hybridfree/eevblog-posts huggingface dataset:
Agilent 34401A switches from ACV to Resistance Measurement - Page 1
Forum section: electronics / testgear

author: ni.st
author_rank: Newbie
timestamp: November 04, 2018, 02:39:34 am
content: I recently bought an Agilent 34401a which shows some strange behavior. Sometimes if I do VAC measurements it changes unexpectedly to Resistance Measurement.It passes the selftest without errors.Does anyone know the reason for this problem?Thanks for your helpNicolas

author: floobydust
author_rank: Super Contributor
timestamp: November 04, 2018, 04:40:57 am
content: The two buttons are next to each other ACV (SW613), 2W ohms (SW614) but different MCU scan lines.So I would suspect the ohms pushbutton sticking/shorting or a solder bridge on the front panel PCB. Try gently pushing and tapping to see if the ohms button is shorting.I take these apart and clean up the front panels, toss the keypad in dishsoap and water to clean it up.Sometimes I find something was spilt inside, or loose strand of copper wire got in.

author: ni.st
author_rank: Newbie
timestamp: November 05, 2018, 11:31:19 pm
content: Thank you for the advice floobydust.I removed the Frontpanel and cleaned everything, but the problem occured again. While measuring DCV, it also switched to 2W ohms after some time.

author: HighVoltage
author_rank: Super Contributor
timestamp: November 05, 2018, 11:51:14 pm
content: Leave the front panel disconnected (Remove the cable ) and try to control the instrument over GPIB or RS232 and see if it still switches to 2W Ohm.

author: ni.st
author_rank: Newbie
timestamp: November 06, 2018, 12:59:41 am
content: I tried what you suggested HighVoltage, but It still switches to 2W Ohm after some time with disconnected ribbon cable and control via RS232.
Krohn-Hite 2200 Function Generator - Page 1
Forum section: electronics / testgear

author: daveyk
author_rank: Frequent Contributor
timestamp: November 02, 2018, 07:31:29 pm
content: Dumpster dived a Krohn-Hite 2200 Generator. After contact cleaning it switches and pots, it seems to work quite nice. If you trigger a single cycle of sinewave, it produces just slightly more than a single cycle. it's not much more, but it does end in with a slightly positive peak after the single cycle.That's probably just how it is. There are a lot of pots in this thing and on that trigger board.I tried looking for a service manual without luck. There may be a calibration for that, or where to end the single triggered cycle.This looks so much nicer than the Wavetek 166 generators I used to use in the 1980s and 1990s. Its sinewave is beautiful and can drive 15 volts in to 50 ohms pretty well. If you set the output attenuation switch and the pot to 1 volt, by goodness, it is darn close to 1VPP!I don't know if I will modify some of my test software to pause and ask the user (me) to set the generator signal rather than being able to control it directly. It would allow equipment versatility while the more modern stuff is out being calibrated. Anyway, it is a cool dumpster find. There was a second one in the dumpster, but I let it there (damn-it) and it's long since been to the re-cyclers. They only go for about $200 on ebay, so it probably is not worth listing.If I'm going to keep it, I am interested in that service manual that appears to made from un-obtainium. lolHopefully, someone on here will have a pdf.Thanks kindly,Dave

author: tautech
author_rank: Super Contributor
timestamp: November 02, 2018, 07:53:59 pm
content: There's enough in this manual for repairs etc:http://www.steampoweredradio.com/pdf/krohn%20hite/krohn%20hite%20model%202200%20lin%20log%20sweep%20generator%20circa%201979.pdf

author: daveyk
author_rank: Frequent Contributor
timestamp: November 05, 2018, 03:29:51 pm
content: Thank you! I couldn't find anything when I binged or googled it. That is fantastic, thank you!

author: daveyk
author_rank: Frequent Contributor
timestamp: November 05, 2018, 03:33:15 pm
content: I pine for the days when manuals like this were produced. Complete schematics and layouts! i have not totally studies yet, but "wow". What can I say, but "Too Cool!!" - lol.
$250 for a Tek 7903? - Page 1
Forum section: electronics / testgear

author: abeyer
author_rank: Frequent Contributor
timestamp: November 04, 2018, 02:29:47 am
content: Given all the caveats about buying an old analog scope...Does $250USD seem like a reasonable deal on a 7903 with what seems like fairly decent modules installed? It's local, so will pay some sales tax, but no insane shipping charges. Seems pretty in line with ebay pricing, but willing to hear opinions.edit: added currency

author: shteii01
author_rank: Frequent Contributor
timestamp: November 04, 2018, 03:03:28 am
content: The R stands for Rack:http://w140.com/tekwiki/wiki/R7903

author: james_s
author_rank: Super Contributor
timestamp: November 04, 2018, 04:29:25 am
content: If it works that seems very reasonable for a 500MHz scope. Typically I figure on about $1/MHz as the going rate for an analog scope in average working condition.

author: Martin.M
author_rank: Frequent Contributor
timestamp: November 04, 2018, 05:04:00 am
content: Oh yes, the 250$ are allready for this setup.For the 7A24 you need 1M probe,for the 7A19 you need 50 Ohm probe.It is the 19" version of the 7904, but only 3 slots, not 4.One of the best 7k, the 500MHz are reality.Later you can look if you need for additional plugins, 7A22 diff is nice, also the 7D14 frequency counter.Known problems : electrolytics in PSU and tantal.greetingsMartin

author: David Hess
author_rank: Super Contributor
timestamp: November 06, 2018, 12:28:17 am
content: The 7A24 is 50 ohms also. The 7A26 was normally the fastest 1M vertical amplifier.Not only is the mainframe 500 MHz but the CRT is unusually sharp and bright making it desirable even at lower bandwidths.The 3 bay R7903 would normally use the 7B92A dual timebase however any of the faster 7000 timebases will work. The older and slower 7000 timebases will still work but cannot display the triggering edge because the vertical delay line in the 400 and 500 MHz 7000 mainframes is not long enough.I bought my 7904 just to get the included 7CT1N curve tracer plug-in but it has become my most used 7000 mainframe.
APPA service manuals - Page 1
Forum section: electronics / testgear

author: 001
author_rank: Super Contributor
timestamp: November 05, 2018, 09:06:03 pm
content: HiI cant find any APPAs schematicsNow I`m looking for APPA 91 service manualCan You help me?

author: coromonadalix
author_rank: Super Contributor
timestamp: November 05, 2018, 11:19:17 pm
content: Why dont you ask Appa directly ?Google fuu gaved nothing for service manuals
Synchronization between two Siglent SDG2122X and SDG1025 - Page 1
Forum section: electronics / testgear

author: Pirapoense
author_rank: Newbie
timestamp: November 04, 2018, 08:56:10 pm
content: Hi All,I am trying to synchronize one Siglent SDG2122X with another Siglent SDG1025 both connected to Rigol MSO1104Z. I am using the clock out of SDG2122X but when selecting the external clock in the SDG1025 both signals from SDG1025 disappears of the scope screen.I guess I am making something wrong and any suggestion/advice will be very appreciated.Regards.

author: rf-loop
author_rank: Super Contributor
timestamp: November 05, 2018, 11:02:21 am
content: Quote from: Pirapoense on November 04, 2018, 08:56:10 pmReason is simple. SDG1000 does not see a valid reference signal.SDG2000X reference clock output level is too low for SDG1000 reference clock input.If SDG1000 Ext Ref is selected and it can not find clock it do not work at all.(you can test it also so that you connect SDG2000X output (Ch1 or 2) to SDG1000 reference input.Set SDG2kX for sine or square and level 5Vpp (do not exceed 6Vpp). Connect it to SDG1k Ref input. Set SDG1000 for Ext Ref. After then you can see SDG1000 works normally. Also you can adjust this 10MHz and you can see how far it follow this reference and you can also test with 10MHz how low level it still can barely sync. Reliable sync need more, just between 5V - 5.5V)SDG2000XserieReference Clock OutputAmplitude2 - 3.3 Vppto HiZ loadOutput impedance50 ΩIs not directly compatible for this:OldSDG1000 serie(not X)Reference Frequency InputLevel need be between5 Vpp - 5.5 VppInput impedance>5kΩ, AC coupling.

author: Pirapoense
author_rank: Newbie
timestamp: November 05, 2018, 07:17:21 pm
content: Quote from: rf-loop on November 05, 2018, 11:02:21 amYou are absolutely right because following the procedure that you suggested I achieved the synchronizatiobn with 10MHz and 5Vpp (minimum is 4Vpp) from SDG2122X.Thank you for sharing your experience and my best regards.
Agilent E44xx ESG series - where is EFC voltage control input? - Page 1
Forum section: electronics / testgear

author: Leo Bodnar
author_rank: Frequent Contributor
timestamp: November 04, 2018, 04:59:50 pm
content: I am using E4435B as a voltage controlled reference source in phase noise test set . Typical set up - DC coupled FM modulation mode with control voltgae fed into Ext.1 input.However, I have found this in the manual:QuoteRelevant part of the service manual shows that internal 10MHz OCXO can be tuned with "EFC CONTROL" voltage, which would be perfect way of injecting PLL steering voltage from the phase noise testset.The question is where is the input port for "EFC CONTROL"? Any ideas?CheersLeo

author: nctnico
author_rank: Super Contributor
timestamp: November 04, 2018, 05:22:25 pm
content: Why aren't you using phase modulation to inject phase noise into the output signal? The advantage is that the base frequency doesn't change. When using FM modulation with DC coupling you'll get a (tiny) frequency offset which may not be what you want.

author: Leo Bodnar
author_rank: Frequent Contributor
timestamp: November 04, 2018, 06:11:58 pm
content: Quote from: nctnico on November 04, 2018, 05:22:25 pmI am tracking quadrature condition in the phase detector, not injecting phase noise.

author: xmo
author_rank: Regular Contributor
timestamp: November 04, 2018, 09:01:12 pm
content: The A11 reference block diagram in the service guide E4400-90335 shows the EFC control input coming from MOD1

author: Leo Bodnar
author_rank: Frequent Contributor
timestamp: November 04, 2018, 09:29:52 pm
content: I can only find MOD1_OPAMP which is, I assume, buffered MOD1 input (EXT 1 INPUT BNC jack on the front panel.)So if this is right, OCXO offset can be controlled by turningEFC Lock = Onand keeping modulation turned off.EXT 1 INPUT needs to be in DC coupling mode as well.

author: xmo
author_rank: Regular Contributor
timestamp: November 05, 2018, 01:33:35 am
content: That would also be my conclusion.

author: Leo Bodnar
author_rank: Frequent Contributor
timestamp: November 05, 2018, 09:54:56 am
content: I have just tried it and it works indeed like expected.ThanksLeo
Agilent MSO 8104A - Page 1
Forum section: electronics / testgear

author: m3
author_rank: Newbie
timestamp: November 04, 2018, 08:07:00 pm
content: Hi,i have a problem with my Agilent MSO 8104A and hope someone here can shed some light into this.My Scope actually died last week. After some general investigations i found that everything except the Scope itself worked fine. Only the agScope V5.71 just crashes everytime so it´s now a very expensive, heavy, loud PC. Beside it´s a bit outdated.After doing a full recovery from the hidden partition agScope (now the older Version 5.10) was able to start again but there are no traces anymore.I am able to access all functions but none them do anything. Knobs on the front also do nothing. LEDs didn´t change.Seems that the whole communication to anything behind the PCI connector is lost but all PCI devices seems to be there and all of them have their drivers loaded.I tried the Keyboard Test but it also fails. I really would like to try the LED Test but this requires a working Keypad, this is genious!Keysight told me that they think the ACQ board is bad but this really confuse me as i could not imagine any reason why the Keyboard Test will fail whith a broken ACQ board.I also tried all the other Tests from the Service Menue but none of them seems to be very helpful. Most of them fail but a few others pass without error.For example the ACQ Register Test will Pass even if i disconnect the Ribbon Cable to the ACQ Board. Don´t know how such a test could help in any way...So the question is how can isolate the problem more further?I have attached a Pic of the PCI devices found on my Scope, hope someone here can confirm that there is no one missing.
Experience with copper alligator clips? - Page 1
Forum section: electronics / testgear

author: thaistatos
author_rank: Contributor
timestamp: November 03, 2018, 09:58:50 am
content: Anyone tried pure copper alligator clips like these:https://de.aliexpress.com/item/10pcs-10A-28mm-Mini-Red-Copper-Alligator-Clip-Cable-Wire-Battery-Crocodile-Clips-Electrical-Clamp-Tester/32700061115.html?spm=a2g0s.8937460.0.0.727c2e0e8yksiLhttps://de.aliexpress.com/item/2pcs-1M-length-13-awg32a-TL335-2-5-square-power-supplier-super-soft-silicone-manostat-alligator/32765990267.html?spm=a2g0s.8937460.0.0.727c2e0e8yksiLhttps://de.aliexpress.com/item/TL337-2-0-square-power-supplier-super-soft-silicone-manostat-alligator-clip-output-line-2pcs-1M/32765620818.html?spm=a2g0s.8937460.0.0.727c2e0e8yksiLI am afraid that there will be oxidation very soon rendering them useless or at least you have to clean them to have good contact. Other probes are usually nickel or gold plated to circumvent these problems.

author: exe
author_rank: Unknown
timestamp: November 04, 2018, 08:28:05 am
content: Doesn't look pure copper to me. More like electroplated. I'd ask seller.Also, not sure about oxidation problem, not about benefits of copper alligator clips. If resistance is a problem just use different type of connection.

author: coromonadalix
author_rank: Super Contributor
timestamp: November 04, 2018, 08:46:37 am
content: Excatly as EXE says, if they are copper they will oxydize, and if you make some shorts they will degrade more, useless to meThe biggest problems with these are the somewhat ''badly crimped'' wires in them, poor contacts, i dismantle them and solder the wire properly.

author: thaistatos
author_rank: Contributor
timestamp: November 04, 2018, 04:29:40 pm
content: The bad connection is my biggest problem on my old one, next to hardened PVC (ageing, exposure to sunlight?) on the clips that makes it impossible to open them.Therefore I was looking for some better quality but I guess you simply have to sort them out after a few years.Next new batch will be opened and soldered, will try to find "normal" clips without copper surface.
What the heck is this device? - Page 1
Forum section: electronics / testgear

author: The_Todd
author_rank: Regular Contributor
timestamp: November 03, 2018, 08:06:41 am
content: Hello guys,I got this at the tip shop, as it piqued my Curiosity. There is absolutely not markings or stickers or anything. The 2 switches on top are 3 position high middle and low. If i put the multimeter in beep mode and hook up the arm swings so I’m guessing its a low amp testing device. However this happes whether there is power or not..... hmmmSent from my iPhone using Tapatalk

author: The_Todd
author_rank: Regular Contributor
timestamp: November 03, 2018, 08:07:48 am
content: PictureSent from my iPhone using Tapatalk

author: RoGeorge
author_rank: Super Contributor
timestamp: November 03, 2018, 08:24:06 am
content: Judging by the Cx and the letter 'p' written on the front panel, it suggests it's a capacimeter.

author: The_Todd
author_rank: Regular Contributor
timestamp: November 03, 2018, 08:37:18 am
content: Quote from: RoGeorge on November 03, 2018, 08:24:06 amWell that would be great, dont have one of those lol. also this looks like its was meant to be mounted on a wall or somthing, not made to sit on the bench at all. Perhaps this is a test device in some bigger device or factory setup?Sent from my iPhone using Tapatalk

author: wraper
author_rank: Unknown
timestamp: November 03, 2018, 08:41:00 am
content: Seems to be capacitance bridge (meter).http://conradhoffman.com/cap_bridge.pdf

author: Chris56000
author_rank: Frequent Contributor
timestamp: November 04, 2018, 01:15:59 am
content: Hi!Look in the September 1976 Issue of the UK's "Practical Television" magazine (free from American Radio History site) and there you'll find construction plans for exactly the sort of instrument you've shown, based on a 555 timer chip!The capacitor is periodically charged and discharged by the 555 and by integrating the area under the voltage – pulses with respect to time over the pulse duration (Vc = 1/C x integral v.dt) the meter will read the average current, which can be shown to be directly proportional to the value of C – a short appendix is provided showing the formulae!Chris Willlams

author: The_Todd
author_rank: Regular Contributor
timestamp: November 04, 2018, 02:41:03 am
content: Quote from: Chris56000 on November 04, 2018, 01:15:59 amWow great find I look this up, thanks again. So what exactly is this thing used for?Sent from my iPhone using Tapatalk
AWG2020 repair - Page 1
Forum section: electronics / testgear

author: analogRF
author_rank: Super Contributor
timestamp: April 06, 2018, 02:03:18 pm
content: I have been working on a defective AWG2020 that I picked up several month ago and I was hoping someone with a working unit could provide me with all or any of the following information. Right now I am getting error 642 which according to the TeK support rep it means "output mult offst adj fail". But besides that, there are a few components that are bad but I have no way of knowing what they are. If someone has a working unit, I will be very grateful if he/she could do me a big favor and have a quick look and measure the following on the analog board A3 (it is right underneath the equipment after the cover is taken out. Easily accessible and exposed)1-Values of resistors R245, R256, R276 (in the middle of the A3 board to the left of U240) I know in-circuit measurement is not conclusive but at least I will know what I should expect.2-markings on Q242 and Q244 and multimeter Diode measurements on their pins? again I know this is in-circuit testing but still a big help if you can report DMM Diode check results on all pin-to-pin tests3-while you are at it, can you please turn the unit on and go to function generator mode and (for example 1MHz sine wave) and measure the DC voltage at TP240 (right next to U240) while you are turning the knob for adjusting the output offset from -2.5V to 2.5V and also the voltage at pin 10 of U300 (output amplitude DAC) while you are changing the output amplitude from 0V to 5Vpp. This is located right above the J410 5 pin connector on the right side of the A3 board. I just need to know the ranges of above two voltages as the offset and amplitude change.I really appreciate your time. I am stuck at this point and asking Tektronix support was not helpful :-(

author: PepaZdepa
author_rank: Contributor
timestamp: November 04, 2018, 12:01:51 am
content: Hi, do you still need the values?
MDO3000 low pass filter - filter out pwm frequency - Page 1
Forum section: electronics / testgear

author: r0d3z1
author_rank: Regular Contributor
timestamp: November 02, 2018, 11:40:18 am
content: Hello, I have an MDO3000 scope and I would like to see the sinusoidal voltage and current of a motor control board. They are obtained with a 20khz pwm and putting the voltage probe between two phases I obviously see the modulated signal (carrier+modulating signal). Is there any function on these scopes series that allow to visualize only the modulating signal ?I need a low pass filter or some other trick that allows me to remove the signal component at PWM frequency.This picture from lecroy shows the function that I am looking forThanks

author: rf-loop
author_rank: Super Contributor
timestamp: November 02, 2018, 01:32:30 pm
content: Just for example using some other scope.Perhaps MDO3000 have some math..Sometimes Math can help (integration in this case). Not perfect solution but... just for example about other ways to display something...Signal to Ch1 is around 1MHz carrier. 1st image PWM using 20kHz and 2nd image 100Hz sine modulating with around 48% duty deviation.~1MHz, PWM ~20kHz sine~1MHz, PWM ~100Hz sine

author: r0d3z1
author_rank: Regular Contributor
timestamp: November 03, 2018, 04:16:15 pm
content: Thanks, integration is a good solution for a symmetrical signal centered in 0. Unfortunately it doesn't works well for noisy signal like the current sensed by a shunt resistor.Still looking for a better solution. As last option I will opt for data export and external filtering, however it isn't fast as a dedicated scope function.
Rigol DS2202E Locks up when changing hostname - Page 1
Forum section: electronics / testgear

author: SpiderKenny
author_rank: Newbie
timestamp: November 02, 2018, 09:31:56 am
content: Hi everyoneI've just got a Rigol DS2202EI'm trying to assign a hostname, to use it on the LAN.I can access the management interface with a web browser, using blank username and password '111111'By default the hostname is blank.If I try to assign a valid hostname, say "DS2202E", the whole scope locks up as soon as I hit "Apply"It's not just a temporary lock up while it applies the config, the whole scope locks up indefinitely.The only button that works whilst in this state is the power button!Same thing happens if I just try to turn on "mDNS"Anyone else seeing this?

author: skander36
author_rank: Frequent Contributor
timestamp: November 02, 2018, 10:46:42 am
content: Hi , on DS2101E I was activating mDNS but no problems . It has automatically set rigollan as hostname .The scope was updated to last firmware (SP4).

author: SpiderKenny
author_rank: Newbie
timestamp: November 02, 2018, 02:58:11 pm
content: Hi SkanderYeah mine has latest firmware too. I did some more testing and it's not just setting the hostname, that hangs it up, anything you try to change on the Network page of the web interface causes the same issue.I've done Storage / Default to be sure but the problem persists.Having just read a thread on here about a DS2072 with the same issues I think it's a long-standing problem with the Rigol network stack. (That thread is here.https://www.eevblog.com/forum/testgear/rigol-ds2072-rma-ed-to-rigol-for.../25/)
HP 1821A timebase plugin trigger light - Page 1
Forum section: electronics / testgear

author: Totoro
author_rank: Contributor
timestamp: November 01, 2018, 09:47:29 pm
content: Hello all,I recently purchased two HP 181A oscilloscope mainframes each with the 1821A timebase. On of the 'scope had obviously been dropped hard which had turned the lower section, including plugins, into a parallelogram. But the other worked, sort of, and I was able to re-build a working unit from the two. (I like old 'scopes!)However, there was still one problem. The trigger reset light didn't work. Testing indicated it was the neon bulb and swapping the switch/lamp from the other unit fixed that. But now I have a question regarding the behavior of that lamp. When I put the timebase in single-shot, the lamp goes on when I press reset and goes out when there is a trigger event. But in auto or normal mode, the lamp is on all of the time. I can kind of understand that for auto mode but even in normal with no trigger the lamp is on. I would expect that in the absence of a trigger, the lamp would be off, especially in normal trigger mode.Does anyone know what is the correct behavior? The manual is not forthcoming or I have missed it.Thanks for any help.- Michael (aka Totoro)

author: Totoro
author_rank: Contributor
timestamp: November 01, 2018, 09:53:34 pm
content: BTW, here's a photo. (This is before I replaced the reset switch/lamp.)
Keithley 2001 calibration error 440 - Page 1
Forum section: electronics / testgear

author: bson
author_rank: Unknown
timestamp: March 26, 2018, 02:06:26 am
content: I've been trying to calibrate my K2001 with B17 firmware to match my Keysight 34465A - absolute accuracy doesn't matter to me, but I'd like the readings to match for convenience, and want the extra precision to implement calibration routines (and multilinear regression analysis) for (of) a 16 bit DAC. I go through the comprehensive calibration, all of which succeeds, enter the dates, and then when I hit enter to store it get an error 440, described as "Calibration not complete" in the calibration manual. Wut.Anyone have any ideas? I set the dates to 3/25/14 and 3/25/15 respectively, just because it insists on putting something there.Drove it through the front panel... Any idea what I might be doing wrong?Hmm, is there a hardware write lock jumper...?

author: TiN
author_rank: Super Contributor
timestamp: March 26, 2018, 01:48:39 pm
content: No, if you poked CAL button near F/R switch, there are no other locks for calibation. Did you follow procedure as manual requires? For standard comprehensive cal on 2001 you need 4-wire short, 2VDC, 20VDC, 20 kOhm 4-wire resistance and 1 Megaohm 2-wire resistance. Watch closely on easy step, as error (e.g. value out of range) might flash just before going to next step. So if you looked away in between steps, you might not notice calibration failure on specific step. If you have GPIB interface, you can read error code/description by executing :SYST:ERR? command after each step.Does meter pass self-test multiple times? 2-wire zero resistance readings look good? (ohms in this test might indicate faulty/dirty F/R switch). Your DC voltage and resistance standards are stable enough?

author: bson
author_rank: Unknown
timestamp: March 26, 2018, 07:22:14 pm
content: Yeah, I did all of them including the automatic AC cal. I've tried a second time with the same result. No self test or other issues, it just refuses to store the data after calibration.

author: websterd
author_rank: Newbie
timestamp: November 01, 2018, 06:41:07 pm
content: Did you ever get a solution for this issue? Same problem for me. I'm quite sure I did every step properly along the way, entered the dates, and get the 440 error every time.
Micsig DP10013 Differential probes VS Tektronix probes ? - Page 1
Forum section: electronics / testgear

author: lordvader88
author_rank: Frequent Contributor
timestamp: October 18, 2018, 06:30:21 am
content: The DP10013 should be fine for my hobby level use, and it's not as if I'm probing anything more than computer SMPS mosfets and flybacks. They are usually under 200kHz. The DP10013 is good for a few MHz. They cost $120Where-as a quality used set of Tek probes will start around $300I know Tektronix is a leader, but for my uses, what would be the real difference ?

author: stenbror
author_rank: Unknown
timestamp: October 18, 2018, 09:39:34 am
content: Works good for me. I have two.

author: nctnico
author_rank: Super Contributor
timestamp: October 18, 2018, 10:05:39 am
content: The MicSig DP10013 works well up to 80MHz or so which is very good value for money.

author: lordvader88
author_rank: Frequent Contributor
timestamp: October 18, 2018, 10:29:12 am
content: I ordered 1, but it will take up to almost 2 months to get here. It will be able to handle any voltage I plan on checking for now.I'll be happy with it I'm sure.

author: Micsig_support
author_rank: Regular Contributor
timestamp: October 30, 2018, 09:52:38 am
content: I think there is no real difference. just brand is not same.Micsig DP10013 adopts USB power, no need extra power adapter. and there is one thread to show comparison our probe and tektronix probe.

author: AllTheGearNoIdea
author_rank: Unknown
timestamp: November 01, 2018, 11:12:37 am
content: I bought both the Migsig and the Picoscope differential probe after my BWD 881 exploded last week . Finding battery usage anoying on the Picoscope and voltage warning regarding input damage worrying for the Migsig at the lower attenuation setting. I had a problem with the Migsig out the box that turned out to be RTFM fault and their technical support was really good. The guys at Picoscope are also great.Not watched your video yet, but will do later as I was going to do a review on my channel and was looking out for some technical tips. Any day my scope doesn’t explode is a good day. Out of the picoscope and micsig I think the migsig wins on the price. They are both good.Thanks for sharingRegards Chris

author: Hydron
author_rank: Super Contributor
timestamp: November 01, 2018, 11:57:53 am
content: Micsig has a 500:1 divider before any of the input circuitry. It is safe to the specified voltage on either range - the only difference between the ranges are the gain resistors on the output stage (which, by they way, are implemented in a way where CMRR is not easy to match between the ranges - one of the issues with this probe). Worst thing that would happen being on the lower range is bad measurements if the output amp clips.
Dm3058e rs232 usage - Page 1
Forum section: electronics / testgear

author: finos
author_rank: Contributor
timestamp: October 31, 2018, 11:39:22 pm
content: Hello this is my first post so please be patient with any stupid questions I ask I just bought the multimeter and I'm wondering how to setup the rs232 port on the back , I've gone through the menu to set the baudrate and parity but when I tried to send the *IDN? comand from a USB to ttl--> ttl to rs232 adapter nothing returnedDid I miss something? Or the serial port on the back isn't scpi capable?Thanks in advance for every answer
TDS7054  TDS7104 Signal Path Compensation Fix - Page 1
Forum section: electronics / testgear

author: jkohout
author_rank: Newbie
timestamp: November 03, 2017, 01:49:37 pm
content: I have two TDS7000 series scopes that fail Signal Path Compensation. Everything else works fine, but it cannot pass cal because of the the failure.I have read all the info about the NVRAM, but it does not look like the issue. It power up and gets the correct serial number and option codes.I also looked at the data acquisition board, and nothing looks bad or damaged.Anyone have any tips on how to fix besides a whole new data acquisition board?Would a bad NVRAM battery possibly cause the SPC failure?Both work working good and passed cal last year. Only been sitting in the lab and being used, so no physical or storage damage is suspected.Thanks in advance.

author: plazma
author_rank: Frequent Contributor
timestamp: February 24, 2018, 10:11:01 pm
content: Did you get it fixed?I have a TDS7104 which usually fails SPC. But after many repeats it passes.Is it possible to see which channel fails? Maybe components could be swapped between channels to see what is faulty.

author: jkohout
author_rank: Newbie
timestamp: October 31, 2018, 09:13:44 pm
content: No, not really. I reset the NVRAM, and it seemed to help. Sometimes it passes SPC and sometimes it fails. If you run it two three times, it eventually passes. Would be good to figure out, but maybe time to upgrade.

author: Johnny10
author_rank: Frequent Contributor
timestamp: October 31, 2018, 10:03:14 pm
content: I had this problem on a Tek 784D Scope... after changing the acquisition board the error went away.Reading on this topic I found a Tek Forum customer that found problem in input channel attenuator hybrid.
Strange Multimeter Behavior - Page 1
Forum section: electronics / testgear

author: User2938
author_rank: Newbie
timestamp: October 31, 2018, 07:43:11 am
content: Hello, I recently bought a new “surplus” Keithley 2015-P DMM and while experimenting with it, I noticed some weird behavior when measuring the DC offset of a mixed AC/DC signal coming from a Siglent SDG-1032X generator. With the meter set to DCV and connected directly to the output of the generator, I set a sine wave, 1kHz, 4Vpp and 2V offset at the generator. Things seemed fine initially w/ the DMM reading something like 2.08V. Then I turned the generator offset down to 0V, and back up to 1V. The DMM then began reading something like 58mV. Slowly turning up the offset, a large error remained (500mV+), until suddenly at an offset of around 2V, the DMM reading jumped back up to 2.08V.Thinking something isn’t right with the meter, I did the same test on a Fluke 87V. The reading remained stable, DCV read about 80mV high no matter what the offset or how frequently I changed it. Finally, I performed the same test on an HP 34401A, and had the same exact result as with the Keithley; the only difference being that the threshold “jump” correction voltage offset value was 1.7V instead of 2V.Can anyone explain why this might be? Turning on and off the generator output when the offset was at 1V and Keithley was reading around 58mV (72mV on the HP) made no difference. In order for either to read the DC offset again correctly, I had to raise it up above a certain threshold, then lower it back down.

author: macboy
author_rank: Super Contributor
timestamp: October 31, 2018, 05:22:53 pm
content: Turn off autorange! Set to 20 V range to cover the DC + AC peak.Set integration period (NPLC) longer.
EEVblog BM235 Multimeter - Page 1
Forum section: electronics / testgear

author: kaevee
author_rank: Regular Contributor
timestamp: October 29, 2018, 02:52:13 am
content: Hi,I am trying to order a EEVblog BM235 Multimeter from India. The shipping calculator does not list India, but lists neighbors. How do one order from India?Note: I know this is not appropriate forum. I could not think of right forum to post.

author: Candid
author_rank: Regular Contributor
timestamp: October 29, 2018, 07:35:16 pm
content: You may order fromhttps://www.welectron.com/Brymen-BM235-Multimeter-EEVBlog-Editionfor a reasonable price. Or the original Brymen BM235 for less.

author: kaevee
author_rank: Regular Contributor
timestamp: October 29, 2018, 11:13:19 pm
content: Quote from: Candid on October 29, 2018, 07:35:16 pmI had been to the site. The listing price is bit misleading (inclusive of VAT) where Brymen's price is about $40 higher compared to EEVBlog. Anyway, they are shipping free to India.Thanks for link.
Tektronix TDS2MEM scope module max memory size? - Page 1
Forum section: electronics / testgear

author: Mrnt
author_rank: Contributor
timestamp: October 21, 2018, 08:09:23 pm
content: I have looked at the docs for this module an tried a Google search but have been unable to determine:The maximum size Compact Flash memory that the module supports.Whether the module will support a SD to Compact Flash adapter.Testing with the Compact Flash I have on hand seems to indicate it only supports up to 128MB but this seems low - does anyone know what it is supposed to support?

author: Muttley Snickers
author_rank: Unknown
timestamp: October 24, 2018, 07:29:59 am
content: Quote from: Mrnt on October 21, 2018, 08:09:23 pmI saw this thread posted a couple days ago but haven't as yet had a chance to check my TDS-1002 and confirm what the maximum compact flash card size the TDS2MEM will accept, the card memory size might also depend on the particular brand or type in regards to compatibility.The documentation I have at hand indicates that the minimum card size required was 8 Megabyte and the maximum size was 1 Gigabyte but again this might vary depending on the particular card, I don't even remember what I was last using in mine so probably need to check it anyway.

author: Bassman59
author_rank: Super Contributor
timestamp: October 24, 2018, 10:51:21 pm
content: Quote from: Muttley Snickers on October 24, 2018, 07:29:59 amI have a TDS2024 with this interface, I will check the manual and the card tonight to see what they say.

author: Mrnt
author_rank: Contributor
timestamp: October 29, 2018, 04:13:59 pm
content: Thank you for that information - I had not seen those product sheets. I'll go back and make sure the larger compact flash modules I have are not fubared and hence not working properly.On a side note - have you found a source to update the firmware for this scope? I have a pretty old version but Tek wants me to send the whole thing in which seems like it would cost more than it is worth.
Tetronix AM 503B current probe amplifier - Error LO - Page 1
Forum section: electronics / testgear

author: e61_phil
author_rank: Frequent Contributor
timestamp: October 29, 2018, 11:02:09 am
content: Hi,I have a Tektronix AM 503B amplifier on which "LO" flashes after switching it on. The old battery was completly dead. Therefore, I replaced the battery with a new one, but the error is still there.I measured the voltage on the battery holder and it is 1.5V. It doesn't look like a contact problem. I also double checked the polarity.Has anyone a hint for me?ThanksPhilipp
HP 8753C Calibration/Use Issue Phase Measurement - Page 1
Forum section: electronics / testgear

author: calmissile
author_rank: Contributor
timestamp: November 01, 2018, 10:45:38 pm
content: We are using a HP 8753C and 85046A S-Parameter Test Set to make some antenna/feedline measurements.The acceptance test has the VNA connected through about 25 feet of 50 Ohm coax and then connected to a 4 ft coax pigtail that connects to a slot antenna.The center frequency we are measuring is 113 Mhz. We are doing a Full 2 Port calibration, and connecting the SOL to the end of the test coax and the antenna pigtail coax is disconnected. The test specs indicate that we should have about 0 deg phase shift at midband (113 Mhz). Our measurements are about 2-4 deg out of tolerance.In order to study the problem, we have disconnected the test coax and performed a Full 2 Port Calibration at the instrument itself. The 85046A has APC7 connectors and we do not have APC7 standards. We use a pair of identical APC7 to N adapters and a calibrated set of Maury N type standards. The calibration kit called up is the 50 ohm N kit. We have not changed or customized any calibration tables in the analyzer.After the 2 port calibration we set the display to Phase format and reinstalled the open and short that were used in the calibration process. The Open standard gives a phase reading of -1.68 deg. The Short standard gives a phase reading of +178.54 deg. This is part of what I do not understand..... The why?We performed the identical tests/calibration on two identical 8753C/85046A and get nearly identical results. In reading the theory of operation it is my understanding that the analyzer reads the phase shift from the Short and Open and makes an average of the two to arrive at the 0 degree reference plane at the calibration standard (end of the coax).The delay specs for the Maury Open and Short standards are 37.026ps and 42.063ps which does not equate to anywhere near 1.5 deg at 113 Mhz.Has anyone encountered this kind of issue in measuring phase of antennas and coax before?

author: TheSteve
author_rank: Unknown
timestamp: November 01, 2018, 11:11:33 pm
content: Why have you not programmed the full spec's for your cal kit into the 8753c?

author: hendorog
author_rank: Super Contributor
timestamp: November 01, 2018, 11:45:56 pm
content: There is a heap of info here about setting up the cal kit on an 8753:https://www.kirkbymicrowave.co.uk/Support/vector-network-analyzers/HP-Agilent-Keysight/8753/Personally I use this application with a GPIB adapter:http://www.vnahelp.com/products.htmlBasically you enter the provided cal kit 'coefficents' into the analyzer for each standard and calibrate the analyzer using those standards.Then when you re-measure the same standards you should see the same coefficents in the measurements.So if your open standard has a 37.026ps delay, then you should get a result similar to that when you measure the open standard after calibration.If not then the only possibility is that you haven't entered the coefficents correctly!i.e. Even if your open standard is knackered, it will still measure ~37.026ps, as you told the analyzer that is what it is.
Rigol DM3058 DMM - Scraped Chips? - Page 1
Forum section: electronics / testgear

author: Chris56000
author_rank: Frequent Contributor
timestamp: October 27, 2018, 09:21:20 pm
content: Hi!I've not got round to looking at my Rigol DM3058 Dead DMM Repair Project yet, can anyone tell me if Rigol have scraped the numbers off any chips, and if so, has anyone been able to identify them, or would it need reverse engineering to do that?Chris Williams

author: Kleinstein
author_rank: Super Contributor
timestamp: October 28, 2018, 07:40:21 am
content: It can depend on the age of the unit if the chip numbers are readable (and useful). Sometimes they scape off the numbers for the early units to make reverse engineering (or just estimating the BOM costs) a little more difficult. Later units might come with normal chips.So the first thing would be to take a look at the actual unit.The first steps are usually a visual inspection anyway and check of the supplies. They usually don't scrape of the number from an 7805The first hurdle is more like not having a circuit diagram. So it is about finding guessing good test points.
Trimble Thunderbolt 48050-61 questions - Page 1
Forum section: electronics / testgear

author: KA1J
author_rank: Contributor
timestamp: October 26, 2018, 04:39:16 pm
content: Hi,Trimble Thunderbolt 48050-61D/C 0509I need a 10MHz reference for my Ham radio and have been using a BG7TBL GPSDO for a few years but its TXCO appears to have bit the bullet. I bought a Trimble Thunderbolt made in 05 to replace it. The seller is unhelpful and I can find no information on powering it and google came up with 12V+ 12V- and 5V but the sticker at the power plug shows only + - and GND. No mention of voltage range.I tried removing the case but it appears there are studs holding it from inside and it will require damaging the case to remove the circuit board. I was able to peek inside and see the TXCO is a Trimble so I at least know it is one of the later versions of the Thunderbolt.In searching I see various mods for this unit but nothing to answer the basic question of proper voltage supply and how to non-destructively remove the board from the case to make any future mods.Suggestions?Thanks.

author: texaspyro
author_rank: Super Contributor
timestamp: October 27, 2018, 02:52:08 am
content: That version runs on 48V (36-75V). I once checked the datasheet of the DC-DC converter in the box.The ones in the flat gold colored case use +/- 12V and 5V.

author: edpalmer42
author_rank: Super Contributor
timestamp: October 27, 2018, 03:43:47 am
content: If yours is the 'red label' version, then it's the retail version. You may be able to find some info on Trimble's site. AFAIK, the +-12, +5 version was a special for telco use.I've never seen the retail version so I can't give you any actual info on opening the case. However, if removing the obvious screws doesn't do the job, feel around under the labels for hidden screws.

author: texaspyro
author_rank: Super Contributor
timestamp: October 27, 2018, 03:57:56 am
content: The telecom specials were built with a much higher quality (phase noise wise) OCXO

author: KA1J
author_rank: Contributor
timestamp: October 28, 2018, 12:58:13 am
content: Thanks for the replies.This does have a red label on the front, I didn't know there was a retail version. I was able to find this page which answers the voltage for this version as 24V. It does not mention how to seperate the halves and access the board. I'll look at it again.Cheers!
Termocouple data logger multi-channel (Low cost) - Page 1
Forum section: electronics / testgear

author: Jester
author_rank: Frequent Contributor
timestamp: October 26, 2018, 02:05:52 pm
content: I'm doing some temperature testing and would prefer to have the measurements recorded automatically.This device seems to have the basic capability, however it uses DS18B20 sensors which are less than ideal when probing small devices on a PCB. I would prefer something similar however with standard type K thermocouple connectors, as I have plenty of them.https://www.ebay.com/itm/Temperature-Data-Logger-to-PC-4-Channel-COM-via-RS-232-No-Sensor-Version-CH015/291295206468?hash=item43d28c1c44:rk:1:pf:0This device accepts regular thermocouple inputs, however it does not log directly to a PC, you have to let it capture and then connect and download data, and max time to auto off is 90 minutes also less than ideal.https://www.ebay.com/itm/UEI-DT304-Apollo-IV-4-Temperature-Logger/323474622332So is anyone aware of a low cost multi-channel thermocouple data logger that accepts regular thermocouple connectors and logs continuously to either a terminal program or whatever software comes with the device?Thanks
Raspberry Pi 3 AD9850 based RF signal gen - Page 1
Forum section: electronics / testgear

author: ultrarunner2018
author_rank: Contributor
timestamp: October 22, 2018, 09:49:05 pm
content: Hi;I want to build an inexpensive RF signal generator using my Raspberry Pi 3 b+ to program an AD9850.I need a 50 ohm output capable of driving coaxial transmission line.Can someone recommend an op-amp for this?I can't really say how what voltage swing I need on the output, but +/- 5V should be enough.I have a bench supply capable of + and - 20V.I am hoping to build this little generator for significantly less than what I could buy a comparable generator. I am aware of several function generators available bran-new and free standing for under $100, but I don't want to spend even $50 on this.Thanks for your helpUltrarunner

author: ebclr
author_rank: Super Contributor
timestamp: October 26, 2018, 07:12:37 am
content: FOR USD 99 you can buy a ready product, that is quite useful and will save your timehttps://www.mouser.com/ProductDetail/Analog-Devices/ADALM-PLUTO?qs=sGAEpiMZZMuqBwn8WqcFUicxGcgINWaRWwjTXaJRopHnbkBAEzXakQ%3d%3d

author: Fungus
author_rank: Super Contributor
timestamp: October 26, 2018, 11:13:29 am
content: An Arduino would be much cheaper/easier than a Pi.

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 26, 2018, 12:44:58 pm
content: Quote from: ultrarunner2018 on October 22, 2018, 09:49:05 pmTHS3091 or THS3095. i used it to amplify my Hantek 3x25 AWG from ±5V to ±12V (from ±15V supply) or ±10V (from ±12V supply). you need to heatsink it as CFB opamp will sucks current and generates heat.
Tektronix DM 5010 Calibration Factor Adjustment Procedure Overview - Page 1
Forum section: electronics / testgear

author: johnlsenchak
author_rank: Frequent Contributor
timestamp: October 25, 2018, 04:47:40 am
content: Tektronix DM 5010 Calibration Factor Adjustment Procedure OverviewElPaso TubeAmpsPublished on Oct 24, 2018Check out the voltage calibration by way of using a tube amp and transformer ! This is insane ! This is a must see videoPosted on 10/25/2018

author: texaspyro
author_rank: Super Contributor
timestamp: October 25, 2018, 06:08:48 am
content: I replaced the batteries in my DM5010's with CR-123 lithium primary cells with a diode in series to block the charge voltage and drop the battery voltage. The original NiCad batteries could self-discharge enough after around 3-4 months of storage to lose the cal values. I've had CR-123's last 10 years.