Funny you mention this tunnel, Tim!  I traversed through this very sad-looking SOX installation just last June.

My parents go through this area year and have for many years now, so I'll ask them. 

 @ Burrito : The Mission Bells are made by GE entirely from GE M-250 & M-400 parts . There's two on eBay : https://www.ebay.com/itm/353203073331 (M-250 parts , 100w HPS) and this : https://www.ebay.com/itm/165525545458 (M-400 parts , unknown wattage/lightsource)

 I don't know the status but I read that's there's been discussion of renovating the tunnel for a few years now.  I wish I could find photos of the original MV lighting ! It was nothing like I've ever seen before !

Looking at white SON running up is kinda fascinating. They sure start and stay for quite long in SOX monochromatic yellow, then gradually turn SON orange, and suddenly get that strange 'brownish' color. Brown is of course a wrong term for radiated light) but I like to call it that way...

Also all Philips SDW lamps flicker for unusually long time when started. I attribute that to simple rod electrode construction, without extra starting aid coils typical for almost all other HID lamps. So it takes a long time to heat the massive rods and do glow-to-arc transition. Wonder if heavy sputtering occurs at that time.


 

Something like this is invaluable for checking to see if the arc tube in a lamp is still good. 

I believe I have a fluorescent lighted sign in my grandmothers basement.

They were still there as of August 2023!

Don’t forget the Wide-Lite 4000.

White SONs have a nice unique warm color that oversaturates yellows, greens and reds in a pleasing way and high CRI, amount of deep red is just ridiculous, but are downgrade from common SON in almost all other ways. They are expensive, life is short and light output drops to about 1/2 of SON of the same power. And of course they need a complex stabilized ballast with a special voltage-current curve.

Will do, RRK and Medved. I'll have a look this evening and let you know my findings. The lamp might be at fault? Not certain. It's a clear 70W 55V BT-25 lamp from 1985 (Philips-Westinghouse).