Two Aspect Colour Light Signal
Reviewed by Anthony Fellows Gazette November 2018 (Vol 20 No.9)
This is a review of the Routemex 2-aspect colour light signal kit. Kit manufacturer John Neville is to be commended for clear information for the constructor, particularly in respect of the technical notes on connecting resistors to LEDs, which have different values for each light colour, and the useful chart identifying resistor values. The kit goes together well, etches are accurate and the preformed ladder saves much soldering. The simple idea of providing a piece of plastic tube to slide over the brass post tube is an asset when assembling the back box, and ladder rest plate, to the post.
Assembly Observations. As the shape of the light hoods does not lend itself to normal clamping, holding them in place whilst soldering them to the front plate is a challenge. So I adopted a less conventional method. I drilled a half inch square piece of hardwood to accept two short dowels, of similar diameter and equal centres to the holes in the front plate. This wooden ‘jig’ was then clamped in the vice and the front plate placed on top, with the dowels poking through about 10 millimetres. Having cleaned and fluxed the front plate and both light hoods, I formed small arcs of low melt solder around the two dowels and simply placed the light hoods against these.
A pencil soldering torch with an open flame quickly melts the solder, so that it flows around the light hoods without moving the components, as would be the risk with a conventional iron. These items can instead be glued, using the aforementioned plastic tube as a spacer, but the wooden dowels would also be a help in this case. When fitting the post tube to the back box, it is essential that the tube is soldered flush to the inside of the base of the box, otherwise the LEDs, when fitted to the front plate, will not go in. An extra millimetre larger all around the box etch would allow some latitude when finally assembling these components.
These kits are well designed and 2-, 3- and 4-aspect signals, with or without ‘feathers’ are available, all at competitive prices.
