I had a similar issue with lighting for two fuel gauges. I rewired the bulbs
to be in series which cut the brightness considerably. Also painted bulbs
red -- used special paint for this designed to take heat. Theatrical supply
places have it as do some mail order auto supply places. If you get lucky
you may actually be able to buy the right bulbs already colored red.
Len

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"William G. Andersen" wrote in message
news:6%j7d.12517$Hz.2496@fed1read04...
Anyone have ideas about how to add a light/backlight to an instrument?
I want to add interior illumination to the display panel of my Si-Tex 525
ADF. It has three lights for operation and they're very bright: I think it
would be easier on my eyes at night if the face of the panel was softly
illuminated. Si-Tex only states they don't offer an illumination mode.
I'm thinking of a small 12 volt bulb inserted in a notch on one edge -
thinking the light would be distributed through the clear panel.
An alternative would be to just mount one or two bulbs inside the case so
that the bulbs aren't directly visible, but so that the light would be
dispersed throughout the case.
In either case, I plan on wiring the bulb(s) to the power switch of the
ADF.