We know that a 10 Mhz Ref input is not that common - that’s why some users would like to see it become more common
Could you (and/or other posters) provide some scenarios where you would find a ref in to be be helpful / necessary when using an "entry level" scope? How much extra would you be willing to pay - in absolute dollars or as a percent of base scope price - for a ref in? And would this need to be a dedicated connector or would it be acceptable to share the ref in connector with other functions (like trigger in)?
I can ask our scopes product manager about this, but I'm curious to get feedback from the forum as well. Thanks!
Thanks for the questions. And Thank You Very Much for the beautiful educational material you produce. I appreciate both the outstanding information you provide and the way in which you ask for and encourage user feedback.
As a preface, my scenarios regarding the 10 MHz Ref input feature are much more likely to be in vicinity of the “helpful” category than in the “necessary” category. Reason being is that my scenarios are based on want rather than need. Reason being is that I’m an electrical enthusiast (“Electro Fan”) vs an Electrical Engineering pro. Fwiw, though, I’m VERY enthusiastic about electro things (both analog and digital). I think my electro enthusiasm virus was fed and fueled by reading tens of thousands of EEVblog posts and writing over a thousand. Having said all that, I get that any one user is just a datapoint, which might or might not be indicative of an addressable marketplace.
Regarding the “market”: if you look at the EEVblog member stats and sort by posts, I might be an “early adopter” at least in terms of enthusiasm if posts are any indication. My post numbers get me to the first page of 1,000 members, but there are 64 more pages of forum members (ie, ~64,000 members). If you go to page 32 you find that the median post per member is about 3. And my guess is that there are many more people out there beyond the current 64k who are also interested in figuring out what’s what, and what causes what, and how to learn and how to get involved at the intersections of electricity and the future.
So I realize it’s sometimes hard to know what the needs and wants are for a marketplace, even if a manufacturer tries to survey the market. One of the reasons that uncovering new market needs and wants can be difficult is that some potential users don’t know what’s available or possible, or even if they do, why something might or might not have value, or how much value it might offer. If we would have asked people in 1900 what their scenarios would be for air travel they might have said “limited” – both the enthusiasts and the pros too.
What all that means is 1) I’m just an enthusiast and not a pro EE, 2) we (I) don’t know for sure what the distribution is here between pros and enthusiasts, and 3) we (I) don’t know if my interests are representative of any other enthusiasts, much less the pros. I get it.
Nonetheless, I would say that I am HIGHLY enthusiastic about the 10 MHz Ref input feature. While I don’t “need” almost any of the test equipment that seems to have taken over my “lab” one of the “system” features/functions that that I find most interesting and compelling is the 10 MHz Ref capability.
As a frame of reference, among the approximately 4 oscilloscopes, 3 signal generators, 3 power supplies, 3 counters, 1 spectrum analyzer, 2 GPSDOs, and dozen plus DMMs that have found their way onto my bench, the 10 MHz Ref capability that connects a GPSDO to a distribution amplifier to 2 counters, the Spec An, and 1 oscilloscope is among the functions that gives me the most “enjoyment.” (I have no clue about how to measure enjoyment - but I’m certain I would get even more enjoyment out of the overall investment of time, money, and space if all or most of the other pieces of test equipment on the bench also had 10 MHz Ref inputs.)
One way I look at all this is that there is an iterative process in learning and science (hypothesize, test/measure, repeat). Of course, what all the gear does is enable me to measure stuff including frequency, amplitude, and phase. The oscilloscope being the “king” of TE is particularly cool because (along with the spectrum analyzer) it gives a wonderful visual insight to signal properties in addition to quantifying them with measured numeric values. What does the oscilloscope measure and enable me to visualize? In my mind, near the top of the list is frequency – which is pretty much related to phase and amplitude. Frequency is arguably (at least metaphorically) the heartbeat of “waves”. So why wouldn’t I be interested in measuring frequency with as much accuracy as possible? And while accuracy is different than resolution, more resolution might be nice too. Of course, there are skeptics who will say “do you really need resolution?”, and “you do know, don’t you, that more resolution does not mean more accuracy, right?” and “btw, how much accuracy do you really need?” And “if you need to measure voltage (amplitude) or maybe even frequency with high accuracy and high resolution the oscilloscope is the wrong tool.” To which I would say “really?” and to which I would further say “sure is interesting how much user engagement the TE forum is getting these days with the introduction and adoption of “HD” oscilloscopes.” Why do we care about “HD” and moving from 8 bits to 12 bits if we don’t care about accuracy and resolution?
So maybe the question (“why would anyone want a Ref input?”) shouldn't be directed at or limited by this or that specific use case. Rather, the question might be better asked “why would anyone not want a 10 MHz Ref input?” Of course this leads to questions about NRE, COGS, and price.
Apparently, we could add a high performance reference in each piece of equipment. According to one of the links above we could do it for about $1199. (Such a deal.) Maybe if it wasn’t designed as an add-in and it was incorporated from the get-go we could get it down to some lower price per unit. But at the end of the day a user would need to multiply the incremental price increase times the number of pieces of test equipment adding a reference quality oscillator.
Or, we could put one high quality reference oscillator on the bench in the form of a GPSDO and then drive maybe 6-8 pieces of equipment. With a ~$200 double oven GPSDO and a ~$100 distribution amplifier and some pretty inexpensive coax cables we could provide relatively higher accuracy to 6-8 pieces of equipment. And btw, all those pieces of equipment would know what time it is in the rest of the world, AND they would all measure pretty much in unison. True, they might all be off by some amount, but to a very great extent they would be off by the same amount. Would you rather have one yardstick that is off by a little, or 8 yardsticks that are all off by differing amounts? Which would be more useful? Of course you would prefer to have one clock that is accurate vs several that are less accurate and that vary from one to another.
So the only real question left is how much NRE and COGS is it going to take for Siglent or R&S or X, Y, and Z to add a 10 MHz Ref input? Once we know that we can get some idea of how much it will increase the price of a unit of Test Equipment. As pointed out earlier in this thread we have under $400 signal generators that manage to include a 10 MHz Ref input (and a 10 MHz Ref output capability). So I think by the time it’s all said and done, the price impact on a $400-$500 oscilloscope is going to be in the realm of “not much.” At which point, for about $300 an enthusiastic user could distribute a GPSDO signal to the oscilloscope and a half a dozen other pieces of equipment.
Maybe some other users here will come up with some specific professional or enthusiast use cases for a 10 MHz ref input, but I think it might be like asking people in about 1920 what would they do with a plane or a car. Back then (ie, still somewhat early in the development of the future marketplace) some people would have had some ideas in mind and some early adopters would have already gained some experience with a plane or a car, but to what extent would the overall feedback been indicative of where the market was headed?
PS, this discussion reminds me a little of the digital camera market, and maybe the CNC market. There is a time in almost every market when people ask “do you really need this feature or that function”? In the photography market some of the pro’s pros would say “nah, if you are a manly man you can get a good photo with what you already have” and “Ansel Adams would tell you that the best camera is the one you have with you” and yada yada. The reality, as we all know, is that the world is not just moving rapidly, but accelerating, fast. And anyone here who doesn’t think there is a market for more accuracy and resolution, and for easily synchronized system-wide interoperability might be missing some opportunities. But hey, I get it, there are manly men who can chop with an axe and only measure with a micrometer as needed. They might have missed the market for CNC machines but with their knowledge, skills, and experience they can still build some beautiful stuff without a CNC machine, no doubt. But I’m betting if they ever did add a CNC machine to their workshop, they might want to hook the CNC machine to a computer, and maybe connect the computer to the Internet. The possibilities are endless – but they often start with frequency, amplitude, and phase – and electricity - which leads to needs and desires for increasing levels of accuracy and resolution to help examine, understand, and manage the ever increasing uses of frequencies and bandwidth.
PSS, it’s just metaphors, I don’t have a CNC machine, or even make much out of wood or metal 😊