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Forum section: electronics / testgear

author: Hootis Tigglebits
author_rank: Contributor
timestamp: September 12, 2024, 04:29:32 pm
content: delete

author: KungFuJosh
author_rank: Super Contributor
timestamp: September 12, 2024, 04:53:07 pm
content: I generally love the quality of ProbeMaster.com probes, but they don't make those specs unless 300MHz is a typo. I've not seen any 1:1 probes that do higher bandwidth. 30MHz is around the limits I've seen, though I haven't looked that hard.

author: tggzzz
author_rank: Super Contributor
timestamp: September 12, 2024, 06:10:14 pm
content: What is "inaccurate" about your existing probes? Having a sharper tip probably won't improve accuracy.At such frequencies there are many ways in which probes can be misused. For example, what is the load they have on the circuit? (Hint: not 10Mohm!) Will that affect your circuit?Significant improvements in accuracy might require improved probing technique and/or a different class of probe. FRI see the references athttps://entertaininghacks.wordpress.com/scope-probe-reference-material/

author: Hootis Tigglebits
author_rank: Contributor
timestamp: September 12, 2024, 06:23:57 pm
content: Sorry for not being more clear, I've noticed when comparing the waveforms that these probes see vs. a Tek probe on the same scope that these tend to have more noise. The finer tip is needed due to the size components I work with, 1.3mm in diameter on the H&S probes vs .75mm in diameter on the Tek probe I have. I'll read the link, but I was trained on using scopes by two seasoned electronics engineers, so I'm confident I'm using them correctly; however anything is possible.

author: David Hess
author_rank: Super Contributor
timestamp: September 12, 2024, 06:31:39 pm
content: The Probemaster 4900 Oscilloscope Probe Deluxe Kit appears to have exactly what you are asking for, but 300 MHz means a x10 probe.

author: Phil1977
author_rank: Frequent Contributor
timestamp: September 12, 2024, 07:37:22 pm
content: Regarding 1x probes:

author: tggzzz
author_rank: Super Contributor
timestamp: September 12, 2024, 08:08:55 pm
content: Quote from: Hootis Tigglebits on September 12, 2024, 06:23:57 pmMany seasoned electronics engineers use scope probes "suboptimally". It isn't a subject explicitly taught during courses, so many end up learning the hard way.I would expect the trace from a *1 40pF scope probe to look less "noisy" than that from a *10 10pF probe, due to attenuation and the low pass filtering effect.What was the signal amplitude, frequency, risetime for digital circuits, impedance and/or logic family?Was the noise broadband or single frequency?Was the noise correlated with the signal?How was the probe connected to the UUT?A photo of the problematic scope traces and how the probe is connected to the UUT would be useful.

author: Fungus
author_rank: Super Contributor
timestamp: September 12, 2024, 08:53:28 pm
content: Quote from: Hootis Tigglebits on September 12, 2024, 04:29:32 pm300Mhz 1:1 ain't happening.

author: BillyO
author_rank: Super Contributor
timestamp: September 13, 2024, 04:54:30 am
content: Quote from: Fungus on September 12, 2024, 08:53:28 pmAll depends on the depths of your pockets. The "under $250" part is what's not happening for a 1:1 probe.However, Tek P6139A probes can be had used in 9.5/10 condition for under $250. They are 10:1 probes but I don't see that as an issue. I don't know why the OP thinks it is. However, they tick all the other boxes. They are thin, miniature probes with a variety of ground options. As well the user can modify the "normal" grond clip if they wish.