Mystery Apparatus: Can You Identify It?

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SUMMARY

The apparatus discussed is identified as the receiver of a Radio Demonstration Apparatus Generator and Receiver, manufactured by the Central Scientific Company (Cenco) between 1935 and 1950. It features two vacuum tubes, specifically the 801A transmitting triode, and includes brass plates likely functioning as a capacitor. The dimensions of the apparatus are 30 cm bulb to bulb, with a base measuring 10 x 16 cm and a height of 13 cm. This identification was confirmed through collaborative research and references to historical catalogs and vacuum tube specifications.

PREREQUISITES
  • Understanding of vacuum tube technology, specifically the 801A transmitting triode.
  • Familiarity with radio demonstration apparatus and their components.
  • Knowledge of historical laboratory equipment from the Central Scientific Company (Cenco).
  • Basic principles of electrical circuits and capacitive components.
NEXT STEPS
  • Research the specifications and applications of the 801A transmitting triode.
  • Explore the design and functionality of radio demonstration apparatuses from the 1930s.
  • Investigate the history and cataloging of laboratory equipment by the Central Scientific Company.
  • Learn about the principles of capacitors and their role in radio technology.
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Physics educators, vintage electronics enthusiasts, and anyone interested in the history of radio technology and laboratory apparatuses.

Scott Kozak
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Hello everyone,

This is my second year teaching Physics and I have come upon an interesting apparatus that no one can seem to identify. It appears to be two vacuum tubes protruding from a casing which includes two sets of three parallel brass plates, presumably with some sort of dielectric in-between. These plates are in turn wired to what I believe is an insulated solenoid of unknown coil number. There is another coil of wire wrapped around a glass test tube connected in parallel to the bulbs and I think to the negative feed (although this connection seems to have worn out). It is made by the Central Scientific Company (Cenco), listed as a "laboratory apparatus" along with "supplies chemical." Dimensions are 30cm bulb to bulb with a 10 x16 cm base and stands 13 cm tall at its highest point (picture attached.

I haven't the slightest clue what this thing is or does but my students are absolutely fascinated with it. Can anyone help me Identify it.

Thanks,
Scott
 

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Would be nice to have a side view and the underneath view of the wiring. Also, there are tube numbers that would be helpful. Initial ques is, the tubes are diodes being used to rectify the potential developed on the single brass loop (transformer secondary) from the coupling of the test-tube windings (transformer primary). But without seeing a side view, that could be completely wrong.
 
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anorlunda's Central Scientific catalog is from 1918 and seems to be arranged alphabetically

page 421 is start of Pyrometers section
page 427 starts Radio Activity Apparatus (electroscopes)
page 433 is rubber goods

no radio equipment... so i think it's newer than 1918

Is there a number on the tubes? How many prongs , 4 ?
Could be a #30 triode , i have an old radio that uses them

mysteryapparatus1.jpg


https://frank.pocnet.net/sheets/021/3/30.pdf

MysteryApparatRCA30.jpg


seems the right flavor for a 1930-ish radio experimenter's tool

i can make out an RCA logo on one tube base but not a number. My #30's have the number on the glass envelope ~midway up.

@dlgoff - you 're the maestro !

old jim
 
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dlgoff said:
Okay, it's the receiver of a Radio Demonstration Apparatus Generator and Receive. There is also the generator that would go with it.
See: http://www.radiomuseum.org/r/centralsc_radio_demonstration_appa.html

edit: here's a copy of their picture.

View attachment 127909

Thank you very much dlgoff and jim hardy. I really appreciate all the help and detective work. My students were becoming discouraged after they looked through the whole Cenco catalog and didn't find anything, they'll be thrilled to have the mystery solved!
 
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