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If someone could identify the following it would be much appreciated. I am assuming it is an oscilloscope of some sort.

The device needs a lot of TLC; grounding the inputs leaves a small Lissajous like figure on the display, so all is not well.

If I could get a manual that would help, I do not have the nous to go in on my own :-(.

Front

Top

"Side panel" (not exactly)

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    \$\begingroup\$ It's of the U.S. Navy OS-8 oscilloscope series (1950s to '60s); IIRC they were made by multiple manufacturers, that should at least give you a start though. Edit: after a quick Google, here is the instruction book for the OS-8C/U and OS-8E/U, which appears to be similar if not identical. \$\endgroup\$ – uint128_t Sep 17 '17 at 1:33
  • \$\begingroup\$ What's a "small Lissajous like figure"? \$\endgroup\$ – winny Sep 17 '17 at 8:32
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    \$\begingroup\$ @winny: The glib answer is en.wikipedia.org/wiki/Lissajous_curve. If you drive the horizontal & vertical axes by \$t \mapsto \sin (at), t \mapsto \sin (bt + \phi)\$ where \$a,b\$ are rationally related you can get come cute curves. Practically, the Lissajous curve can be used to look at the phase difference between two signals of the same frequency. \$\endgroup\$ – copper.hat Sep 17 '17 at 10:34
  • \$\begingroup\$ Oh! Learned something new today. \$\endgroup\$ – winny Sep 17 '17 at 10:53
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The OS-8 is a series of oscilloscopes built for the U.S. Navy/U.S. Army, I'm not sure exactly which manufacturer yours is from, but an "Instruction Book" is here, which includes instructions for "Corrective Maintenance" as well as both a pictorial wiring diagram and schematic wiring diagram, which will prove invaluable if you need to service it (and are also quite pretty, see pages 46-47). It appears the the OS-8C/U and the OS-8E/U are very similar, so manuals for one are sufficient for the other.

See also TM11-1214A, the technical manual for the OS-8C/U, which is very similar to the document above, but not identical (perhaps Army vs. Navy). It seems that this oscilloscope was manufacturered by Carol Electronics Corp. (Martinsville, WV) but it could also be from The Hickok Electrical Instrument Co. (Cleveland, OH).

You may find the time base behaviour to be a little strange, because this scope uses a "repetitive time" horizontal sweep, rather than a triggered sweep, which is what most modern oscilloscopes use or emulate. In other words, the sweep is driven directly by a sawtooth generator, and the sweep frequency must match (or be an integer multiple) of the input signal to get a stable display, and therefore it's rather difficult to measure the actual time shown by the scope.

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