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Kodak 75000 Vacum tube or bulb

Photo51

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i have several of these Kodak 75000 tubes, or bulbs? I wonder if anyone knows what they were used for?
 

Leigh B

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Why are there two threads on the same subject? That's a no-no.

I already answered the first one.

- Leigh
 

ic-racer

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Like this?
If so, the RCA Phototube guide suggests it is a 917 style used in "relays and measurements." Perhaps even a re-branded RCA 917.
 

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Leigh B

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Like this?
Looks just like the one I posted in the other thread, but mine is horizontal.

(there was a url link here which no longer exists)

- Leigh
 
OP
OP

Photo51

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Like this?
If so, the RCA Phototube guide suggests it is a 917 style used in "relays and measurements." Perhaps even a re-branded RCA 917.

That is just what it looks like. Thanks for answering. I searched Google, and Duck and couldn't find any info on it. Posted other thread by mistake.

Still wonder what these were used for.
Got a box of vacuum tubes at an estate sale that had several of these 75000 in it.
 

ic-racer

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Still wonder what these were used for.

I read "relays and measurements" as "densitometer." The other phototubes types were used for film soundtrack reproduction.
 

AgX

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They are the predessors to the photodiode.