Scope Probes

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myker
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Scope Probes

Postby myker » Mon 09/10/12 12:31 pm

Hey Guys, this seemed like the most appropriate forum for my question, I apologize in advance if it is not.
I just purchased my first Scope (Tektronix 2215) and am curious which probes I should buy for working with tube gear? I would be using the scope on everything from 100 watt tube amps to solid state amplifiers for biasing and troubleshooting...
Thanks in advance, and again I apologize if this is not the proper forum for this post.
-mike
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Stefan_E
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Postby Stefan_E » Tue 09/11/12 10:02 am

Hi, not a very informed answer but go for at least switchable attenuation between 1x and 10x. If you find with even more attenuation, go with that. Problem i have is that the scope cannot handle all signals in a tube amp due to amplitude, i need to make a voltage divider for measuring some stuff.

Don't worry about MHz/capacitances unless you are doing radio stuff etc
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myker
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Postby myker » Tue 09/11/12 10:35 am

Thank you, I was curious about what the x10 meant, I think it means that whatever you are probing is attenuated by 10%, like a 350vac signal will appear as 35vac at the input of the scope. I am reading and learning because I don't want to burn this thing up.
Thanks again,
Mike
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CurtissRobin
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Postby CurtissRobin » Tue 09/11/12 11:45 am

The probe has a built in voltage divider. Read x1 as the full voltage, no attenuation, x10 as "times ten" and x100 as "times one hundred." x10 means it's attenuated by 90% and x100, by 99%. e.g. A plate voltage of 340 VDC will read as 340 VDC with an x1 probe, as 34 VDC with an x10 probe and as 3.4 VDC with an x100.

http://www.youtube.com/watch?v=SX4HGNWBe5M

KennyO
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myker
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Postby myker » Sat 09/15/12 7:39 pm

Hey guys, this may be dumb but I need to know if the probe that I bought is working as it should. I made a coaxial probe and use a generator or the built in probe adjust and I get a nice square waveform, no problem. But When I plug in the P6105A that I bought used from E*ay, I cant get a waveform no matter how I adjust the controls. I measure no continuity or resistance on the cable part or the attenuator part. Pretty sure it's junk.
-mike
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Stefan_E
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Postby Stefan_E » Mon 09/17/12 11:59 am

Sounds like you got a broken probe, try measure resistance between center pin on bnc and pin on probe, should get a reading - not 0 ohms but something like 100-200ohm maybe with attentuation on 1x. Grounds should read 0 ohms.

Also, you can try to unscrew (no pun intended) the tip of the probe and measuse directly on the sharp pin to center bnc. If that is possible with your probe.

Lastly, if you just tap the probe while it's connected to your scope you should get some nonsense readings
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katopan
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Postby katopan » Mon 09/17/12 5:28 pm

I agree that you're probe is broken. You should measure some resistance between probe tip and the centre of the BNC connector.
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myker
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Postby myker » Wed 09/19/12 2:17 pm

Thanks guys, It's great to have you for support, you saved me $40 bucks and hours of frustration!
-Mike
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