Scope WTF Follow-Up - BEWARE Dodgy Connectors

Dodgy Brothers scope grounding!
Beware of dodgy BNC connectors.
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#ElectronicsCreators

[@iamdarkyoshi]

I work in PCB assembly and testing. It is ASTONISHING how unreliable connectors and cables can be!

[@GalgoczkiAdam]

That's why ElectroBoom is still alive.

[@gblargg]

This reminds me of the time I had a faulty LED backlight driver board and the culprit turned out to be the freaking vias in the PCB. They would start to get intermittent once it heated up a bit. Took forever to lose so much trust in things to consider them a possibility.

[@gblargg]

So the Rigol being ungrounded allows you to force signal grounding issues to be more prominent. Then toggling grounding of the scope modulates these issues, narrowing the cause more quickly.

[@antoineroquentin2297]

That was my first thought. Those t-pices have caused me already a lot of anger. They seem to have notoriously bad connectors. Some of them are also for 75 Ohm. They fit, but have smaller inner pin diameter, making unreliable connections with 50 Ohm sockets.

[@mikebarushok5361]

A series on testing the test setup would be very interesting. I don't know how many times I have had, or seen others to have much wasted time and energy chasing down a fault that wasn't in the equipment being tested. Cabling being the number one offender and number two probably trusting a reading outside of the specified calibration range.

[@gblargg]

Chasing down equipment problems is like one of those movies that keeps having twists that totally change your view of things. You think you've solved the problem then find it was some connector at fault all along.

[@Robstafarian]

@@gblargg I experienced this with an audio patch cable a few weeks ago, that coincided with a software update which (for some reason) enabled settings I have never used such that I thought I had both faulty inputs and outputs at the source when all I really had was a bad solder joint in a single connector (at an output).

[@Dust599]

I'm still eyeing that crimped BNC, back when I was working with 10BASE2 thin coaxial Ethernet, the crimped connectors where a constant pain in the backside. Always failing and needing replaced with decent soldered versions.

[@Svuppedasker]

Could it be that you have a 75 Ohm T? I think they may have a slightly smaller diameter center pin.

[@donondre7314]

BNC connectors...they all share a common fate of becoming unreliable one day. And when that day has come, they won't tell you straight away 🙂

[@888DaveT]

When I was an Electrical Engineer at RCA/GE, one project required a High-Quality Spectrum Analyzer to measure Low-Level signals at 1 GHz. I quickly found out that BNC connectors and adapters are not only generally unreliable & intermittent, but especially so at low signal levels. Any job measuring, or transferring, low-level high-frequency signals requires the use of N-type, or properly torqued SMA-type, connectors to achieve the necessary reliability.

[@brianhginc.2140]

How many hours of fiddling? You are not alone, I also have use T BNC connectors for 5-wire RGB+HV video distribution and had occasionally had 1 lemon in the lot causing random problems in the picture on one of my monitors. Even worse, I have had noisy 75ohm BNC terminators. One on the H-sync pin and the picture would have minute horizontal noise depending on the day and ambient temperature.

[@Petertronic]

I've had a lot of flaky BNC connectors from ebay etc. A lot of the moulded BNC cables you can buy are truly awful. I make all my own BNC cables using branded connectors, branded cable (eg. VanDamme) and my trusty old RS crimp tool. 🤠

[@mostlypostie1]

Same here!

[@RB9522]

Don't use chrome-plated (Chineseam) connectors on test cables. Get some name-brand silver-plated ones.

[@galileo_rs]

Went down the same rabbit hole a few times, now I only use reputable T connectors (scored a few used HUBER SUHNER a while back).

[@johnwright8814]

There I was, thinking you broke it during the teardown. Turns out you haven't heard of dodgy connectors.

[@shubus]

Let us know when a good BNC T-connector is found....all mine are dodgy as hell, too.

[@barrieshepherd7694]

My personal go to rule, when results on scopes (and Spectrum Analysers) are not as expected, is to check/substitute all connecting leads. Over the years dealing with RF and Video at a hobbyists and professional level I have amassed a number of leads and coax adaptors and some are just incompatible with each other. BNC tends to be the worse because there are two different standards 50 & 75 Ohm impedance and both are heavily used in industry so there are many examples around. Cheap T connectors seem to be the worse ones and impedance is rarely marked on the connectors / adaptors. I have also caught a cold with N connectors - but in my field they tend to be only 50 Ohm varieties. I keep telling myself that I should sort my box of adaptors/connectors out and paint a red blob on the 75 Ohm ones and also that if I find a questionable lead I should toss it - but I never get that far 🤣🤣🤣🤣🤣🤣

[@JamesCutlervk2tim]

I've seen plenty of cheap / nasty BNC connectors. You get what you pay for, thats for sure.

[@calholli]

If you take some pilers and physically squeeze the BNC connector just slightly.. it will more tightly latch on when you lock it in-- and will prevent it from losing connection so easily by wiggling around. It's just a bit oversized and not locking securely.

[@conodigrom]

BNC are simple, small, handy, reliablw and good performance until they suddenly switch to Dr.Jekill mode.

[@KeritechElectronics]

It's not FuzzyWuzzy if it's not Frantone, haha!

[@technishn]

Have seen issues with some cheap Bnc connectors. I think the ground in the barrel only occurs at the end not down the length due to differences. A VNA should show something.

[@nezbrun872]

Anyone here getting flashbacks to 10Base2 networks?

[@SystemX1983]

Bloody T-Connectors... the root of all evil signals 😉

[@recursoseninternet]

I am looking to buy the DHO924S but I am concerned about several things that I have read. It seems that Rigol does not keep its word and in the updates, they deactivate the capture and decoding functions that you have to pay for separately from the oscilloscope price. This seems very unprofessional on Rigol’s part. Additionally, other channels and networks are reporting issues with blocking and freezing during normal use, especially in the 250MHz models. Could it be that their FPGA/CPU is insufficient? Maybe the burning smell you detected in your video review was actually a slow burn.

[@Stefan_Payne]

when there is an issue we always forget the easiest solution and look at the cheapest parts. We assume the worst, but forget that it might be something tiny...

[@GeorgeFoot]

I reckon you weren't holding your tongue at the right angle

[@MarkPalmer1000]

Rudimentary discovery of a problem in the test setup, fault of the operator. We all do it, cables and connectors get sketchy, etc. Don't smack the equipment or call out the manufacturer before checking your physical setup first.

[@MrDoneboy]

You just can't beat the old process of elimination!

[@ZlayaCo6aka]

I stopped listing quality connectors for sale five years ago because few ever sold. Most buy the "cheap" typically nickel and faux-gold plated backalley junk. Seems test results like this are preferable.

[@Drew-Dastardly]

When a few connectors and cables cost more than the bloody test instrument there is no wonder. It's kind of like the audiophools obsession with OFC pure gold cables and connectors for a mains plug.

[@MrAwyork]

I thought I saw the thing move funny like it's broken. Maybe me I was seeing things and maybe it was a trick of the camera. Try wiggling the connector piece on the bad one and see if it's loose.

[@rogerorchard2317]

I had show kit messed up with the 50 and 75 ohm BNC problem, the pins are diff sizes

[@erikdenhouter]

(Cheap) BNC ( T- ) connectors have play in the ground. I have seen this many times.

[@microknigh7]

I've had no end of issues with those T-adapters. Prossibly cheap s#!t ones. But having said that, some of mine are probably 40 years old LOL

[@LUNORTEK]

Can it be a small main ground fault in your building?

[@Drekkag]

Rule number one of troubleshooting. Always check connectors and cables before blaming equipment

[@pientaszek0785]

When do you planning to release a review?

[@EEVblog2]

About half way through shooting and editing.

[@pientaszek0785]

Thanks, I'm waiting with purchase for your opinion.

[@SystemX1983]

​@@pientaszek0785if it's good, maybe prices will shoot up and none will be left in stock after releasing the review 😅

[@Drew-Dastardly]

@@pientaszek0785 PMSL

[@canadavey]

Wow, down-under Dave finds a flaw in a sub-par piece of equipment and exploits it for views. This episode sponsered by, Rohde & Schwarz.

[@shazam6274]

I, and dozens of others told you so! 😂

[@5Breaker]

Fiddeling intensifies

[@michaelmoore7975]

Yep. Kookaburra. Just like I said. Called it.

[@pcwrangler09]

Can't count how many bad t-connectors I've had.

[@anthonywilliams7052]

Called it!

[@radarmusen]

It was only high frequency noise there was BeiNg Ceeing (sorry me trying to do a dad joke)

[@artip777]

Cheapy-creepy 😁

[@clems6989]

Glad is wasnt the scope...

[@BMRStudio]

So the real question here is: Who make good BNC stuffs? The market is fulfilled with Chinese crap...

[@tamasszekffy1895]

I am about to upgrade from my still great Rigol 1054 to something better at serial decoding. Well, based on this crap, no more Rigol. Thank you very much...

[@Drew-Dastardly]

That Rigol BNC connector not sold by Rigol was terrible it has to be said.

[@ats89117]

Terrible video. There are a lot of good reasons to have a connection to a safety ground. Noise reduction isn't one of them...

[@NeverTalkToCops1]

Daiyve, you're being bombarded by electromagnetic trash from PINE GAP! Scully...? ...Mulder?...

[@barrieshepherd7694]

My experience, from when I was living in Sydney, is that the radio spectrum below 50 Mhz is saturated with crap, traffic light loops, household WiFi range extenders, Ethernet over power, baby alarms, RF air con controllers, thousands of chinesium plug packs and crap from Solar inverters makes any Shortwave listening an impossibility. In a block of flats all this crap seems to get impressed on the mains wiring making the whole building a vertical radiator so I'm not surprised that Dave's lab is less than quiet. 😊