Unfortunately I won't have probes with me when I go to pickup the thing. Why is it concerning that the scope is missing the probes? The person who is selling it says its an estates sales thing and he doesn't even know how to use or test it.
I don't see any capacitance listed in the manual. What are the usual terms used for that?
So far, the max signals I've come across are the 14 ish MhZ clock signal from a C64. By the time all the processing is done and it reaches the CPU, it drops to about 1. I intend to work on old electronics or small arduino based projects.
Thanks for the suggestions.
However, I am not sure how to interpret the test method you suggested. Are you asking me to connect something to the input channels and then do something?
The Input capacitance is listed under "Input Impedance" of the Vertical Deflection System. pF as in Pico(a trillionth)-Farad is what you're looking for.
As for testing you should make sure that every switch, rotary or sliding, is working correctly mechanically and is actually switching something.
For the screen itself there is usually a Focus knob and a Brightness/Illumination knob. The former expands and contracts the scanning dot or trace on the screen. Going from fuzzy like 360P video to sharper and then fuzzy again. The latter increases or decreases the brightness of the dot or trace. At around halfway travel of the knob there should be a perfectly visibly trace/dot on the screen without sunshine shining on it directly. If it is still dim or hardly visible it is evidence of "tired" CRT screen. Which is unrecoverable apart from getting a CRT tube with less operating hours or even a new old stock one.
For the Horizontal Deflection or "Timebase" it should vary the scanning speed of the dot across the screen. Going ever faster the further you decrease the scanned amount of time.
The Vertical Section/Input should vary for a given constant signal the displayed amplitude. And do so so it looks symetrical if split horizontally along the graticules of the screen.
For the position knobs those should vary the space over or under the displayed line, or "trace", for the Vertical Postion and the centricity for the Horizontal Position. With the latter the whole scanned line will vary left to right and can be even made to begin away from the edge of the screen towards the center.
For analog scopes all turnable knobs that don't have detents when you turn them are usually variable resistors, called Potentiometers, and those can get dirty due to intruding dust or other dirt. Any glitchyness or sudden jumps on the screen when turning them is evidence of that. To clean those there are various cleaning sprays but those are best used only in moderation! Do not coat the whole inside of the Scope with them.
Taking the Potentiometers out by desoldering them and carefully prying open the crimping to pull them apart and clean them with isopropanol alcohol can be done. If you can desolder and have reasonably steady hands. The alternative would be to desolder the old ones and and put in new ones with the same resistance values, shaft length and diameter.
More I can't think off off the top of my head. If you don't want to troubleshoot any receiver sections of radios or anything beyond 80ies computers it should serve you fine for the beginning. Anything audio it will do and also the slow clocks of Arduino or anything Z80, 8088, 6502, 68000. The only problem with digital signals is it has no storage capability. It only displays continuous real time signals. So viewing split second events of a C64 RAM bus will require some patience and squinting.
Dude! You're a legend!
That's one of the simplest way to explain it all to a noob that I've ever come across.
Thank you all for your inputs.
So I did some basic tests on the scope and everything seems functional. I don't have probes or a foot long cable now. But I do have jumper wires and so I tested the built in test with it. Here is the output:
(https://i.ibb.co/vQRz0r1/337470355-1566109373887395-4707436423357772515-n.jpg)
It's set at 0.5 V div and 0.2 ms time/div.
Is this the sort of square wave I am supposed to be seeing?
Also! The trace needs rotating. Do I need to use a plastic screwdriver or something? I am afraid of putting a metal one inside that hole.
Just posting for the sake of closure.
Tested both channels with 100 Mhz probes:
(https://i.ibb.co/cc8RdWy/IMG-9615.jpg)
(https://i.ibb.co/BKkbTbL/IMG-9616.jpg)
Had to use the adjustment tool provided with the probes to trim them until the outputs looked the way they do in the above images for channels 1 and 2. Looks like it's all working okay so far. :D