QUOTE (poliss @ 27 May 2008, 08:56)
<{POST_SNAPBACK}>There shouldn't be problems with a Hornby DCC ready loco and a Hornby NMRA compliant decoder. Try to eliminate all other possible causes before blaming the decoder. Does it stop in the same place every time, or just randomly? What controller are you using btw?
***No there shouldn't be but there very often are problems with Hornby DCC ready loco's and decoders.
Poliss you are modelling in N scale and if this modeller was too - and not using the H decoder - then perhaps I'm make the same comment.
but
This is not an issue related in any way to whether the decoder is compliant or not: Compliance is primarily a software issue and in this case the issue is Power handling which is a factor of the low power hardware that the decoder is made of.
Hornby decoders are low powered at 500mA which is usually the top rating for an ultra micro N/Z scale decoder and so they do have a tendency to run warm and are very easily damaged - to the point the comment was once coined "they don't need feedback, they give off smoke signals". This is a shame as the difference between a 1/2 amp and 1 amp decoder size wise is zero and component cost-wise is about 10p!
Hornby loco's generally draw well less than 200Ma when running, however the odd combination will be higher than that. Heat is cumulative so under load for a while the low powered decoder will heat up considerably. There is about zero tolerance in the hornby decoder so it is not uncommon for the combination of larger hornby locos + hornby decoders to let the smoke out.
Its good advice to use a 1 amp of higher decoder on 4mm scale loco's where possible or decoder death can be expected more often than is really acceptable. My recommendation for a cost effective high power and really competent decoder that will do the job every time is either TCS DP2x (wireless direct plug in to even the tightes of them), or TCS MC2 or M1 which both have option of bare wires or 8 pin plug. Yes they are a wee bit more exxy but they perform better every time!
Oh... and Fabben - ingore the Hornby diagramme and DO remove the capacitor. It will always affect the best slow speed performance as any component, especially a capacitor, masks the real motor back EMF from the decoder.
Regards
Richard
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