hybridfree/eevblog-posts huggingface dataset:
TEKTRONIX  A622  CURRENT PROBE Chinese clone - Page 1
Forum section: electronics / testgear

author: R_G_B_
author_rank: Frequent Contributor
timestamp: October 02, 2016, 07:14:33 pm
content: Chinese clone..look like a Tektronix A622 or fluke.http://www.ebay.co.uk/itm/221919330855A lot of high end stuff is manufactured in China to keep cost down for the companies making test gear in the West. So why is it not possible to find a clone that works as good as the original?The Chinese are capable of making decent test equipment right?R_G_B

author: HighVoltage
author_rank: Super Contributor
timestamp: October 02, 2016, 08:41:40 pm
content: This probe is originally made by AEMC and not by Tektronix or FlukeWho knows, may be it is not a clone but a real one.I don't think that they are that easy to fake with all the details looking the same.But then, we thought the same of the Agilent GPIB to USB adapter and found out they were all fake..May be someone here bought one and can take it apart?I have a few real, original and different branded once and could open them for comparison sake.

author: Ice-Tea
author_rank: Super Contributor
timestamp: October 02, 2016, 08:53:03 pm
content: Quote from: R_G_B_ on October 02, 2016, 07:14:33 pmSure. But most people knocking on their door don't ask for "as decent as possible". They ask for "as cheap as possible".

author: tautech
author_rank: Super Contributor
timestamp: October 03, 2016, 08:28:35 pm
content: I'd happily bet it's one of these:http://www.ypioneer.com/htmlmodel/cpxx/2008148823.html

author: mos6502
author_rank: Frequent Contributor
timestamp: October 03, 2016, 10:40:07 pm
content: Specs aren't that great, though. 3%+50mA accuracy, 50mA lowest current. For comparison, a Wavetek 238 has 1%+2mA and can be had for half the price (used).
Tektronix 2445B vertical problem (solved) - Page 1
Forum section: electronics / testgear

author: mmaseda
author_rank: Contributor
timestamp: October 02, 2016, 08:10:36 pm
content: I was using my 2445B today and noticed that when using the vertical position knob that the amplitude of the waveform gets larger as it is moved towards the bottom of the display. This happens on both channels 1 and 2 but not on 3 and 4. See attached pictures. Any ideas what the problem is ?

author: Orange
author_rank: Frequent Contributor
timestamp: October 03, 2016, 06:56:53 am
content: I would start by checking the power supplies first. If that is within reasonable limits. You probably have a faulty channel switch hybridU400, 155-0236-00It's a common malfunction in the 2445/2465 series.

author: mmaseda
author_rank: Contributor
timestamp: October 03, 2016, 01:45:55 pm
content: U400 was the problem. Thanks !!!!
$150 Protek/rygol 6920c. Bargain? - Page 1
Forum section: electronics / testgear

author: ryan123
author_rank: Contributor
timestamp: September 26, 2016, 08:06:35 am
content: I found a chap selling a working $150 Protek/rygol 6920c for $150 AU.......its 2 channel and 200MHZI cant find any info about it online, perhaps its an old model or made for a special task?Any info or input would be quite helpful since i am fairly certain there is no other posts on this forum about this specific scope.Anyone else think i should give it a go?Thanks in advanced!(btw i haven't inspected it yet,just communicated via phone)

author: wraper
author_rank: Unknown
timestamp: September 26, 2016, 08:16:02 am
content: Neither. Just an old scope with 4k of memory which I wouldn't recommend to buy.

author: ryan123
author_rank: Contributor
timestamp: September 26, 2016, 09:41:21 am
content: Im looking at getting it as my first scope, is it really no good?i thought it was a half decent deal?Quote from: wraper on September 26, 2016, 08:16:02 am

author: tpy
author_rank: Newbie
timestamp: September 26, 2016, 10:34:56 am
content: Protek is a korea brand, so you can find it on korea website.

author: pascal_sweden
author_rank: Super Contributor
timestamp: September 26, 2016, 05:00:40 pm
content: It could have some collector item value for the Rigol afficionados

author: ebclr
author_rank: Super Contributor
timestamp: September 26, 2016, 05:25:18 pm
content: It's a nice instrument for the price, If you affordability is on that point, buy, will take years before you can really need a upgrade since this is your 1st scope.Take look one bays for price reference on used oneshttp://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=osciloscope&rt=nc&_mPrRngCbx=1&_udlo=100&_udhi=600

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 26, 2016, 07:10:06 pm
content: It is probably a Rigol-manufactured Agilent DSO3000 scope.http://www.keysight.com/en/pc-1000003120%3Aepsg%3Apgr/3000-series-oscilloscopes-2-channel-60-200-mhz?nid=-32455.0&cc=CZ&lc=engIt was nice back in 2005.

author: wraper
author_rank: Unknown
timestamp: September 26, 2016, 09:55:49 pm
content: Quote from: Hydrawerk on September 26, 2016, 07:10:06 pmCompletely different front panel.

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 27, 2016, 02:18:31 pm
content: Yes, but note the similar rotating handle. I still think that these scopes are very similar.

author: ryan123
author_rank: Contributor
timestamp: October 03, 2016, 05:01:37 am
content: Thanks for the input everyone!i managed to get if for $100 after some bargaining!I am a uni student and hopefully this suits my needs for the next few yearsCheers
HPS40 internal battery charging circuit - Page 1
Forum section: electronics / testgear

author: tzok
author_rank: Regular Contributor
timestamp: October 02, 2016, 10:05:07 pm
content: I've recently scored an old Velleman HPS40 Handheld Scope. It was described as in working condition, but works only on external adapter. When the scope arrived, I discovered that the only reason for not working on batteries was the fact that batteries leaked and the contacts corroded. This was an easy fix, but later I discovered, that the internal charging circuit overcharges batteries. Originally it was designed for 5 Ni-Cd rechargeable AA size batteries, but the charging circuit heavily depends on the external adapter. Manual says that it should be 9VDC non-stabilized or 12VDC stabilized power supply of at least 300mA.Pleas look at the charging circuit schematic:...and its simulation:http://tnij.org/hps40Any ideas how to improve it to make it more safe to the NiMh batteries, but not radically complicating it?P.S.The scope is exactly the same as modern HPS50, the only differences in the hardware of HPS50 are USB out circuit and battery charging circuit (as it uses Li-Ion battery).
What I can use a HP 5372A for? - Page 1
Forum section: electronics / testgear

author: davorin
author_rank: Unknown
timestamp: July 12, 2015, 10:27:33 pm
content: The HP 5372A is listed as a frequency and time interval analyzer....But what can I actually measure with this device?Can I use it for example as a high resolution frequency counter to measure like 1.0000000023 Hz?

author: edpalmer42
author_rank: Super Contributor
timestamp: July 12, 2015, 11:13:19 pm
content: Well, yes, but that's like asking if you can use a Lamborghini Countach to drive to the corner store to get bread and milk.I've got a 5372A but I've barely scratched the surface of it's capabilities. The 'condensed' Reference & Specification Guide is 103 pages long! Depending on the options, it can do things like period, frequency, time interval, phase noise, FFT, Histogram Time Interval (one of my favorites!), Allan Deviation, phase deviation, time deviation, etc. It's basic resolution is 150 ps. Frequency limit is 500 MHz or 2 GHz with the right option.To directly answer your question, I just measured the frequency of the 1 PPS signal from my GPSDO. The 5372A measured it as 1.000 000 000 0 Hz. The measurement took one second. If you want more digits, average over a longer time interval.

author: fujimuji
author_rank: Newbie
timestamp: October 01, 2016, 07:39:28 pm
content: I know it's been a while for this post, but I just came across it as I was looking for more info on the HP 5372A. I too just wanted a frequency counter in the lab, and this was the closest piece of equipment not being used :-PI found a handy feature for this function is to display the results in large numbers that are easier to read while working in the lab. To do so, set it to "Numeric" results mode (top left button), then use the soft button to choose "Formats" and choose the "Bold" soft button.

author: TAMHAN
author_rank: Frequent Contributor
timestamp: October 02, 2016, 06:48:12 pm
content: Hello,if I am not completely wrong, it is, in fact, the predecessor of the 53310A.This is a modulation domain analyzer, which can - among other things - be used to qualify frequency stabilities. More on that can be seen here:
Excel - Visual Basic - Tektronix data transfer via USB - Page 1
Forum section: electronics / testgear

author: Jester
author_rank: Frequent Contributor
timestamp: October 02, 2016, 12:52:11 am
content: I'm attempting to talk with various instruments (tektronix, Agilent etc.) using VB in excel, using this as a starting point:I have no problem communicating with the scope using the Tektronix excel add-in, to send and receive data, however theAgilent VB code hangs during initialization. I want to be able to communicate with other instruments so need a moregeneric and flexible method, so I'm giving VB a try.Using the Agilent code in the spreadsheet (2nd version below), I'm getting the following error when I click the Start button "An IO error occured: HRESULT =80040011" This code appears to be a "OLE_E_CANTCONVERT code meaning Not able to convert object.In the Agilent/Youtube example shown in the video the init code is as follows:Public Sub Intialize_Click()On Error GoTo ioErrorinstrAddress = Range("B4").ValueSet ioMgr = New VisaComLib.ResourceManagerSet instrAny = New VisaComLib.FormattedIO488Set instrAny.IO = ioMgr.Open(instrAddress)Exit SubioError:MsgBox "An IO error occured:" & vbCrLf & Err.DescriptionEnd Suband the code in the supplied spreadsheet is slightly different:Public Sub Intialize_Click()On Error GoTo ioErrorinstrAddress = Range("B4").ValueSet ioMgr = New VisaComLib.ResourceManagerSet instrAny = New VisaComLib.FormattedIO488Set instrAny.IO = ioMgr.Open("DMM3")Exit SubioError:MsgBox "An IO error occured:" & vbCrLf & Err.DescriptionEnd SubThe 3rd Set instruction is the one causing the error.The 2nd version creates the HRESULT = 80040011 error, and the first version, causes excel to outright crash requiring a restart.Does anyone have any insight or have experience communicating with an USB based Tektronix instrument fromexcel using VB?The excel file is available here:https://community.keysight.com/thread/21917

author: Jeff_Birt
author_rank: Regular Contributor
timestamp: October 02, 2016, 02:52:26 am
content: The third instruction takes a argument that is the device address. The string "DMM3" can be converted to an understandable address. The variable 'instAddress' is probably not initialized, that is set to a real address, so it is causing an error.

author: Jester
author_rank: Frequent Contributor
timestamp: October 02, 2016, 03:34:44 am
content: Quote from: Jeff_Birt on October 02, 2016, 02:52:26 amI changed:Set instrAny.IO = ioMgr.Open("DMM3") to Set instrAny.IO = ioMgr.Open("USBInstrument1") and it now worksUSBInstrument1 is the VISA Alias from the Keysight connection expert.Thanks for your help

author: PA0PBZ
author_rank: Super Contributor
timestamp: October 02, 2016, 10:21:47 am
content: Did you notice that the instrument address is pasted in cell B4 on the spreadsheet?After that it is read by the VB program here:instrAddress = Range("B4").ValueThen the variableinstrAddressis used to open the connection.So if you put "USBInstrument1" in cell B4 the example should work unmodified.
Protek 2700 Power Meter - Page 1
Forum section: electronics / testgear

author: joeqsmith
author_rank: Super Contributor
timestamp: October 02, 2016, 01:50:43 am
content: I bought this meter new and it started acting up. Never was a real great meter but good for a ballpark with low frequencies. This is the first time I have had it apart.

author: joeqsmith
author_rank: Super Contributor
timestamp: October 02, 2016, 01:52:54 am
content: Can is made from two parts. One brass. Soldered together. The two circuit boards are also soldered together.

author: joeqsmith
author_rank: Super Contributor
timestamp: October 02, 2016, 01:56:33 am
content: The meter became very unstable. It has not been abused. When I removed the can, there is some crazy rework in there. Once apart, the thing started working. Spent a fair amount of time trying to find a cracked joint in this mess.

author: joeqsmith
author_rank: Super Contributor
timestamp: October 02, 2016, 02:01:44 am
content: Really, not that bad for low frequency. They claim +/-10% of full scale from 10MHz to 1GHz. Full scale ranges are 2W, 200mW, 20mW and 2mW.Shown with 10,1 and -1dBm.

author: joeqsmith
author_rank: Super Contributor
timestamp: October 02, 2016, 02:04:38 am
content: Shown with 2G, 10dBm. Not so great. There are 4 pots to align it but I doubt there is anything to trim it for flatness. I suspect that's what the crazy pile of soldered together mess was for.
Keysight eevblog coupon - Page 1
Forum section: electronics / testgear

author: ebclr
author_rank: Super Contributor
timestamp: October 01, 2016, 04:45:09 am
content: Any US store that handles keysight and have a coupon for eevblog members ?

author: JonM
author_rank: Unknown
timestamp: October 01, 2016, 05:34:18 am
content: I don't know of any EEVblog discounts for Keysight products. However, TestEquity seems to give a small discount when asked for a quote and they were very helpful to me with a recent purchase. They do collect state sales tax in almost every US state which might be more than the discount.Jon

author: Pinkus
author_rank: Frequent Contributor
timestamp: October 01, 2016, 11:02:56 am
content: ZORO have 20-25% offers for a week about 3-4 times per year (the last 25% offer just ended Sept. 28) and they do have several Keysight products (though not all).
Adding tracking to a TS3022S PSU as per model TSTS3023S - Page 1
Forum section: electronics / testgear

author: hazzer
author_rank: Regular Contributor
timestamp: October 03, 2016, 03:14:38 pm
content: I have the TS3022S and on a recent project found I was having to manual track the outputs, later I decided to see what would be involved in adding a tacking option to the twin output PSU. Searching the web I found there was ano version, the TS3023S, with triple outputs and tracking.It looks to be quite a straight forward mod - just 1 DPDT switch and some resistors - though the switch does have to be rated to the full output current - the manual describes the front panel switches as having gold on silver contacts.For anyone wanting to look into this mod - I've posted below links to the circuit and the user manual describing the tracking feature on a TS3023S.My switches are on order...... more when its up and running.service manual for this psu series.http://www.testsell.co.uk/test_equipment_manuals/TTi/TTi%20'S'%20series%20power%20supplies%20manual.pdfoperational manual - see page 7 for the description of tracking.http://www.av.it.pt/medidas/data/Manuais%20&%20Tutoriais/07%20-%20TTi%20Power%20Supply%20TSP3222/TS%20Series%20Instruction%20Manual%20-%20Iss%208.pdfupdate...https://youtu.be/2UsBJLu-8iIswitch was from RS, part 692-5488https://uk.rs-online.com/web/p/rocker-switches/6925488/Harry
eevblog uCurrent OP-AMP Die Photos - Page 1
Forum section: electronics / testgear

author: electronupdate
author_rank: Regular Contributor
timestamp: September 30, 2016, 07:38:33 am
content: Took a few pictures of the OP-AMPs on a ucurrent. Video here:VIDEOPICTURESThe LM321 was not as expected!

author: TheBay
author_rank: Unknown
timestamp: September 30, 2016, 09:42:47 am
content: Very interesting video, enjoyed that!Now viewing some more of your videos, subscribed!

author: Kleinstein
author_rank: Super Contributor
timestamp: September 30, 2016, 09:51:40 am
content: There is a difference between LMV321 and LM321.The LM321 is rare - seems to be just one half of an LM358 used as s single OP.Still strange to find a different die marking inside. Was the LMV321 marked as a Fairchild one ?
Brymen bm235 continuity voltage - Page 1
Forum section: electronics / testgear

author: xrogers
author_rank: Newbie
timestamp: September 28, 2016, 09:49:58 pm
content: Hi All,I need to do some continuity testing on a broken PCB, but my old meter is both slow and too high voltage (about 5v). I can't find either the continuity voltage or maximum current specs for the bm235 in the manual or in web searches.Can someone who knows tell me these numbers, or check their meter and tell me?Thanks!Buck

author: TheSteve
author_rank: Unknown
timestamp: September 28, 2016, 10:03:00 pm
content: Why not measure it with your older meter?

author: xrogers
author_rank: Newbie
timestamp: September 28, 2016, 11:27:25 pm
content: I don't own the meter, I'm considering buying it and want to be certain it'll work for me.Thanks,Buck

author: IanB
author_rank: Super Contributor
timestamp: September 28, 2016, 11:30:26 pm
content: I can measure it later after I get home, if nobody else answers sooner.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 28, 2016, 11:51:13 pm
content: Quote from: xrogers on September 28, 2016, 09:49:58 pmIt's all in the spreadsheet.https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/

author: xrogers
author_rank: Newbie
timestamp: September 29, 2016, 12:53:20 am
content: Exactly the info I was looking for, thank you! And thanks also for the offer to check.

author: retiredcaps
author_rank: Super Contributor
timestamp: September 29, 2016, 01:40:21 am
content: Specs are right in the manual. Page 23http://www.eevblog.com/files/BM235-Manual-EEVblog.pdfDiode Tester - Test Current: 0.3mA typicalOpen Circuit Voltage: < 3.2VDC typicalOhm -1)Open Circuit Voltage: 1.6VDC typical2)Constant Test Current: 0.2uA Typical3)Constant Test Current: 0.02uA TypicalIn most meters, lowest ohm range (600) is the same as continuity.I also listed the diode test because some people use that to check for shorts.

author: IanB
author_rank: Super Contributor
timestamp: September 29, 2016, 03:20:10 am
content: On my meter the open circuit test voltage for continuity is 1.71 V and the test current is 162 µA. These match closely with Joe's measurement on his meter.
update on tektronix 2230 var button - Page 1
Forum section: electronics / testgear

author: nkurtar
author_rank: Newbie
timestamp: September 24, 2016, 01:51:09 pm
content: In terms of Tektronix my cal buttons of vertical atennuators cannot detent. Anybody help me out with possible cure?

author: alsetalokin4017
author_rank: Super Contributor
timestamp: September 24, 2016, 02:19:21 pm
content: Don't worry about it. The extreme clockwise rotation of the CAL knob should give the same value as when it is in the detent position. The detent is just there so that you don't inadvertently change the CAL pot setting when you change the main switch setting. Sometimes it can take quite a forceful twist to get into the detent position on these 22xx series scopes, and this risks breaking the little tabs on the plastic knobs.

author: David Hess
author_rank: Super Contributor
timestamp: September 24, 2016, 06:59:29 pm
content: Are the variable controls stiff? If so, then the potentiometer shafts need to be lubricated.Is your 2230 a rebuild or in original condition? Does it have any signs of having been stored improperly?I just checked my 2230 and 2232 variable controls and the only problem I found is that on my much used rebuilt 2232, the detents are softer than on my others but they are still present.The danger alsetalokin4017 mentions is with the plastic and aluminum flexible shaft couplers between the shaft and potentiometer which are fragile and do not tolerate excessive torque well; the thin aluminum around the set screws tends to crack.http://www.qservice.tv/vpasp/shopexd.asp?id=9444http://www.qservice.tv/vpasp/shopexd.asp?id=4202

author: nkurtar
author_rank: Newbie
timestamp: September 28, 2016, 06:44:16 pm
content: @alsetalokin4017 the shaft 1/8 " is turning freely no detent is possible i mean one of the shafts of my 2 vertical swiches is really loosely turning. Why is it?

author: nkurtar
author_rank: Newbie
timestamp: September 28, 2016, 07:49:30 pm
content: @David no the variable controls are not stiff. I do not know what you mean rebuild but if it is what i think it is in original condition. No it dont have sign of improperly storage.

author: David Hess
author_rank: Super Contributor
timestamp: September 28, 2016, 08:24:32 pm
content: Quote from: nkurtar on September 28, 2016, 06:44:16 pmIf it is turning freely through 360 degrees, then the flexible shaft coupler that I mentioned was probably broken from excessive torque.Unfortunately it is difficult to inspect this area of the 2230 because of how the storage board on top is mounted. It is designed to tilt out of the way but the front panel switches along the top need to be pulled apart.
Tenma 72-10500 How to use OCP and OVP ? - Page 1
Forum section: electronics / testgear

author: alin_im
author_rank: Regular Contributor
timestamp: September 27, 2016, 04:55:07 pm
content: Hey guys,I recently bought a cheap Tenma PSU (re-badge of the Korad KA3005p) and I was playing around with it, but I have some problems figuring out how to operate the Over Current Protection and Over Voltage Protection on it. In the manual there is nothing specified about it and if the current is set too low (<200 mA) and the OCP is on, the Output is shutting down. Can you help me?Kind regards,Alin I.
Analoguge discovery as a in circuit  componet tester I V tracer curve tracer  - Page 1
Forum section: electronics / testgear

author: R_G_B_
author_rank: Frequent Contributor
timestamp: September 27, 2016, 05:12:26 pm
content: I have been trying to repair a graphing multi meter and have found this method the most usefulI thought I would share a link for those who have a analogue discovery to hand the for use of in circuit component testing.http://www.jhongelectronics.org/2014/03/using-analog-discovery-as-iv-curve.htmllink
Measuring current > 50MHz  (i.e. what to do when the A6302 rolls off) - Page 1
Forum section: electronics / testgear

author: Jester
author_rank: Frequent Contributor
timestamp: September 26, 2016, 08:49:42 pm
content: This does not have to be clip on like the A6302 probe, assume I have access to the signal and can pass it through a CT or circuit if need be.How high a frequency? anything beyond 50MHz would be an improvement, 500MHz would be ideal.

author: nctnico
author_rank: Super Contributor
timestamp: September 26, 2016, 08:54:33 pm
content: IIRC Tektronix has some high frequency AC only current probes. Connecting it to the circuit may be a challenge though.

author: David Hess
author_rank: Super Contributor
timestamp: September 26, 2016, 09:32:10 pm
content: The Tektronix CT-1 is 200 MHz and the CT-2 is 1 GHz. These were used inside some of their products.http://w140.com/tekwiki/wiki/CT-1With a suitable (small) core you could make your own. The difficulty would be testing unless you have a vector network analyser.
Eico 950 Help!!! This is not your run of the mill Eico 950 Capacitor Analyzer!!! - Page 1
Forum section: electronics / testgear

author: finom1
author_rank: Regular Contributor
timestamp: September 26, 2016, 12:02:16 am
content: Hello everyone,Here is an opportunity for all you Geniuses to share your wisdom with the world again!!!The Old64goat needs help. He has a Eico 950 and one of the last problems to solve is: Both "Expanded Ranges" do not work.Parts have been replaced, including the eye tube.1. To save time you could start with 2nd to the last Video, Time Index of 35:40 on this video - UPDATE On The EICO 950 (RE UPLOAD)2. This is the last video from today Sept 25, 2016. To save time start at Time Index of 4:35 - The Blind Tinkerer Does An Update Flap -3. The videos in order are:A. EBAY Un-Boxing EICO 950 -B. This Is Not Your Run Of The Mill EICO 950 -C. The EICO 950 Story by The Blind Tinkerer -D. This Eico 950 Has Got Me Stumped -E. Still Playing Around With The EICO 950 -F. UPDATE On The EICO 950 (RE UPLOAD) -G. The Blind Tinkerer Does An Update Flap -The OldGoat is a very nice person in need of some help. He is trying to start up an Electronics Repair/Test Bench again. The people on this forum are extremely friendly and intelligent, could you please help him with the last issue on his Eico 950 Capacitor Analyzer and Resistance Bridge?Thank you for any advice!!!
Silent fan for tek dpo3000 - Page 1
Forum section: electronics / testgear

author: ehsmeng
author_rank: Contributor
timestamp: September 25, 2016, 08:22:24 pm
content: I have a lovely Tek DPO3000 that I really enjoy, but the fan sound is ridiculous. It's a 120x120x25 12v sanyo fan. Does anyone have a recommendation where to get a very silent replacement?Apologies for not having removed the bar on the attached image, but it appeared glued and I chickened out.

author: nctnico
author_rank: Super Contributor
timestamp: September 25, 2016, 10:14:17 pm
content: I'd try rubber fan mounts first. Chances are the noise gets coupled into the scope's casing.
Rigol 1054 triggering - Page 1
Forum section: electronics / testgear

author: sndchaser
author_rank: Newbie
timestamp: September 25, 2016, 01:41:50 am
content: Question with a problem (likely user error) I'm having with my Rigol 1054 that I didn't have with my Tektronix scopes. I'm edge triggering, have the trigger level set, and on some signals I get the expected triggering (1st picture) and on others I get a blur (like the other pictures). I'd appreciate it if someone could point out what I'm doing wrong. Thanks

author: sndchaser
author_rank: Newbie
timestamp: September 25, 2016, 02:06:07 am
content: Persistence is on Min. I put it on normal triggering and still get the blur. With single triggering I see that my duty cycle is irregular, so I guess this triggering behavior for auto and normal is as intended?

author: tautech
author_rank: Super Contributor
timestamp: September 25, 2016, 02:22:32 am
content: Quote from: sndchaser on September 25, 2016, 02:06:07 amThis looks like a data stream and your rising edge triggering probably isn't helping for a negative going signal.Also if it is a data stream it'snota repetitive waveform and therefore triggering will not be stable without additional trigger parameters being set.The clue is a blurry waveform that it's not repetitive and confirmed with the Single shot.

author: sndchaser
author_rank: Newbie
timestamp: September 25, 2016, 02:27:42 am
content: Surprisingly, it's actually not a data stream, it's an apparently defective frequency divider IC (it should take the 500kHz signal from the stable shot and divide it down to each frequency in an octave of musical notes). I've seen the blur on other analog signals with this scope, just curious what other triggering parameters I could be trying to get stable triggering?

author: Fungus
author_rank: Super Contributor
timestamp: September 25, 2016, 05:37:47 am
content: Quote from: sndchaser on September 25, 2016, 02:27:42 amYour triggerisstable. It's the signal that's wonky.If you pick a random rising edge in that signal then the data on either side is unpredictable.

author: sndchaser
author_rank: Newbie
timestamp: September 25, 2016, 10:51:32 am
content: Yes, the chip is an MK50240 from the 1970's:http://www.datasheetspdf.com/datasheet/MK50240.htmlIt really just divides a square wave into 13 slower square waves. Way before I2S was even dreamed of. The triggering wasn't working as I expected it to because the chip has failed.

author: David Hess
author_rank: Super Contributor
timestamp: September 25, 2016, 08:30:53 pm
content: Automatic triggering just means that after a period of time without a valid trigger, the acquisition or sweep is started anyway so at least something is displayed. Normal triggering always waits for a valid trigger. On a Tektronix you can check this condition via the trigger indicator; I don't know if Rigol includes this.You should have gotten the same results with a Rigol or Tektronix oscilloscope.
Why does my spectrum analyzer do this? - Page 1
Forum section: electronics / testgear

author: luckyflyer
author_rank: Contributor
timestamp: September 28, 2016, 04:44:38 pm
content: My new to me HP 8560E displays a signal at 0 hz. I'm told that this is normal but why does this happen?

author: 0xfede
author_rank: Regular Contributor
timestamp: September 28, 2016, 05:16:20 pm
content: It's the LO feedhtrough.Searching it with google will give you lots of results. For example here:http://wireless.ictp.it/school_2005/download/rohdeschwarz/SpectrumAnalysysis.pdfin chapter 5.7 LO feedthrough is explained.Best,0xfede

author: chris_leyson
author_rank: Super Contributor
timestamp: September 28, 2016, 05:24:53 pm
content: It's normal, all swept spectrum analyzers do this, the combination of the swept oscillator and fixed oscillators in the RF and IF chains if set the the right frequencies will sweep through DC or 0Hz. Say you had your span set to 20MHz for sake of argument and you center frequency was 0Hz, you sweep would start at -10MHz and sweep throught 0Hz at the center and then end up at +10MHz. In fact because the analyzer is scaler and not vector it sees -10MHz and +10MHz as the same thing, there is no phase information.FFT analyzers will work down to DC, all depending on the signal chain before the ADC, but will not see negative frequencies. It needs to be a vector analyzer to see the -ve frequencies. An FFT will only see -ve frequncies if the input to the FFT processor is an I-Q or complex or vector signal, different terms the same thing.

author: chris_leyson
author_rank: Super Contributor
timestamp: September 28, 2016, 05:27:58 pm
content: Damn it, I'm forgetting some fundamental RF issues, thanks Oxfed, LO feedthroughI really miss RF designThat's why the response at DC is there and not because the oscillators can effectively sweep between -ve and +ve frequencies. Shit, take FFT head off and put RF head on

author: luckyflyer
author_rank: Contributor
timestamp: September 29, 2016, 12:36:15 am
content: Thanks guys I appreciate the explanation.
BK / Dynascan 830 capacitance meter - Page 1
Forum section: electronics / testgear

author: Back2Volts
author_rank: Unknown
timestamp: September 22, 2016, 06:10:29 pm
content: I got this meter in an auction. I cleaned up the corrosion on the battery terminals, installed new ones and seems to work.Is anybody familiar with this device? Any ideas on how to check calibration status ?Pictures in "What have you bought today"https://www.eevblog.com/forum/chat/what-did-you-buy-today-post-your-latest-purchase!/msg1032708/#msg1032708

author: radhaz
author_rank: Regular Contributor
timestamp: September 23, 2016, 02:11:53 am
content: I have that unit on a shelf at work. If I remember, I'll check it against my DER-EE5000.

author: MosherIV
author_rank: Super Contributor
timestamp: September 23, 2016, 12:54:02 pm
content: QuoteTry buying/getting some silver mica or polycarb film 1% capacitors. They are pretty accurate out of the box.It will not give exact calibration confidence but will give you some confidence.

author: Back2Volts
author_rank: Unknown
timestamp: September 24, 2016, 04:50:35 am
content: Quote from: MosherIV on September 23, 2016, 12:54:02 pmI will get some on my next Mouser round.
In circuit Capacitor tester - Page 1
Forum section: electronics / testgear

author: dan3460
author_rank: Frequent Contributor
timestamp: September 22, 2016, 03:25:17 pm
content: I have been repairing oscilloscopes for a while and I would like to test suspected caps in circuit. I have seen a whole bunch on ebay from China that are very inexpensive. It seems to me that many of those do not test capacitance, only ESR.Can you guys recommend testers? I will not expend $500+, but i'm willing to pay $100-200. It doesn't need to be new, but I don't want something from 1950's.Thanks

author: HighVoltage
author_rank: Super Contributor
timestamp: September 22, 2016, 04:39:51 pm
content: Take a look at the Peak Electronic ESR60I got it for the same reason and it works perfectly

author: dan3460
author_rank: Frequent Contributor
timestamp: September 22, 2016, 07:48:01 pm
content: I read somewhere that this model was hard to use in circuit? Any truth on that?

author: stj
author_rank: Super Contributor
timestamp: September 22, 2016, 11:24:08 pm
content: the peak and the chinese $15 component testers work equally well and equally badly at in-circuit testing - as will a $1000 device.the problem is parallel components making the cap hard to scan.

author: Tim T
author_rank: Contributor
timestamp: September 23, 2016, 12:15:27 am
content: Not exactly what you are looking for but the method w2aew describes on YouTube for ESR measurement with a scope (#135) has worked for me on a couple of occasions in detecting bad electrolytics in circuit. The waveform of a really bad cap is easy to distinguish from good with a few minutes of practice.tim

author: ruairi
author_rank: Frequent Contributor
timestamp: September 23, 2016, 02:33:25 am
content: I bought the Peak recently and within the first week used it to track down and replace 6 bad caps in a large mixing console power supply. Yes, the in circuit measurement of capacitance can be off with parallel components but if you have the schematic and an idea how things work it makes sense. I couldn't recommend it highly enough.I have no idea who it compares to cheaper options.

author: dan3460
author_rank: Frequent Contributor
timestamp: September 23, 2016, 11:41:41 am
content: Quote from: Tim T on September 23, 2016, 12:15:27 amYes, and yesterday I played with it. I have trashed all the bad electrolytic last week, so I could not test with a bad one, but this system makes sense. I have a scope that I have to work on that has a bad power supply, I will test this method on that board.

author: zaoka
author_rank: Frequent Contributor
timestamp: September 23, 2016, 09:20:56 pm
content: Get analog ESR meter its way faster for troubleshooting than digital.I used MUL-3333 it was $50 peace of crap and did its job perfectly.
Pulse expander option - Page 1
Forum section: electronics / testgear

author: qwaarjet
author_rank: Regular Contributor
timestamp: September 19, 2016, 04:36:13 pm
content: Are there any function generators that have pulse expanding option. If you input a 1us pulse get a 1ms pulse out and 2us in 2ms out. I have taken 3021b but I don't see away to get proportional pulses out just fixed.

author: David Hess
author_rank: Super Contributor
timestamp: September 19, 2016, 09:02:58 pm
content: I have never heard of a pulse or function generator with that capability. Pulse *stretching* is an option with some generators but that only produces a fixed output pulse length from a variable and usually narrow input pulse.It would not be difficult to design a dedicated circuit for this. Make the input pulse trigger the first edge of the output pulse. Integrate the input pulse with one current and integrate the output pulse with a fraction of the current back to zero. Pulse stretching time to digital converters work this way.

author: tautech
author_rank: Super Contributor
timestamp: September 19, 2016, 10:17:57 pm
content: Quote from: qwaarjet on September 19, 2016, 04:36:13 pmNot proportional that I'm aware of.However most AWG's that have an external trigger will do this, just you'll have to set the output pulse length you require.

author: MarkL
author_rank: Unknown
timestamp: September 23, 2016, 01:47:18 am
content: I don't have a product recommendation for you either, but if your pulses are digital and you can tolerate an output where the width is not linearly controlled, this would be pretty easy with a microcontrollerMany microcontroller timer peripherals have capture capability and you can use that feature to time the leading and falling edges of the input pulse. And then use another timer to generate the output multiplied by 1000, or simply clock the output timer 1000 times slower.Some of the faster parts allow the timer clocks to run as fast as 216MHz, providing a resolution of a little less than 5ns to measure your input pulse. The STM32F7xx is one example I'm familiar with, but other manufacturers have similar or could have even faster capture capabilities.You're a little light on the details, but thought I'd throw this suggestion out there.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: September 23, 2016, 03:29:03 am
content: Sounds like a dual-slope ADC type of thing. You'd use your input pulse to switch in a current source to charge a capacitor, and discharge it with current source/1000 for the output pulse.

author: qwaarjet
author_rank: Regular Contributor
timestamp: September 23, 2016, 04:37:54 am
content: The goal was to find a COTS system that could do this for proof of concept. long term I would spin a FPGA and custom interface.
Good mixed signal DSO with Protocol analyser etc that is NOT WINDOWS based - Page 1
Forum section: electronics / testgear

author: David Spicer
author_rank: Contributor
timestamp: September 23, 2016, 01:11:42 am
content: Looking for high quality NON WINDOWS mixed signal scope with protocol analyser.Fingers burned by Windows based test gear twice now. It appears to provide TEK, Keysight etc with a terrific "not our fault" built in obsolescence. Cause in point : My TLA715. W2K HDD dies, replaced with new IDE drive with XP, New Tek software. A total nightmare of windows hell and "unsupported" operating system. Only 10 years old. Absolutely legal XP license, but XP is now obsolete. Without the help of some smart dudes on this forum I'd not have succeeded at all. Immense difficulty just getting validation code etc. Still cannot get drivers for ethernet card. I had to format and install WXP on an old P3 system I dug out, then move HDD to TLA. Jeez.Besides, Windows for test gear?? Please! A poor desktop choice ev en for Wives and other loved ones. Ms seem to want to take over the Enterprise server space. Good luck against the Linux lads there boys! But Test equipment. Errrrrrr I don't think so.So: Can anyone recommend a good 500Mhz (at least) mixed signal DSO, just like the ones Tek and Keysight are making but NO WINDOWS.Afterword: I have a 1995 Tek. 200Mhz, CRT display, does frequency domain analysis, spectrum etc, remote logging thru RS232 or GPIB. 20 years old, still good as new. Problem is, I need at least 500Mhz and serial protocol (USB3/USB3.1/PCIe etc) analysis.I'd like one of those DSO, 16bit LA, Serial protocol analyser 'scopes. I have a pretty sizeable budget if I find it. But I will not be burned a third time by Microsoft. I don't want to be told it's all obsolete in ten years time. My workshop is entirely MS free. Goodbye ALtium I'm afraid, but hello Cadence, which was always a "better" EDA tools anyway. Fedora Linux and Apple OSX. Vivado, Cadence, Various open source compilers etc.Current project is aimed at Zynq and Zynq Ultra scale BTW.
USB Driver(s) for UNI-T oscilloscope - Page 1
Forum section: electronics / testgear

author: resurgance2001
author_rank: Newbie
timestamp: September 22, 2016, 12:30:15 am
content: HiCould anyone tell me where I can download the sub driver(s) and software for a UNI-T scope: UTD2052Cl?I lost this CD that came with the scope and the software seems to have got corrupted. I have searched all over the net but not found anything yet.Thanks in advance for any help.Cheers.Peter

author: resurgance2001
author_rank: Newbie
timestamp: September 22, 2016, 08:42:36 pm
content: Thanks BlueskullI tried that. The problem seems to be more complicated. I really need the original disk. The oscilloscopedoes not want to accept anything else. Really pissed because I had the disk but accidentally left in the IT support office at my school and it went missing.I only want this so I can show to my students what's on the oscilloscope via a projector. I am now at the point of considering purchasing a Hantek PC scope. I've seen one that claims to be 250 MHz with IG/sec sampling, and less than 200 pounds. At least it would mean that if I was moving from classroom to classroom (which is often), I would not have to lug around the bench top scope. Still pissed though - I like the UNI-T stuff. For what it is - budget - it mostly does the job, but getting any supporting software to work is difficult. Had similar problems before with one of their DMM's

author: tautech
author_rank: Super Contributor
timestamp: September 22, 2016, 09:04:02 pm
content: IFthe DSO software requires NI VISA, the USB drivers are within that package.Typically for Siglent ausbtmc.inf is supplied in the NI VISA package.(Possibly in: C:\Program Files\IVI Foundation\VISA\IVI USB Staging)You need to point your OS to use the correct driver in the correct file location for it to work.
Ohmite 3416 Decade-Ranger, Decade Box - Page 1
Forum section: electronics / testgear

author: Jeff_Birt
author_rank: Regular Contributor
timestamp: September 13, 2016, 02:17:42 pm
content: I bought this from EBay and had to take it apart before heading off to work this morning. I noticed two screws missing after taking it out of the box which is never a good sign, but I did find one of them in the box. In general it is in good shape except for 4 burnt 1K resistorsLooking at Ohmite's website it does not look like they still make the same series of resistor that is in the box. The 1K resistors are marked:GP 1/2, 1K, 0.1%, TC25Which I take as 1/2W, 1K 0.1% (duh), and a TC of 25PPM. The closest I saw on Ohmites website was the Arcol MRA series. Arcol is hardish to get in the USA though, not a large selection have I found. I did find some suitable Vishay resistors in the CMF55 series (about $1 ea.). I sent Ohmite a note to see if they have any suggestions from their product line, after all they have to use some product of theirs to make them as they are still a current offering.

author: Vgkid
author_rank: Super Contributor
timestamp: September 13, 2016, 03:34:51 pm
content: Thanks for the teardown. I almost bought one a few years ago.

author: Jeff_Birt
author_rank: Regular Contributor
timestamp: September 22, 2016, 01:17:05 pm
content: I heard back from Ohmite who confirmed the decoding of the burnt resistor part number and that the MRA Arcol series was the closest match. Alas, these are hard to get in the USA so I chose the Vishay resistors which were ordered and came in yesterday.I was able to take the damaged switch loose without having to disassemble the whole unit which was a big time saver. The burnt resistors were extracted and replaced with the Vishay parts. Both resistors are 1/2W metal file, 25PPM TC but the Vishay resistors are noticeably smaller in diameter.After reinstalling the switch it was tested with my freshly calibrated HP 3478A. I calibrated the meter yesterday in 2 wire mode so understandably the single ohms range reading was off more than 0.1%. But the higher ranges were all well within spec. The zero ohm reading (all switches to zero) was 70 milli-ohms, but given the meter can only read down to 30 milli-ohms and I was using it in 2 wire mode I would not bank on that value, but non-the-less the switch contact resistance is low.

author: Jeff_Birt
author_rank: Regular Contributor
timestamp: September 22, 2016, 01:22:01 pm
content: And finally the fixed switch. Since the switch body is ceramic the residue from the burnt resistors was easily cleaned up with a Q-tip and alcohol. Even with having to do the repair I am very happy with this purchase.
LISN 50uH Solar Electronics 9252-50 Teardown - Page 1
Forum section: electronics / testgear

author: Jester
author_rank: Frequent Contributor
timestamp: September 21, 2016, 03:06:46 pm
content: I was going to build a 50uH LISN, and then I spotted this one for less than the parts to build one.Pretty old, the GE calibration stickers were intact until I opened it.

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: September 22, 2016, 01:23:04 am
content: Hi,Thank you for posting the pictures.If I had to guess the schematic, I would guess this:If you still have the unit open, may be you can confirm the component values?Make sure that you protect your spectrum analyzer input, preferably a dc block and a limiter or as a minimum a high power 10dB attenuator.Regards,Jay_Diddy_B

author: Jester
author_rank: Frequent Contributor
timestamp: September 22, 2016, 02:28:21 am
content: Quote from: Jay_Diddy_B on September 22, 2016, 01:23:04 amGood guess:- the 4uF's are actually 5uF- the 1k is actually 1k1, (only one) and is connected from the BNC out to chassis- there is a 560k in parallel with the 5uF capacitors- There is a 51r in the switch circuitGood advive, I will use a DC block and attenuator, or perhaps add one internally to be on the safe side.
Positive / Negative Voltage with Siglent SPD3303X-E - Page 1
Forum section: electronics / testgear

author: Ducttape
author_rank: Regular Contributor
timestamp: September 18, 2016, 09:55:56 pm
content: Can the Siglent SPD3303X-E provide a +/- voltage output? Attached image shows how they describe the 'series mode':In series mode would you simply connect to Channel 1 '+' or Channel 2 '-' for the zero reference? Or ignore 'series mode' and just jumper externally?/a/csCaG]http://imgur.com/a/csCaG

author: tautech
author_rank: Super Contributor
timestamp: September 18, 2016, 11:59:57 pm
content: Series mode is using 2 channels connected in series internally to double the output voltage but in doing so you only then have 1 fully adjustable channel. As the outputs are isolated from mains ground you can indeed just reverse the leads to provide the negative supply you need.

author: Ducttape
author_rank: Regular Contributor
timestamp: September 19, 2016, 03:09:59 pm
content: I probably should have been clearer than '+/-'. What I wanted to verify was that it could provide dual polarity, supplying both + and - voltage to, say, an op amp. It's pretty clear to me now that it will be able to and not have any bizarre hidden gotchas in the design or user interface.I was just being overly cautious since I was about to order the Siglent, which I've now done.I'm pretty new to electronics. I was going to order the Rigol DP832 but then I decided that the floating outputs on the Siglent were worth more, to me at least, than any other advantages of the Rigol.

author: Mark
author_rank: Frequent Contributor
timestamp: September 20, 2016, 05:22:40 pm
content: Yes it will give you 0V as you describe:"simply connect to Channel 1 '+' or Channel 2 '-' for the zero reference"