WE 505C question

[JimNY]

I have a WE 505C that was converted for civil defense use.  I spent quite a long time trying to figure out how it was supposed to work. But with some patience and some very minor repair I managed to get two extension and the attendant phone all doing what they are supposed to. I noticed that inside there is a 1930's vintage light bulb. However, in it's present set up doesn't appear to do anything. Does anyone know what the function of the bulb is? I would like to get it working if it is supposed to light.  I did test the bulb and it does work.  Also, what are your thoughts on the civil defense conversion? I toyed with the idea of refinishing / refurbishing to original.

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[Doug Rose]

That is in just amazing condition....Doug

[JimNY]

Thanks Doug. Legend has it that it spent 60 years in a central office storage room. Story seems accurate because there are 'testing' tags on it, the latest one dated early 1960's.  It came to me encrusted in 50 years of dirt and dust though, which took a fair amount of work to remove.

[poplar1]

I noticed that inside there is a 1930's vintage light bulb. However, in it's present set up doesn't appear to do anything. Does anyone know what the function of the bulb is? I would like to get it working if it is supposed to light.  I did test the bulb and it does work. 

"A resistance lamp is provided in the PBX to prevent a trouble from overloading the supply."

Here is a description of the Civil Defense version of the 505C:

https://www.telephonecollectors.info/index.php/browse/bsps-bell-system/bsp-categories-by-early-letter-code-by-doc/b-series-pbx-installation-and-maintenance/3520-b303-011-1-ia-ny-cordless-pbx-switchboard-for-civil-defense-units/file

[JimNY]

Poplar, thanks for the explanation. I used that document you linked when setting up my board, it was very helpful.