I cut something off of my Rigol Scope Probes - Page 1
Forum section: electronics / projects

author: xrunner
author_rank: Super Contributor
timestamp: May 27, 2016, 01:49:59 pm
content: Ah that's better! I hate those rubber rings with a passion.

author: Pjotr
author_rank: Frequent Contributor
timestamp: May 27, 2016, 02:26:30 pm
content: Better buy yourself a set of decent fixed 1:10 Testec probes. The Rigol probes are somewhat use able, but that is all to say about.

author: xrunner
author_rank: Super Contributor
timestamp: May 27, 2016, 03:52:06 pm
content: Quote from: Pjotr on May 27, 2016, 02:26:30 pmYea I know, I need to do that soon.

author: Monkeh
author_rank: Super Contributor
timestamp: May 27, 2016, 03:57:26 pm
content: Right, where's me knife..

author: m98
author_rank: Frequent Contributor
timestamp: May 27, 2016, 09:28:24 pm
content: What's wrong with the rubber rings?

author: Monkeh
author_rank: Super Contributor
timestamp: May 27, 2016, 09:29:17 pm
content: Quote from: m98 on May 27, 2016, 09:28:24 pmThe ones around the BNC are slippery and badly shaped. Just plain awkward to get on and off.

author: xrunner
author_rank: Super Contributor
timestamp: May 27, 2016, 09:39:51 pm
content: Quote from: Monkeh on May 27, 2016, 09:29:17 pmRight. They suck - I usually have to pull on the cable to get 'em off the scope. Too slippery.

author: tautech
author_rank: Super Contributor
timestamp: May 27, 2016, 10:12:07 pm
content: Quote from: xrunner on May 27, 2016, 09:39:51 pmI wouldn't recommend your *mod* universally.For those with an unearthed mains supply no insulation of the BNC connectors may expose the user to some stray voltages.Furthermore for those that isolate their DSO's from mains ground to enable scope connectionwithoutGND loops, this *mod* would expose the user to the same voltage as to where the probes reference lead is connected.This also applies toall the exposed BNC connectorswhen doing *isolated* measurements.Be careful out there.

author: xrunner
author_rank: Super Contributor
timestamp: May 27, 2016, 10:24:14 pm
content: All the scope probes I used for 24 years in industry didn't have that rubber ring, and even the Testec probes recommended in this thread don't have a rubber ring, neither do most of the replacement scope probes. Ultimately you need to understand what you are doing.

author: tautech
author_rank: Super Contributor
timestamp: May 27, 2016, 10:37:11 pm
content: Quote from: xrunner on May 27, 2016, 10:24:14 pmExactly.One must remember there's many DSO/scope newbies on this forum that aren't aware ofall the dangersthan can arise from probing DUT's, hence my warning.All my old probes don't have insulated BNC's either and I've used then at elevated isolated voltages KNOWING the risks, and with metal cased CRO's too.Brings new meaning to: IT'S ALIVE.Most new DSO's however are supplied with insulated BNC's on probes as OEM for good reason IMHO.Be careful out there.

author: xrunner
author_rank: Super Contributor
timestamp: May 27, 2016, 10:45:55 pm
content: Quote from: tautech on May 27, 2016, 10:37:11 pmTo add to your concerns though, which I respect, be aware that even if you connect a scope probe to channel 1, with an insulated BNC, guess what? If there is a danger in touching it, all three other channels outside BNC metal is now connected to the potential of the channel 1 outside barrel. So if you touch any of the other three channels with your finger accidentally, you now get zapped even though channel 1 has a rubber ring ...

author: m98
author_rank: Frequent Contributor
timestamp: May 27, 2016, 10:58:24 pm
content: Quote from: Monkeh on May 27, 2016, 09:29:17 pmWell, maybe one likes them and one doesn't. I think that they're a quite nice touch and look way better than just blank BNCs. Rigol could've used a grippier surface pattern, but overall I can't recall that the connector ever slipped out of my grip.

author: Monkeh
author_rank: Super Contributor
timestamp: May 27, 2016, 10:59:49 pm
content: Utility first, looks second. It's a scope probe, not a car.

author: Unknown
author_rank: Unknown
timestamp: May 27, 2016, 11:01:42 pm
content: Ouch! You circumcised your probe!

author: tautech
author_rank: Super Contributor
timestamp: May 27, 2016, 11:11:02 pm
content: Quote from: xrunner on May 27, 2016, 10:45:55 pmYes, as explained in my first reply:Quote from: tautech on May 27, 2016, 10:12:07 pmPost edited to highlight this ^^^

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: May 27, 2016, 11:56:47 pm
content: Yes! I find the raised plastic makes removing them difficult! I gotta try that.

author: Unknown
author_rank: Unknown
timestamp: May 28, 2016, 12:06:33 am
content: On a more serious note. Isn't it common to plug in a non insulated bnc tee, for example, to terminate into 50 Ohms? There will always be a potential issue if you defeat the grounding of the scope, no? As Mr. Carlson says, "you do so at your own risk".

author: xrunner
author_rank: Super Contributor
timestamp: May 28, 2016, 12:23:56 am
content: Quote from: steverino on May 28, 2016, 12:06:33 amAbsolutely.If the oscilloscope industry wanted to really protect people, they would do a complete connector solution, something like DMMs, where not only the internal but the external connections are completely insulated from the user. As it is now, you can still touch the same potential on other BNCs that one or more probe covers are insulating you from, as has been pointed out.Do all of this testing and modification at your own risk!

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 28, 2016, 01:43:58 am
content: You can then add heat shrink to get a new cover that doesn't slip. And put plastic caps over the unused BNCs when probing high voltages, although those tend to get lost.

author: xrunner
author_rank: Super Contributor
timestamp: May 28, 2016, 02:47:56 am
content: Quote from: NiHaoMike on May 28, 2016, 01:43:58 amWho does the ergonomics at Rigol? The thing is, I wouldn't even have considered cutting the rings off if they had been easy to remove. They are too slippery when pulingawayfrom the scope. That could have been easily fixed simply by the way the molding was done.There is no need for me, or many users, to have a rubber ring there in the first place, because that metal is grounded and safe. But if they want to put a rubber ring on it, it needs to be easier to grab.And as I've said, many replacement probes, which are in fact made better anyway, do not have rubber rings there.Probing electronics is inherently a risk, and in the end if you don't have a clue what you are doing, you should not be probing withanytest equipment!

author: tautech
author_rank: Super Contributor
timestamp: May 28, 2016, 03:37:20 am
content: I doubt whether any of the Asian DSO manufacturers make their own probes.My investigations have found at least 3 scope probe manufacturers and for at least 1 of them it's theircorebusiness.Most offer insulated BNC's in a range of BW's but in the case of these Rigol probes IMO they've chosen unwisely in the way they commandeer most of the physical space available around the BNC's and force those without the fine fingers of most Asians to struggle with connection/disconnection.Spacing between BNC's is also an issue that was bought up in other threads.But overall IMO how the front panel layout has been organised hasn't helped matters...ie. by placing the larger knob of channel attenuation directly above the BNC's.Knob swap time....much safer than removing the BNC connector insulation.

author: Monkeh
author_rank: Super Contributor
timestamp: May 28, 2016, 03:46:43 am
content: A knob swap won't help, and removing the 'insulation' (pretty looking plastic with no real purpose) does not create a safety issue.

author: RogerRowland
author_rank: Regular Contributor
timestamp: May 28, 2016, 07:15:51 am
content: Stupid question #1:Why do you need to keep connecting/disconnecting your probes? I connected two probes to my Siglent when I bought it two years ago and I haven't unplugged them since.Is it because you're needing to use different probes or what?

author: oldway
author_rank: Super Contributor
timestamp: May 28, 2016, 07:29:36 am
content: xrunner is right.This oscilloscope can't be used with an unearthed mains. This isolation of BNC connector is useless.Those probes are probably intended to be used with battery powered oscilloscopes.

author: BravoV
author_rank: Super Contributor
timestamp: May 28, 2016, 08:21:09 am
content: Those rubber are NOT for isolation, I guess its just for aesthetically purpose.Both sides, either at the scope and probe BNC need to be fully protected and secured, not just wrapped with some cheap rubber that can easily be detached or cut.Example below Tek's portable scope with isolated BNC connectors, and also at the probe's BNC for total isolation. The probe's head BNC metal part is fully molded with plastic, don't think can be easily detached like that cheap rubber without destroying the whole BNC head.

author: plazma
author_rank: Frequent Contributor
timestamp: May 28, 2016, 08:26:04 am
content: I also cut my probed so they fit a Tektronix scope.

author: Psi
author_rank: Super Contributor
timestamp: May 28, 2016, 08:26:09 am
content: Just don't float your scope.Or it may end badly.

author: xrunner
author_rank: Super Contributor
timestamp: May 28, 2016, 11:16:03 am
content: Quote from: oldway on May 28, 2016, 07:29:36 amCheck the safety instructions from the DS1054Z manual -Page IIGround the Instrument.The instrument is grounded through the Protective Earth lead of the power cord. To avoid electric shock, it is essential to connect the earth terminal of the power cord to the Protective Earth terminal before connecting any inputs or outputs.Connect the Probe Correctly.If a probe is used, do not connect the ground lead to high voltage since it has the isobaric electric potential as ground.Safety Class Class 1– Grounded ProductNowhere in the manual does it specifically state to use probes with "rubberized" coatings over the BNC connectors to satisfy any safety requirements.So, as has been noted, any operation of the scope outside it's safety notices is done at your own personal risk.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 28, 2016, 02:50:50 pm
content: ds1000e probe is better ergonomically compared to the newer design ds1000z probe, this perharps another good example why you dont want the new kids on the block to design the so called "modern design". admittedly several times i got pissed off already with the slippery new ds1000z probe design. but i dont think a full circumcision is a good idea, see below for suggestion, ie cutting small part of the rubber to make groove or negative slope for you to grab on while pulling...as far as the isolation is concerned, few days ago i got loose earth connection to my scope (DS1000Z) so i got the usual annoying tingling going on on the gnd pigtail, i said what the hell, i push all my main sockets in the line properly and the tingling is gone. this tingling sensation of "elevated gnd" is only sensible to my thinner skin such as back of my finger, lower back body etc, i dont feel it on my face front of my finger due to thick skin i guess, or if i grab the contact point firmly with significant amount of skin surface area (making big portion of me elevated as well i guess). the worst case of "elevated gnd" / isolated device scenario i remember was few years ago when i was handling a LCD projector in a ballroom, its a brand name not one hung low, things like epson if i'm not mistaken, but it can be samsung etc, cant really remember, but the point is, not a one hung low. it has 2 pin cable, ie unearthed, so i gave up and let anybody incharged handling it. i also got occasionally from things like tv, laptop, etc. so this isolation problem is real, to my belief, anything involving SMPS inside, not particularly a DSO, but it is included... so this matter probably wont matter to you if you have thick skin from back of your palm to the lower latissimus dorsi and external oblique..

author: Unknown
author_rank: Unknown
timestamp: May 28, 2016, 05:19:35 pm
content: Quote from: Mechatrommer on May 28, 2016, 02:50:50 pmThis may be a stupid question, but what is the source of the elevated gnd when the mains ground is compromised? It certainly isn't a fault, right?. Is this an induced voltage? Does this imply there is always a current running to ground when the mains ground is properly connected? Thanks.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 28, 2016, 06:48:07 pm
content: who knows? someone should make a teardown study on this. probably there is capacitive coupling between power and chasis... but with a floating scope, once you connect the gnd clip to the hot line, there is no telling, no warning that the chasis is isobarically hot.

author: Gary350z
author_rank: Regular Contributor
timestamp: May 28, 2016, 08:47:46 pm
content: Quote from: xrunner on May 27, 2016, 01:49:59 pmGreat idea.I hate those slippery connectors.How hard was it to cut off the rubber?Is the rubber stuck to the metal or just molded around it?In your photo it looks like there is some residue on the BNC. Did the BNC come out clean?I will cut mine off if it doesn't make a mess.Thanks xrunner.

author: Monkeh
author_rank: Super Contributor
timestamp: May 28, 2016, 08:55:35 pm
content: It's plastic with an overmould, so it takes a good sharp knife, but it's not hard. Just moulded on, so cut a slot down it and pry it free.E: Actually, I think they were just pushed on, but they'll probably resist being yanked off quite aggressively.

author: xrunner
author_rank: Super Contributor
timestamp: May 28, 2016, 09:29:30 pm
content: Quote from: Gary350z on May 28, 2016, 08:47:46 pmYes Monkeh answered your questions.I wouldn't have bothered to cut them off if they had not been so slippery to remove. I have other cables (from China) that have coverings on the BNC and they are no problem at all to remove. Rigol simply picked a bad design IMHO.In picture left = easy; right = hard.

author: Pjotr
author_rank: Frequent Contributor
timestamp: May 28, 2016, 11:17:32 pm
content: What's the problem with al that isolation issues? The Rigols are NEVER made and intended to probe mains levels like the portable Tek with full isolated channels. Doing so is simply stupid and that belongs to basic knowledge. This not only holds for the Rigols but any instrument not specially made for dealing mains voltages.The probes that come with the Rigol scopes are at the $10 level you find on Ebay. They have to cut costs somewhere... That plastic boots are only cosmetic (and good to make a lot of noise about safety is seems).

author: Gary350z
author_rank: Regular Contributor
timestamp: May 29, 2016, 12:22:50 am
content: Quote from: xrunner on May 28, 2016, 09:29:30 pmMine are so slippery I sometimes have to pull on the cable. I'll give the knife a try.

author: Unknown
author_rank: Unknown
timestamp: June 03, 2016, 11:46:41 pm
content: Quote from: steverino on May 28, 2016, 05:19:35 pmI just ran across this document from Fluke which discusses "leakage current". I wasn't aware of this and it probably provides the answer to my own question.http://www.fluke.com/fluke/uses/comunidad/fluke-news-plus/articlecategories/electrical/leakagebasics

author: LukeW
author_rank: Frequent Contributor
timestamp: June 04, 2016, 03:16:14 am
content: Quote from: xrunner on May 28, 2016, 12:23:56 amIf the oscilloscope industry wanted to really protect people... they would sell scopes, or probes and adapter units, that are fully galvanically isolated and appropriately tested/rated for a certain level of safety in these kinds of differential floating applications. Which of course they do sell.If you work with a floating scope, then you need to know what you're doing, and it's not the manufacturer's responsibility to babysit you. The oscilloscope chassis, and every connector and port that is normally grounded, is floating relative to mains earth.

author: karoru
author_rank: Regular Contributor
timestamp: June 05, 2016, 05:22:25 pm
content: Quote from: LukeW on June 04, 2016, 03:16:14 amYup, for example my Philips PM3540 is floating by design. It doesn't even have ground pin on plug. If it had plug from one of countries where all plugs are 3-terminal, the only thing one could notice is that there's one line like "Hey, it's floating, because TV's, mon. Beware!" written in small print in the manual:)

author: TheSteve
author_rank: Unknown
timestamp: June 05, 2016, 05:34:56 pm
content: The moldings do look quite nice but are shaped rather poorly. The BNC jacks feel almost like they suction themselves onto the scope. I don't see removing the molding as any kind of safely issue on a scope with common probe grounds.In the case of the Tektronix THS portable scopes pictured earlier in this thread then the shrouding is critical for safety and has nothing to do with aesthetics as it has isolated inputs.

author: electr_peter
author_rank: Unknown
timestamp: June 06, 2016, 08:34:17 pm
content: As a user of DS1000Z, I agree with comment about bad form factor of BNC mouldings. At first glance, they look OK and connect to scope very easily, but disconnection is definitely more difficult - connector tend to stick and your fingers cannot grip and generate enough pull to remove it in one go.However, in my setup I do not reconnect probes too often for this to be an issue requiring mechanical intervention.

author: bitseeker
author_rank: Super Contributor
timestamp: June 06, 2016, 10:06:36 pm
content: Two good grip mods here. Thanks, I'll keep these in mind should mine annoy me. It's better to mod the inconsequential rubber jacket than to pull on the cables and shorten the probe's life.