Sound in Heljan Class 33 - Directional Lighting Query

[steveNCB7754]

Preparing for DCC sound installation in only my second loco, I finally popped the body off my new Heljan class 33 (Part #34321 '33059' in BR Blue w/full yellow ends) this evening.  This was bought at the Bristol Model Railex two weeks ago, following Paul Chetter's excellent article ('Crompton Consist') in May's Hornby magazine.  Obviously, its early days yet, but I see a slight disparity regarding the directional lighting in my example and the alterations detailed in the article.

 

My loco has a single (white) light at each end, with an associated clear plastic 'light pipe' which not only illuminates the headcode board, but has twin branches to light up the pairs of 'side lights' at each end.  Quick insertion of the Zimo MX645R DCC sound chip, shows that the main light does indeed light up at each end, dependant upon direction.  However, this is different to Paul's article, where there is also a separate bulb (Red?) which is supposed to illuminate one of the pair at the 'Tail' end, dependant upon direction.  My chassis has the 'gallery' cast in it at each end for such a lamp/wire, but none is fitted and the plastic light shield/cover even has a blanking 'nib' which sits in the hole where the bulb would have been.

 

Question: Does that mean I can ignore all the stuff about the directional wiring mods ('FO1'/'FO2' and all that), as I have no lamps connected to plug 'R', since the main bulb is working (directionally) with the DCC chip fitted?  Conversley, could I retrofit such a bulb and (presumably), remove the offending light pipe 'branch' and associated blanking 'nib' in the shield/cover -  suitable bulb anyone?

 

Supplementary: Why no directional tail lamp wiring on my version of Heljan's 33?  Are there other versions without it and if so, why some and not others?

TIA

 

Steve N

 

[SRman]

For a blue 33, there would have been no tail lights, or even marker lights in use. Any tail indication, where the locomotive was either light engine or pushing stock, would have been through double red blanks in the headcode.

The marker lights were often painted, or even plated over, or simply removed.

 

So, technically, your model as supplied by Heljan is correct and you won't need to do those lighting mods.

 

If you do want a tail indication, you'll need to alter the lighting to turn on the trailing headcode lights and put in the double red blinds. This could be done by altering a couple of CVs in the decoder. An alternative to this, which would require rather more work, would be to put in  white blanks in the headcode and rework the lights so that the headcode lights show white one way or red the other (with the red light illuminating the white blanks to give the illusion of red a red display). While the wiring would be similar to that in the article you refer to, the lights themselves would have to be where your existing white bulb or LED is. My suggestion would be to substitute a bi-coloured red/white LED.

[steveNCB7754]

Thanks SRman, that's a pretty comprehensive reply. Given what you've said, I think I'll leave well alone as my 33 will only be hauling mineral traffic and there is already quite enough to do, fitting the sound in.

 

Regards

Steve N