Post by: Bill Nelson on February 28, 2001, 10:54:00 pm
The bulbs have a coiled tungsten filament, a heavy but seemingly original coat of two-tone enamel paint, are 15 volt, and a common black glass insulator is in the miniature size base. The base is completely unmarked, and is made of a metal I'm not familiar with. It seems to have an odor similar to old brass, but is silver in color and tarnishes. Anybody have an idae as to country of manufacture and age? Thanks in advance for your help!
Post by: James on March 01, 2001, 06:18:00 am
Those look similar to a couple of old Osram-GEC British bulbs I have, but only in terms of their shape and cap. 15V bulbs are virtually unheard of here, in this country most older sets were 20V bulbs wired in 12-lamp strings for the 240V supply so I think they were probably made elsewhere.
The cap is most probably silver plated. They were offered at higher cost for lamps to be used in outdoor or damp locations since they minimised corrosion and the likelihood of and caps sticking in the holders. Silver or nickel plating is still standard practice today for high value lamps to be used outdoors, such as on railway signal and certain other projection lamps.
James.
Post by: Bill Nelson on March 01, 2001, 09:44:00 pm
Thanks for your kind reply. A close inspection of the metal base confirms that it is indeed plated, and a bit of silver cleaner removed the tarnish instantly. Do you have a guess as to the age of these lamps?