Fitting Decoders to Hornby Dublo and other Old Locos

QUOTE (TonyUSA @ 18 Sep 2008, 21:12) <{POST_SNAPBACK}>Hello Richard,

Thanks for the advise, but I have tried what you suggest, see my reply to Zmil.

TonyUSA

*** Then you will need to look again at the installation.

Old Dublo often has one brush live to the chassis.... and its not always easy to correct that.

Are you sure BOTH brushes have been totally isolated from the chassis? - to test this remove the decoder wires from the brushes, place the loco on the track and use a multimeter to check that there is no continuity between either brush holder and either rail.

a digital photo of the installs may help me to help you.

I suspect there maybe is a sneak path between brush and rail. (BTW - did you remove all the suppression parts)

Richard

QUOTE (Richard Johnson @ 18 Sep 2008, 11:08) <{POST_SNAPBACK}>*** Then you will need to look again at the installation.

Old Dublo often has one brush live to the chassis.... and its not always easy to correct that.

Are you sure BOTH brushes have been totally isolated from the chassis? - to test this remove the decoder wires from the brushes, place the loco on the track and use a multimeter to check that there is no continuity between either brush holder and either rail.

a digital photo of the installs may help me to help you.

I suspect there maybe is a sneak path between brush and rail. (BTW - did you remove all the suppression parts)

Richard

Thanks Richard,

I have sleeved the V spring which holds in place the motor brushes and I thought they were isolated from the chassis. I will revist the installation this weekend and take a picture for you. The loco in question is a convert from HD 3-rail using Romford Wheels. I will do a thorough check of all conducting paths to see what I can find.

What doesn't make sense is the fact it runs perfectly on the default factory 03 address in forward and reverse as if communication with the decoder is fine. I just cannot communicate to change the address or any CVs whether I use the progarmming track or the main. When I had the same problem on an old Airfix County Class Loco, I started wondering if there was a common problem with old pre DCC locomotives DCC ready or otherwsie.

As long as the motor is completly isolated from the track pick ups I don't see why old locos shouldn't work with DCC.

Anyhow thanks again, I will be back to you next week.

TonyUSA

QUOTE (TonyUSA @ 20 Sep 2008, 21:07) <{POST_SNAPBACK}>Hello Richard,

I have to admit I am new to using the Model Rail Forum and I am having a problem trying to attach some pictures I took for you of the decoder installation. The insert an image button comes up with a script promt and asks for a URL, the pictures are just in a folder on my commputer. How do I get them to attach to the message? I have tried copying over, but that does not work. I cannot find any help info on the site about attaching pictures.

I did examine the installation and I still cannot see anything wrong. Why does the loco run perfectly on the factory default 03 address both forward and reverse? i would have thought that if there were any shorts or the installation was incorrect, it would not have run at all.

Thanks for any guidance,

TonyUSA

***Hi

To add images you first have to post them online in a photobucket or similar image holding website.... there is a thread explaining this in detail.

re the decoder your question is a fair one. it SHOULD be Ok if it runs on 3.

can you put it on aprogramming track wired to the programming track outputs of the DCS50 and get the controller to read the decoder in paged mode (Pg on the digitrax display)?

If install and decoder are both OK, then this should be no problem

Richard