BB 16007 vue de profil

BB 16007 Roco equipped with LS Models pantographs.

Installing a decoder and improving headlights

BB 16007 Roco ref. 43568: an old-fashioned electrical circuit, with incandescent lamps and no red lights.

Lifting and fitting of the body

We have just to move the body bottom apart, and the chassis falls easily (from not too high!). Also, be careful to the bulbs simply placed in their chassis housing and which will escape if you turn the chassis upside down.

As I don’t have a functional catenary (no catenary at all), I have removed the contact strips between pantograph and PCB, which take up a lot of space.


This machine has no separated white and red lights. So the red and white light sources must be on the same axis. I chose bicolor PLCC LEDs, apparently unavailable at the time I write these lines (end of 2012). You can also find them, at a much more attractive price, on E-Bay.

I first measured the dimensions of the lamp housing: 4 wide × 4.5 high × 4.4 deep, then those of a PLCC LED: 2.8 × 3.5 × 1.8 (all dimensions in millimeters). It was therefore possible to insert it into the existing housing without hazardous machining.

Front headlight

Obviously, since the chassis housing is metallic, this assembly must be carefully isolated. At the housing bottom, I placed a small pad of electrician adhesive (8a). Around the LED equipped with an orange filter (small translucent plastic rectangle cut in a soft ring binder cover), after soldering the wires, I put a piece of translucent silicone sheath (8b). If I’d have it on hand, I’d have preferred using a transparent heat shrink sleeve. Finally, the wires are protected to about 5 mm at the LED output by a conventional heat shrink sleeve (8c).

Here is the connecting diagram.

Note the notch to the LED corner which gives its direction. Caution: this may vary. You should consult the LED technical data on the Internet.

Connecting the LED

How to find the direction (polarity) of an LED

If you own an electronic multimeter, set it to Diode Test. Put the red probe on the + (red) terminal and the black one on the − (black) terminal. Place the test probes on the connections of the LED to be tested. No need to look at the tester display: if the LED lights up, it is polarized in the right direction (one says forward). With this method, no chance of breaking it.

Batch of 10 bicolor red-white LEDs
Dimensions 3,4 × 3 × 2,1 mm
16,00 € — price 2013
CDF ref. 80111002

25 red-white 3500 K PLCC LEDs
4,65 € — price 2013
electron-discount ref. 142/25