problem specific to your loco, possibly a brief transient short circuit via the front bogie that corrupts the decoder commands i.e the decoder loses the knowledge of what it is supposed to be doing such as travelling forward.

[ColinB]

That is a weird one, normally you associate that with it defaulting to thinking the DCC signal is DC. Generally on TTS decoders DC running is turned off, so unless it is an old decoder that should not be the issue. I know it involves more expense but have you tried replacing the TTS decoder with a normal decoder and see if the fault is still there. I have recently been trying to upgrade my old Hornby HST by using the later bogies and from what I remember the pickups are pretty good on these. It could be one of those wonderful TTS decoder faults, which is why I suggest trying a normal decoder.