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Dantali0n :arch: :i3:

There is just something magical about the construction of vintage electronics. Here is the PM3410 analog sampling oscilloscope. A scope that samples using a storage plate inside the CRT.

More on museum.dantalion.nl/item/phili

Circuit board constructed inside steel frame on a carriage card for the PM3410 analog sampling oscilloscope. The circuit board is made of discrete transistors and does not contain any integrated circuits. Several metal cans protect sensitive areas from interference. The front of the carriage contains many important dials and knobs used to control the instrument
Side view of the interior of the PM3410 analog sampling oscilloscope. Many sliding pcbs on carriage cards are shown. They mostly contain large capacitors but also a lot of discrete transistors and resistors. On the top of the interior is the large shield for the Cathode Ray Tube (CRT).
Front panel of the Philips PM3410 analog sampling oscilloscope. This front panel features to carriage modules, the main display and the display controls. Many different carriage modules exist for this unit. Currently the default PM3419 B and PM3419 A are fitted.
Top side PCB for the PM3419 B carriage module showing many discrete resistors, capacitors and trimmer resistors. It also shows the ganged knob assembly that is part of the front of the unit.
Nov 07, 2023, 06:51 AM·Public
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mike805

@dantalion There were some graphics displays built in the 1970s with that type of tube. They could slowly draw a very complex scene, with the same flash to clear effect.

Before those tubes, there was a camera that could be clamped onto the front of the scope to capture a one-off event.

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Dantali0n :arch: :i3:

@mike805 interesting, I knew about the cameras but not of other storage plate uses.

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mike805

@dantalion There are some demos of the Tektronix vector graphics displays on Youtube. They look a lot like your scope display except bigger. As I understand it the plate either attracts or repels low velocity electrons.

The charge storage tubes were even used as memory in some early computers, although they were not reliable enough for commercial use.

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Dantali0n :arch: :i3:

@mike805 yeah I am quite suprised, fast weak signals have a tendency to 'under expose' and very strong signals can damage the plate so its all a bit finnicky.

But I guess in vector displays you can keep the draw speed constant and tune the sensitivity to match. So that might make vector displays a better fit then scopes.

As in scopes, the draw speed is tied to the time base. Although I imagine advent users memorize plate sensitivity and timebase relations naturally

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