Forums

Itty bitty O-scope probes

Started by Tim Wescott July 19, 2016
The world is getting smaller, and my O-scope probes are the same size as 
they were in the 1980s.

A search on "miniature oscilloscope probes" got hits on stuff not much 
smaller than I'm using now, although my Google Fu is generally spotty.

Does anyone make Really Small oscilloscope probes?  Something that'll 
clip onto a 30-gauge wire and not rip it off of a board, or that (be 
still my heart) may actually clip onto a leg of a 0.5mm pitch chip?

And -- do they cost less than a car?

And -- who makes 'em, and who sells 'em?

I think that if I could just get something that would stay on an 0603 
test point loop I'd be happy -- but smaller is better.

-- 

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

I'm looking for work -- see my website!
On Tue, 19 Jul 2016 18:20:19 -0500, Tim Wescott
<seemywebsite@myfooter.really> wrote:

>The world is getting smaller, and my O-scope probes are the same size as >they were in the 1980s. > >A search on "miniature oscilloscope probes" got hits on stuff not much >smaller than I'm using now, although my Google Fu is generally spotty.
I found this one: <http://www.keysight.com/en/pd-1000004488%3Aepsg%3Apro-pn-1165A/miniature-passive-probe-101-10-mohm-15m?cc=US&lc=eng> <http://www.newark.com/keysight-technologies/1165a/test-probe-oscilloscope/dp/95H8259> <https://www.google.com/search?q=agilent+1165a+miniature+passive+probe&source=lnms&tbm=isch> Sorry, but no experience with using or buying one.
>I think that if I could just get something that would stay on an 0603 >test point loop I'd be happy -- but smaller is better.
Maybe one of these scope probe holding contraptions might be better (and cheaper): <https://www.google.com/search?q=scope+test+probe+holder&tbm=isch> <https://www.google.com/search?tbm=isch&q=oscilloscope+third+hand> -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
On Tuesday, July 19, 2016 at 7:20:28 PM UTC-4, Tim Wescott wrote:
> The world is getting smaller, and my O-scope probes are the same size as > they were in the 1980s. > > A search on "miniature oscilloscope probes" got hits on stuff not much > smaller than I'm using now, although my Google Fu is generally spotty. > > Does anyone make Really Small oscilloscope probes? Something that'll > clip onto a 30-gauge wire and not rip it off of a board, or that (be > still my heart) may actually clip onto a leg of a 0.5mm pitch chip? > > And -- do they cost less than a car? > > And -- who makes 'em, and who sells 'em? > > I think that if I could just get something that would stay on an 0603 > test point loop I'd be happy -- but smaller is better. > > -- > > Tim Wescott > Wescott Design Services > http://www.wescottdesign.com > > I'm looking for work -- see my website!
I've often thought about how to make a cheap x-y-z manipulator/ probe. Store bought ones are ~$1k+ George H.
On Tue, 19 Jul 2016 18:20:19 -0500, Tim Wescott
<seemywebsite@myfooter.really> wrote:

>The world is getting smaller, and my O-scope probes are the same size as >they were in the 1980s. > >A search on "miniature oscilloscope probes" got hits on stuff not much >smaller than I'm using now, although my Google Fu is generally spotty. > >Does anyone make Really Small oscilloscope probes? Something that'll >clip onto a 30-gauge wire and not rip it off of a board, or that (be >still my heart) may actually clip onto a leg of a 0.5mm pitch chip? > >And -- do they cost less than a car? > >And -- who makes 'em, and who sells 'em? > >I think that if I could just get something that would stay on an 0603 >test point loop I'd be happy -- but smaller is better.
Rhode and Schwartz (I think it was) has some really slick scope probes.
I'm a big fan of Probemaster: http://www.probemaster.com. 

Cheers

Phil Hobbs
On 7/19/2016 8:14 PM, Jeff Liebermann wrote:
> On Tue, 19 Jul 2016 18:20:19 -0500, Tim Wescott > <seemywebsite@myfooter.really> wrote: > >> The world is getting smaller, and my O-scope probes are the same size as >> they were in the 1980s. >> >> A search on "miniature oscilloscope probes" got hits on stuff not much >> smaller than I'm using now, although my Google Fu is generally spotty. > > I found this one: > <http://www.keysight.com/en/pd-1000004488%3Aepsg%3Apro-pn-1165A/miniature-passive-probe-101-10-mohm-15m?cc=US&lc=eng> > <http://www.newark.com/keysight-technologies/1165a/test-probe-oscilloscope/dp/95H8259> > <https://www.google.com/search?q=agilent+1165a+miniature+passive+probe&source=lnms&tbm=isch> > > Sorry, but no experience with using or buying one. > >> I think that if I could just get something that would stay on an 0603 >> test point loop I'd be happy -- but smaller is better. > > Maybe one of these scope probe holding contraptions might be better > (and cheaper): > <https://www.google.com/search?q=scope+test+probe+holder&tbm=isch> > <https://www.google.com/search?tbm=isch&q=oscilloscope+third+hand>
I would use a piece of 18 gauge bus wire and shape my own holders. Usually I support the bus wire from the legs or holes in the board I'm testing. Drape the cable over the free form bus wire frame and let gravity hold the probe tip in place. 16 gauge AC power wiring should work too. -- Rick C
Tim Wescott wrote...
> > The world is getting smaller, and my O-scope probes are the > same size as they were in the 1980s. > > A search on "miniature oscilloscope probes" got hits on stuff > not much smaller than I'm using now ... > > Does anyone make Really Small oscilloscope probes? Something > that'll clip onto a 30-gauge wire and not rip it off of a board, > or that (be still my heart) may actually clip onto a leg of a > 0.5mm pitch chip? ... > > I think that if I could just get something that would stay on > an 0603 test point loop I'd be happy -- but smaller is better.
It sounds like your'e more concerned with the clip than the rest of the probe. For the rest of the probe, there are some alternates. Do you need fast ns-scale probing? If you have moderately-low impedances, the resistive-probe trick may work well for you. Here's an s.e.d. post from 15 Sep 2004 04:55:44 -0700: "I suggest a simple 500-ohm low-capacitance probe made from a resistor and some thin RG-174 coax cable. . ___ ________________BNC . <--|___|--)________________) SCOPE input with . 450 RG-174 coax 50-ohm termination This 10x divider probe has a 500-ohm input impedance, and almost no input capacitance, certainly less than 0.2pF, and that's low. The 500-ohm loading will have almost no deleterious effect on CMOS gate outputs, with their 5 to 20-ohm output resistances, and the very low capacitance insures the waveform under observation is not disturbed" Mike Monett answered with a pile of useful comments and links, including a Howard Johnson newsletter issue, Vol. 5, Issue 04. ---- I have an HP 54006A probe. It's just a MG type Caddock high-voltage, long (e.g. 1-inch), low capacitance resistor, plus fixture, sharp tip, and coax cabling. "0.25 pF input capacitance (0.1pF with lead cut) and sophisticated ground design of the Agilent 54006A probe lets you probe multi-GHz systems with minimal loading of the circuit. The small size of this probe also allows you to access very small components." Caddock resistor choices: MG710, 950-ohms 20:1 MG680, 450-ohms 10:1 MG710, 1950-ohms 40:1 2kV-to-50V 50-ohms, MG710, 4950-ohms 100:1 5kV-to-50V 50-ohms, MG710, 9950-ohms 200:1 10kV-to-50V 50-ohms, etc -- Thanks, - Win
On 20-Jul-16 8:31 AM, George Herold wrote:
> On Tuesday, July 19, 2016 at 7:20:28 PM UTC-4, Tim Wescott wrote: >> The world is getting smaller, and my O-scope probes are the same size as >> they were in the 1980s. >> >> A search on "miniature oscilloscope probes" got hits on stuff not much >> smaller than I'm using now, although my Google Fu is generally spotty. >> >> Does anyone make Really Small oscilloscope probes? Something that'll >> clip onto a 30-gauge wire and not rip it off of a board, or that (be >> still my heart) may actually clip onto a leg of a 0.5mm pitch chip? >> >> And -- do they cost less than a car? >> >> And -- who makes 'em, and who sells 'em? >> >> I think that if I could just get something that would stay on an 0603 >> test point loop I'd be happy -- but smaller is better. >> >> -- >> >> Tim Wescott >> Wescott Design Services >> http://www.wescottdesign.com >> >> I'm looking for work -- see my website! > > I've often thought about how to make a cheap x-y-z manipulator/ probe. > Store bought ones are ~$1k+ > > George H. >
I've pondered the same thing, maybe Amish style using a mechanical panto-graph arrangement. Might be useful for pushing parts around when soldering as well.
On Tue, 19 Jul 2016 18:44:43 -0700, Winfield Hill wrote:

> Tim Wescott wrote... >> >> The world is getting smaller, and my O-scope probes are the same size >> as they were in the 1980s. >> >> A search on "miniature oscilloscope probes" got hits on stuff not much >> smaller than I'm using now ... >> >> Does anyone make Really Small oscilloscope probes? Something that'll >> clip onto a 30-gauge wire and not rip it off of a board, >> or that (be still my heart) may actually clip onto a leg of a 0.5mm >> pitch chip? ... >> >> I think that if I could just get something that would stay on an 0603 >> test point loop I'd be happy -- but smaller is better. > > It sounds like your'e more concerned with the clip than the rest of the > probe. For the rest of the probe, there are some alternates.
That's correct, up to a point. For 90% of what I do I could use a set of mini-clips on the end of some really flexible audio cable. It's mostly low-speed digital stuff, and I really only need a scope to tell when the damn thing isn't quite at correct logic levels. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com I'm looking for work -- see my website!
On 7/19/2016 11:47 PM, Tim Wescott wrote:
> On Tue, 19 Jul 2016 18:44:43 -0700, Winfield Hill wrote: > >> Tim Wescott wrote... >>> >>> The world is getting smaller, and my O-scope probes are the same size >>> as they were in the 1980s. >>> >>> A search on "miniature oscilloscope probes" got hits on stuff not much >>> smaller than I'm using now ... >>> >>> Does anyone make Really Small oscilloscope probes? Something that'll >>> clip onto a 30-gauge wire and not rip it off of a board, >>> or that (be still my heart) may actually clip onto a leg of a 0.5mm >>> pitch chip? ... >>> >>> I think that if I could just get something that would stay on an 0603 >>> test point loop I'd be happy -- but smaller is better. >> >> It sounds like your'e more concerned with the clip than the rest of the >> probe. For the rest of the probe, there are some alternates. > > That's correct, up to a point. For 90% of what I do I could use a set of > mini-clips on the end of some really flexible audio cable. It's mostly > low-speed digital stuff, and I really only need a scope to tell when the > damn thing isn't quite at correct logic levels.
My experience has been that there is no such thing as "low speed" digital electronics. Nearly all digital circuits are sensitive to noise and signal integrity issues that can involve many MHz considerations. -- Rick C