Retro fit decoders or buy new.

[Mike Parkes]

The fit in smokebox goes back to the Well Tank they did for Kernow and then appeared on locos produced by the now extent DJ Models.Not entirely concvinced by it as the potential exists for damage to details on the front of a loco - lamp irons in particular.

[Walkingthedog]

Wouldn’t have thought so. Open the smokebox door and slide out the PCB. Well away from any detail.

[RAF96]

The problem with a slide in card decoder system is handling the current across contact connectors. The loco mentioned also has a slot in additional speaker which relies upon touch contacts, hence relies upon a firm fitting not just snap or press in. Tech will catch up but getting it standardised across the industry will take more time.
I can see things getting so complex the decoder and all the other gubbins is built into the main PCB, which makes firm contact with the rest of the loco and does away with flimsy wiring, etc.

[darkscot]

If you already have non-DCC's trains then there is little choice but, as I'm starting afresh, I'm wondering whether second hand non DCC locos are worth it, when you factor in time to fit, test and then it's still a second hand motor that may not run smooth, versus a 2 year g'tee and time spent on less fiddly aspects of hobby.

When I first got back into the hobby I added decoders to two existing locos I had. It was an interesting exercise and worth doing for the learning experience, though neither run particularly well compared to modern locos. I then bought two 2nd hand locos off eBay, one (Hornby) because it was 'a bargain' and very nicely weathered, and the other (Bachmann) as it was half the price of a new one. I have never been able to get the Hornby to run under DCC and have finally given up after blowing two decoders. The Bachmann was DCC ready, but I damaged the drive gear fitting the decoder and it eventually cost me over £50 to have it repaired by Bachmann, and it still is a pretty poor runner compared with the two new locos I have bought since then.

In short, I will never(?) by a 2nd hand loco again. Also I will probably only ever buy 'DCC equipped' as fitting the decoder to my 'DCC ready' Bachmann 08 turned into a right saga!