Kit: MX699KS; YLR603010; Cab Lights; ModelU Figures
One of Heljan's more recent additions to its' vast 7mm diesel range, the Class 33 is excellent, here in DRS livery.
Basically, remove the factory PCB and put the MX699KS decoder in its' place (pretty much identical footprint). Remember to
include resistors for the lighting, as the original protective resistors were on the board that is removed. Heljan have at last
produced a model with almost standard DCC wire colours too, so less confusion!
Below we show the factory PCB removed, and the MX699KS in position.
The YLR603010 is the ideal indoor speaker to use here - loud enough, but not deafening, with a good quality output, especially
as it can be placed directly in the fuel tank where the sound can escape properly. Really neat fit.
We did experiment with a 2nd speaker (YLR302815) underneath the decoder, where there is certainly enough space, but the
acoustic effect didn't really work and the sounds ended up being boomy and echoy, loosing crispness, so we decided it was
better with just the single YLR603010 in the fuel tank. Many other options are possible of course, but this we found to work
very well, as well as being simple to do.
Just the process of insulating under the decoder, and working through the wiring, screwing them into the appropriate terminals
of the MX699KS. We've given this model independent head and tail light control, as well as connection for the fan, and
directional cab lights, so 7 outputs used in total. Let us know if you'd like this configuration, and we can alter your
decoder before shipping.
Note the resistors, which we've put on the FA (negative) side for each output. Normally we prefer to put them on a split
common output, but in this case it was neater to have them individual from the negative to save extra wire joins.
Remember that the motor and pickup wire colours are reversed for each end bogie, as per normal Heljan practise, so you'll have
red from one end with black from the other for one side of the track, and vice versa for the other side. Similar for the motor
- grey+orange one end, and orange+grey the other end (otherwise the motors will work in opposite directions!
The ModelU crew figures go in too...
Here's another one in green with similar kit, and weathering applied...