NavList:

Does anyone out there know if one can obtain LED arc illumination bulbs for a C.Plath/Cassens and Plath?

Robert,

Yes there are many types to be used. I’ve changed all my illumination set-ups on each of my sextants to use LEDs.

Mail order houses/catalogs such as Newark, mouser, Digi-Key etc have what you will need. In your town I’ll wager there are surplus electronic houses that can give you what you need.

On all my sextants the power for illumination is from a bank of two AA batteries stacked in series in the handle.This will give you about 3 vdc. The LED should drop about 1.7 vdc of this across itself. Sometimes you will need to add a current limiting resistor in series with the LED to limit the current to about 20 m.a. At 3 vdc that will be about 75 ohms.

On mine I just didn’t use the resistor because the light is not activated for long periods of time and I’ve yet had one burn out.

I really like using the H.P. single element light bars in my set up. The yellow wavelength lights I like the best. Red works but, for me, the yellow is easier to see.