Dave, you've taught me so much about electronics. Thank you. I bet no one at my college will ever cover this!

Thank You! You just saved me from trying to fix a local oscillator circuit that wasn't broke due to a low level reading on my scope with 1x probe at 36 mhz. I switched to x10 and there was my correct level! I really enjoy your videos.

I've been using scopes for twenty years and never knew this. I was taught to always use 10x because of the higher bandwidth, and noticed it on the datasheet, but never needed to take the time to figure out WHY.

"Now, the first thing you should say is, well, bullshit; show us!" Thats gold, love it!

Yes, highly recommended. I wanted to cover the x1 mode issue that Doug and everyone else seem to skip in their talks that focus more on x10 probes.

So many answer to questions I didn't know I wanted to ask until you asked answered them. Very groovy Mr Dave you got my sub for the ride

Thanks again Dave.... Your video's are much appreciated. I learn so much information each time. Keep them coming... Your a fantastic TEACHER.

Dave, this was great. You do tons of entertaining things, and you do them really well. Your educational stuff is absolute gold. Keep it up.

Very grateful for this video seeing as I'm currently playing with building an 80MHz RF front-end and was wondering how best to model probes for LTSpice to understand what voltages the ADC will be seeing. Nice one Dave!

Dave, that was hugely informative, thank you

Thank you Dave for this excellent video! I love all your videos but it is nice to pick things up like this which weren't discussed in the university (unfortunately). It may take some work but I'd hope the appreciation from the community encourages more in the future! Thanks!

Good stuff, well explained and showed. Keep them up Dave!

Holy crap, I learnt so much! Thanks Dave! Btw: Could you do more videos like this?

Brilliant explanation Dave. It would be great to continue this by explaining differential probes, how they work and possibly design one to build. Low frequency of course.

excellent explanation, spot on. I had this explanation as a baby ship's radio officer in the late 80's in those days our radio and even some radar kit was lower then your average CPU FSB. - times change. This should really be compulsory stuff for new engineers yet as you say it's rarely mentioned, almost forgotten knowledge - tell us more Mr von Daniken !

Awesome stuff Dave, really enjoyed this one! Whiteboard looks great

Awesome video! The diagram with the lossy transmission line modeled as a series of RC circuits says it all.

You should go into teaching Dave, I've learnt more in this video alone than a whole year in a master's EE course, keep it up!

This is very usefull information, THX a lot. The resistant core of the coax also helps to block from signal ringing and mirroring at the input of the scope.

Thanks Dave. When I first started work at an electronics repair centre (many, many years ago) my supervisor handed me a brand new scope, then switched both of my probes to x10 before handing them to me.

Dave's probing genius rocks! Thank you for the video!

Thank you! Please Dave continue with this stuff and explanations! Greetings from Bulgaria!

I loved this video. I know a fair bit of theory and thought we were going to get into rise time limitations of the R/C compensation. I NEVER knew about the deliberately lossy transmission line. Dave, please do more theory vids.

Excellent video Dave!

Great video. Very well explained. Easy to understand for even a challenged hack such as myself.

They're great for me, because I'm just doing audio (20-20k Hz) right now using an old analog 30MHz scope. I do want to do radio at some point though, so a 1GHz scope and probes would be nice to have when I start with it.

very useful video. A series on sources/corrections for measurement errors would be a good video/series.

Love the explanation, Dave...

1X probes are not useless, they are very good for low voltage measurements, in order to keep the signal-to-noise ration as high as possible. Great video, though!

Excellent! As always! Thank you!

Good subject to investigate and a Great presentation! Thank You!

Great tutorial thanks we learn somethings every day.!!

I had so many issues with transmission line theory when i was working on my degree its a very difficult subject

Great video Dave, I'm glad you explained this. Yes, the big white board on the wall is much nicer.

And again, I hope I learned something! That was useful and most informative - thanks a lot :)

Blew my mind. I didnt have a clue about that. Never bothered to measure probe resistance. Excellent.

Yes, it's big subject actually, and you could spend ages investigating how it all works and is optimised for best performance.

Sometimes the route is much more enjoyable than the destination!!!! I'll not take for granted the X10 scale and will think thrice before I use the X1!!! Thanks so much!

Great video, thanks.

Low level signal measurement, e.g. 1mV/DIV. With x10 you trade signal level for more bandwidth, so your scope becomes 10mV or 20mV/DIV minimum

Thank you for answering this. Had trouble finding this anywhere else. Didn't realize a coax had so much capacitance. This threw me off on a high impedance measurement when trying to use 1x mode, now I know why.

Thank you Dave. I learned something I didn't know.👍😊

Learned a lot. Thanks.

Another great video mate

Man, I love these videos

Thanks for the information :)

Very useful video!

Whenever I simulate things like this I am wondering if group delay should worry us too...

Hi Dave, can you make some quick video on measurement of smd capacitors and coils?

very useful stuff! Thanks

Very nice video, Keep it up.

Yes, the 50ohm coax of course needs proper termination to work well, a whole other topic. As is the transmission line matching.

Now I am 10x more optimized to watch another EEVblog!

thanks Dave, I had no idea about probes, but you're right about those switches on the probes, they can drive you crazy.

Another reason why x1 probes are designed that way (internal lossy transmission line) is protection of the sensitive input circuitry of the oscilloscope. A direct coax cable surely has the best bandwidth, but it will also allow anything to pass, including signal under test as well as any static HV peaks which might easily damage the ESD devices inside the scope. The design of ultra-high bandwidth/high gain voltage amplifiers combined with effective protection circuitry is a form of art in the electronics world.

Your videos is a brilliant youtube mine. 👍🏼

Back for a "2nd suck of the sav". Good stuff! Ok, I'm a slow learner. Re: wiggle wiggle center conductor. I was told back in the day (elect shop) that the wiggle was to help [center] the conductor in the dialectic more consistently. On some coax's they will include a plastic/teflon? spiral to do the same thing. That being said I like the "flexibility reason" too. Could easily be both 😁 Thanks again for the gray matter re-charge. Cheers. 🇺🇸

100x is also useful for low voltage sensitive ccts, e.g. 32K xtal oscillators and micropower /low leakage stuff. For low voltage, low frequency use, a 90M resistor in series with the top of a 10x probe is a cheap option.

Great vid thanks. What do you think about the iPad app oscilloscopes that are available for those who don't have the $ to buy a proper one?

Eric Wasatonic did a fascination series on building his own x100 probe as well. Look at this series starting 25 Feb 2013

Dave, One missing element in your trasmission line analysis is INDUCTANCE. Impedance (Z) is equal to the square root of the ratio of L /C. The whole problem of BW in your case is related to matching (optimal transfer of power) the input and output Z's to the trasmission line. The 9 Mohms helps expanding the BW but introduces resistive losses, hence the X10. A 50 ohms coax will not help without proper matching or termination. I think it is time to review transmission line theory. Cheers!

Hi Dave you never said anything about the 50 ohm resistor of the signal gen. That should be included in your calcs in order to be more precise on the -3dB point. I have seen a lot of your videos. As always they were extremely helpful. Thanks again.

Big thumbs up,,, that was good stuff.

Mr. Jones, thank you! :D

No, it's all to do with transmission line matching and compensation. The probe is transmission line optimised for x10 mode, so is all mis-matched when you switch to x1.

Very interesting! Nobody in my company (one of the aorld leaders for telecom base station power supplys) could explain me this "phenomen".

I like this DaveCAD-HD! It looks great.

Great! Thanks man.

Great stuff I love your videos

Brilliant info...so what is the advantage of having ORIGINAL probes , say for a Tektronic 465M if it did not come with original probes? Cheers

You are a true god of electronics!

Thank you Dave for pointing that out. It is useful to know the X1 is so low BW and that a coax is actually better in low volt and hi BW applications. Non intuitive. I love your blogs ( I love your accent, LOL). BTW, how do you pick coax for that condition. 50ohm, 75ohm, etc.

Fave, I have a ds2000 and the 350mhz rigol probes that came with it. I just noticed that above the 1x 10x switch there is a rubber plug, remove it and there is another adjustment, how does that fit into this?

I would say that everything is little simpler, since i had to design my own cable for oscilloscope probe. Most important feature of lossy cable is to have very low capacitance, so wire must be as thin as possible. If you try to replace it with regular coax you still can compensate everything for any bandwidth but input impedance will be terrible, what makes measurements impossible( done that and was puzzled why everything stops working when i attach my probe) probe impedance is basically cable impedance divided by multiplier. lossy cable allows you to achieve higher input impedance resistance does not seem to play significant role however it ensures that there will be no reflection because of improper termination and also it may improve impedance by turning cable itself into atenuator

excellent video.

Learnt EMT + Control system + Network Theory in one video, Thanks

Nice One Dave!!! hahahah very usefulll I say hahaha because I suddenly remember this subject being taught and the teacher was boring so I didnt take much notice )))

Best video so far !!!

Thanks !

Did you what, watched like 2 of them? They are all great!

Thanks for the video! But I can't understand how a passive circuit can have higher amplitude at the output than at the input. I mean the 'funny business' at 27:45, but I get the idea what was meant.

thanks for interesting video :-)

So, is it best to get dedicated separate high frequency 1x and 10x high frequency probes if you need to test high frequencies?

I am no engineer. But what I picture when you're talking about this is Eddy currents going back and forth. Or electricity, A/C ...It can only travel so fast on such a thin wire with such a great resistance.

@25:18" It doesn't matter a rats ass" ... gold aussie Tech talk hehe love it

What is the compensation network compensating?

Just going to go ahead and subscribe now. Thanks for the content.

Dave, do you always chop up your videos and shuffle them around as much as you did in this one? (I got distracted with the changing 'doodles' on the whiteboard and noticed parts were out of order as you initially recorded them).

😊 Again. Where that 1k resistance parallel to the oscilloscope input comes from?

Since I am fairly new to electronics I am trying to understand oscilloscopes and probe use. I watched this with keen interest, others concerning 10x probe use and even W2EWs video about the effects of ground lead length on signal quality. Frankly, I still can't quite understand the value of 1x probes, rather than just using a 10x probe for everything. What am I missing? Many thanks.

The x10 probe reduces the signal amplitude by ten times. This forces the scope to amplify the input signal by ten to get back to the original scaling (which means it will also amplify any input noise by ten as well). So the x1 probe is more sensitive and can capture low level signals with better resolution and less noise.

Do people prefer that one to the old hand held one? I think it works much better.

I was right there with you until about the 24 minute mark. The scope probe as you mentioned is a distributed, lossy transmission line. You measured it to be around 330 ohms at DC / low frequency. It will be different at higher frequencies and as you mentioned is optimized for 10x mode and to achieve high bandwidth. The characteristics of the transmission line, however, are determined by geometry and materials and are the same whether you are on 1x mode or 10x mode. The transmission line doesn't look any different at 20 MHz (just picked a number) in 1x mode than it does at 20 MHz in 10x mode. Which means the effect of its interaction with the 15pF scope input capacitance would be the same at 1x mode or 10x mode. Also, what you are changing between 1x and 10x mode is whether the 9Meg resistor and ~15pF tip capacitance are in circuit or bypassed. So wouldn't the bandwidth limitation in 1x mode have to do with the interaction between the lossy line's RLC and whether or not the 15pF tip capacitance is in-circuit or shorted, and not the interaction between the lossy line and the scope's input capacitance? If not, what am I missing? Great video in either case. Thanks for posting.

Hi, Dave! In case of x1 position, you say about voltage devider model with cabel distributed 330 Ohm and 1 kOhm capacitive resistance. But what about x10 position? If we discuss with voltage devider model, it shoul be 9 megOhm + 330 cable distributed Ohm resistance, so that thing makes signal almost zero amplitude. How it works in x10 position?

Good to mention this, anyone who works in electronics has to know this, otherwise they should never have been hired.

Hi Dave, You didn't do one thing when you damage this probe already: measure the whole lenght of this inner cable. You will be suprised how long is it!

Wow, didn't know that, now I have to go measure R on leads of my brand new Siglent. I just wonder if that resistance wire is Ni-chrome, same resistive stuff they use in electric heaters and blankets - easy way to tell is, try to solder it, Ni-chrome absolutely will not stick to normal solder. (if you ever wreck an electric blanket, salvage the resistance wire, but you have to crimp all connections.)

Cool! thanks

However coax will change impedance at large change of frequency. The "crincle" form choke points in the signal that changes with the frequency. the cables are rated at 50 Homs up to 900 mhz 5

c'est bon à savoir, et très intéressent