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Picked up cheap vintage oscilloscope, now what...

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  • Picked up cheap vintage oscilloscope, now what...

    It lights up so I'm pretty sure it works but it didn't come with any parts. I know I need a dummy load and a probe, but don't have a clue which ones to buy. I have a collection of tube amps and would like to use the oscilloscope to bias them (I use a compubias now). Is there anything else I can do with it? I'm hoping to learn more as I go along, but kind of need the cliff notes version so I can see it do something.

  • #2
    My scope is most used for signal tracing and checking power supplies for ripple. Of course there are a multitude of other uses. Google "using an oscilloscope". You'll find plenty of tutorials. That is, BTW, a dual trace scope, which can be quite handy for waveform comparison. You'll need 2 probes if you intend to make full use of its features. A single probe will certainly get you started, though.
    "I took a photo of my ohm meter... It didn't help." Enzo 8/20/22

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    • #3
      That's a Tektronics 454A. A real workhorse at the time. Here's a link for the operator's manual:
      Tektronix If that isn't close, there is literature all over the internet for free. It is a 30mhz scope that is plenty for audio. Check out the "calibration" instructions in the owner's manual. There should be a 1khz square wave source lug somewhere on the front panel where you can set the symmetry, check the trigger and all of that when you get a probe. You don't need expensive probes. There was a time that many benches had one of those. Quite expensive and well made in their day. But if it doesn't trigger or is asymmetrical or something, I wouldn't put a lot of time or money into it.

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      • #4
        Look again, it's a 545, not a 454. And if you look at the panel, the triggering is upper right. You got the right manual though, so I assume that's a typo.
        Education is what you're left with after you have forgotten what you have learned.

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        • #5
          Originally posted by Enzo View Post
          Look again, it's a 545, not a 454. And if you look at the panel, the triggering is upper right. You got the right manual though, so I assume that's a typo.
          Right again Enzo, I lost my glasses traveling to NYC last week. Lots of typos and weird auto corrections lately! Especially on a smart phone. Sucks getting old!

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          • #6
            That's actually a nice scope for audio, and pretty much bulletproof. The new stuff won't take what THAT one will. Hell, I'm using an old Bell and Howell school scope. Works just fine for audio. Mike.

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            • #7
              That is the bonus here. Guitar amp circuitry is not at all demanding of a scope, just about any scope will work for us.
              Education is what you're left with after you have forgotten what you have learned.

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              • #8
                I didn't check the manual, but one actual advantage of older scopes is they often have higher voltage tolerance and more intuitive protective circuitry for higher power circuits. This makes the older scopes particularly suited for tube audio work.

                Alldayphila, you'll also want a signal generator (also cheap on auction sites) and you'll want a scaled probe for high voltage work. 10X will work but most here think 100X is better. My scope has a 200V input tolererance though so even with a 10X I'm not likely to damage anything. One thing that's been mentioned is that, when clipping, tube amps can create voltage spikes of many times the normal high voltage. So read the provided manual and find out what you may need to prepare for. You'll also want an unscaled probe for small signal testing. My scaling probe has a switch to change from 1X to 10X. Very convenient on the bench so I'm not changing probes all the time.
                "Take two placebos, works twice as well." Enzo

                "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

                "If you're not interested in opinions and the experience of others, why even start a thread?
                You can't just expect consent." Helmholtz

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