NXT 18 Pin Hornby HM7000 decoder

[Stese]

let me state before I start, i'm not interested in the safety discussions going on in the previous thread on H&M7000...

Having just watched Sam's Trains review (https://www.youtube.com/watch?v=xsx7IAMBZhA) of the system as a whole... I'm left with 2 questions...

1 :- The photos I've seen of the NXT18 Decoder seem to show a PCB that doesn't have any components at the last 5th or so of the board. Does anyone have one of these in their hands that they could look at and see? or even post some good closeups. If it is unpopulated... I'm wondering if that portion of the board can be removed to improve the compatibility with other locos. (I know hornby won't do this, and doing it is likely to void warranties),

2 :- He's only briefly mentioned that his decoder burnt out within a day of use. Does anyone have a similar tale? Do you think it was related to the use of the Gaugemaster controller as a power source? I'm aware hornby recommend using their 15v PSU.

[Brian]

AFAIK the Next 18 decoder standards are as set by the NMRA https://www.nmra.org/sites/default/file ... erface.pdf and Hornby have it appears exceeded these specs. by around 3mm in length and 4.5mm in width! and about 0.8mm in height! (Scroll down to NMRA page 2 for sizes). Hornby size 28.5 x 14 x 4.9 mm Next 18 sound size 25 x 9.5 x 4.1 mm
So while the Hornby plug is Next 18 the actual decoder is not to the recommended spec. size.

[cadman]

Stese.......the apparently blank area is the Bluetooth aerial.
Nobody on the Hornby forum has reported a burnout HM7000 decoder.

[Steve M]

I had the misfortune to view that video yesterday - full of inaccuracies. He didn’t read the instructions and if he had, most of the issues he had would have been easily resolved.
Hornby recommend that only their PSUs be used for a reason. Others may work but there are no guarantees. He certainly appears to have made a mess of it by not using a recommended power source, and if he had read the manual.....well you know the rest.

As has been said, the ‘blank’ area contains the Bluetooth aerial. These chips are standard DCC decoders with extra components for the Bluetooth side of things. Hornby have used readily available (read that as less expensive) components to integrate the two systems into a decoder that uses a Next18 interface. These components allow for a competitive price but they do compromise space. At this stage Hornby have adopted the Next18 only for their TT locos (the locos are designed to fit the slightly larger chip) and they have already said that the 2nd generation of decoders will be more compact.

As to my own experiences, I have now fitted five of these decoders, 8, 21 and Next18, to locos from Hornby, Heljan and Bachmann and yes, I have had to use some modelling skills to achieve this - just as I quite often had to do with ‘standard’ DCC decoders.

As for Sam, I think he should take up a different hobby.

[Victoria]

Hi, Could I please ask how you got one of the Hornby 21 pin decoders to work in a Bachmann.. I have a Bachmann class 37 with a 21 pin socket fitted but was told its not compatible. The Bachmann has got 2 speakers fitted as standard.
Thanks for any information.

[Steve M]

The question will always be around available space. A 21 pin decoder will engage with a 21 pin socket but you may find that the space available is restricted - but as I said before, Hornby locos being designed now and in future, will be designed around their decoders while existing Bachmann locos were designed around old style decoders.

Be careful to fit the decoder the right way up as it is possible to fit the upside down which won’t work.

Additionally Hornby have set the loco profiles to suit the motors they use in their locos, performance of non Hornby locos may be less than smooth. However, the decoders have an autocalibrate function which will automatically tunes the CVs to the loco being used.

Bear in mind also that Hornby have yet to release a class 37 sound file but they will undoubtedly do so at some point.

[Steve M]

As a postscript to my last post, I have just fitted a 21 pin TXS decoder and stayalive pack to a Bachmann V2. The decoder fits in the prescribed position although the plug for the stay alive just fouls the inside edge of the running plate. I slightly eased the side out and the decoder slipped straight in with the stayalive comfortably above it in the firebox.
Completed the autocalibrate function and it runs well and sounds superb with the factory fitted speaker.

[Victoria]

Thanks for your help

[RAF96]

The likely reason Sam burnt out his decoder was feeding it from that controller which is listed in the decoder manual as unsuitable. Tests have shown there can be spikes up to 48volts, from these types on DC controller, certain death for any decoder.
Some 7000 decodes are oversize to standard spec and this has been widely reported. The actual sizes are in the manual for each decoder type.
I watched Sams video purely to see how many errors he made this time and yes he didn't read the guides, screwed it up, then apologised at the end as if that would retract his false review. He did exactly the same for his HM6K analogue system review. He has been described by a fellow ‘influencer’ as simply click-baiting supported by his groupie fanboys.