Bill-354351

@LT&SR_NSE I checked the power difference and it is minimal, only about 50 miilli amps at very slow shunter speed. So that is not the reason. Hornby are aware of other examples of erratic behaviour when these decoders are run from a DCC Controller. I am interested to find out if others on this forum have similar issues.

I am concerned about the HM7000 decoders. I know of 3 other examples of this strange, similar behaviour (data related) on other layouts. This is not posted for a defensive response, it is meant as informative information for Hornby to learn from.

It makes complete sense and actually happens as quoted. The loco works fine with other decoders but NOT with the R7336. Yes, there is some reason why this happens on this loco but it sure displays an issue with the decoder.

HM7000 8-pin TXS bluetooth and DCC sound decoder. R7336 I have this 8 pin sound decoder for an 08 shunter. The file download went well and has really good sound features. A long story short - it works in the Bachmann 08 without issue. When inserted in the Hornby 08, it stutters and stops - making it useless. Switching emergency stop off/on recovers the sound before it fails again. When a Hattons 8 pin non sound is inserted into this Hornby 08, it works fine with no stalling. I suspect there is an issue with data retention within this HM7000 decoder, especially with micro interruption of contact to the rails/wheels. Sometimes after recovery, the sound increases with speed but the loco does not move. I have reported this issue to Hornby.

The fit issues are relevant in that decoders must meet NMRA standards for fit and performance.