I inherited a box of 9 NIB GE lamps. These are big guys with a flange base, type T5 maybe? Anyway, the package is marked "Code-1A/T5/7 Sound Reproducer Clear 1 Amp T5 6 Volts"

The flange is about 1 in+ diameter, and the envelope is about 1-1/2 in. tall and 1/2 in. diameter- cylindrical with a rounded top. The twist flange captures 3 studs when socketed.

I don't quite get the "sound reproducer" part. Any ideas? I'm pretty sure these must be at least 50 years old, based on how and where I got 'em, condition of the box, etc.

Thanks, David

P.S. I'll put up a photo if that would help.

They are probably for film projectors, to provide light for the phototube that reads the film soundtrack. I have 14 of these lamps, I'm at work now so I don't have access to the type numbers to confirm that they are the same as those. I received the lamps with some Mills Projector Amplifiers, audio amps for Mills Panoram film type jukeboxes. The projector amplifiers have an input for the phototube and a push-pull audio amplifier and they also include a circuit for generating a high frequency current to supply the lamp, presumably to eliminate the 60Hz hum from the phototube output.

Thanks, Jeff-

I had a hunch they had something to do with movie projectors.

David

Many of the Victor Animatograph projectors (no relation to RCA Victor) used 6-volt, 1-amp sound exciter bulbs of the style you describe. The ANSI code type for them was BVS. If that's what they are, they may have some value to vintage film equipment collectors. BVS bulbs went out of production about 20 years ago.

Unlike RCA, Bell & Howell, and other projector manufacturers which used high freqency AC generated by tube oscillators and low-current exciter lamps to prevent hum, Victor went the opposite route and used very thick filaments which had enough thermal inertia to overcome the AC ripple (and they also rolled off the amplifier response at lower frequencies).

I have a case of lamps like that, but of different voltage. They sit in a socket in a way
that positions the filament precisely behind a lens , and on some, bolts can be adjusted
on the spring loaded base to position the socket just where it is wanted.

Out of the great plentitude of 6-packs of lamps, I have used only a few to make some
demo stuff. These shown are 8.5 Volt 4 Amp G.E.

I burnt a couple out, and broke a few too. It is good to have spares .

Thanks, Chris-

Perhaps I'll offer them in the Classifieds- or maybe research vintage film equipment online for a better forum.

Great photos- thanks Steve! Those look like mine, with 'T5 base'.