FIT DCC SOUND IN A ‘OO9’ STEAM LOCOMOTIVE

Chris Bone explains how he installed digital sound into Heljan’s L&B Lyn, while George Dent follows his instructions and treats his own Baldwin 2-4-2T.

While Heljan makes provision for digital control in its range of ‘OO9’ steam locomotives, the Danish firm has so far omitted sound-fitted options. Moreover, Heljan’s models haven’t offered any easy options for sound-fitting by customers either, unlike Bachmann’s tiny Baldwin ‘10‑12‑D’ and more recent double Fairlie, both of which are offered in sound-fitted format.

Installing DCC sound into Heljan’s ‘OO9’ Manning Wardle proved to be a bit of a challenge, but I had a ‘light bulb’ moment when faced with converting the more recent Lynton & Barnstaple Lyn.

In Chris Leigh’s review of Heljan’s Lyn

(MR291), he mentioned the number of steps (and screws!) involved in getting inside the model. While it might have put Mr Leigh off opening it up, it’s not too difficult if you study the instructions carefully. There are three screws to remove, but first it’s necessary to unscrew the pony truck pivots. Beware – the rear truck features delicate power collecting strips and the accompanying cables are very easily broken (as I soon found out!). Having already used Zimo M649N decoders in my two Bachmann ‘Baldwins’ I decided to use the same chips again, obtained from Digitrains with its active sound project. I also bought a Mini Sugar Cube speaker from the same source.

The plan was to plug the decoder into the Heljan trailing socket, which would be relocated into the cab interior. However, the combined length of the decoder and socket was too long to fit inside the cab.

I overcame this problem by carefully bending the decoder pins through 90º, then shortening them by approximately 3mm. A small slot had to be cut into the right-hand side of the backhead, to provide a few extra millimetres of space and allow the power cables to enter the cab safely. When placed at a suitable angle, the combined circuit board and decoder now fit happily inside the cab and the speaker was fixed under the cab roof with Black Tack.

Testing proved that all was well, the decoder’s address was changed to 762 to match the locomotive’s running number and the body was carefully replaced, along with the pony trucks. While replacing the rear truck, one of the aforementioned pickup wires came adrift, and required a repair.

As the wire had broken above the original soldered bond, thus shortening the overall length, the whole wire had to be replaced, which proved tricky.

Anyway, Lyn is now running successfully, and I’ll eventually get round to fine-tuning the decoder. For now, she sounds chuffing good!