Pintek DP-60HS differential probe (low-voltage, high-sensitivity, 60 MHz BW) - Page 1
Forum section: electronics / testgear

author: pascal_sweden
author_rank: Super Contributor
timestamp: July 25, 2016, 09:52:36 am
content: Several months ago I contacted Pintek and asked them to design a new differential probe with specific characteristics: a low-voltage (65V) high-sensitivity (1mVrms) differential probe that works nicely together with the upgraded Rigol DS1054Z (100 MHz BW).The idea was that it would give hobbyists the chance to turn their upgraded Rigol DS1054Z into a fully fledged 4-channel 100MHz digital isolated scope, without loosing bandwidthThey actually liked my suggestion, and handed it over as a task to one of their engineers.I followed up with Pintek recently to check on their progress, and they confirmed that the differential probe is ready in the mean time. In attachment are some specifications.While I asked for 100 MHz bandwidth, the final design is limited to 60 MHz. I will come back with more details on that limitation and also a price range, when I get this information from Pintek.For reference:My original email to Pintek:"Hello,I read more information about the DP-30HS differential probe.Really nice feature set.Only a pity that you don't have the low voltage (65V) high sensitivity (1mVrms) differential probe in 100MHz version. If you would have 4 of those differential probes, you could turn an upgraded Rigol DS1054Z into a fully-fledged 4-channel 100MHz digital isolated scopeThis would be a unique piece of equipment!Why does high bandwidth (100 MHz) always go hand in hand with high voltages (+1KV)?Do you see my point about low voltage, high speed differential probe with 100 MHz?It could turn every hobbyist's 100 MHz scope into an isolated scope, without loosing bandwidth. Hobbyists working on digital design projects, need the bandwidth, and at same time can make mistakes when measuring in their circuits. So I believe it makes sense.Regards,Pascal"The feedback from Pintek:"Dear Pascal,Thank you for your e-mail.I have passed your info to our engineer.We will develop a new model of different probe.The spec is:Bandwidth: 100MHz,Voltage: 65VSensitivity: 1mVrmsBy the way, can you please let me know your location? In Europe? Or US?Thank you"

author: technogeeky
author_rank: Frequent Contributor
timestamp: July 25, 2016, 01:54:14 pm
content: Good to see a company listening to their customers!Here is the closest, current product:Pintek DP-30HSThis looks to be about $225 to $250, so I'd guess $250 to $300 for this new one.Too expensive for me, but still a step in the right direction.

author: setu
author_rank: Newbie
timestamp: February 27, 2017, 09:40:04 am
content: Hello, how/where does one buy this particular probe in the US? Thanks

author: alank2
author_rank: Super Contributor
timestamp: May 12, 2017, 04:52:35 pm
content: Did this probe ever get released? If so, where is it available for sale?

author: pascal_sweden
author_rank: Super Contributor
timestamp: May 12, 2017, 09:06:00 pm
content: Yes, it has been released in the mean time.www.pintek.com.tw/product_detail/landersound/index.php?Product_SN=224408&Company_SN=6002&Product_Site_Classify_SN=17072You can buy directly from Pintek. Or check with them for a local distributor in your area.

author: David Hess
author_rank: Super Contributor
timestamp: May 13, 2017, 11:02:56 am
content: I was going to say that 1mV sensitivity is too good to be true over that bandwidth and input voltage range unless they used a high voltage input cascode (1) which none of these do and the specifications agree.The specifications list the bandwidth at x1 as 15 MHz (limited to reduce noise?) and the input voltage range as +/-3.5 volts. The input voltage range is limited because of the low common mode range of the amplifier and an input divider would multiply the noise level limiting the practical sensitivity.On the other hand, it is almost an order of magnitude less expensive than a 1mV 100MHz +/-10 volt design with an input noise of 250uVrms.(1) And even that would not quite be enough. The best example I know of (currently produced by LeCroy) could implement an input voltage range of +/-40 volts but would require an input divider and amplifiers like this are difficult to design and manufacture; they tend to become VHF oscillators.

author: IDEngineer
author_rank: Super Contributor
timestamp: October 13, 2017, 09:48:46 pm
content: I ended up ordering the DP-60HS through a company called "Global Media Pro" out of New Zealand. None of Pintek's US sources carry it, though Cal Test may start after I directed their attention to it and the unique place it holds in the market for small signal development work (as opposed to the usual high voltage isolation). I was a little squeamish about ordering from a company that I'd never heard of, and doesn't appear to be a test equipment vendor most of the time. but an email exchange with Pintek in Taiwan confirmed GMP is an authorized distributor so I went to my bank and wired them USD 352.00 (including USD 46.00 in shipping).Literally overnight, I got my order confirmation. Later that day, I got my tracking number. The tracking number worked in Taiwan's postal service website, and then amazingly it worked in the USPS website too. They estimated 4-5 business days for delivery and that's exactly how it turned out. I'm very happy with GMP and would order from them again without hesitation, unless Cal Test brings in the DP-60HS on their own.The DP-60HS was nicely boxed for shipment. It does not have an option to run on a battery, so it includes a dedicated 9V wall wart power supply. It also includes two banana plug test leads and two sets of tips for them. One set is a huge and lengthy dual-jaw grabber style pair, and the other is a huge set of alligator clips. I think they just include the typical tips they use for their high voltage units because it's unlikely I'd use these for anything this probe would measure. For my first tests, I used a set of micrograbber-to-bananas which worked perfectly. They also include a short BNC-BNC cable to connect the probe to your scope.The probe is mind-numbingly simple to use. It has only a single four position control, Off/x10/x5/x1, which serves as both the power and range switches. It has an LED to indicate power and another to indicate overrange. That's it. And frankly that's enough, because you don't really need a whole lot more even on an active probe. What you're after is on the scope screen.I'm working on a lot of galvanically isolated stuff right now, plus a bunch of capacitor charging applications, so this probe looked perfect for those jobs. I've needed a diff probe many times in the past but the cost was always a deterrent; but now it's almost a necessity and finally finding one that had a x1 range tipped me over. Besides, who doesn't like new toys once in a while?First up, I did a diff measurement of the grounds on opposite sides of a galvanically isolated power supply that is on the bench. This revealed some interesting things that weren't visible with our traditional grounded scope probes, such as the amount of differential 60Hz they're picking up and the amount of switching power supply noise that is there when a grounded probe isn't connected (read: under normal operating conditions!). We suddenly have some possible answers to some things we've been seeing, AND some ideas about how to address them. Worth it right there.Next, I tried measuring the floating/isolated supply within one of our breadboards. This worked perfectly too, and frankly gave a lot more visibility to some things we knew were there but never could quite see very well.During this process I also discovered something I had never needed before: My Rigol DS4000 series scope has a whole suite of native probe ratios, happily including the oddball 5x middle range of the DP-60HS. I was a little concerned about all the mental gymnastics I'd have to be doing, but instead I just dialed in the 5x range on the Rigol when I was using it on the diff probe and everything read natively on the screen. So I'm lazy... it's one less thing, you know.Then I tried the killer test: Measuring a very small cap that is used for timing purposes within one of our circuits. We charge and discharge this cap on a regular basis, about every 500mS. Actually seeing what this charging waveform looks like is something we've always needed to do, but a grounded scope probe cannot work because its ground has too much effect on the circuit. This yielded some extremely odd results. Initially, when the diff probe was connected, the circuit's operation was utterly unaffected (first time ever!) but the display on the scope screen was unreadable; all sorts of square waves and other artifacts that, if they were actually there, would render the circuit inoperable.But then came the really weird part: After leaving the DP-60HS connected for more than about 30 seconds, the charging voltage started drooping, until the circuit saturated and stopped working. This looked exactly like the probe had added a bunch of capacitance to the circuit, and that capacitance had finally saturated. But what was going on during that first ~30 seconds? Disconnecting the probe instantly restored normal operation, and leaving it connected for less than ~30 seconds had no effect. But then the effect ramped up and killed off the circuit. This is 100% repeatable and occurs on all ranges of the probe.Granted this is a high impedance environment (constant current charging a cap to obtain a linear ramp) working into a very small capacitance. But why the ~30 second delay? More investigation is needed for sure.One other unexpected artifact: Isolation power supplies have a figure of merit called "isolation capacitance" that is a measurement of the effective capacitance across the galvanic isolation barrier. One reason for the diff probe was because connecting a normal probe to the isolated circuitry would result in an effective increase in the isolation capacitance, yielding a net reduction in the AC isolation (greater capacitance = lower AC reactance). Our expectation was that a fully isolated, fully differential probe would eliminate this effect because no ground reference could exist.To my complete surprise, unfortunately, the diff probe still causes the effect! Connecting even ONE (either one!) of the leads of the diff probe to the isolated circuit instantly generates the effective increase in isolation capacitance (i.e. less isolation). I am at an utter loss to explain this, but I'm on the hunt. First clue: Disconnecting the BNC cable to the scope (and its earth ground reference) eliminates the effect, which strongly suggests the probe isn't as "isolated" as one would expect.The typical way to build probes like this is to use a differential or instrumentation amp so the inputs aren't directly related to ground. However, if you're doing a pure differential measurement there is often not a path for the amplifier input bias current, so you're forced to use a high value resistor to either ground or the supply rail so the input bias current has a path. (It's always bothered me that this basically violates the very isolation and high input impedance that you're usually looking for when using an in-amp.) In the case of probes, you also often want a known and predictable input impedance and a fixed resistor would yield that as well.If they did indeed employ bias current resistors, and those tie to the same ground as the BNC heading out to the scope, that would exactly explain the behavior I'm seeing. Substituting an actual discrete 1M resistor, I can duplicate almost exactly the effect of connecting this diff probe. The next step will be to crack the case open and see if I can reverse engineer what they did at their input stage.A future step may be to design up a TRULY isolated differential probe. Getting DC response poses a challenge; one way would be to have an A/D front end and optocouple the data stream across the isolation barrier, such that there is absolutely positively ZERO galvanic connection from front to back. Sigh... another project for another day.I'll continue to post as we gain experience with the DP-60HS. So far it works well in most of the applications we intended for it. Granted some of our stuff is a little esoteric so I might be a bit harsh in my expectations, but when I think "differential" I think "utterly unreferenced" or "truly floating". Apparently that's not necessarily the case.

author: CustomEngineerer
author_rank: Frequent Contributor
timestamp: October 14, 2017, 12:38:36 am
content: Pretty sure the user manual explains exactly that.Also, Dave explains the isolation (or lack thereof) in #932:https://www.eevblog.com/2016/10/11/eevblog-932-how-does-a-hv-differential-probe-work/

author: CustomEngineerer
author_rank: Frequent Contributor
timestamp: October 14, 2017, 12:40:37 am
content: Wanted to add, thank you for sharing your experience with the probe. Please continue to share as you use it more. Definitely looks interesting.

author: David Hess
author_rank: Super Contributor
timestamp: October 14, 2017, 01:52:19 am
content: Quote from: IDEngineer on October 13, 2017, 09:48:46 pmUsing a differential probe to measure galvanically isolated stuff? Ah oh, I know where this is going.QuoteDifferential probes have *three* connections whether the third connection is made available to the user or not. The third connection is ground and it is *required* for the differential probe to operate correctly. For probes that lack the ground connection at the probe tip, there is even a warning not to use them with isolated oscilloscope inputs. Without the ground, the probe's common mode input voltage will drift around and possibly be exceeded or worse.QuoteHigh voltage differential probes include input dividers. Low voltage differential probes might not but have a much more limited common mode input range.Without the common mode input resistance, the bias current from the amplifier inputs still needs to go somewhere. Some old differential probes have a switch to disconnect the input terminations so only the input bias currents are present and the input resistance becomes that of the high impedance input amplifiers which will typically be gigaohms or higher.QuoteSome oscilloscopes have galvanically isolated inputs which work exactly the way you describe. Galvanically isolated single ended probes are also possible like the old 20 MHz Tektronix A6902.Two single ended galvanically isolated probes can be combined to make a differential measurement. Or a differential probe could be used with a galvanically isolated oscilloscope input *if* the differential ground is attached to the circuit.

author: IDEngineer
author_rank: Super Contributor
timestamp: October 14, 2017, 02:29:22 pm
content: Quote from: CustomEngineerer on October 14, 2017, 12:38:36 amHmm, you're exactly right. And I missed that ground reference (if you'll pardon the pun!) when reviewing the user manual prior to purchase. My fault.

author: IDEngineer
author_rank: Super Contributor
timestamp: October 14, 2017, 03:29:09 pm
content: Quote from: David Hess on October 14, 2017, 01:52:19 amYes, certainly the front end of a diff probe has something it considers "ground" (for this discussion, I'll refer to that as "common"). But in an isolated probe, common and ground are and must be separate things.In this case, now that it's clear (to me!) this isn't an isolated probe, some of the behavior is explained. But with respect to common mode input voltage causing the "saturation" behavior, I'm not sure that's the explanation.In the circuit in question, charging a small capacitance with a constant current (read: high impedance) source brings with it the very likely possibility of spurious charges building up on the cap. So, when the timing circuit is not in use, we actively short both sides of the cap to common (continuing the use of that term for a "ground" in the isolated portion of the system).Some hard numbers: We charge for ~28uS, and the A/D conversion time is ~14uS. Outside of this ~42uS period, the two sides of the cap are connected to common by ultra-low impedance paths. We perform this measurement every 500mS, so the cap is shorted (42E-06 / 500E-03 =) well over 99% of the time. When the diff probe is connected across this cap, its leads are also shorted >99% of the time. Thus it is unlikely that residual charge is building up *across* the diff probe leads over a time period measured in 10's of seconds. (I realize you didn't suggest that, I'm just covering all the bases.)As for common mode voltage, that's certainly a possibility. Except in this case, both sides of the cap - and thus both sides of the diff probe - are within the isolated subsystem. So while technically they could be offset by any amount from the diff probe's common, without a return path such an offset is meaningless. There has to be a return path for a voltage potential to exist.Stated another way: Say we short the diff probe's leads together, then touch them to one terminal on a 12V battery. The other terminal is not connected to anything. Does the probe "see" 12V of common mode? I would argue no, because there is no return path to the other battery terminal. The battery is isolated, and its "12V potential" only exists relative to the other terminal. Likewise this isolated subsystem... it can have various potentials within it, but if the two points to which the diff probe's leads are connected are themselves shorted by a low impedance path, then the diff probe only has a single connection.Let's take this thought experiment one step further. Let's take another 12V battery and connect its positive terminal to the first battery's negative terminal. Now, measured relative to the second battery's negative terminal, the first battery has an offset of 12V. If we considered the second battery's negative terminal to be "ground", then the first battery has a common mode voltage of 12V; its own 12V has a separate, 12V bias (i.e. the first battery's positive terminal is at 24V relative to the second battery's negative terminal). But that's only relative to the second battery. What will the diff probe see if we connect its shorted leads to just one terminal (either one) of the first battery? Will it experience 12VDC of common mode voltage? I would argue no. It has no reference to the negative terminal of the second battery, so it does not experience the common mode offset.Then: What will the diff probe see if we separate its leads and connect them to the two terminals of the first battery? Referenced to the negative terminal of the second battery, the first battery's terminals have 12V of potential with a common mode offset of 12V. You and I, visually looking at the setup, would "feel" like the first battery's terminals are at 12V and 24V. But the diff probe has no return path to that negative terminal; all it sees is what appears between its two leads. And the potential between its two leads - the potential across the first battery - is 12V.Again, I agree that the non-isolated diff probe has a common rail, and my own experiments have confirmed that common rail is connected to the ground on the BNC back to the scope, and that scope's BNC grounds are connected to earth ground. But if that common/BNC/scope/earth ground is isolated from the circuit under test, then anything the leads of the diff probe see within such an isolated circuit is just like them being connected across a battery sitting on the bench: All they see is the potential across the leads, because any common mode that may exist doesn't have a return path that is connected to the diff probe.If I've got this all wrong (and I might!), I'd appreciate an explanation. Thanks!

author: David Hess
author_rank: Super Contributor
timestamp: October 14, 2017, 06:57:29 pm
content: Depending on exactly how the input protect is arranged on a low voltage differential probe, if the common mode range is exceeded, then the input protection diodes will have the effect of shorting the inputs together through an offset voltage referenced to the probe common. Usually this will be through a parallel RC protection circuit in series with each input (470k and 1000pF is typical) which limits the current while providing a low AC impedance. On a high voltage differential probe, the inputs will be shorted together after the input attenuators.Your description of everything working for 10s of seconds sure sounds like the common mode capacitance across an isolation barrier is being charged while the probe is connected until the common mode input range of the probe is exceeded.

author: IDEngineer
author_rank: Super Contributor
timestamp: October 15, 2017, 01:48:35 am
content: Quote from: David Hess on October 14, 2017, 06:57:29 pmAgreed. The question is, how does the probe common get that reference? If the only two connections it has to a truly isolated circuit are its input leads, then probe common can't be the other reference.This is similar to why a bird sitting on a multi-kilovolt power line doesn't become an LEB (Light Emitting Bird). Its two feet (read: probes) are together raised to a huge "common mode" voltage, but because its body (read: common) has no connection to anything else associated with the power line, it doesn't experience any common mode voltage. Without another reference point, there can be no *difference* in potential. Unless the probe's common is connected to something related to the isolated circuit, there is no common mode voltage - just the difference across its two probes.QuoteI absolutely agree, yet based on the above thought experiment I don't yet understand how the probe can be seeing a common mode potential. More investigation is required!

author: IDEngineer
author_rank: Super Contributor
timestamp: October 15, 2017, 07:39:50 pm
content: Quote from: IDEngineer on October 15, 2017, 01:48:35 amAn update....During all of the initial testing, I moved the power input to a couple of different supplies. The most recent one, and where I'd left the power leads, is a nice big analog power supply. As noted in our discussions above, there pretty much had to be a return path for the diff probe's internal common back to ground, I had a hunch... and sure enough, this supply does not isolate its negative side.So I switched the power back to the new Instek GPE-4323 that claims in its documentation to be isolated, and (more importantly) that I have personally confirmed IS isolated. Voila - problem solved. The return path that the diff probe's common found back through the BNC cable, scope, earth ground, power supply, and then the negative side of the supply has been eliminated.The probe has now been running for 30+ minutes without saturating as before. An interesting side note is that, since this measurement is taking place within the isolated section of the circuitry, the capacitance that was being charged is likely the isolation capacitance of the DC-DC isolation module (spec'd at ~10pF nominal). This proves that a non-isolated differential probe can be used on isolated circuitry if you're excruciatingly careful about return paths to the probe's internal common.There's still work to do. Connecting the diff probe adds a significant percentage to the capacitance being measured so it strongly affects the circuit behavior; some firmware mods may be able to accommodate that. And the diff probe is still picking up a source of square wave noise, not surprising since a constant current source is a high impedance circuit and thus very susceptible to noise. At this point in getting familiar with the diff probe I'm just using a pair of ~12in long banana-to-micrograbber test leads, which I'm sure are excellent antennas. Despite my careful routing, those leads are also probably contributing to the parasitic capacitance.I need to figure out a way to dramatically shorten the connection to the diff probe. I'd love to use short shielded wires, or even a pair of 1x scope probes with their shields tied to the diff probe's internal common, but I'm concerned that will add more parasitic capacitance. IIRC Tektronix made/makes a diff probe that has a very short pair of fixed probe tips coming out of its handheld enclosure. I might try to duplicate that with a pair of bare banana plugs and short solid wires.In any case, my conclusion so far is that the DP-60HS can in fact be used on isolated circuits IF its BNC ground is isolated at some point from the ground feeding into the circuit under test. That could happen with an isolated oscilloscope (my old Phillips PM3214 has isolated inputs), or as in this case at the DC power supply. Going forward my problems appear to be parasitic capacitance and noise, very traditional problems with lots of ways to attack them.I'll update as I learn more.Edit: The Tek probe is the old P6046, its inputs look like this, literally on the end of the probe body. I used one of these long ago but had forgotten the specifics. I'm going to experiment with duplicating this arrangement on the DP-60HS.

author: David Hess
author_rank: Super Contributor
timestamp: October 15, 2017, 09:35:40 pm
content: What I have sometimes done in the past with circuits where it is difficult to attach a probe without affecting the circuit is to build essentially the front end of the probe into the circuit to drive a test point. Something like a pair of bipolar or FET buffers can work into the 100s of MHz or simple operational amplifier followers for DC precision at lower frequencies.For power supplies, the built in test circuit might involve something like a wide bandwidth high side current sense circuit with a transconductance output driving a low side termination resistance to take the place of an AC/DC current probe.

author: IDEngineer
author_rank: Super Contributor
timestamp: October 15, 2017, 09:53:47 pm
content: Quote from: David Hess on October 15, 2017, 09:35:40 pmYou're a mind reader! I've already spec'd in a dual FET opamp for the prototype PCB's, for a low leakage front end that has a nice low impedance output to drive test equipment. Then we can selectively populate it for development vs. production, or remove the artwork if the real estate is needed for other purposes. I included opamps in an earlier breadboard and the concept worked extremely well. This breadboard is more focused on the isolation aspect of things and adding the opamps would be inconvenient; I'd have to build another breadboard with both isolation and opamps. We're close enough to PCB layout that I'm going to wait for that.In the meantime, I have this breadboard on the bench and it would be nice to use the diff probe with it, so I'm going to proceed with the Rube Goldberg "banana tip" probe idea and see where that, ahem, "leads". I expect improvement, but not perfection. Worst case I gain more experience with the diff probe.

author: IDEngineer
author_rank: Super Contributor
timestamp: November 04, 2017, 04:11:36 am
content: Just checking in with some observations after a couple of weeks of experience with the DP-60HS.Short version: I love having a diff probe. I have learned so much in such a short time, it's amazing.Longer version: First, the "banana leads" work great. I purchased a few sets of banana plug tips from DigiKey. They have screws on the back that make it easy to add short wires clipped from resistor leads. These short wires can be carefully attached to the circuit in question. While the bulk and weight of the diff probe body makes for some unwieldy positioning, you get nice clean signals that are entirely isolated from ground (as long as you're careful to insure no other connections to a common ground exist, as discussed elsewhere in this thread).And wow, those signals reveal a lot. I know all the theory about scope ground leads, removing them for sensitive measurements, etc. What I didn't realize until now was the effect of having an earth ground reference (from the scope probe ground) applied directly to the circuit being evaluated. It's amazing. Way more effect than I ever realized. It's almost entertaining... I find myself thinking "I wonder what THAT signal *really* looks like" and probing all sorts of stuff I thought we understood. Boy, did some uglies crawl out from under the rocks!As just one example, we have a measurement circuit that has long had a weird sort of variability to it in the real world. Connecting up a traditional (grounded) scope probe shows nothing... all is well, signals as we'd expect them, etc. But with the (isolated) diff probe, suddenly it all made sense because it turns out we're picking up some nasty square waves from elsewhere in the system! Depending upon when the measurement is taken, that square wave introduces variability - and we've never been able to see it before.Of course, the very next thing we did was to leave the diff probe hooked up and connect a traditional scope probe to it too. Voila - the superimposed square wave disappeared, because now this circuit had a ground reference from the traditional scope probe. You could see everything happen on the diff probe's trace. This allowed us to correct for the noise problem, a problem we didn't even understand before. Couldn't even SEE before, because the traditional (grounded) probe was hiding the problem.Keep in mind, this specific diff probe is intended for small signal work - unlike most diff probes which are intended for high voltage isolation. This one has x1/x5/x10 ranges whereas many start at x100 and sometimes go to x1000! Your typical diff probe won't necessarily reveal the stuff we're seeing with this "high sensitivity" (hence its HS suffix) diff probe. You need the correct tool for the job.As I said, it's almost not work anymore to use the diff probe. It's fun to connect it to things and see how they differ from what we thought, expected, or had seen with a traditional grounded probe. I wouldn't be surprised to find another one (or three, one for each of four channels!) around here soon. I'm almost to the point that I don't trust what I see on the scope unless it was measured with the diff probe.Highly, highly recommended.

author: David Hess
author_rank: Super Contributor
timestamp: November 06, 2017, 05:06:23 am
content: Now you know why I am so attached to my Tektronix 7A13 and 7A22 differential amplifiers.

author: IDEngineer
author_rank: Super Contributor
timestamp: November 06, 2017, 05:50:18 pm
content: Indeed... a Tek mainframe with a good selection of properly functioning modules is a very nice thing to have.Long ago I had one of those TM500(?) series standalone mainframes with a few specialized modules in it, feeding into the standalone scope it sat next to. My favorite module was the current probe amp, which connected to one of their clamp-around probes. It measured low currents with pretty wide bandwidth. I wish I could have taken that mainframe with me when I left the company, I suspect no one else there knew what it was or how to use anything in it.

author: tautech
author_rank: Super Contributor
timestamp: November 06, 2017, 06:07:35 pm
content: Quote from: IDEngineer on November 06, 2017, 05:50:18 pmThe Tek 134 current probe amp is a reasonable substitute if you have P6021/6022 probes although the probe terminator is better as you don't need 50 ohm inputs in your scope like with a 134.

author: David Hess
author_rank: Super Contributor
timestamp: November 08, 2017, 03:11:53 am
content: Quote from: tautech on November 06, 2017, 06:07:35 pmI have the 134 and P6021.

author: tautech
author_rank: Super Contributor
timestamp: November 08, 2017, 04:17:54 am
content: Quote from: David Hess on November 08, 2017, 03:11:53 amI suspected you would.I've got two of themone with a 134 and the other with the switchable BNC terminator.My 134 came with a 110V PSU but member whitevamp found some 230V Tek PSU's so I grabbed one.They're an excellent AC current probe.

author: kwinz
author_rank: Newbie
timestamp: January 16, 2021, 02:20:43 pm
content: One of the first search results for "Pintek DP-60HS"gives a seller stating that the DP-60HS is "discontinued":https://www.globalmediapro.com/dp/A2LQM4/Pintek-DP-60HS-Differential-Probe-60MHz-70V/Is this still being manufactured? Anything wrong with this probe or is this just this one seller?Thanks!

author: IDEngineer
author_rank: Super Contributor
timestamp: January 16, 2021, 06:50:49 pm
content: Quote from: kwinz on January 16, 2021, 02:20:43 pmI'm not sure what "discontinued" means in this context, but I have one of those probes and GlobalMediaPro is where I bought it. They appear to be one of the few companies that will (did?) ship that probe to the USA.I always thought it was a weird product for them to carry, since their emphasis appears to be professional video and lighting. How many roadies do you know that would have a need for a diffprobe? I was a bit worried when I sent the wire transfer, but good as gold the probe arrived in a timely fashion and is sitting here on my bench as I type this. It has gotten me out of several difficult R&D situations so far and I'm very happy to have it.I wish there were more sources for low(er) voltage, high bandwidth diffprobes. Most of them target high voltage applications but there are lots of uses/needs for small signal probes. I do have a Tek P6247 too but it needs work and I've only done about half of the repair work so the Pintek has been carrying the load in the meantime. Besides, the cost difference between a Pintek and a Tek/HPAK is literally at least one order of magnitude and you don't always need the kind of performance that extra money can buy.If you find an alternative source for the DP-60HS please post it. I actually had a discussion with folks at Pintek about expanding their distribution of this probe in the USA and at that time they seemed very interested, but I don't know if that went anywhere.

author: Zlotnik
author_rank: Regular Contributor
timestamp: May 17, 2021, 03:09:08 pm
content: I was researching getting an affordable low voltage differential probe and stumbled over this thread. Interesting option! FWIW eleshop.eu carries the DP60-HS, but states "Please ask for lead time"...If it proves hard to actually get one, I found Testec have a similar probe:TT-SI-7005Only 15MHz @1x instead of 30MHz@1x as the DP60-HS, but otherwise almost identical specs. TT-SI-7005 noise is spec'ed at 2mVrms instead of the 1mVrms mentioned in this thread, but I did not actually see the 1mVrms in theDP60-HS specs, and some doubted it's realistic, so I'd call this a tie unless someone posts test results.The Testec capacitance is a bit lower than the Pintek one (2.5pF vs 10pF differential, 6pF vs 20pF to ground) which starts to play a role towards the upper end of the bandwidth but may not be a huge advantage depending on the application. The DC impedance is spec'ed identical as 1M differential / 0.5M to ground. Input range / output swing is identical.The TT-SI-7005 is easily available here in Europe, eg Batronix, Reichelt or Conrad seem to have it in stock. Price is about comparable to the eleshop.eu price of the DP60-HS.

author: leowood
author_rank: Newbie
timestamp: July 19, 2023, 12:58:07 pm
content: I just post a noise floor comparison between micsig DP10007 and this Pintech DP-60HSI am very satisfy the noise performance of Pintech,However the price of Pintech is crazy, 4 times higher than DP10007here is linkalso I attached the screenshot hereDP10007 1:10 VS DP-60HS 1:10alsoDP10007 1:10 VS DP=60HS 1:1

author: leowood
author_rank: Newbie
timestamp: July 19, 2023, 01:07:17 pm
content: below I set the input impedance from 1M to 50ohmthe noise looks like1:10 Pintech DP-60HS VS 1:10 Micsig 100071:1 Pintech DP-60HS VS 1:10 Miscig 10007

author: David Hess
author_rank: Super Contributor
timestamp: July 20, 2023, 08:48:12 am
content: The Micsig has a lot more noise because it is a high voltage differential probe with more input attenuation and the Pintek is an allegedly low voltage differential probe with less input attenuation. In order to meet their common mode input voltage specifications, they first attenuate and then apply differential gain to achieve the required differential sensitivity. The more they attenuate the input signal, the more differential gain is required and the higher their noise is.I do not really consider the Pintek to be a low voltage differential probe because it has input attenuation. It still has a lot more noise than a true low voltage differential probe, which would have noise in the 50 to 200 microvolt range.