Re: From 2014: Tektronix Announces Winner of Europe’s Oldest Working Oscilloscope Contest

Dave Wise
 

< The vertical amplifier, and attenuator wasn't calibrated, so to make things work, you adjusted the vertical amplifier variable attenuation to exactly fit the waveform on the graticule lines. Then you switched the vertical input to the calibrator, and adjusted it to match the same graticule lines... reading the peak-peak voltage off of the calibrator's pointer dial.>

Thanks for explaining that so clearly. I suppose that using the graticule as a transfer standard was a good idea back when the amp and CRT deflection were not so linear.
I used to think "calibrated graticule" was just marketing. I didn't realize it was an inversion of methodology.

Still, if they gave me one now, I'd be happy to fix it and play with it, oil can and all.

Dave Wise

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Chuck Harris
Sent: Monday, September 16, 2019 2:38 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] From 2014: Tektronix Announces Winner of Europe’s Oldest Working Oscilloscope Contest

The old 500 series worked quite differently from what
became the standard analog scope interface, the 545.

The vertical amplifier, and attenuator wasn't calibrated,
so to make things work, you adjusted the vertical amplifier
variable attenuation to exactly fit the waveform on the
graticule lines. Then you switched the vertical input
to the calibrator, and adjusted it to match the same
graticule lines... reading the peak-peak voltage off of
the calibrator's pointer dial.

The horizontal time was similarly odd.... but at least it
was calibrated to the graticule.

The main time switch selected the decade you were in: 1000us,
100us, 10us, 1us, 0.1us per cm. The secondary time switch
was a two dial multiplier, that had 0-10 on one dial, and 0-0.9
on the second. Typically, you adjusted the timing so that
you had one cycle on the graticule, and read the time off of
the dials.

-Chuck Harris

OBTW, the HV section was in a sealed can full of oil. Which
was a good thing for the bumble bee capacitors in it, but not
too convenient when a 5642 rectifier burned out. You unscrew
the HV insulators, to keep the pressure down, unsolder the
can lid, and extract the HV section. It is exactly the same
configuration as all of the later 500 series, only the HV
transformer is the much larger 2.75" W5 E core... and ran at
400Hz, as I recall... maybe 1KHz.

Dave Wise wrote:
Closest I got was high school (Benson Polytechnic in Portland OR) in the early 70's, where one electronics classroom had a 514D in a back corner. I always felt sorry for the poor old thing, which was never touched as far as I know. Also covetous; but the teacher wouldn't give it up. It was the best instrument in the room, our assigned tools being RCA service-grade boxes.

Dave Wise

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