Heljan O gauge 61XX Prairie - Zimo sound

[John YouChoos]

Heljan have done well with their new 7mm model of a large 61XX Prairie Tank - really like the model, but sadly they've scrimped on provision for speaker (just a 23mm round chamber underneath), and the loco has a socket in the boiler designed specifically for an ESU LokSound V4 'L' sound decoder.  There is no standard for large scale sockets, and Zimo's equivalent (the MX696S) is not a compatible fit.

 

In order to improve on this, we remove the socket and wire in a Zimo ADAMTC board, which takes a 21pin MX644D sound decoder (normally for OO models), boosting the motor output to 1.8A continuous running, and peaks at 2.5A for short periods... this is sufficient for the Prairie model.

 

By removing the ESU socket board, this frees up enough space in the boiler for the super Zimo LS40X22X09-2W dual Dumbo speaker, and also a YouChoos SuperCap17000uF for stay-alive (that's the other benefit of the ADAMTC board - it gives connections for a 16V stay-alive instead of the usual 25V connection that the MX644D normally provides).

 

Full install guide here: http://youchoos.co.uk/Index-Resource.php?L1=Guides&Item=OHeljPrairie

 

..for the forum, here are a few photos and words to give you the idea:

 

Here's the model's ESU socket board:

Now the Zimo ADAMTC board and MX644D sound decoer:

Now the model with the ESU board removed, and all re-wired up with the Zimo kit... speaker on top, and SuperCap at the front:

Ensuring that all wires are neatly tucked in, the boiler should just slide back into place. The result is stunning - really loud, sound from the right part of the model, and the SuperCap17000uF gives 4-5 seconds of backup power too!

 

Enjoy!

John