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I have recently purchased two Bachmann class 166's in first Great Western livery. I always move the powered chassis from the centre into one of the driving coaches, which is quite easy to do. I do this will all three car DMU's as it then allows the set to run as a 2 car set if you wish. I Fit a Bachamnn function 3 decoder on the powered chassis, as per the intructions which I printed off from: www.electricnose.co.uk/dcc/bachmann 158
Using minature connectors and spare drawbars from Heljan class 47's (just the right length) I through wire to the other trailing coach. I have done this on numerous class 158 and 159's, which have the same chassis arrangement as the class 166's. However, with the 166's, the red tail lights are very bright, and the white lights quite dull. I have never had this happen on the 158's etc, and just wondered if anyone has experienced the same problem.
 

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QUOTE (Brian - Cornwall @ 1 Oct 2008, 00:43) <{POST_SNAPBACK}>I have recently purchased two Bachmann class 166's in first Great Western livery. I always move the powered chassis from the centre into one of the driving coaches, which is quite easy to do. I do this will all three car DMU's as it then allows the set to run as a 2 car set if you wish. I Fit a Bachamnn function 3 decoder on the powered chassis, as per the intructions which I printed off from: www.electricnose.co.uk/dcc/bachmann 158
Using minature connectors and spare drawbars from Heljan class 47's (just the right length) I through wire to the other trailing coach. I have done this on numerous class 158 and 159's, which have the same chassis arrangement as the class 166's. However, with the 166's, the red tail lights are very bright, and the white lights quite dull. I have never had this happen on the 158's etc, and just wondered if anyone has experienced the same problem.

***As you are using a 3fn decoder which is not enough for full light selection as individual pairs, I presume the red and white are on the same functions. (red rear + white front = one function).

If so you while its OK for them to be in parallel, you also need to make sure that you use appropriate resistors for each colour of LED, not sharing a common value resistor on the blue for both red and white.

This because differing colours have very different power needs

Try something like white = 1k and red = 2k, or if you like it lots brighter than reality, white = 640 and red = appx 1500. (higher resistor values lower light level).

You may want to play with these values, but while you can increase either quite a lot, don't drop below 640ohms for white or about 560 ohms for red.

regards

Richard
 
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