N Gauge Forum

Your Layout and Models => DCC => Topic started by: davanuk on December 13, 2018, 11:17:37 AM

Title: Suitable decoders for Dapol N scale locos
Post by: davanuk on December 13, 2018, 11:17:37 AM
Hi,
I have just started an N scale layout after years in 00. Also I am starting in DCC. All this at 73! I was advised that a Zimo  MX622N Would be suitable for my two locos. Both Dapol, one a 57xx tank and the other a Grange.
I sent for one and fitted it and it did give excellent running. However, when I tried to refit the bodies I found the decoder was too long and the bodies wouldnít fit.
Suggestions would be appreciated as to which decoders would suit. Many thanks.
Regards,
Dave
Title: Re: Suitable decoders for Dapol N scale locos
Post by: Nigel Cliffe on December 13, 2018, 02:29:16 PM
How much too long, and how much modification are you willing to undertake ?

If its just a tiny bit too long, and its because the pins are over-long, then they can be trimmed a little.  But it needs some care to not end up removing the pins from the decoder.    Or, the model could have the socket removed and everything hard-wired.    Either practise will invalidate any warranties.

In terms of control quality for the small motors found in N, there are two outstanding small decoder makers:  Zimo and CT Elektronik. 
Zimo have decent documentation, a warranty service which works within the UK, and a help desk which answers questions in English. 
CT can be difficult to deal with, documentation has gaps, support variable to poor.    What CT have going for them is size, they make by far the smallest decoders available. 

Small six-pin options, which means you don't have to re-wire the loco:
Zimo MX622.  Cheap for a top-end decoder (around £20), and very good.  But you say too big. (14x9x2.5mm)
Zimo  MX617.  Marginally smaller than the MX622, but nearer £30.
Zimo MX616.  Considerably smaller ( 8x8x2.4mm), but nearly twice the price of a MX622 at around £39

CT DCX76.  small  (11 x 7 x 1.3),  around £30
CT DCX77.  really small (5 x 7.5 x 1.8 mm), around £30. 

In all cases they are available with six-pin connections, either directly on the decoder (like the MX622N), or with a plug on the end of wires.   

I wrote an article, its on the 2mm Scale Association website, on how to setup (tune) CT decoders to get the most out of them.  Though some years old, its still valid as an approach. 

There are other small decoders around from other makers.  They don't provide the same quality of control. Some people find them to be OK. 

- Nigel
Title: Re: Suitable decoders for Dapol N scale locos
Post by: davanuk on December 13, 2018, 04:10:38 PM
Nigel,
I am very grateful for your informative reply and will check out the decoders you mention.
In the 57 the decoder fitted right up to the socket. In the Grange it didnít so I did as you suggested and shortened the connectors. Still too long.
I will try one of the smaller ones you mention, after a good read, and have to accept the extra cost.
Hardwiring is out for me. Soldering has never been a strong point.
Many thanks, regards,
Dave
Title: Re: Suitable decoders for Dapol N scale locos
Post by: rhysapthomas on December 13, 2018, 04:17:24 PM
Hi have just had the same problem with a Dapol Class 56 it seems they fit Gaugemaster which will just fit

As Nigel said Zimmo as excellent chips and it is a pity the 620 does not fit, in the end i bit the bullet and fitted a 616 which cost £32 at warley
Title: Re: Suitable decoders for Dapol N scale locos
Post by: Dizz on December 13, 2018, 04:51:35 PM
I have used Gaugemaster DC23 decoders in most of my Dapol locos without any issues.
Pete
Title: Re: Suitable decoders for Dapol N scale locos
Post by: Only Me on December 13, 2018, 05:38:51 PM
The digitrax dz136 chips fit fine in all dapol locos as do the dcc23ís which is what dapol use
Title: Re: Suitable decoders for Dapol N scale locos
Post by: Paul-H on December 13, 2018, 07:57:29 PM
As said above Gaugemaster DCC23 seems to fit them all,but if you want a bit more finesse the Zimo MX616 is even small and a better decoder but about £10 dearer than the DCC23.  I did find I got rather noisy running with the DCC23 in my 2 57xx which they didn't have on DC or with the MX616.

Paul
Title: Re: Suitable decoders for Dapol N scale locos
Post by: longbow on December 13, 2018, 09:29:07 PM
The DCC23 decoder is OK but it's an earlier generation Digitrax design that lacks the advanced motor control features of more modern decoders. If your loco is a smooth runner under DC and you don't need sophisticated acceleration and braking control then it will perform adequately.

The MX622N or its Bachmann equivalent is excellent and easily the best value chip of the ones mentioned. It should fit in both large and small Dapol GWR tenders (the Grange comes with both) although the PCB mounting screws may need to be removed to allow it to be repositioned. There have been some reports of Granges with older PCBs that won't allow this.

CT decoders are high spec but erratic and are now hard to source in the UK. If you can find one, their DCX77z is tiny and will fit the 57xx and small tank locos requiring a right angled decoder.
Title: Re: Suitable decoders for Dapol N scale locos
Post by: lil chris on December 13, 2018, 10:03:10 PM
All the above are true, I have fitted a CT DCX77z in a Union mills, it is tiny. It took me ages to fine tune it though, I ended up using JMRI decoder pro, a program Nigel wrote, that sorted it but it was a long winded process, but it runs so slow now.
Title: Re: Suitable decoders for Dapol N scale locos
Post by: Paul-H on December 14, 2018, 06:00:47 AM
I have a couple of CT decoders DCX76 IIRC and a very odd issue with them all, using my Gaugemaster Prodigy Advance2 if I change any CV value ie CV5 to 128, it also changes CV1 to that value, so I have to change a CV then change CV1 back to what it was, this odd behaviour happens on both programming track and main track and not on any other make of decoder, and not on DecoderPro using a Sprog3.

Anyone else find this?

Paul
Title: Re: Suitable decoders for Dapol N scale locos
Post by: davanuk on December 14, 2018, 10:12:55 AM
Hi,
I would like to thank everyone for their help and advice. It is much appreciated.

Regards,
Dave
Title: Re: Suitable decoders for Dapol N scale locos
Post by: Paul-H on December 14, 2018, 11:00:09 AM
Anyone know of a UK supplier that actually stocks the CT DCX77z

Thanks
Title: Re: Suitable decoders for Dapol N scale locos
Post by: Nigel Cliffe on December 14, 2018, 04:46:04 PM
Anyone know of a UK supplier that actually stocks the CT DCX77z


Possibly DCC Train Automation.   
But, CT have been going through a "pain in the a**e" phase with a few retailers, causing them to stop re-stocking.   

There are German and Austrian retailers, which are no problem to deal with until March2019/Dec2020/whenever-the-brexit-mess gets sorted out. 

- Nigel