hybridfree/eevblog-posts huggingface dataset:
Increase accuracy of Owon P4305 DC power by self-calibrating in hidden menu - Page 1
Forum section: electronics / testgear

author: dophuc
author_rank: Contributor
timestamp: August 29, 2023, 12:49:02 pm
content: Hi everybody,I use the Owon P4305 DC power supply for about 1 year, this power supply has a hidden menu to recalibrate the V, A parameters. If recalibrated with a high-precision device, the Owon P4305 also has a fairly high accuracy. I tried calibrating with a 34410A multimeter and the results were better than expected, the P4305 holds the voltage very well both at no load and at full load.I'm curious if the power supply from other brands of Keysight, Tek, Siglent, Rigol... users can self-calibrate V, A during use, both official and hidden menu ?

author: thm_w
author_rank: Super Contributor
timestamp: August 29, 2023, 10:09:23 pm
content: Will you tell us how to access the hidden menu?Rigol DP8xx has a calibration menu, with a given password, where you can manually calibrate the unit. Although many here found it easier to send USB commands to the unit to do an automated calibration instead, as there are just so many data points to enter (1V, 2V, 5V, etc.).Owon has very few commands in the comms guide:https://www.owontechnology.eu/product/1315598/owon-p4305-1ch-0-30v-0-5a-1-ch-150w-linear-dc-power-supply

author: dophuc
author_rank: Contributor
timestamp: August 30, 2023, 02:56:21 am
content: Instructions to access the hidden menu of Owon P4305 are available on Youtube. I present again how to press the key as follows:- Connect Owon P4305 with high precision DMM for calibration, pay attention if you want to calibrate the current, the DMM should be greater than 5A- Press the keys in order: System - up - OK - right - down- After entering the hidden menu, use the up and down keys to choose between "Man Volt" or "Man Curr".- After selecting "Man Volt" (or Man Curr) will appear a table with 3 rows, 2 columns. The top line is the voltage or current levels, the 2nd line is the input, the 3rd line is the display. Use the dial to match the input and display.- After adjusting the values, exit the hidden menu with the same press when accessing: System - up - OK - right - down
R&S ZVR VNA cant update Firmware and other questions - Page 1
Forum section: electronics / testgear

author: VanBudd
author_rank: Contributor
timestamp: March 21, 2023, 10:27:53 pm
content: Hi,Ive got an old Rohde&Schwarz ZVR Vector Analyzer (9kHz-4GHz) and want to update to the FW from V2.05 to V3.52.I followed the update guide an created the five floppy discs.But if i press System->Setup at my unit, there is no side menu and no Firmware-Update softkey.I tried to reinstall V2.05, nothing changed.I searched all submenues, theres no FW-Update option.Does somebody know another option to update?Or an answere for my problem?Also did someone tried an USB Floppy emulator for the ZVR or tried to change the loud fan?Would be nice to save some data on an USB drive instead of floppy.If someone knows any other "mods" for the ZVR to get it a little bit up to date or that it will survive the next 10 years easily i would be happy to hear about

author: rf-messkopf
author_rank: Regular Contributor
timestamp: March 21, 2023, 10:55:58 pm
content: Quote from: VanBudd on March 21, 2023, 10:27:53 pmI don't have a ZVR, but themanualshows a procedure (see page 12 of the pdf) how to update directly under Win NT, without the analyzer firmware. Maybe the firmware on your device is too old to have the update feature.Quote from: VanBudd on March 21, 2023, 10:27:53 pmSome people have successfully used floppy emulators with this vintage of R&S equipment. Be careful with changing fans. There is a bunch of them in these units, and they need sufficient airflow to stay comfortably cool.

author: VanBudd
author_rank: Contributor
timestamp: March 21, 2023, 11:09:06 pm
content: Actually i allready ordered a Keyboard and mouse that works with the unit, it is my last hope

author: Rayus
author_rank: Newbie
timestamp: August 18, 2023, 06:42:25 pm
content: You can not upgrade a 2.x firmware to 3.x one - the 2.x device works with 486 CPU with OS DOS/RMX , the 3.x with Pentium 233 MMX with WIN NT.4. - but - no need to worry about - IMHO the DOX+RMX works more stable and the WINNT4.0 "Blue screen of death" occures quite often.

author: MindBender
author_rank: Regular Contributor
timestamp: August 29, 2023, 10:10:17 am
content: Quote from: VanBudd on March 21, 2023, 10:27:53 pmI know it's not what you mean, but if you give me the serial number, I can generate the software option keys for you.Or you can do it yourself:https://github.com/rdelien/fsxx_keygenThe ZVM isn't supported as a machine type, but I know raw key 7 activates option K9 (Virtual Embedding Networks) and key 8 activates option B2(Time Domain). I would really like to have to have the complete list, so I can at it as a machine time, but fuzzy eBay photos are my best material...
Siglent sds1202xe strange behavior - Page 1
Forum section: electronics / testgear

author: MarioBros69
author_rank: Contributor
timestamp: August 28, 2023, 02:45:15 pm
content: I had an SDS1202x-e for a couple of days and while measuring a half-wave rectifier the following occurs to meI ask the forum experts because I don't know if this is normal behavior or a malfunctionI take the measurement in automatic and everything is correct in 5v/divI go down to a 2v division and everything is correctI go down to 1v dvision and the bottom of the signal is completely deformed

author: MarioBros69
author_rank: Contributor
timestamp: August 28, 2023, 08:41:36 pm
content: Thanks... that's exactly what happened to me
BK Precison Model 8540 DC Load - Page 1
Forum section: electronics / testgear

author: bostonman
author_rank: Super Contributor
timestamp: July 24, 2023, 01:02:34 am
content: I have a BK Precision 8540 DC load and the front panel controls don't seem to be working.The front dial doesn't change any values and most of the buttons don't seem to work.I haven't dove too deep into it yet, but have measured 5v on the front panel and looked for the obvious issues such as broken wires, connectors, and solder joints.Has anyone seen such an issue and been able to fix it?

author: electr_peter
author_rank: Unknown
timestamp: August 28, 2023, 08:17:03 pm
content: Quote from: bostonman on July 24, 2023, 01:02:34 amCan you elaborate which buttons still function?

author: bostonman
author_rank: Super Contributor
timestamp: August 29, 2023, 01:09:26 am
content: Thanks for the reply. This somewhat got diverted to another message. Initially I posted this message, but then had a question about trying to obtain a datasheet for one of the chips, so I began a thread on that, however, it developed into somewhat of a repair.I hope this isn't an issue as I was hoping to continue this thread as it's a 'repair' forum along with my original message.The new thread is at :https://www.eevblog.com/forum/projects/m430f4250-datasheet/new/#new

author: electr_peter
author_rank: Unknown
timestamp: August 29, 2023, 03:41:53 pm
content: Quote from: bostonman on August 29, 2023, 01:09:26 amThat is clear, I consider this thread closed. I will check thread in the link.
Tektronix 067-1840-00 Fixture. What is it? - Page 1
Forum section: electronics / testgear

author: calibrationfixture
author_rank: Regular Contributor
timestamp: August 26, 2023, 08:04:21 am
content: Hi to All,Spotted on eBay.com:https://www.ebay.com/itm/354899425221By mistake described as 065-1840-00. Anybody who knows the in and outs of this Fixture?Greetings,Calibrationfixture

author: smaultre
author_rank: Regular Contributor
timestamp: August 26, 2023, 06:33:24 pm
content: HF electronic board with connectors and (couplers ?)

author: calibrationfixture
author_rank: Regular Contributor
timestamp: August 28, 2023, 05:40:16 am
content: Hi,It is a Calibrationfixture (067-xxxx-xx PN), needed to calibrate which Probe or what kind of Device or Instrument?Calibrationfixture
Peaktech 4145 - 3 Phase Power Analyzer - Format Memory - Page 1
Forum section: electronics / testgear

author: rakibsolshare2023
author_rank: Newbie
timestamp: August 29, 2023, 07:49:12 am
content: Hi,I recently used a Peaktech 4145 3 Phase power analyser to do a power profile for a site which was successful. Now to prepare it for another site, I "Formatted" the memory from the Memory>Format memory and I can only see 2.2GB free whereas at the time of turning it on for the first time, I had 14.4GB free?, What happened to the memory? How can I recover it as I need to do another power profile for another site but because of the limited memory, it is not allowing logging at 1s for 7 days but rather logging at 5s for 7 days. Please advise.
Advantest R3132 help request - Page 1
Forum section: electronics / testgear

author: Gianni
author_rank: Contributor
timestamp: August 28, 2023, 09:18:01 pm
content: I got for free an Advantest R3132 with TG.It "seems" to work but really doesn't:- almost every menu or key is apparently working- the initial self test says all OK- the calibrator out is OK (precise and stable)- the TG seems to work- the trace seems OK but is exactly 20MHz and 5dBm shifted. Using offsets it "appears" to be correct- the trace is however very "noisy", especially if I reduce the bandwidth- the manual self test (SHIFT/1) says that CPU and RF are KO. I can believe that RF is not OK, but it's hard to think that the CPU is KO.I could not find any service manual or schematic. Could someone kindly help me? Thanks in advance
Feeltech FEELTECH FPA0510S power amplifier for signal generator - Page 1
Forum section: electronics / testgear

author: CosteC
author_rank: Regular Contributor
timestamp: July 24, 2023, 06:33:58 am
content: TL;DR: Don't.Long story:I needed amplifier for signal generator. Something in ballpark of +/- 10 V 1 A, 100 kHz.I found FEELTECH FPA0510S, but failed to find datasheet, jet this power amplifier had appealing size, parameters and price. It requirers only +12VDC - nice. Power rating is 1.25 A on label.Mechanical:Overally small. Enclosure is fine, design is sensible, for price at least. Bottom is not flat: screw stick out, holes are not deburred. Adding heatsink will be irritating.PCBA:Soldering is OK-ish, flux remains here and there. Component placement is rather horrible, resulting in nothing exactly matching anything. Not for anybody with even slight OCD.PCB design is poor: Footprints are too small, not fitting real parts. Crowded components and large empty areas. Component sizes seem random.Electrical:Input, output and power input share same GND/minus potential. Heatsink it GND connected, internally with one screw. Can be changed quite easily. One can imagine short circuit from TDA2030 thermal pad to enclosure/GND.ElectronicsIt is, as I suspected build around TDA2030. Negative voltage is generated with LM2596S-ADJ. TDA2030 is powered directly from input +12 VDC and generated -12 VDC. 2x2200 uF inside seems a lot. No other filtering than couple of ceramic chip capacitors. RUN and PWR LEDs does not seem to do anything, despite SMPS seem to have some extra circuitry like UVLO.Tests:System is DC coupled as advertised.All tests done with 100 Ohm load (not at full load of 1-2 A depending on seller)DC offset is around 20 mV.Bandwidth: at Gain 1x, input 1 V, -3 dB bandwidth is around 467 kHz. Risetime/falltime around 2 us @ 10 V amplitude. Graph has some artefacts (sorry)HORRIBLE noise at 153 kHz coupled from PSU. See screenshoots.Coil and negative voltage capacitor (C6) are noticeably warm, despite total power consumption of 0.17 A.This gives some hope for upgrade/repair...

author: makerman
author_rank: Regular Contributor
timestamp: August 26, 2023, 12:59:53 pm
content: Thanks, was thinking about buying one.Looking at this instead now :https://tinyurl.com/45kr437s

author: makerman
author_rank: Regular Contributor
timestamp: August 26, 2023, 01:00:44 pm
content: I think i remember feeltech doing a badly built function generator also, which is why i searched before buying, the name rang a bell.

author: nctnico
author_rank: Super Contributor
timestamp: August 26, 2023, 01:05:09 pm
content: Quote from: makerman on August 26, 2023, 12:59:53 pmThat one likely has the same design & 'problem'. Filtering noise from a step-up converter like that isn't easy. If you want to fix this, then replace the step-up converter with one that switches at a much higher frequency (>500kHz) and add input and output filtering.

author: Kean
author_rank: Unknown
timestamp: August 26, 2023, 04:01:04 pm
content: There are a few topics here about the Juntek DPA-1698 and DPA-2698 that are probably worth a read.e.g.https://www.eevblog.com/forum/testgear/awg-buffer-amp/
Transforming a Standard TLA7012 into an Option 18 (= Touchscreen) - Page 1
Forum section: electronics / testgear

author: calibrationfixture
author_rank: Regular Contributor
timestamp: February 23, 2023, 07:20:50 am
content: Hi,TLA7012 compatible Touchscreens can be bought thesedays on eBay. I have a Standard TLA7012. During Powering Up I see on the Location of the Option 18 Touchscreen On/Off Button a light flashing from on to off. My conclusion: the Operator Panel is prepared for Touchscreen. What I want to know is if Standard TLA7012's are fully equipped with all hardware to transplant these eBay Touchscreens succesfully. Anybody who knows the in and outs? In the past Tektronix provided these as a whole assembly, more substantial as the eBay Touchscreens. Thus maybe something is absent in a Standard TLA7012.Calibrationfixture

author: calibrationfixture
author_rank: Regular Contributor
timestamp: July 29, 2023, 06:16:02 am
content: Hi to All,An Update and an answer to my own question:Some time ago I had to replace a broken TLA7012 Display. This TLA7012 had no Touchscreen. I acquired an used original replacement Display with one exception: the (thick) Touchscreen was removed. Resulting in a new Display which is little recessed. The Alu Frame which hold both has more depth than the Non-Touchscreen Version. Changing Frames fixed this. All other Hardware including Electronics is the same. As far as I see it now all Non-Touchscreen Displays can thus easily be transformed into a Touchscreen with the thin versions from eBay. You only miss the Touchscreen On/Off Button.Calibrationfixture

author: calibrationfixture
author_rank: Regular Contributor
timestamp: August 26, 2023, 06:56:43 am
content: Hi,I missed it then, but Google leads me to another eevblog Thread:https://www.eevblog.com/forum/repair/tektronixtla7012-repair-question/Calibrationfixture
HP  Agilent 8702  8703  Lightwave Component Analyzer? - Page 1
Forum section: electronics / testgear

author: wd5jfr
author_rank: Regular Contributor
timestamp: August 21, 2023, 11:22:10 pm
content: The basic 8702x and 8703x from outward appearance look like a relabeled 8753 VNA. Looks like they use black boxes to convert nm light waves down to GHz RF for lightwave component analysis. I'm curious if these units with 2 RF ports are useable as a regular VNA or are there some gotchyas?ThanksHank

author: Kean
author_rank: Unknown
timestamp: August 25, 2023, 10:15:19 am
content: I know almost nothing about these, other than they can be used for S-parameter measurements of any combination of optical and electrical connections. i.e. O/O, E/O, O/E, E/E.Also be aware that if used with a 3.5" floppy they store data using LIF format which makes data transfers a bit difficult. GPIB should be quite usable but finding software to work with them.. ??I would expect other gotchas!
Another MSO5000 logic probe design - Page 1
Forum section: electronics / testgear

author: fest
author_rank: Contributor
timestamp: March 17, 2023, 02:41:49 am
content: As I mentioned in Gandalf_Sr's thread, I'm taking a stab at cheap'o MSO5000 logic probe design which does utilize voltage threshold selection in oscilloscope (since it's there, why not use it?).I have come up with the following design:https://github.com/festlv/mso5000-logic-probeI'll order the PCBs as soon as I finish some other designs, so proceed with caution if you want to build one yourself.

author: fest
author_rank: Contributor
timestamp: April 11, 2023, 05:09:34 pm
content: Just got back the rev0 PCBs and can report that the design works as expected (with one BOM change as documented in repository)- I can select the threshold on the scope which sets the VCC for the input buffer accordingly.I'll perform some more testing later (i.e. how well do the thresholds work for various common use cases, what happens when the input actually exceeds the VCC of the buffers etc).

author: Robbie-Mac
author_rank: Newbie
timestamp: August 24, 2023, 07:33:20 am
content: I ordered a set of boards tonight... some parts not available from my regular (read familiar) supplier. This is the first board I am attempting with parts this small... any suggestions? Also, before I sink money into parts, how has the testing gone? Any results you can share?

author: fest
author_rank: Contributor
timestamp: August 24, 2023, 08:47:51 am
content: I didn't get around to a rigid test procedure, but so far it has held up nicely for my use cases.The most complicated thing it has seen is ~single clock cycle pulses at 176MHz (6ns or so), which showed up fine.

author: Robbie-Mac
author_rank: Newbie
timestamp: August 24, 2023, 04:01:03 pm
content: Awesome! That will cover my use cases very nicely as well. Thank you very much for the quick reply.

author: fest
author_rank: Contributor
timestamp: August 24, 2023, 08:54:48 pm
content: BTW I think I have parts for a few sets left over. If you're in Europe AND can't find the parts from mouser/digikey, PM me with the parts you need, might be able to ship them to you.
Sony-Tektronix A6909 - Page 1
Forum section: electronics / testgear

author: ToHu
author_rank: Newbie
timestamp: August 24, 2023, 08:41:32 pm
content: Probably this is one of the cheapest option for isolated scope. So I bought few of those and spend some time to repair/calibrate them. The common issue with all of them are the A10 board electrolytic capacitors, they all leak and is quite an ugly picture. Based on my experience 5 of 6 cases the issue is related only to the capacitors and the leaks. Replacing the capacitors solve the problems, but in most cases the leak is all around so you need to remove all the components around and clean under. I try in my US bath it didn't help, also because of the leak a 0805 capacitors become a 30 Ohm resistors. So don't be lazy, take off all parts around, wash firmly and put them back.The main problem after that is to calibrate the channel, the service manual is pretty much useless, since it miss a very important steps. There is a test point TP300, and you should set the offset and the gain based on that point, not the isolated output. Let it work for at least 20-30 min before you set the offset and the gain. You should let it work also 20-30 min after you assemble the AMP unit. At that point use R430 to set the isolated output offset, and finally if required to do small gain adjustment. R430 set the LED current, respectively the offset for the output. If you try to compensate a large offset with R210 as described in the manual, you will bring your preamp close to one end and it will start limiting there, also the LED will start work in a region that probably is not adequately compensate on the receiving side, so you will lost the linearity.Attached is A10 schematic with some notes on the calibration and control bits meaning. Not all values are measured, some of them are guess values, especially the capacitors, but the schematic itself is more important than the components value, you can measure them from the board you have. Unfortunately there is no any information about the LED used, the only marking i have is BM and BH on the bottom side. The channel that is with BH diode do not work properly, you may pass initial calibration, but will fail at range calibration. Initially I was thinking the led was the issue but more and more I am thinking is not the proper type, probably a different bin. It works, but at some of the ranges the calibration didn't pass.p.s. The BH led was scratched on the bottom side, so I suppose someone replace it. It can be from a different device, but i suppose if that the case they are some other differences as well in the LED driver and may be the receiver side amp.
Tek 475 Bandwidth Limit Switch Not Functioning - Page 1
Forum section: electronics / testgear

author: wlzed279
author_rank: Contributor
timestamp: August 23, 2023, 10:15:37 pm
content: I have a newly acquired Tek 475 scope. The power rails are good and everything is functioning as it should with one exception. The bandwidth limit switch seem to be on the fritz. Left in the default position, I assume the 200mhz position, I get no trace at all. If I pull the switch to 100mhz, I get a somewhat noisy trace using a signal from the internal calibrator. I get the same results if i pull the switch to the 20mhz position. Interestingly, there is no change in the noise level between 100mhz and 20mhz. I have cleaned the switch contacts using the paper/IPA method with no luck. Pushing the switch in I get a clean trace with no signal.Not sure where to start on this. Should I be looking at U370/155-0091-00? How do I measure that IC to see if it is functioning properly.

author: wasedadoc
author_rank: Super Contributor
timestamp: August 24, 2023, 07:50:40 am
content: Why are you mentioning 20, 100 and 200 MHz positions of the switch? There is only one filter in that schematic. Pushing the switch changes from input signal to the trigger signal.Do you have access to another 'scope?

author: David Hess
author_rank: Super Contributor
timestamp: August 24, 2023, 09:42:14 am
content: Something should sure change when the switch is used and it does not depend on U370. The switch must still be dirty, or perhaps just broken.

author: wlzed279
author_rank: Contributor
timestamp: August 24, 2023, 02:35:55 pm
content: Thanks David and wasedadoc for your replies. Attached is the corrected schematic. I do have another scope that I can use to trace the switch contacts. Looking at the schematic, U370 supplies the full bandwidth signal and the switch directs the signal to the appropriate filters, correct?

author: wasedadoc
author_rank: Super Contributor
timestamp: August 24, 2023, 03:11:30 pm
content: Apply some known signal to the 475 scope input, set the coupling to AC and the Volt/div to the appropriate setting.Check the 200 MHz position of the switch, as that is straight through and does not go though any filter components. On the good scope you should see identical signals at A input and G output. Similarly the signal at B input and H output should be identical.Signals at A input and B input should be complementary (equal except inverted polarity.) If not there is a problem in U370 or before that.With the switch pushed and held in you should see, with the good scope, trigger signals at outputs G and H. If yes, but not on the 475 screen, there is a problem with the delay line or subsequent stages. If no, and the outputs of U370 are not OK, problem is likely before the U370, ie at a point before the trigger signal is tapped off.

author: David Hess
author_rank: Super Contributor
timestamp: August 24, 2023, 03:18:57 pm
content: Quote from: wlzed279 on August 24, 2023, 02:35:55 pmThat is correct.
CENTER 110 - Page 1
Forum section: electronics / testgear

author: vippernskippern
author_rank: Newbie
timestamp: August 30, 2023, 09:32:26 am
content: Does anyone know if this one is any good? You can read more here:impex.no/produkt/elektro/multimeter-elektro/center-110-multimeter/Thank you for answering!

author: MiroS
author_rank: Regular Contributor
timestamp: August 30, 2023, 09:39:46 am
content: They claim 'Solid, prisgunstig og godt multimeter.'No need for capacitance measurement or backlight?

author: Aldo22
author_rank: Super Contributor
timestamp: August 30, 2023, 10:50:37 am
content: I don't know how well it's built, but it looks a bit old-fashioned to me.That's about 60 euros, isn't it?,From the specs, for example,AN870is better and cheaper.

author: Gyro
author_rank: Super Contributor
timestamp: August 30, 2023, 12:35:50 pm
content: Any meter that shares its Volts and mA inputs on the same input jacks is a recipe for nusance fuse blowing and damaged switch contacts.
Etendre la bande passante Rigol DSA 815 - Page 1
Forum section: electronics / testgear

author: balvenie
author_rank: Newbie
timestamp: August 25, 2023, 03:35:44 pm
content: BonjourJ'ai entendu dire qu'il était possible de porte la bande passante de l'analyseur DSA 815 TG , comme je l'avais deja fait sur un oscillo de la marque simplement avec une modification du software.Merci d'avanceJean Pierre

author: BILLPOD
author_rank: Frequent Contributor
timestamp: August 25, 2023, 05:42:53 pm
content: No comprende vou.

author: uargo
author_rank: Regular Contributor
timestamp: August 25, 2023, 05:55:04 pm
content: Lo siento no se entiende

author: axantas
author_rank: Regular Contributor
timestamp: August 25, 2023, 06:07:05 pm
content: Quote from: balvenie on August 25, 2023, 03:35:44 pmJe me permets de traduire…He is asking about an opportunity to hack the Rigol DSA 815TG bandwidth trough a software modification.

author: coromonadalix
author_rank: Super Contributor
timestamp: August 25, 2023, 07:12:00 pm
content: il y a toutes les infos sur ce forum faire une recherche merciall is here do a proper search thks

author: RoGeorge
author_rank: Super Contributor
timestamp: August 25, 2023, 07:17:39 pm
content: Ce zice, ce zice?
8340B or modified 8341B? - Page 1
Forum section: electronics / testgear

author: pe2ben
author_rank: Contributor
timestamp: August 02, 2023, 10:07:52 am
content: Hello,I have a 8340B with a N RF output connector.On other 8340B pictures i only see SMA RF output connectors.Could it be that i have a modified 8341B or are some 8340B's are delivered with N RF connector?Thanks, Ben

author: Tony_G
author_rank: Super Contributor
timestamp: August 02, 2023, 07:02:32 pm
content: Interesting - I'm only ever seen the 8340B's with an APC 3.5mm connector on them (not an SMA) but I think that HP did do a specific version of the N-Type connector that they specified up to 26.5GHz (or maybe it was 20GHz, can't remember I looked it up quite some time ago) so there might have been an option to get the 8340B with that as the RF connector.That said, I looked for a HP catalog that mentioned the units and saw this:So maybe what you have is a frankenunit...TonyG

author: pe2ben
author_rank: Contributor
timestamp: August 04, 2023, 12:16:54 am
content: Hi Tony,I read that also.I hoped that maybe an older version had the N connector because the calibration sheet inside with the correct s/n# show me calibration data range is including 26.5 GHz. Strange...Regards Ben

author: dxl
author_rank: Regular Contributor
timestamp: August 23, 2023, 07:33:10 pm
content: My 8340A had an a APC-3.5mm connector initially - but it was broken, so i replaced it with an N connector from other HP gear that was specified up to 26.5GHz. At least for the 8563E spectrum analyzer they had to made a 'high-frequency' N connector i guess...
Tonghui TH8411 DC Load - CP and CR mode abnormal behaviour - Page 1
Forum section: electronics / testgear

author: danils
author_rank: Contributor
timestamp: October 08, 2022, 11:57:52 am
content: Hi All,Because I was looking for a high voltage capability DC electronic load, I acquired a Tonghui TH8411. The overall build quality looks quite good and the software looks good too.Firmware version is: 1.0.8,2.003 @ 2022 - 04 - 12BTW I am experiencing some abnormal behaviour:1) In the system setting menu I cannot cycle between "Source" CV an CC. CV is always selected2) In Constant Power mode, the power set on the TH8411 has nothing to do with the power drawn from the DUT. It's much more lower and there is no correlation between the two.3) In Constant Resistance mode, again, there is no correlation between values set and DUT behavior.I tested the same DUT with an Array 3710A spare DC Load I have in my lab and it performs correctly in bot CR and CP mode.Does anybody own a TH8411 and experienced the same?ThanksDanils

author: danils
author_rank: Contributor
timestamp: October 09, 2022, 08:51:03 pm
content: Follow up for everyone maybe interested in:Issues 2) and 3)I contacted their service department. CP and CR were bugged to the core in that FW revision. In less than 24 hours, on Sunday, they sent me a firmware update that completely solved the problem. So customer service looks first class so far. What looks odd is releasing to the market a product with such a severe issue.Issue 1)The function is not implemented yet and will be activated in a future FW update.It looks a very interesting product for the bucks. Maybe it could deserve a teardown by Dave. I did not open it but looking inside the ventilation holes I spotted premium components (ST power MOSFETs for example)

author: frankvh2
author_rank: Newbie
timestamp: August 22, 2023, 08:26:02 pm
content: Reviving an old thread I know...Just wondering if you have any further feedback on your e-load? Has the TH8411 been making you happy?
Rødetest FuzzMeasure obsolete? - Page 1
Forum section: electronics / testgear

author: davorin
author_rank: Unknown
timestamp: August 22, 2023, 01:17:26 pm
content: Good afternoon (o;Came across FuzzMeasure a while ago when I was looking for some frequency response measurement software on macOS.But seems it is completely abandoned since 2018, but they still charge for money...Last reply I got from them was in February 2022:"You will still get support for the product even though there have not been any updates.There are also future plans to refresh the whole Fuzzmeasure brand as well, this is taking some time due to other RØDE products taking precedence."Anyone still using FuzzMeasure?Any other options or doing audio measurements, either with UMIK or direct line-out/in?I know of REW, but don't like this Java monster (o;
Hacking a scope, general considerations - Page 1
Forum section: electronics / testgear

author: ErnestB
author_rank: Contributor
timestamp: August 22, 2023, 11:22:58 am
content: Question: As a lot of people already hacked their scope (bandwidth), I wanted to know what are the experiences regarding the calibration (before and after the hack)? Like: does the lower bandwidth stays as true as after the hack, and that the higher frequency maybe are not so true? But, on the other hand, if you legally buy the higher bandwidth option, they do not re-calibrate the scope after that. So, I was interested in the general experiences. Specifically I am considering one of the Siglents. The model consideration is also based on "to hack or not to hack" issue. Cheers.

author: RoGeorge
author_rank: Super Contributor
timestamp: August 22, 2023, 02:13:17 pm
content: For the instrument, there is no distinguishable difference between a bought upgrade and a hacked upgrade.

author: axantas
author_rank: Regular Contributor
timestamp: August 22, 2023, 02:39:53 pm
content: QuoteYou answer the question yourself. You buy a code, insert it in your scope and you are set. The only difference: You can only buy codes, your scope is made for. If you manage to hack your scope to 500 MHz, and the hardware cannot handle that, but accepts your code anyway, you might get unsatisfactory results.

author: Fungus
author_rank: Super Contributor
timestamp: August 22, 2023, 02:44:10 pm
content: Quote from: ErnestB on August 22, 2023, 11:22:58 ama) Most of them offer the upgrade as an paid option via. a license key. The hacks are exactly the same as installing a license key.b) Oscilloscopes are self-calibrating. You press the auto-cal button and they recalibrate themselves. You're supposed to do it whenever the temperature changes by a few degrees but hardly anybody ever does because it's not very important. Oscilloscopes are about looking at the shapes of things and accuracy within few percent is good enough.
Rohde Schwarz Polyskop III SWOB BN42472 1970 41kg monster unit - Page 1
Forum section: electronics / testgear

author: oz2cpu
author_rank: Frequent Contributor
timestamp: August 22, 2023, 09:35:05 am
content: here is my latest videoabout my Rohde Schwarz Polyskop III SWOB BN42472 1970 41kg monster unita really funny and special unithttps://youtu.be/liUB-mqCrY4
Agilent DSO 7014B can't be put into self-calibration mode - Page 1
Forum section: electronics / testgear

author: swperk
author_rank: Regular Contributor
timestamp: August 24, 2023, 04:36:10 am
content: I just received an Agilent DSO 7014B Scope. It looks great and works fine, except that user calibration couldn't be enabled. The calibration enable slide switch on the rear of the scope didn't enable calibration, even though it was mechanically in the proper position.I opened up the scope and found that the calibration enable switch itself was defective, reading open in either position. I replaced it with an identical switch that I tested prior to installation. Unfortunately, the problem remains. Measuring the new switch in-circuit shows that it is essentially zero ohms across the closed contacts. Looking closer, I found a couple of traces coming off the switch that each go to SMD solder pads. One set of pads has an 0603 SMD component with the label 01C installed. It measures 10.01 kOhms.The other set of pads has no component on it, and doesn't appear that it ever did. (see photos).I think this might be the explanation for the problem I'm having, but if the pad never had any component installed on it, it had to have left the factory this way. Does this sound like a reasonable theory? Can anyone tell me if there is supposed to be a 10K resistor in the blank spot?My other questions are about the possibility of upgrading the bandwidth of this scope. ISTR reading that a motherboard that has five BGA chips with heat sinks is upgradeable. Is that correct? If so, what sort of bandwidth upgrade is possible?Thanks,Stan
BSide Z1 Pen DMM out of spec - Page 1
Forum section: electronics / testgear

author: runni
author_rank: Newbie
timestamp: August 20, 2023, 11:28:28 am
content: Hello, I have a Z1 here that always shows 20? digits too little at DC measurement. So at 1V shows 0.8V and at 10V shows 8V and so on. The EEPROM 24C02 I have unsoldered and read out, as well as the values for the DC calibration set to default. This had no effect at all. Analog seems to be ok, 1.24V Ref. and at 1V input 100mV on ADC PIN.Is there anyone who has disassembled a Z1 and can provide the EEPROM content? Or an idea how to start the calibration on the DMM itself? Thanks, yes the Z1 is super cheap, I like the form factor, for quick measurements in the circuit.THX & Best wishes, from Munich.
Repair / Fluke 6060B RF signal generator.  <245 MHz missing ,  >245 MHz OK - Page 1
Forum section: electronics / testgear

author: Goody
author_rank: Newbie
timestamp: August 18, 2023, 11:58:05 pm
content: I've had this Fluke 6060B sig gen for 15 years and great performance on all frequencies. July 2023, I discovered the frequencies below 245 MHz were missing. Above 245 MHz every thing was OK. Signal HETL toggles between the two frequency bands.After much troubleshooting it was discovered the HETL signal path to pin diode CR 210 was 1.6 ohms above ground.Trouble shooting required cutting some traces with an exacto knife.The problem located toward the 2.2 UF electrolytic capacitor C276.The fault turned out to be a whisker had grown from the positive terminalof the solder joint of C276 to ground. The short remained after the capacitorwas removed. I had to cut the area around the square solder land with an exactoknife to clear the short. C276 was good and soldered back in place. It took 30+ yearsfor the whisker to grow across the gap between the Positive terminal of C276 and ground.
Agilent 81150A distorted sine and ramp waveforms - Page 1
Forum section: electronics / testgear

author: Jeff_Birt
author_rank: Regular Contributor
timestamp: August 18, 2023, 05:32:18 pm
content: Hi all,I'm looking at an Agilent 81150A Pulse Function Arbitrary Generator. It fails the POST with; Channel 1: Selftest of Data Out failed. There is no service documentation or even an explanation of what each self-test does test.In operation it seems to work fine for square waves, but sine and ramp waveforms are distorted at amplitudes above 100mv. Distortion increases with amplitude. This sort of failure seems familiar, but I can't remember where I have seen it before.
eevblog meters, comparison chart? - Page 1
Forum section: electronics / testgear

author: mastershake
author_rank: Frequent Contributor
timestamp: August 17, 2023, 06:28:02 pm
content: is there somewhere that has the full list of everything they have and the differences between them? i need a couple new field meters and i dont want to spend fluke money at the moment, these might get lost or who knows what so id like to keep cost down to 300 max ish or less which would be even better, looking for at least 2-3 of them. i have not been able to find a complete list to compare the three models. or is there one which is just recc over the other two.i have a few of the redfish meters which i got for SUPER cheap still sealed and they work okay but they lack a lot and eat batteries lol. unless they are better then i give them credit for.

author: J-R
author_rank: Super Contributor
timestamp: August 17, 2023, 06:48:06 pm
content: Many of the stores that sell the EEVblog and Brymen DMMs like Welectron have the datasheets and manuals on each product page for easy access.

author: coromonadalix
author_rank: Super Contributor
timestamp: August 18, 2023, 12:34:10 am
content: https://www.eevblog.com/forum/testgear/multimeter-spreadsheet/msg393947/#msg393947

author: EEVblog
author_rank: Unknown
timestamp: August 18, 2023, 01:27:13 am
content: Quote from: mastershake on August 17, 2023, 06:28:02 pmI don't think any such detailed comparison exists.For field use I wouldn't get the 121GW, it's more of a lab meter.The BM235 is the best if you want a small size, big display or a LowZ function.BM786 is better if you want higher accuracy and count.CAT rating wise the BM786 is technically better, but I don't think I'd ever make a buying decision over that unless you are on the extreme edge of that sort of industry.
Need recommendation for electrical installation testing - Page 1
Forum section: electronics / testgear

author: neikalo
author_rank: Contributor
timestamp: August 16, 2023, 08:56:57 pm
content: I need a cheap and cheerful meter that has a high current (200mA) resistance range for testing earth bonding. Ideally in the same meter as a loop or RCD tester. Or part of an insulation tester.I can't find anything by browsing Aliexpress.

author: Gyro
author_rank: Super Contributor
timestamp: August 16, 2023, 09:14:19 pm
content: Aliexpress isabsolutelythe wrong place to be looking!You haven't got your country flag set so it's only possible to give limited suggestions. You also haven't said what context you are doing this testing in. There are legal implications in many countries.Multtifunction testers (MFTs) -the resistance, insulation, RCD etc tester that you are takling about, are available from several manufacturers of professional equipment, again depending on location. In the UK for instance it would be Martindale, Kewtech, AVO, Fluke plus probably a few others.As electricians move over to MFTs, they often sell off their single function testers on ebay, for instance an Insulation (high voltage) and Continuity (=low resistance higher current) tester, RCD tester, Loop impedance tester etc for little money. They will be out of cal, so can't be used for installation certification but can still be useful and verifiable. For example, it is easy to check the accuracy of an Insulation and Continuity tester with a few low and high value resistors and a DMM [Edit: others are more difficult].You really need to give more detail of where you are and what you are trying to do.

author: themadhippy
author_rank: Super Contributor
timestamp: August 16, 2023, 09:26:05 pm
content: Another option is a pat tester,high voltage insulation test and high current continuity all in the one box, although you may have to get creative with your test lead set up.

author: mahyarJbr
author_rank: Newbie
timestamp: August 17, 2023, 07:17:55 am
content: Considering your specific requirements for both functionality and budget, I recommend exploring brands like Fluke, Hioki, and Kyoritsu, and if you wanted to buy from an installation testing distributor visit Amazon,mme-ae or aabtools
Owon HDS310S (14-bit) what?  - Page 1
Forum section: electronics / testgear

author: u666sa
author_rank: Frequent Contributor
timestamp: August 17, 2023, 04:47:43 am
content: linklinkEverything seems to be the same, even the price is the same, except the new 14-bit resolution.I e-mailed Owon asking them where is the product page. They asked me to send links to where this is sold, so I guess it's either a fake, or it is a test model or something like that.I did not find 200 Mhz versions, only 100 Mhz and 70 Mhz.As it often happens, I bought HDS2202S several days ago, having to clue about this version, because obviously it is not on their product page on official website.Yesterday, aliexpress just decided to show it to me on recommended page.

author: markus_jlrb
author_rank: Regular Contributor
timestamp: August 17, 2023, 06:54:23 am
content: Same to me. I have purchased view days ago the 200MHz HDS2202S version too.But as I already have the 2042S, 2072S and the 2102S versions in my lab, would befine to have the next generation of a HDS device with 14bit ADC if it really exist inthe product pipeline.If someone has more details concerning this issue please share with us.Markus

author: Aldo22
author_rank: Super Contributor
timestamp: August 17, 2023, 08:52:18 am
content: Apparently this is no longer available.The 14 bit vertical resolution refer to the waveform generator afaics.https://www.saelig.com/product/hds310s.htm

author: u666sa
author_rank: Frequent Contributor
timestamp: August 17, 2023, 10:12:38 am
content: Yea, but what is it? Original Owon or fake or what? In terms of new-ness, is it newer or older the current HDS2202S models?

author: Aldo22
author_rank: Super Contributor
timestamp: August 17, 2023, 10:46:12 am
content: Quote from: u666sa on August 17, 2023, 10:12:38 amI don't think this is a fake.Here is a quick guide from the Owon China website:http://www.owon.com.cn/probook/HDS300_series_quick_guide.pdfBut I don't know when it was released and it seems to have somehow disappeared from support etc.Strange.EDIT: In this forum it was mentioned here:https://www.eevblog.com/forum/testgear/owon-hds-200-handheld-oscilloscope-w-builtin-dmmawg/msg4298842/#msg4298842
Variac wiper carbon brush  lifts off the wiper track - Page 1
Forum section: electronics / testgear

author: Faringdon
author_rank: Super Contributor
timestamp: August 15, 2023, 02:19:21 pm
content: Hi,Just cleaning a three phase variac that was showing different L's and R's......i now see that the top coil's wiper comes off the coil track completely when you get down to the lower and higher voltage levels......so the carbon doesnt even contact one of the coils for a lot of the wiper track....only the middle of the track does it contact....other two coils are OK.(ends of the coil)Do you know what has caused this, and how to fix?....Looks like the brass brush holder is getting stuck in the metal shaft piece...will file it down inside...and apply grease.Any other tips appreciated?I found this out whilst cleaning it...this was going to be my question, before the above became known....(Just cleaning a three phase variac...just replaced the carbon wiper...and now its squeaky and a bit stiff and unsmooth as the knob is turned....is there any grease for this purpose?...obviously a non conducting grease.).Also, do you know where to buy the wee carbon brushs?...its just a piece of carbon (graphite?) of dims 13.4mm x 9.3mm x 2.5mm

author: jpanhalt
author_rank: Super Contributor
timestamp: August 15, 2023, 03:25:15 pm
content: Pictures ..... pictures..........

author: AVGresponding
author_rank: Super Contributor
timestamp: August 15, 2023, 04:30:04 pm
content: Sounds like the shaft is bent or somehow misaligned.Yes, it's just normal brush material. Any brush the right size will do, or if you can, machine one down to size.Don't use grease on the wiper; you'll cause connection issues. Carbon is a pretty good lubricant on its own, it'll improve as it beds in. Unless you've too much spring pressure on it.

author: factory
author_rank: Super Contributor
timestamp: August 16, 2023, 04:51:53 pm
content: Erm no, variac brushes are not just any brush material, in use the brush will short out turns.The weblink below gives examples of methods used for preventing damage from the shorted turns, either by special brush material, or separate wipers & diodes.https://sound-au.com/articles/variac.htmDavid

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 16, 2023, 06:29:20 pm
content: I think some variac brushes use a sandwich of layers of copper and graphite, to preferentially conduct in the wire-to-base direction without shorting turns. May only be the case for higher powered ones.RS sell replacementshttps://docs.rs-online.com/8007/0900766b8157d4f4.pdf

author: AVGresponding
author_rank: Super Contributor
timestamp: August 17, 2023, 05:22:04 am
content: Copper and graphite... exactly the same as high power brushes. Plain graphite, exactly the same as normal brushes.The brushes in my variacs are plain graphite, but then they are only 500VA and 3kVA.
Anritsu - EEPROM reading/writing (S/N, Model ID, Options, etc.) - Page 1
Forum section: electronics / testgear

author: tv84
author_rank: Super Contributor
timestamp: August 13, 2023, 10:56:02 am
content: I've came across some infos about models/options on Anritsu devices, that I would like to share just to provide some reference for all.Maybe this is common knowledge but nonetheless...AFAIK the device EEPROM contains, among other things, the active options bitmasks which can be activated by loading specific licenses or by rewriting the EEPROM directly (requires desoldering).I was told the list of options was recreated from the MS2720T_V4.60 FW but should be the same of other models FW.Beware that the whole EEPROM contents has the bytes bit-reversed. The fields are Low-Endian as usual.To (re-)calculate the EEPROM Checksum, you just need to sum all bytes inside the red areas (see picture). The result should be placed in the green area.

author: anmony
author_rank: Newbie
timestamp: August 15, 2023, 03:14:08 pm
content: On my MT8222A I was able to telnet into the VxWorks shell, and they left a handy command to update the options and EEPROM checksum for you. Checking a few of the option numbers against your list, it looks like roughly the same option list was in my firmware (v1.80). The VxWorks command is "sysSetOpts" and just takes a byte array as input that gets written to EEPROM. There is also a "readEEPROM" command that you could use to backup the contents of your EEPROM before messing with it, for example I had run "readEEPROM 0x240, 0x10" to look at my options data before and after modifications (looks like you have identified that offset as "OldOpts (*** OPTIONS ***)").The attached script is what I used to generate the sysSetOpts command to enable all of the (sensible) options on my device. VxWorks shell did not require any login, just telnet on default port (23). The sysSetOpts command just calls statUnprotectEeprom/gstatRWEEPROM/statProtectEeprom so you may be able to do the same things if sysSetOpts isn't directly available in your firmware.I was able to extend the frequency range of the VNA in my device from 4GHz to 6GHz with this, and although the performance is somewhat degraded beyond 4GHz (maybe missing some factory calibration or something? or could just be hardware limitations), it does work fine after calibration with reduced dynamic range. I tend to just use my LiteVNA now instead though because it's so much faster and easier to use, and the MT82222A occasionally stops working (UI still responds but acquisition does not, not sure if hardware or software issue). It's still a useful spectrum analyzer though apart from being a bit slow.

author: tv84
author_rank: Super Contributor
timestamp: August 15, 2023, 08:05:32 pm
content: Some other commands:sysSetMACAddrsysSetExtSNsysSetIntSNsysSetModelsysSetOpts - updates Options of the first 2 UInt64 bitmask (1_to_128)sysSetNewOpts - updates Options of the second 2 UInt64 bitmask (129_to_256)