DIY Logic Analyzer Probe and Pods for Siglent (and LeCroy) scopes

[Martin72]

I wanted to fix the criticized positions first, because e.g. the front panel for the display is actually thinner than 0.8mm, so I had canceled everything.
Most parts were titled as OK.

[TERRA Operative]

Ok, my turn to make one of these.... Was any further development done to improve the performance or is as it stands good enough?
Did anyone ever take a look inside the Siglent probe?

I think I wouldn't mind having a go at modifying the design a little to match the Siglent with the way the probes attach, maybe using some 2.54mm rectangular header sockets.

[tautech]

thanks a lot mate, that saved me a lot of trouble :-)

could have been cool if only they existed in correct color codes from 0 to 9
so i have to find a way to add a label, and if they are colored at the same time, i end up being confused
since i cant turn off my brains color decoder

Coloured LA/MSO channel tabs are being rolled out into all models that support MSO.
Then if you have coloured grabbers you might be able to match them up to the displayed tabs. 

[TheDefpom]

Then if you have coloured grabbers you might be able to match them up to the displayed tabs. 

Damnit, now I need to buy coloured grabbers...

[tautech]

Then if you have coloured grabbers you might be able to match them up to the displayed tabs. 

Damnit, now I need to buy coloured grabbers...

Link listed in my reply #13, long expired but the ePay listing description might help with a search.
Be sure to get the same style as OEM for best holding power.
Pics here:
https://www.eevblog.com/forum/testgear/diy-logic-analyzer-probe-and-pods-for-siglent-scopes/msg3496458/#msg3496458

[KungFuJosh]

Are you referring to the E-Z Hook brand grabbers? I have them in my list: https://www.amazon.com/dp/B00R3R7IVC/

[TheDefpom]

Damn, those aren't cheap.... so I only got 2 pairs, you always need a spare.

[tautech]

Are you referring to the E-Z Hook brand grabbers? I have them in my list: https://www.amazon.com/dp/B00R3R7IVC/

Perfect. 
10 for $34 is well priced compared to the 10 lot of Tek grabbers a mate and I shared 20 yrs back, they were $5ea !

[tautech]

Another bit cheaper $21 set linked by ePay:
https://www.amazon.com/10PCS-Grabber-Jumper-Analyzer-Colors/dp/B083PRVPCR/ref=pd_vtp_h_pd_vtp_h_d_sccl_3/143-5889884-9612055?

[ebastler]

Another bit cheaper $21 set linked by ePay:
https://www.amazon.com/10PCS-Grabber-Jumper-Analyzer-Colors/dp/B083PRVPCR/ref=pd_vtp_h_pd_vtp_h_d_sccl_3/143-5889884-9612055?

Wrong colors though, if you are after a match with the new SDS display.

[KungFuJosh]

Another bit cheaper $21 set linked by ePay:
https://www.amazon.com/10PCS-Grabber-Jumper-Analyzer-Colors/dp/B083PRVPCR/ref=pd_vtp_h_pd_vtp_h_d_sccl_3/143-5889884-9612055?

I wouldn't trust those, especially not for the $10 savings. Some of the reviews mentioned the springs failing, or the grabbers being too soft metal to properly hold things.

[fredo_]

Hi there,
Did anyone try the PCB Assembly service of JLCPCB for oz2cpu's design ?
Maybe someone as working BOM and CPL files ?

[fredo_]

Well I'm proud to join the team of oz2cpu's design probe owners ! 
I ended up ordering on JLCPCB with PCB assembly (single side). Boards arrived with half the 120R resistor soldered on the scope board (upper side) and the 86K6 and 120R soldered on the pod boards :

Soldering the missing 120R resistors and the 8p2 caps stacked on top of the 86K6 resistors was not a simple task for me, as it was my first time doing SMD stuff
I ended up doing it with solder paste and an hot-air gun (couldn't make a clean work on 0603 parts with a soldering iron...)
Everything works as expected (tested with an ESP32 board providing approx. 10Mhz output)  :

[fredo_]

I ended up ordering on JLCPCB with PCB assembly (single side).

In case someone needs it, here are the BOM and pick and place files I used.

[mawyatt]

Ok, my turn to make one of these.... Was any further development done to improve the performance or is as it stands good enough?
Did anyone ever take a look inside the Siglent probe?

I think I wouldn't mind having a go at modifying the design a little to match the Siglent with the way the probes attach, maybe using some 2.54mm rectangular header sockets.

If you go back and start searching with our inputs (like #72 or earlier then onto #138) we posted a version of Thomas's that included the ability to mimic the responses that the OEM Probe produces after modeling the probe with Rob's help. Our version worked well from the start with both twisted-pair ribbon cable and simple ribbon cable (didn't have any micro-coax) that we never followed up on optimizing the probe & cables.

This might be a good start if one wants to squeeze the most out of these probes.

Best,

[rosenrot]

Hi,
I've desided I want my own design of the PCB for RF1.37 (https://aliexpress.ru/item/1005003601266058.html) coaxial cables (1 ground pad for each input) :   and also make it more "equal". I think I'll try to have input-end 120 ohm resistor directly on the cable, without additional boards -- like here: https://community.element14.com/technologies/test-and-measurement/b/blog/posts/building-solderable-in-circuit-oscilloscope-probes

github repo with kicad project is here: https://github.com/aystarik/siglent-la

Any recommendations (signal quality/or anything else) getting one of these? Did we hear back if this design is working out?

I added some holes to hold a 3d printed enclosure later on.

[MathWizard]

I'm making a version using a male PCI-e 1x connector, and 2-3cm of it's cable I made into twisted pairs. And the LVDS cables from inside one of my old LCD monitors, all twisted pairs, with an outer shielding for the bundle, they are between the POD and BASE. On one end they have connectors that fit standard 2.54mm headers.

None of my wire strippers are meant to strip wires that small, I think the LVDS cable is 28AWG. My strippers can do it holding them side-ways, but it's easy to cut a few strands from the wire.

None of this has a GND plane, including the cheap PCI-e 1x PCB. So I just went with 240R and 91k||8pF on the POD, and for the BASE I'm using a 2pF shunt and 360R series into the 1x PCB. And all these resisotrs are 5% and the caps are probably 2p +/-1pF.

Using the 3 transmission lines Maywaytt used, for the 2 connectors and twisted pair, I get something that looks about right in LTS.

Now to finish making the BASE, using some more through-hole proto-board, and some cut up charge cards/gift cards. And maybe some thick paper packaging material, and of course lots more electric tape.


If it works any good, I might try making an SMD version on proto-board. Or trying island style with copper clad boards, I forget I've made stuff like that before.  Or I could just order the PCBs.

[KungFuJosh]

Or I could just order the PCBs.

 

[Coldblackice]

I'm making a version using a male PCI-e 1x connector, and 2-3cm of it's cable I made into twisted pairs.

If it works any good, I might try making an SMD version on proto-board. Or trying island style with copper clad boards, I forget I've made stuff like that before.  Or I could just order the PCBs.

Would love to see this! Please share progress, if willing.

[MathWizard]

I can test up to a 25MHz square wave, and 120MHz sinewave. Now for the tedious task of wiring the 1x connector, to a one sided proto-board...

[tautech]

I can test up to a 25MHz square wave, and 120MHz sinewave. Now for the tedious task of wiring the 1x connector, to a one sided proto-board...

FYI
Digital channels run through a comparator and thereby only display perfect edges, very unlike the behaviour observed with analog channels.

[MathWizard]

Well I got it all made, but I had to modify the PCI-e 1x connector, since the scope doesn't use the same standard pinout. So I soldered little wires right onto the the contact pads of the connector. Not all the way to the tip, but so far I can't get the connector to fit into the slot.

It looks like the jacks lines up pretty well, and even feels like I can get part of the connectors to mate, and move in a few milli-meters, but at no time was it enough to even get continuity to GND. And every 2nd pad is GND.

So IDK if the little wires I soldered onto the back of the connector, and jamming in the slot, or if it's just not lined up enough, or going deep enough in.

For now I'll take all the tape and support of the PCIe connector, just so I can see what really happens when the jack goes in the slot. But it would be easier to sand down some of the solder/wires, sticking up off the connector, then trying to move them all back.

This is the connector pin out I've used on both top/bottom, I think from Tautech

[tautech]

Well I got it all made, but I had to modify the PCI-e 1x connector, since the scope doesn't use the same standard pinout. So I soldered little wires right onto the the contact pads of the connector. Not all the way to the tip, but so far I can't get the connector to fit into the slot.

It looks like the jacks lines up pretty well, and even feels like I can get part of the connectors to mate, and move in a few milli-meters, but at no time was it enough to even get continuity to GND. And every 2nd pad is GND.

So IDK if the little wires I soldered onto the back of the connector, and jamming in the slot, or if it's just not lined up enough, or going deep enough in.

For now I'll take all the tape and support of the PCIe connector, just so I can see what really happens when the jack goes in the slot. But it would be easier to sand down some of the solder/wires, sticking up off the connector, then trying to move them all back.

This is the connector pin out I've used on both top/bottom, I think from Tautech

Nah, can't take credit for Mike Wyatt's work. 

See Sig at top right.

[MathWizard]

Ok, I filed down the connector, it's barely any thicker than normal. But at best I can only get about 6-7 ohms to GND, and the only way I can get any digital signals is if I hold the jack pushed in pretty hard, which is bad. And at least 1 channel had noise way faster than the serial signals I'm looking at.

IDK if I have the vertical position lined up good enough, or if the connector pads are still a little too thick, but I'm talking tenths of a mm. Maybe I took too much off the outside edge. It feels more like it wants to pop back out tho, like something
s too big/high.

I used calipers, for some measurements, I don't think anything else is holding it up.

[KungFuJosh]

Did you read what oz2cpu said about the PCB design? He was pretty adamant about 4 layer PCB with tight specifications.

I got the generic one with (I think) only 2 layers (before I knew about the awkwardness of that situation), but I'm sure it's not as good as the proper 4-layer design.