[VntgRads]

I'm looking for info on the correct bulb for the shadowmeter in a 16B cathedral.  Looks to be screw in bulb but not sure of the number.  Who might stock one of these?  Thanks much!

Craig R

[klondike98]

According to Chuck's Philco Repair info a type 46 should work for the screw type.

http://www.philcorepairbench.com/tips/svctip01.htm

Many suppliers of those including RadioDaze.

[VntgRads]

Thanks for the reply!  I did see that reference.  Do you know if that bulb is available in a straight filament?  I've been told that the more common curved filament supposedly doesn't work quite as well.

Craig R

[Mondial]

You have to select one for the straightest filament, as the bulbs come with a lot of variation. Also look for one which centers the filament over the opening in the meter housing. You want to orient the bulb so that the filament is vertical and directly over the opening.

[VntgRads]

^^^  Thanks for the very useful info.  I assume this relates to a U-shaped filament.  Does anyone know if the straight filament bulb is still available?

Craig R

[Mondial]

As far as I know, there are no straight filament bulbs available. Each manufacturer had their own variation in filament design. Some early production NOS GE bulbs have a reasonably straight filament and I select the best one from those.
 
http://i.ebayimg.com/images/g/W7kAAOSwUE...-l1600.jpg