Hi David,
Given free choice, I will normally go for an HP/Agilent/Keysight model. That doesn't mean I won't use one, or fix them. My 2465B is being a good little fella right now, and I have decided to rebuild my 465 and give my 468 a try. HP didn't use any tantalum caps that I could find in the 1722A. It was "struck by technician" and had a "TIM. Technician Induced Failure. Someone lost a good 'scope due to careless servicing. That is always too bad.
I have a PHilips PM3070 I have a love-hate relationship with. An idiot destroyed the faceplate, he had no business in there for a calibration check. I rebuilt that best I could, but I am waiting for the character generator to sweep board to die again, which would make that the 4th time, maybe 5th. Not impressed, but it has an excellent trace and is great for eye patterns. Bloody thing was tres expensive (got it new).
I keep an old 15 MHz Gould 'scope around for working on tube equipment. It does what it does very well. Not my go - to 'scope, but it has its place.
I just rebuilt a transistor curve tracer (a Heathkit), so I might also fix a Heathkit IO-102 for a permanent display for it. I may not have the space though.
I also have a B&K (dead 20 MHz) and the Ramsey. I'm a sucker "to see if I can get it working again". Usually I can, and some of my friends have benefited from this. I fixed another PM3070 for my brother in law. He didn't have anything decent to use. Now he does. He likes it I think. Prices for parts are about the only reason I'll not repair something. Maybe time crunch occasionally, and if it is too rough. Once a messy tech gets into something, it might be over. Bad techs and lightening.
I don't have a stiff rule about what I use or fix. I don't care for equipment that is hard to use, and that is a personality thing.
-Chris
Given free choice, I will normally go for an HP/Agilent/Keysight model. That doesn't mean I won't use one, or fix them. My 2465B is being a good little fella right now, and I have decided to rebuild my 465 and give my 468 a try. HP didn't use any tantalum caps that I could find in the 1722A. It was "struck by technician" and had a "TIM. Technician Induced Failure. Someone lost a good 'scope due to careless servicing. That is always too bad.
I have a PHilips PM3070 I have a love-hate relationship with. An idiot destroyed the faceplate, he had no business in there for a calibration check. I rebuilt that best I could, but I am waiting for the character generator to sweep board to die again, which would make that the 4th time, maybe 5th. Not impressed, but it has an excellent trace and is great for eye patterns. Bloody thing was tres expensive (got it new).
I keep an old 15 MHz Gould 'scope around for working on tube equipment. It does what it does very well. Not my go - to 'scope, but it has its place.
I just rebuilt a transistor curve tracer (a Heathkit), so I might also fix a Heathkit IO-102 for a permanent display for it. I may not have the space though.
I also have a B&K (dead 20 MHz) and the Ramsey. I'm a sucker "to see if I can get it working again". Usually I can, and some of my friends have benefited from this. I fixed another PM3070 for my brother in law. He didn't have anything decent to use. Now he does. He likes it I think. Prices for parts are about the only reason I'll not repair something. Maybe time crunch occasionally, and if it is too rough. Once a messy tech gets into something, it might be over. Bad techs and lightening.
I don't have a stiff rule about what I use or fix. I don't care for equipment that is hard to use, and that is a personality thing.
-Chris
Yesterday, I ordered a Rigol DS1074Z-S. I was planning on buying the cheaper 1054Z and a separate generator some other time. But the 1054Z is in such high demand that getting one can take months.
The 1074Z-S has a built-in dual channel arbitrary waveform generator and seems a bit better value for money than the 1074Z without the gen, so I ended up ordering the 1074Z-S. Can't wait for it to arrive...
The 1074Z-S has a built-in dual channel arbitrary waveform generator and seems a bit better value for money than the 1074Z without the gen, so I ended up ordering the 1074Z-S. Can't wait for it to arrive...
That scope is also on my list. It's all the rage over at EEVBlog, and you can unlock all features (including the extra memory depth, it is on the board already) and full bandwidth with a simple hack (but don't enable the high vertical sensitivity feature, consult the EEVblog forum). That also goes for the 1054Z, they're the same hardware but without the AWG. What drives me to the 1074Z-S is that the built-in AWG is of comparable spec to their low end stand-alone AWG, and that the price of 1054Z plus stand-alone AWG is about the same as that of a 1074Z-S.
Please let us know if you like your new scope. Although my scope was in a very different price bracket when it was new, the cheap Rigol line shows us that those older DSOs have been overtaken by new technology quite spectacularly.
Please let us know if you like your new scope. Although my scope was in a very different price bracket when it was new, the cheap Rigol line shows us that those older DSOs have been overtaken by new technology quite spectacularly.
Thanks for the tips. It is through the EEVblog videos that I found out about this Rigol scope...
I'm expecting the scope at the end of the week, and I'll certainly post about my experiences with this scope/AWG.
It may come as no surprise that lower end scopes and gens from e.g. LeCroy are rebranded Siglents...
Well, the low end scopes are getting much, much better. Rigol especially. However, the old technology Agilent I have toasted the Rigol in actual scope work. Having said that, I would really love a new Agilent - Keysight product! The scope I am using now is an Agilent 54642D. Too bad the display is only green, but it is easier to see detail than a display in blue would be.
If I were just starting out today, a Rigol DSO is massively better than what I had to buy in the 80's and 90's. A 100 MHz dual trace Leader was over $1 K list. All you need to do is look back to what others started with. My first scope? A 500 KHz, single trace Stark without any form of decent triggering. Back then you needed skill to create a stable display. My next scope was a 10 MHz, dual trace Philips. Nice scope, but expensive as all heck! So ignoring the value of a dollar, you newer folks have it pretty darned good if you ask me. Enjoy your improved tools!
DSO's can have a "fat" trace. Try using averaging to create a fine line. You only need to average 4 to have a good trace and good update times. Another good test to gauge the quality of a DSO is to look at an eye pattern off a CD player. It needs to be a good cd player though as the cheap Philips transports have closed eyes.
I think you will like your new DSO jitter. Now, connectivity is your next joy. Is that one USB, or network aware?
-Chris
If I were just starting out today, a Rigol DSO is massively better than what I had to buy in the 80's and 90's. A 100 MHz dual trace Leader was over $1 K list. All you need to do is look back to what others started with. My first scope? A 500 KHz, single trace Stark without any form of decent triggering. Back then you needed skill to create a stable display. My next scope was a 10 MHz, dual trace Philips. Nice scope, but expensive as all heck! So ignoring the value of a dollar, you newer folks have it pretty darned good if you ask me. Enjoy your improved tools!
DSO's can have a "fat" trace. Try using averaging to create a fine line. You only need to average 4 to have a good trace and good update times. Another good test to gauge the quality of a DSO is to look at an eye pattern off a CD player. It needs to be a good cd player though as the cheap Philips transports have closed eyes.
I think you will like your new DSO jitter. Now, connectivity is your next joy. Is that one USB, or network aware?
-Chris
You bragger ;-) That scope still goes for ten times the price of an entry-level Rigol. I would love to have something like that on my bench!
The DS1000Z series has a USB host connector on the front for thumb drives, a USB device connector at the rear and a LAN connection as standard. That is pretty nice at this price point I think.
My first scope was a Philips 10 MHz single channel scope, which I bought at a surplus store. I was a teenager then, and it cost me a substantial part of my savings, but I can not think of a better scope to learn using one than the one I had. Good enough to be useful and accurate, but simple enough to get me going quickly. My second scope was a Philips dual beam unit which I got for nothing. I was asked if I could get one working scope out of two non-working units, but I got them both working. My third one (the PM3384A) was a write-off at work, so i could get it for very little, and was I happy with it! It has served me well for almost ten years, but it is developing problems now, and I have trouble sourcing parts. That was a mid-market scope from the nineties, and its DSO functionality is now obsolete when you compare its capabilities to that of a current entry level scope. My attitude towards older scopes is the following (there may be exceptions):
- mid to high-end analog: worth keeping alive for usefulness
- high-end older DSO: worth keeping alive for usefulness
- mid-end, 20 year old DSO: use it as long as it still works, otherwise don't waste too much money on repairing it, before you know it, a new toy that beats it costs less than the repair
- vintage scopes: worth keeping alive out of historical interest
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Hi timpert,
Well, I agree with your list there. I guess HP / Agilent would be classified as high end product. I was trying to draw attention to the fact that some older DSOs have a lot of hidden functionality and simple acquisition superiority over some of the less expensive new products from companies like Rigol. My personal feeling is that Rigol offers amazing value, but you should also look at what Keysight offers in their low end. HP / Agilent / Keysight (now) have a long history of delivering far more quality than first appearances might suggest. You really do have to play with these instruments these days before you can which scope offers the best value.
That Agilent I have is one I just got. I paid less than $1K CDN for it - screaming deal. Still, my work promised to pay for it, then reneged on the offer just after I bought it. I can't send it back, nor would I ever want to, as you pointed out. So while I love the thing, it hurt to buy it. Would I sell it? Ahhhh, no!
Anyone who uses products like Rigol should keep an analog scope on their bench. DSO's still have trouble displaying an analogue signal unless they cost an arm and a leg. I keep some analogue scopes around for various reasons, one 15 MHz Advance because it is used for tube circuits.
I recently got an HP 1722A scope (made in 1974 !!). So it was finally repaired, and I discovered it is still an amazing scope! It has a digital readout (remember those old calculator displays under the magnifying bubbles?). It works great and has 275 MHz bandwidth. I am still not going to throw out older scopes that still work though. As you get older, you tend to accumulate stuff. You even gain an appreciation for these older war horses. This one classifies as a museum piece, one that still kicks butt! HP didn't use a single tantalum in this scope, everything is designed to last forever - and it has. A previous technician caused the failure from what was a very minor problem at first. I did replace some electrolytic caps since I was there and they tested less than perfect.
So, the Rigol line is a winner it seems, but hang onto your analogue scopes until the DSO types fully mature for displaying analogue signals. You should see some of the things coming down the pipe for Keysight products! There will be a crop of great low end (for Keysight) products that smoke what is now. It may be a couple years, so just try Keysight out as well when looking at Rigol. Keysight is eying that market segment.
-Chris
Well, I agree with your list there. I guess HP / Agilent would be classified as high end product. I was trying to draw attention to the fact that some older DSOs have a lot of hidden functionality and simple acquisition superiority over some of the less expensive new products from companies like Rigol. My personal feeling is that Rigol offers amazing value, but you should also look at what Keysight offers in their low end. HP / Agilent / Keysight (now) have a long history of delivering far more quality than first appearances might suggest. You really do have to play with these instruments these days before you can which scope offers the best value.
That Agilent I have is one I just got. I paid less than $1K CDN for it - screaming deal. Still, my work promised to pay for it, then reneged on the offer just after I bought it. I can't send it back, nor would I ever want to, as you pointed out. So while I love the thing, it hurt to buy it. Would I sell it? Ahhhh, no!
Anyone who uses products like Rigol should keep an analog scope on their bench. DSO's still have trouble displaying an analogue signal unless they cost an arm and a leg. I keep some analogue scopes around for various reasons, one 15 MHz Advance because it is used for tube circuits.
I recently got an HP 1722A scope (made in 1974 !!). So it was finally repaired, and I discovered it is still an amazing scope! It has a digital readout (remember those old calculator displays under the magnifying bubbles?). It works great and has 275 MHz bandwidth. I am still not going to throw out older scopes that still work though. As you get older, you tend to accumulate stuff. You even gain an appreciation for these older war horses. This one classifies as a museum piece, one that still kicks butt! HP didn't use a single tantalum in this scope, everything is designed to last forever - and it has. A previous technician caused the failure from what was a very minor problem at first. I did replace some electrolytic caps since I was there and they tested less than perfect.
So, the Rigol line is a winner it seems, but hang onto your analogue scopes until the DSO types fully mature for displaying analogue signals. You should see some of the things coming down the pipe for Keysight products! There will be a crop of great low end (for Keysight) products that smoke what is now. It may be a couple years, so just try Keysight out as well when looking at Rigol. Keysight is eying that market segment.
-Chris
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Sometimes the fine trace of an analogue scopes misses some information that a DSO captures. Here's a short demo of that.
I certainly hope so. I already have the first "assignment" for it. Recently I was just poking around with the Philips scope in my diy headphone amp when I noticed some oscillation in the MHz (IIRC) in both channels. The connectivity will help me communicate what I measure on this forum.
In the meantime I have kept myself busy tracing a defect in my washer. Leave it to Murphy to give me a very uncommon fault... a deformed drum that knocked the heating element open circuit during the spin cycle... Glad I bought an affordable Rigol, so now I have some money left for a new washer.
Hi Anatech,
Rumour has it that the low-end scopes from Keysight are actually manufactured by Rigol, and that (as Jitter also stated), the low end LeCroy scopes come from Siglent. Rigol has a reputation of making good hardware loaded with good firmware, while Siglent has a reputation of making potentially great hardware (at least in their new 2000 series) that is held back by so-so firmware. I think that in the case of the Siglent, LeCroy still add their touch of magic to the firmware before they attach their badge. Maybe something similar happens with Keysight/Rigol?
With current technology advances, there is always an incentive to hold on to the hard-earned cash a little longer, because you know a new scope is going to mop the floor with its predecessor, and probably for a little less money. Makes me think of this one:
https://xkcd.com/989/
So I guess I'll just buy a new scope when I really need it...
Rumour has it that the low-end scopes from Keysight are actually manufactured by Rigol, and that (as Jitter also stated), the low end LeCroy scopes come from Siglent. Rigol has a reputation of making good hardware loaded with good firmware, while Siglent has a reputation of making potentially great hardware (at least in their new 2000 series) that is held back by so-so firmware. I think that in the case of the Siglent, LeCroy still add their touch of magic to the firmware before they attach their badge. Maybe something similar happens with Keysight/Rigol?
With current technology advances, there is always an incentive to hold on to the hard-earned cash a little longer, because you know a new scope is going to mop the floor with its predecessor, and probably for a little less money. Makes me think of this one:
https://xkcd.com/989/
So I guess I'll just buy a new scope when I really need it...
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Hi jitter,
He's off the mark completely! Sorry.
The standard 8 bit resolution limits detail that an analogue scope easily picks up. What is coming down the pipe are better acquisition A to D sections that will be 10 bits first. This doesn't sound like much, but that is a massive difference! Later you will see 12 bit more commonly. This is a really big deal!
Missing detail ... any time you get a fat trace with a good analogue scope, investigate your sweep speed!!!!! You would pick his common mode test in a flash. This is more an indication of an operator being unfamiliar with his instrument. A fat trace in analog land means you have waveforms well outside of the optimum sweep rate. So when looking at an eye pattern, 60Hz (50Hz) power line noise looks like a fat trace.
With digital scopes that aren't the best, every capture is assumed valid. An analogue scope captures continuously with next to the equivalent of infinite samples. A DSO captures maybe 500 to 1000 sample points, the less expensive ones even less. Because random noise is captured by so few data points, it is weighted far too high and you end up with many data points that do not lie in a straight line. Fuzzy in other words. By averaging with few samples you give noise less weight as a normal analogue scope would. This noise isn't valid data once you consider how many adjacent data points you are missing. That is why I suggested 4 averages instead of 32 or more.
DSOs are blind at various times. Most DSOs require some dead time to process and display the data. During those times your DSO is blind to the world. That is the concept behind the "MegaZoom" technology with deep memory (just a lot of memory). Agilent uses more than one processor so that one can pack samples in memory and the other can do math and display. These scopes miss less than the average DSO. Many DSO's have variable persistence where you can keep every captured waveform and build up one trace with all of them. On mine you can either turn it off or on. That is different than turning the sampling off (run - stop).
Analogue scopes have next to infinite sampling and will display much finer detail than your average DSO can. The DSO can give artificially high weights to transient noise, and because of the persistence it may look like more detail. Nope, you just lost the forest behind the leaves.
Analogue scopes do miss some information between trigger events. It will trigger, complete the sweep and then sit and wait until the next trigger event. Want a scope that constantly runs sweeps? Find a really old one that does not have triggering. My first scope was not a "triggered" scope. Using it was a pain in the rear as you tried to get a stable display. You younger people will not have any clue as to what I am talking about unless you go out, dust off some history and fire it up. Now try to get a stable display. That is unless you get a stiff electrical shock from the case of that old scope. (just unplug it and turn the plug around the other way and plug it in again. That should be better).
In general, the detail war is won by the analogue scope. Its vertical resolution is near infinite compared to an 8 or 10 bit DSO. The same applies to the horizontal resolution. Each has its weaknesses and strengths. Keep both on your bench, because the DSO that looks like an analogue scope is priced north of $50K. That is why my new bench will have a spot for both. They are really two different instruments.
-Chris
He's off the mark completely! Sorry.
The standard 8 bit resolution limits detail that an analogue scope easily picks up. What is coming down the pipe are better acquisition A to D sections that will be 10 bits first. This doesn't sound like much, but that is a massive difference! Later you will see 12 bit more commonly. This is a really big deal!
Missing detail ... any time you get a fat trace with a good analogue scope, investigate your sweep speed!!!!! You would pick his common mode test in a flash. This is more an indication of an operator being unfamiliar with his instrument. A fat trace in analog land means you have waveforms well outside of the optimum sweep rate. So when looking at an eye pattern, 60Hz (50Hz) power line noise looks like a fat trace.
With digital scopes that aren't the best, every capture is assumed valid. An analogue scope captures continuously with next to the equivalent of infinite samples. A DSO captures maybe 500 to 1000 sample points, the less expensive ones even less. Because random noise is captured by so few data points, it is weighted far too high and you end up with many data points that do not lie in a straight line. Fuzzy in other words. By averaging with few samples you give noise less weight as a normal analogue scope would. This noise isn't valid data once you consider how many adjacent data points you are missing. That is why I suggested 4 averages instead of 32 or more.
DSOs are blind at various times. Most DSOs require some dead time to process and display the data. During those times your DSO is blind to the world. That is the concept behind the "MegaZoom" technology with deep memory (just a lot of memory). Agilent uses more than one processor so that one can pack samples in memory and the other can do math and display. These scopes miss less than the average DSO. Many DSO's have variable persistence where you can keep every captured waveform and build up one trace with all of them. On mine you can either turn it off or on. That is different than turning the sampling off (run - stop).
Analogue scopes have next to infinite sampling and will display much finer detail than your average DSO can. The DSO can give artificially high weights to transient noise, and because of the persistence it may look like more detail. Nope, you just lost the forest behind the leaves.
Analogue scopes do miss some information between trigger events. It will trigger, complete the sweep and then sit and wait until the next trigger event. Want a scope that constantly runs sweeps? Find a really old one that does not have triggering. My first scope was not a "triggered" scope. Using it was a pain in the rear as you tried to get a stable display. You younger people will not have any clue as to what I am talking about unless you go out, dust off some history and fire it up. Now try to get a stable display. That is unless you get a stiff electrical shock from the case of that old scope. (just unplug it and turn the plug around the other way and plug it in again. That should be better).
In general, the detail war is won by the analogue scope. Its vertical resolution is near infinite compared to an 8 or 10 bit DSO. The same applies to the horizontal resolution. Each has its weaknesses and strengths. Keep both on your bench, because the DSO that looks like an analogue scope is priced north of $50K. That is why my new bench will have a spot for both. They are really two different instruments.
-Chris
Hi timpert,
Yes.
However, the same factory does not mean the same instrument comes from both name plates. What you are familiar with is called an OEM that deals with anyone and everyone. Rigol had good reliability and a great "in control" process. Agilent could work with that, so Rigol got improved technology and even more improved manufacturing. Agilent was able to produce very high quality equipment at the price point that allows more people to buy the Agilent (Keysight) name. Get them young and train them right. When you buy Keysight, you buy very, very high quality, and a road map into even better equipment when you can afford it. Professionals and serious hobbyists both understand the need for good equipment. The more average hobbyist will benefit from the higher quality equipment, but is well served by the "entry level" equipment. Please note that the entry level Keysight / Tek / LeCroy is normally far above the no-name entry level stuff. Your average hobbyist is not an unskilled person, but they simply have less time and other obligations that limit what they can buy. A serious hobbyist will sacrifice more to assemble a work area where they can get those answers they want that require more time and better equipment. Guess who has a better marriage? Its the same with any hobby.
-Chris
Yes.
However, the same factory does not mean the same instrument comes from both name plates. What you are familiar with is called an OEM that deals with anyone and everyone. Rigol had good reliability and a great "in control" process. Agilent could work with that, so Rigol got improved technology and even more improved manufacturing. Agilent was able to produce very high quality equipment at the price point that allows more people to buy the Agilent (Keysight) name. Get them young and train them right. When you buy Keysight, you buy very, very high quality, and a road map into even better equipment when you can afford it. Professionals and serious hobbyists both understand the need for good equipment. The more average hobbyist will benefit from the higher quality equipment, but is well served by the "entry level" equipment. Please note that the entry level Keysight / Tek / LeCroy is normally far above the no-name entry level stuff. Your average hobbyist is not an unskilled person, but they simply have less time and other obligations that limit what they can buy. A serious hobbyist will sacrifice more to assemble a work area where they can get those answers they want that require more time and better equipment. Guess who has a better marriage? Its the same with any hobby.
-Chris
I am familiar with the OEM principle. I have found some discussions and Youtube videos on the Siglent SDG1000 being identical to the Lecroy WaveStation, with the latter being three times as expensive. The similarity goes on to include firmware bugs being the same for both models, and the ability to cross-upgrade the firmware: the Siglent would work just fine on LeCroy firmware and vice versa. This also includes the optional AWG. Now, understandably, that has led to some people feeling ripped off by LeCroy. The OEMs have learned to make good scopes themselves, there really isn't a reason to go for a low-end Keysight or Lecroy instead of a Rigol or Siglent, unless for some reason, you want to show that you work with traditionally recognized brands. The high-end scopes are a totally different matter though.
At work we have a Tek TDS2014B. It has a maximum record length of 2.5 k samples. That is pathetic, and it has all the issues of a cheap DSO you just mentioned. Zoom and scroll are very limited. Yet it's current successor (the TDS2000C series) still comes with 2.5k samples per channel, while the Rigol DS1104Z, which costs less than half the amount of the Tek, has 1200 (yes, one thousand two hundred!) times the memory depth of the Tek, when all four channels are in use. The available memory is divided across active channels, so with only one channel in use, it will store 4800 times the amount of data that the Tek does. Consequently, it will likely have none of the issues associated with poor memory depth. I am saying this, because I think that the traditional manufacturers have lost the battle for the low end from the Chinese. The Chinese scopes simply offer a lot more for less money, and are getting better and better at it. So if you don't care about posh brand badges, you can actually have a decent scope and a good marriage as a hobbyist!
When displaying only a single channel, the "blind time" of an analog scope can be very small, but this changes as soon as more channels need to be displayed. Many scopes can either chop or alternate the traces, with alternate being the only option at the faster sweep times. When displaying 2 channels, each channel is blind half the time. With a DSO, sampling is staggered, so it will always (sort of) chop, avoiding blind time at the cost of lowered sample rate per channel.
I think that the EEVblog example shows you that a DSO can be easier to use than an analog scope when dealing with a signal that has both LF and HF features, provided that the DSO has enough memory. But that boundary condition isn't mentioned explicitly, and that is really my main gripe with the video.
At work we have a Tek TDS2014B. It has a maximum record length of 2.5 k samples. That is pathetic, and it has all the issues of a cheap DSO you just mentioned. Zoom and scroll are very limited. Yet it's current successor (the TDS2000C series) still comes with 2.5k samples per channel, while the Rigol DS1104Z, which costs less than half the amount of the Tek, has 1200 (yes, one thousand two hundred!) times the memory depth of the Tek, when all four channels are in use. The available memory is divided across active channels, so with only one channel in use, it will store 4800 times the amount of data that the Tek does. Consequently, it will likely have none of the issues associated with poor memory depth. I am saying this, because I think that the traditional manufacturers have lost the battle for the low end from the Chinese. The Chinese scopes simply offer a lot more for less money, and are getting better and better at it. So if you don't care about posh brand badges, you can actually have a decent scope and a good marriage as a hobbyist!
When displaying only a single channel, the "blind time" of an analog scope can be very small, but this changes as soon as more channels need to be displayed. Many scopes can either chop or alternate the traces, with alternate being the only option at the faster sweep times. When displaying 2 channels, each channel is blind half the time. With a DSO, sampling is staggered, so it will always (sort of) chop, avoiding blind time at the cost of lowered sample rate per channel.
I think that the EEVblog example shows you that a DSO can be easier to use than an analog scope when dealing with a signal that has both LF and HF features, provided that the DSO has enough memory. But that boundary condition isn't mentioned explicitly, and that is really my main gripe with the video.
Chris is correct here,
If you want to catch runt pulse or low level HF oscillation Analogue scopes are the best - I have some Mega expensive 20Gs digital scopes and still my good old Tek 7000's series and Tek 11302A outperforms them all...
For analogue work I tend to use the analogue scopes, for digital - the digital scopes...
Its nice with digital scopes to be able to store, save and print waveforms, but on a usability basis the analogue scopes win hands down, you can trust what an analogue scope shows, with digital scopes its a bit hit and miss.
Thanks for the explanation.
I watched the video again, and discovered the topic wasn't actually about detail, as I had interpreted it at first, but about noise and how a DSO isn't per definition always noisier than an analogue scope.
Yes, I do know about the shortcomings of DSOs and will definitely keep my analogue scope. If all goes well, I'm delivered the Rigol tomorrow, so I'll be able to do some comparisons. To be continued...
I watched the video again, and discovered the topic wasn't actually about detail, as I had interpreted it at first, but about noise and how a DSO isn't per definition always noisier than an analogue scope.
Yes, I do know about the shortcomings of DSOs and will definitely keep my analogue scope. If all goes well, I'm delivered the Rigol tomorrow, so I'll be able to do some comparisons. To be continued...
Hi JohnW,
Many thanks.
The newer Keysight scopes with the touch screen make catching runt pulses pretty easy, and they can be set up to only capture runt pulse events (plus run up time!). But if I want to see the quality of a signal, it is an analogue scope's domain. Those $50K plus scopes are simply out of my reach - even at a screaming deal. They do close the gap between analogue and digital though, don't they?
Hi jitter,
You will love your Rigol, even if it isn't identical to the Keysight. They did differentiate the two products. The Rigol is very probably the best new entry into the test equipment world.
-Chris
Many thanks.
The newer Keysight scopes with the touch screen make catching runt pulses pretty easy, and they can be set up to only capture runt pulse events (plus run up time!). But if I want to see the quality of a signal, it is an analogue scope's domain. Those $50K plus scopes are simply out of my reach - even at a screaming deal. They do close the gap between analogue and digital though, don't they?
Hi jitter,
You will love your Rigol, even if it isn't identical to the Keysight. They did differentiate the two products. The Rigol is very probably the best new entry into the test equipment world.
-Chris
Hi timpert,
-Chris
It's more the other readers I was worried about. From what you said earlier it seemed you did.
Yup, for good reason.
When the market went to DSO land, Agilent took over with superior products. I personally found that the Tek scopes were more difficult to learn as I was calibrating various scopes for a living.
Varies by make and model. You might be very disappointed with the truth on some well known brands. I have been keeping up on this by attending local seminars put on my the large manufacturers.
I hate to disagree with you on that, but knowing how to operate your equipment and being aware of its short comings is expected (not you, you .. the everyone you). Only an unskilled operator could have fallen into the trap the presenter did. I'll bet he just went to the seminar from the DSO people and came back to show what he had been told. Aliasing is a real problem with a DSO, but you can always trust what a half decent analogue scope will display. Of course you have to know enough to interpret what you are seeing. If you see a fat trace from a normally nice thin trace, you know you have another waveform far removed from your sweep rate. That is a certainty - so go find it. The DSO, although with more powerful features, can easily lead you astray. You need to be aware of the weaknesses using a DSO.
-Chris
For sure - If you know what your looking for in the first instance. I'd be working on say a PWM modulators output when I would see occasional flickers of an odd pulse - on a digital scope you would miss these unless you knew what you where looking for and setup the scope to capture them...
I've got a couple of the new "Crazy Money" Agilent Digital scopes, they are not even setup on the bench - nice but after playing with them for a few hours I always fall back on my good old analogue scopes... I'll use them when I need to save and print waveforms for presentations etc.. otherwise the just block the door to our bedroom! (I've just built a new lab but need to install 67 Mains AC wall sockets... I installed 6 and got frustrate and been too busy since)!
Hi Anatech,
The whole discussion makes me think of a discussion I had when I was younger (still a kid, basically), and in the market for my first multimeter. My fellow hobbyists (who were older than me) urged me to get an analog one, because needle movements tell a story that a slowly updating display can't. They were absolutely right, and so I ignored their advice and went for a swanky digital one. I never regretted it though, because I have grown up to use the strengths of a digital multimeter and live with its shortcomings.
I think it will be the same with analog scopes and DSO's, eventually with DSO's replacing the analog scopes on the workbench when more and more people grow up using digital scopes. There will always be areas where the analog scope outshines the digital one, just like the analog multimeter can do things that a digital one can't. But other qualities do make up for that, and the appreciation of those qualities varies with (us)age.
To take an entirely different path, there are also PC scopes such as the Picoscope. Their 5000 series has switchable resolution (up to 16 bits) at the cost of sample rate and thus the risk of aliasing. The size of the built-in buffer is insane, and I think it is (partially) an attempt to overcome the fact that the USB scope is even further behind the analog scope when it comes to interpretation of trace phenomena like a fat trace. But at the same time, the instrument can be used to judge signal quality to a degree that even the best analog scopes can not match, due to its resolution and buffer size (provided that the dreaded aliasing trap doesn't slip into the equation). A totally different beast altogether! And one that keeps its place on my list of wannahaves. Some day...
That had me scratching my head when first using my DSO. A quick check is to simply turn up the timebase and see if things change the way you'd expect. Once you (yes, the same you as you mean) realize what is happening, you probably won't fall for it again. Hopefully. I haven't watched the video end to end (I find his voice quite irritating to listen to), but I saw the presenter use zoom quite extensively. That's nice- if your scope supports it and fills it with a high enough sample rate. Quite a few don't do that to such a degree, and finding out what happens in the situation in the video would be almost impossible with the aforementioned Tek, but rather easy with an analog scope (contrary to what the presenter is saying). Just remember the importance of the intensity control...
The whole discussion makes me think of a discussion I had when I was younger (still a kid, basically), and in the market for my first multimeter. My fellow hobbyists (who were older than me) urged me to get an analog one, because needle movements tell a story that a slowly updating display can't. They were absolutely right, and so I ignored their advice and went for a swanky digital one. I never regretted it though, because I have grown up to use the strengths of a digital multimeter and live with its shortcomings.
I think it will be the same with analog scopes and DSO's, eventually with DSO's replacing the analog scopes on the workbench when more and more people grow up using digital scopes. There will always be areas where the analog scope outshines the digital one, just like the analog multimeter can do things that a digital one can't. But other qualities do make up for that, and the appreciation of those qualities varies with (us)age.
To take an entirely different path, there are also PC scopes such as the Picoscope. Their 5000 series has switchable resolution (up to 16 bits) at the cost of sample rate and thus the risk of aliasing. The size of the built-in buffer is insane, and I think it is (partially) an attempt to overcome the fact that the USB scope is even further behind the analog scope when it comes to interpretation of trace phenomena like a fat trace. But at the same time, the instrument can be used to judge signal quality to a degree that even the best analog scopes can not match, due to its resolution and buffer size (provided that the dreaded aliasing trap doesn't slip into the equation). A totally different beast altogether! And one that keeps its place on my list of wannahaves. Some day...
Hi JohnW,
Totally agree. Those crazy money scopes are really useful, but you are correct that they need to be properly set up first. Operating an oscilloscope requires a skill that people will develop as they use them and have to deal with problems. Never having a problem means never learning to the extent that you can by experimenting.
Like you, I will always keep a couple analogue scopes around, and I do enough so that when I have one on the bench, I miss the other one. New bench will solve that problem.
For your lab, consider using power bars where you can. I have the same issue that you do, but not to that extent. I am considering installing two 15 A circuits for the bench equipment. The equipment under test shall have its own circuit as well.
Think they would miss one of those newer Agilent scopes?
-Chris
Totally agree. Those crazy money scopes are really useful, but you are correct that they need to be properly set up first. Operating an oscilloscope requires a skill that people will develop as they use them and have to deal with problems. Never having a problem means never learning to the extent that you can by experimenting.
Like you, I will always keep a couple analogue scopes around, and I do enough so that when I have one on the bench, I miss the other one. New bench will solve that problem.
For your lab, consider using power bars where you can. I have the same issue that you do, but not to that extent. I am considering installing two 15 A circuits for the bench equipment. The equipment under test shall have its own circuit as well.
Think they would miss one of those newer Agilent scopes?
-Chris
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