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National CRO Oscilliscope
So I stumbled across this Early scope (If you call it a scope) in an antique store, any information on it? I've seen bare bones minimum from my searches, namely a few photos and limited info.
It's kinda cool though, not really much practical use, but it would be cool to see it working again. No labels on any of the knobs either, I figure a manual must be in existence somewhere. Datatag says Thanks all,NATIONAL Model: CRO Number: E Cycles: 50~60 Volts:105-120 National Company INC. Malden, Mass. U.S.A. Zach |
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#3
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Looks like a simple ham modulation monitor, likely for displaying trapezoid patterns when connected to an AM transmitter. I suspect that it is very similar to this smaller CRM model:
http://www.oscilloscopemuseum.com/os...-crm-sxxx.html http://www.oscilloscopemuseum.com/up..._schematic.jpg jr |
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Well, some of the values on the resistors differ, but they're known values. Any idea for a range for the filter caps?
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#5
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The 2 inch model (CRU) isn't much different in design from the 1 inch CRM:
https://stevenjohnson.com/oscillosco...tional-cru.pdf But i'm guessing that the 3 inch model might use somewhat higher voltage. The max for the 3 inch CRT is specified as 1500 Volts, so C2 might have to be rated at a higher voltage. jr |
Audiokarma |
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Quote:
Chuck
__________________
www.myvintagetv.com Learn from the mistakes of others - You can't live long enough to make them all yourself. |
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Then, anyone have any advice on where to get this type of a capacitor? I've yet to see an electrolytic with such little capacitance but such a high voltage. I've seen quite a few of the film style though, and at reasonable prices. Would using one of there in series with a diode (say a 4007) work as a substitute? I'm not very well versed with caps, but something tells me that this wouldn't work (Though doesn't stop me from asking)
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