Author Topic: Oscilloscope probes  (Read 17108 times)

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Offline srb1954

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Re: Oscilloscope probes
« Reply #75 on: December 21, 2020, 01:22:36 am »
Yes, but you're looking at Low-Z probes past 500-700 MHz or so. Keysight offers 10:1 passive probes up to 1.5 GHz. I, personally, have a Tek P6055 low-Z probe and accessories.
Are you sure about the Tek P6055? My catalog says it is a 10M \$\Omega\$ x10 probe for use with differential amplifiers.

Perhaps you have a P6056 or P6057, which are both low-Z probes.
 

Offline 0culus

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Re: Oscilloscope probes
« Reply #76 on: December 21, 2020, 02:43:43 am »
Yep, off-by-one.  ;)
 

Offline Anthocyanina

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Re: Oscilloscope probes
« Reply #77 on: December 21, 2020, 07:49:11 am »
Hi! i thought to ask here about the parts of the probes, i would like to know the "real" name for the detachable hook tip of the probe, and also wondering if they are a standard size for probes of the same bandwidth even if they are from different manufacturers. Ive seen some appear much thicker than others but wonder if that's just an illusion caused by a probe being shorter or longer than other ones. Also, if anyone happens to know where i may find those hook tips online to purchase them without the probe, that would be great. Thank you!
 

Online BravoV

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Re: Oscilloscope probes
« Reply #78 on: December 21, 2020, 08:21:31 am »
Hi! i thought to ask here about the parts of the probes, i would like to know the "real" name for the detachable hook tip of the probe, and also wondering if they are a standard size for probes of the same bandwidth even if they are from different manufacturers. Ive seen some appear much thicker than others but wonder if that's just an illusion caused by a probe being shorter or longer than other ones. Also, if anyone happens to know where i may find those hook tips online to purchase them without the probe, that would be great. Thank you!


Random image from Google

If you mean the one like above example, yep, they get lost easily, I made my self, use piano/guitar wire, wind it on a stiff steel, such as a nail, but abit smaller in diameter compared to the probe's ground near tip, as it will un-wind a bit by itself, it will be nice fit & snug to the tip, suggesting to do trial and error 1st.

Reheat with hot air if needed during the winding at certain wire.

Actually copper wire works too, but not as robust as the steel wire, once the winding is done, wrapped it with heat shrink tubing to maintain the tight winding.

Offline Anthocyanina

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Re: Oscilloscope probes
« Reply #79 on: December 21, 2020, 09:24:39 am »
Thank you, i meant the grabber part which ends in a tiny hook and has a plastic sleeve around it which you pull back and the hook is exposed
 

Offline rernexy

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Re: Oscilloscope probes
« Reply #80 on: December 21, 2020, 09:39:38 am »
Thank you, i meant the grabber part which ends in a tiny hook and has a plastic sleeve around it which you pull back and the hook is exposed

In the datasheet for the probes I have Keysight/Agilent names them a "Retractable Hook". Look at the screenshot from the datasheet I've included.
 
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Offline Anthocyanina

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Re: Oscilloscope probes
« Reply #81 on: December 21, 2020, 08:02:16 pm »
Great, thank you! now having the name for them will help me find replacements!  :)
 

Offline smaultre

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Re: Oscilloscope probes
« Reply #82 on: December 22, 2020, 05:46:04 pm »
Good HF (>300MHz) probe, is a ACTIVE probe,
You can combine the TEK 1103 Power, +any TEK P5..6.. active probe,
Is the best way, with the lowest cost.
 

Offline todorp

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Re: Oscilloscope probes
« Reply #83 on: December 23, 2020, 09:34:49 am »
Slightly off topic. Inspired by this thread I would like to measure the response of my oscilloscope and different probes I have. Can someone describe the setup you are using to perform this measurement. I have geathered diffrent photos from this thread:

@jjoonathan

[attach=1]

[attach=2]

@Dexter2

[attach=3]

I see people use Leo Bodnar's fast pulse generator but do you need any attenuators? Is the rise time of the pulse generator adjustable? Than what exactly is the connector/part where you insert the probe tip?

Thanks a lot,
    Tod


 

Offline todorp

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Re: Oscilloscope probes
« Reply #84 on: December 24, 2020, 10:58:38 am »
Ok, I found out what the accessory to connect a probe to a BNC was.

But I still have a few questions regarding the measurement:
1. If the oscilloscope does not have 50 Ohm input termination should one use external 50 Ohm BNC termination on the scope input?
2. Again, are any attenuators necessary?
3. Besides qualitative assessements such as "there is ringing" or "the shape of the square wave is distorted" what quantitative measurements does one perform in order to be able to say this scope + probe system is good up to XXX MHz?

Any pointers to docs/reading are very welcome.

Thanks a lot to anyone who can shed some light,
    Tod
 

Offline tggzzz

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Re: Oscilloscope probes
« Reply #85 on: December 24, 2020, 11:07:57 am »
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
Having fun doing more, with less
 

Online exe

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Re: Oscilloscope probes
« Reply #86 on: December 24, 2020, 11:27:41 am »
3. Besides qualitative assessements such as "there is ringing" or "the shape of the square wave is distorted" what quantitative measurements does one perform in order to be able to say this scope + probe system is good up to XXX MHz?

I measured amplitude of sinewave over a range of frequencies.
 

Offline todorp

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Re: Oscilloscope probes
« Reply #87 on: December 24, 2020, 11:35:28 am »
3. Besides qualitative assessements such as "there is ringing" or "the shape of the square wave is distorted" what quantitative measurements does one perform in order to be able to say this scope + probe system is good up to XXX MHz?

I measured amplitude of sinewave over a range of frequencies.

Ok, I get that. What about the "fast rise time" square wave tests?

Any pointers to docs/reading are very welcome.

See the references at https://entertaininghacks.wordpress.com/library-2/scope-probe-reference-material/

Thanks @tggzzz I will start reading :-)
 


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