Decoder Question
I have a Bavarian D XII by Trix which is fitted with 6- and 8-pin sockets for a decoder. There is an equivalent DRG model as well. It works perfectly well with an 8-pin decoder, but when I put a Zimo 6-pin DCC decoder in... nothing. I know it is expecting a Selectrix 6-pin decoder in theory, but I thought the wiring and pins were NEM-standardised? Am I missing something here? The advantage of a small fixed 6-pin decoder would be that it takes the same space as the removable plug used for DC-mode and which is hidden inside the boiler. Whereas an 8-pin decoder has to find room in the open cab.

Paul, AFAIK Selectrix doesn't conform to any NEM standard. It's got to be worth testing the decoder in another model though. Just to make sure it works. Also worth considering that an N-gauge decoder may not be able to handle the current required to run the model anyway. Trix locos are fairly old-fashioned in terms of their technology. I'm reasonably certain that the Zimo MX620 should be okay, it's a small decoder with a sensible current rating. There is a version available with an NEM652 8-pin plug too. Or hard wire the loco, taking out both sockets and putting the decoder wherever you want to. A trick I'm partial to with the odd shunting loco that's tight for space (especially if I want to use an on-board energy store). Steph

Hi Steph, What do you use for an on-board energy store, and how do you wire it in? Cheers John

John, The newer Zimo decoders (including late MX62, plus all MX63 and MX64 and MX620) can use a home brewed capacitor energy store. It's quite a simple circuit that's outlined in the instructions for the decoders. http://www.euram-online.co.uk/dcc/zimopp/zimopp.htm is the page on my website for building the power packs, which may be useful for you. It's a large version used in an 0-gauge loco, but the principles are the same and it means you can see what's going on. In practise on some of smaller locos I've managed to successfully use a small (250uF) 25v capacitor directly connected to the decoder pads. Alternatively, the Lenz Gold decoders can use a Power1 module which also works well. In fact it's somewhat more effective than the Zimo equivalent, but also much more expensive! http://www.euram-online.co.uk/dcc/decoders/lenzgoldsilver.htm is a review of the Gold and Silver decoders. This page includes pics of my Brawa V15 that's been hard-wired to save space, so that I could fit the Power1. The information is in the DCC section of my 'site http://www.euram-online.co.uk/. I hope you find it useful. Steph