hybridfree/eevblog-posts huggingface dataset:
Curve Tracer of LockyZ: Better UI and Translation - Page 1
Forum section: electronics / testgear

author: EinErik
author_rank: Contributor
timestamp: July 06, 2021, 10:53:49 pm
content: Hi,Here is 3rd-party work for LKZ's tracer, the Github repo:https://github.com/Erikovsky/Tracer-SystemYou can also download the latest main software, ads7871_V3S.exehttps://github.com/Erikovsky/Tracer-System/releases/download/V1.1/ads7871_v3s.zipSee attachents for the updated UI, the diagram can be enlarged and clearer to see.Also, there's another thread on DIYAudio for this UI optmization.https://www.diyaudio.com/forums/equipment-and-tools/360635-curve-tracer-lockyz-ui-translation-4.html
8590 series CRT slant - Page 1
Forum section: electronics / testgear

author: veedub565
author_rank: Frequent Contributor
timestamp: June 19, 2021, 08:13:09 pm
content: I have a HP 8590 series SA with a decent display, but it's slanted and I don't see any adjustment for that. Any idea what needs tweaking here ?

author: MarkL
author_rank: Unknown
timestamp: June 20, 2021, 12:39:28 am
content: It doesn't look too bad, but if it bothers you...You need to open the CRT case and slightly twist the magnetic deflection assembly (aka "yoke") that sits on the neck of the CRT. I haven't opened the CRT on the 859x series specifically, but there should be a compression clamp on the yoke that you will have to loosen first. Even after loosening the clamp the yolk may be stuck after being on there for many years. Be gentle.Safety notes:- There is high voltage in this area and in other areas inside the CRT case, even when off.- When done, don't over tighten the clamp because too much pressure can cause the CRT neck to crack or shatter.There are some youtube videos on CRT yoke adjustment if you search for them.

author: veedub565
author_rank: Frequent Contributor
timestamp: June 24, 2021, 07:50:05 am
content: I think rotating the yoke would rotate the whole image. The horizontals are fine it's the verticals which are a bit skewed, especially towards the right hand side. I've been having a read, and wondering now if it's a problem with the S correction. I've had a couple of these CRT's where the capacitors have changed value with age and it's killed the drive. Maybe a similar thing has happened here. I'm going to try a ew capacitor in the deflection circuit and see if that helps.

author: MarkL
author_rank: Unknown
timestamp: June 25, 2021, 03:38:05 am
content: Yes, rotating the yoke would indeed rotate the whole image. I wasn't completely sure what distortion you were referring to.Take a look at this manual for the Panasonic TR-60S1A monitor:https://elektrotanya.com/panasonic_tr-60s1a_chassis_y21_sm.pdf/download.htmlIf you have this monitor or something similar, the manual describes some additional tweaking magnets that may help the distortion.It doesn't seem to me like a capacitor problem, but I'm interested if you don't mind posting the fix when you figure it out.

author: veedub565
author_rank: Frequent Contributor
timestamp: July 06, 2021, 05:08:04 pm
content: Thanks Mark, I've decided to leave it alone. Tweaking the yoke and/or magnets might or might not sort it. Or it might make things worse by me messing with it. I did replace some of the caps in the deflection coil circuit just in case there was an s correction problem. didn't make any difference.
BK Precision 875B LCR meter repair attempt - Page 1
Forum section: electronics / testgear

author: henas
author_rank: Contributor
timestamp: July 03, 2021, 12:57:25 pm
content: I am looking for schematic for BK Precision 875B LCR meter or perhaps someone has some experience repairing them.By mistake I connected nearly twice the voltage to its external power socket. Now, after turning the unit on, plus power rail is slowly floating down. In a minute or so the display starts showing low battery status. Minus power rail is OK. Steady -6 Volts. Without the schematic I can't see what regulates plus power rail. I can't see any regulator??,

author: antimatter503
author_rank: Contributor
timestamp: July 04, 2021, 04:51:45 pm
content: You will probably be out of luck with finding a full schematic.Have you taken the unit apart yet?If you post good HQ pictures of the pcb, people will be much more likely to help.EDIT:You can trace out the board to find what regulates the positive rail by going backwards from input. It wont be far away in fact it really should be obvious. I highly suggest posting pictures. Also, probably not a good idea to continue powering the board when you know regulation is fried.

author: henas
author_rank: Contributor
timestamp: July 05, 2021, 08:20:37 am
content: Thank you for your time. Yes I agree it will be hard to get schematic but I searched archives and someone claimed on another blog he got one but it was more then 10 years ago.I opened the unit. Nothing is visually fried. The unit has two boards and after disconnecting the second board the symptoms stayed the same so I suspect the problem is on the first board. It is the mixture off CMOS logic and a few TL061/062/27L2C op-amps. So far what I can see -6V is derived directly from the battery through -6V regulator and serves as negative rail for op-amps only. Battery plus appears to be connected directly to plus op-amps rail and serves as Vdd for CMOS I suspect, there is some circuitry somewhere which creates phantom GND and possibly serves as Vss for CMOS logic. I checked some transistors and ICs for shorts. So far no success.I will get some pictures as you suggested.

author: henas
author_rank: Contributor
timestamp: July 06, 2021, 09:44:02 am
content: Missing Ic is TL061 which I tested off circuit as inverting amplifier and nothing connected to offset pins 1 @ 5. It appears to be OK. Q2 is 3906 and Q3 3904 both tested OK on curve tracer.
How to test a RF Gen board out of circuit - Page 1
Forum section: electronics / testgear

author: NY2KW
author_rank: Regular Contributor
timestamp: November 08, 2019, 02:29:20 pm
content: I have a R&S SM300 RF board that appears to have a bad HMC307 digital attenuator. There are 4 of them that control the RF level output (-125 to +13 dBm) and each can attenuate in 1 dBm steps from 0 - 31 dBm. Service manual is useless and no schematics available (i called R&S) Picture is attached. The HMC307 has control lines that are controlled by (-5v). The HMC307 datasheet is also attached.I know what has to be done - tie in Vee and a GND then test each control line while providing a input signal and look at the output on my SA. The issue for me is the space is so damn tight.Any advice appreciatedJerry NY2KWHMC307.pdf(207.97 kB - downloaded 103 times.)

author: NY2KW
author_rank: Regular Contributor
timestamp: November 08, 2019, 02:30:14 pm
content: sorry here is the picture

author: PA0PBZ
author_rank: Super Contributor
timestamp: November 08, 2019, 03:03:23 pm
content: Are they controlled from the same board or from somewhere else? If it is from the same board you can probably not override the lines without the chance damaging the controlling stuff? On the other hand, if they are controlled from outside you could maybe pickup the control lines...

author: NY2KW
author_rank: Regular Contributor
timestamp: November 08, 2019, 03:45:00 pm
content: It has a PC control board (Linux) for display and remote. The generator is made of 2 boards, an analog and digital. No schematics so hard to say where the control circuitry is located but it is probably located on the PC control card or the generator digital board. The attenuators are on the analog generator board. Any advice how to work in such tight space around each HMC307?

author: PA0PBZ
author_rank: Super Contributor
timestamp: November 08, 2019, 04:09:35 pm
content: There is some kind of controller IC (D8) on the analog board:The control lines for D8 are coming from the digital board:Maybe it is possible to use the control lines if you are able to find out how they work?"Service manual" is here:https://elektrotanya.com/rohde_schwarz_rs_sm300_vector_signal_generator_sm.pdf/download.html

author: chick0n
author_rank: Regular Contributor
timestamp: July 06, 2021, 08:17:38 am
content: I built an Extender Cable for the RF-Board, out of this:https://www.amazon.de/gp/product/B071794QXD/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1Works great. You have to cut it for 30Pins.
NI ELVIS Protoboard - Mk1 - Power Supply pinout - Page 1
Forum section: electronics / testgear

author: HarryDoPECC
author_rank: Regular Contributor
timestamp: January 24, 2020, 07:46:58 am
content: I picked up one of these, decent proto area, power supplies, basic fn gen, it would be a nice little stand alone proto system. No power supply but it said +/- 15v and I though "how hard can it be to work out the pins"HaHa - no useful silkscreen, Google-fu finds nothing. One pin is zero ohms to the proto board gnd, but two others are not quite zero..? And no continuity to the 15v supplies because of course there are current limit and protection circuits in the way. Multilayer SMD board is not immediately easy to trace.So, before I get out the magnifier and try to reverse engineer where those power pins go - does anyone have one of these and can you tell me the pinout of your power supply?Thanks soooo much!

author: qzqmom
author_rank: Contributor
timestamp: July 06, 2021, 01:04:20 pm
content: Hi I got one too but I found that NI Don't give this tool kit suppily anymore😭 and I cant find the adapt Elvismx 3.0.7 driver did anyhave or knew where to get？ thanks A lot

author: gslick
author_rank: Frequent Contributor
timestamp: July 07, 2021, 02:39:38 am
content: From images in eBay listings it looks like an XP Power HUP45-32 power supplyPIN1: GNDPIN2: COMMONPIN3: +5V, 5APIN4: -15V, 0.8APIN5: KeyPIN6: +15V, 2A
TEK 466 picture - Page 1
Forum section: electronics / testgear

author: frantisek
author_rank: Regular Contributor
timestamp: July 01, 2021, 04:25:43 pm
content: Hello! Does anyone have any experience with the effect of the value of the series resistor R1514 7.5 Ohm in the glow circuit of the TEK 466 screen on the brightness of the image? Mine has 8.6 Ohms and the screen doesn't seem to be in good condition ... And can the C 1514 in the same circuit be replaced with an electrolyte? I had him shorted. Thank you!

author: David Hess
author_rank: Super Contributor
timestamp: July 02, 2021, 02:47:17 am
content: I do not know about those components, but as I recall, the 464/466 storage CRT had a pretty poor display. Others reported better performance so maybe it was just the particular 464 that I used.My experience with the 7834 storage CRT is completely different and while dim compared to an equivalent non-storage CRT, they are very sharp compared to the 464 I used.

author: BrokenYugo
author_rank: Super Contributor
timestamp: July 02, 2021, 03:21:34 am
content: What is your measurement setup? It can be tricky to get an accurate reading at values that low.

author: frantisek
author_rank: Regular Contributor
timestamp: July 02, 2021, 09:47:01 am
content: Measured when the socket is removed from the screen, so nothing can distort the value of the resistance. How do I insert a photo or video here? Is the size limited? Thanks!

author: David Hess
author_rank: Super Contributor
timestamp: July 02, 2021, 10:41:22 am
content: Before deciding that something is wrong, I would go through the CRT and especially the CRT storage calibration procedures.
FNIRSI CC/CV buck converter module: operational issues. - Page 1
Forum section: electronics / testgear

author: Fezder
author_rank: Regular Contributor
timestamp: July 03, 2021, 08:44:08 am
content: Hello folks!Sorry if this is either in wrong place, or has been discussed before.So, bought mentioned FNIRSI (logo shown during boot) buck converters, and there are few operational issues which personally really bugs me. All appear to be software problems.Anyone else having these problems, or did I get bad batch?-CC setpoint value has around 50mA error compared to actual current.-CV value can be adjusted to be OVER input voltage; I didn't buy boost, or buck boost.-Increasing CV too high over input causes module to reset.-CC/CV values can be changed only on one screen, where these setpoints are in smallest font. Not that big deal, but I don't care always about Ah, Wh, time, or temperature.-Screen update rate is VERY slow, maybe 1 or 2Hz. Rotary encoder is also read with same speed.There are at least few issues I noticed during operation.
Fy6800, function generator, why this pin is unconnected? - Page 1
Forum section: electronics / testgear

author: ptluis
author_rank: Frequent Contributor
timestamp: July 02, 2021, 12:24:37 pm
content: Hi friends,I opened my function generator FY6800 and found that pin 19 (BW) of the DAC904 is not connected. I wonder if connecting this pin as indicated in the datasheet could improve some known issues?According to the datasheet:"Pin 19, Bandwidth/Noise Reduction Pin:Bypass with 0.1μF to +VA for OptimumPerformance. (Optional)For optional ac performance, an additional capacitor(CCOMPEXT) should be applied between the BW pin and theanalog supply, +VA, as shown in Figure 7. Using a 0.1μFcapacitor, the small-signal bandwidth and output impedance ofthe control amplifier is further diminished, reducing the noisethat is fed into the current source array. This also helps shuntingfeedthrough signals more effectively, and improving the noiseperformance of the DAC904."
Strange behavior of DER EE DE-5000 with connected power supply - Page 1
Forum section: electronics / testgear

author: sky666
author_rank: Contributor
timestamp: June 30, 2021, 08:43:20 pm
content: I would appreciate some information from someone who owns an original power supply for the DER EE DE-5000. Namely, I have two non-original 9V power supplies. What I can notice is that in the manual inductance measuring range (nothing attached), by touching the insulation of the alligator clips and moving them slightly, the device behaves as if it wants to measure a value - shows dashes. This condition normalizes after a few seconds. Obviously there is some interference, but I'm interested in whether this is the case with the original power supply. This does not happen when the device uses a 9 volt battery.

author: sky666
author_rank: Contributor
timestamp: July 02, 2021, 06:51:06 am
content: Anyone with an original power supply?
HP 8591c  restoring CATV function after DLP erasure - Page 1
Forum section: electronics / testgear

author: Kitski
author_rank: Newbie
timestamp: July 02, 2021, 01:34:18 am
content: I have an HP 8591c which had the default CATV personality installed by HP and the SPECAN operation was fully-functional, passing all self-tests. The instrument also has Opt 130 - Narrow BW – installed.In a moment of stupid inattention, incorrect front-panel keys were entered causing the DLP memory contents to be erased. This resulted in the CATV personality ‘disappearing’, leaving only the SPECAN function seemingly operational.While I could live without the CATV personality, the DLP erasure also removed other important SPECAN links. Now only the narrow RBW (30Hz, 100Hz & 300Hz) function and show a correct trace. Any other RBW settings result in no display.Inspecting the Service Manual shows the Narrow BW card (A130) contains a MUX switch that routes the 21.4MHz IF signal to/from the following A14 Log Amp/Detector card. At first glance, it seems the MUX is now missing the appropriate commands due to DLP erasure. I have not tried removing the NBW option A130 card and inserting jumper W1 on A14 as I’d prefer to keep the narrow RBW settings.Fortunately, I have access to an identical donor machine. Is it possible to export the CATV firmware from the donor machine and re-load it back into my instrument ? If so, would a blank HP memory card be required ? HP memory cards preloaded with CATV personality (HP-85721A) are available from eBay, but I’m unsure whether reloading the CATV personality this way would also restore RBW operation back to normal.Any assistance gratefully appreciated.Kit
Budget source unit meter and in-circuit LCR meters ? - Page 1
Forum section: electronics / testgear

author: MathWizard
author_rank: Super Contributor
timestamp: July 08, 2021, 05:08:00 am
content: I don't have the money or the need for a $2k SMU, so what are more repairable older models , to watch out for on ebay? And is there any new cheaper models, than the top brands ? I don't need dozens of volts or 10A currents.I have a cheap mastech LCR meter that is fine for having really just 1 or 2 chips, and nothing else in it. But it's slow settling. Also it's not really good enough to use in-circuit, (I just de-capped a PSU to measure all the values, I should check the in-circuit now to refresh my memory on that).Something like a BK-precision . 879 would be a nice step up, then I see something like used BK-P 889, going for twice the money and I'm wondering how well they really do in-circuit testing. And aside from AC powered, how much better are the bench models vs all the other handheld models like from Fluke/KeySight ? For the amount I'd use it, a handheld would save a lot of space tho.

author: Schenkenstein
author_rank: Contributor
timestamp: July 08, 2021, 12:29:21 pm
content: If +-110V and +-100mA are enough for your needs, I would recommend you a Keithley 236 (or 237/238). Sometimes, you can get them for <500€ and since the schematics are available, they are easy to repair (at least those I came across). Their lowest resolution is 100µV/100fA for sourcing and 10µV/10fA for measuring. The only downside is that you also have to spend some $$$ on triax cables.
How does LCR meter test voltage affect value? - Page 1
Forum section: electronics / testgear

author: EricNava
author_rank: Contributor
timestamp: July 01, 2021, 09:35:26 am
content: Hi all, I am working on designing a circuit based on the BQ51013B to enable QI wireless charging for my DIY watch.The datasheet for the IC discuss how to calculate the situational inductance of the power receiving coil. The inductance value is crucial in order to calculate the correct resonance capacitor values.The datasheet says the inductance should be measured at a test frequency of 100kHz at 1V.So all of that is a long winded way of asking, will I still get a close enough measurement if I use an lcr meter that has a test voltage of 0.7V instead of the 1V stated in the datasheet? I need to buy an LCR meter, and am looking at the De-5000 which has the 0.7V test voltage I believe. Alternatives with higher test voltages are considerably more expensive.

author: graybeard
author_rank: Frequent Contributor
timestamp: July 01, 2021, 02:01:20 pm
content: For most passive components the AC test voltage usually does not have much effect unless it is very large. In most cases component to component variation will be much larger than any difference you see with the small variation in your test signal amplitude.The value of of many ceramic capacitors is voltage dependent. Many types can have loss vary with voltage.The value of inductors with iron or ferrite cores is current dependent.Just get the DE-5000. I have one and it is one of my most used pieces of test equipment in my home lab. I have been very happy with mine.

author: EricNava
author_rank: Contributor
timestamp: July 01, 2021, 02:48:45 pm
content: Thanks so much for your response graybead. I had a hunch the test voltage wouldn't be too big of a deal, glad you confirmed that. I will be ordering the DE-5000 soon then 👍

author: TimFox
author_rank: Super Contributor
timestamp: July 01, 2021, 03:26:11 pm
content: Bench top LCR meters often have a variable test voltage, so it makes sense when writing a specification to specify it as well as the test frequency to get repeatable results. The small difference between 1 V rms and the DE-5000 with a fixed value, approximately 0.6 to 0.7 V rms (my measurement, I’m not sure DER states it), should not be important, but the frequency is important. I concur with graybeard’s recommendation of the DE-5000.

author: EricNava
author_rank: Contributor
timestamp: July 01, 2021, 06:22:15 pm
content: Ah I see that makes sense. Yeah if the test voltage was indeed very important I was going to get the East tester ET4410 meter, which has an adjustable test voltage like you mentioned and some higher accuracy. It works out to about twice the price for me though for something I won't use that much so the DER DE-5000 makes much more sense in my case. Thanks for the recommendation as well
Keysight multimeters disclaimer/discouragement - Page 1
Forum section: electronics / testgear

author: iXod
author_rank: Frequent Contributor
timestamp: June 30, 2021, 09:23:20 pm
content: Looking on Amazon at Keysighe multimeters, the first thing I see in the Features list:"Product is intended for professional use only"https://www.amazon.com/s?k=keysight+multimeter&ref=nb_sb_noss_1Since when is a meter manufacturer actually trying to put off anyone interested in spending their $$ on a common test meter (ie, not specialized one--power meter, PQ meter, insulation tester, etc.) and lead with a discouragement?Not that I'm in the least discouraged (being the owner of many meters), just amazed.When did this practice start? I can't think of any other TE manufacturer that does this.Cheers.

author: kingsolmn
author_rank: Contributor
timestamp: June 30, 2021, 09:27:26 pm
content: I've always just kind of ignored those types of statements in product listings. I've just chalked it up to some kind of legal CYA. Ya know, so that some 1d10t doesn't sue them for some stupid reason.

author: ataradov
author_rank: Super Contributor
timestamp: June 30, 2021, 09:42:22 pm
content: They don't want a bunch of support calls/emails with stuff like "I tried to measure in the wall outlet and now nothing works".

author: MAS3
author_rank: Regular Contributor
timestamp: June 30, 2021, 10:50:44 pm
content: A similar remark (i think it was "Not for domestic use") was printed on the back of my my METEX DMM from the late 80s or early 90s.If i remember i'll show a picture after digging up the still working DMM (the dial knob doesn't work anymore due to a broken, brittle ancient plastic shaft).

author: bdunham7
author_rank: Super Contributor
timestamp: June 30, 2021, 11:02:10 pm
content: Quote from: iXod on June 30, 2021, 09:23:20 pmWell, you could ask why their products are sold on eBay and Amazon but not TEquipment or Saelig if they are so concerned about only selling to professionals. Of course, to be fair, the ones on Amazon all appear to be unauthorized third party sellers. So I'm not sure who is making that statement, Keysight or the seller.

author: Kleinstein
author_rank: Super Contributor
timestamp: July 01, 2021, 04:00:43 am
content: It could be a problem with EMC test for some products. Another point may be regulations for electronic waste disposal - though I don't think it would be so hard to also comply with the private user rules. For the 3458 the RoHs rules may be such a reason - though even a broken 3458 usually does not end up in the normal waste so fast.Another point could be a system with autherrized dealers and limitations in the contracts there.
Power supply recomendation - Page 1
Forum section: electronics / testgear

author: rauldm
author_rank: Regular Contributor
timestamp: June 30, 2021, 08:16:25 pm
content: Now I'm calibrating servo motors based on BLDC motors, I'm zeroing the Resolver sensor, for this work I need feed two phase of motor for locking the rotor, I'm using a power supply Agilent E3631A, on 6V-5A output can lock very fine the motor while I lock the resolver's rotor, I'm recibing other brand of motor named MOOG, when I try to locking, the rotor with this power supply is not lock very strong, this generate an angle offset error in calibration procedure. I bought a chinese switching power supply 30V-10A, but noise generated on power supplly is induced to resolver output, I see all noise reflejated on oscilloscope is more difficult calibrate. I found an economical power supply with next highligts:-Two output with 30V-5A, an aditional with 5V-3 A.-Encoder type knobs.-series and parallel mode, serie: 62V-5.1A, parallel 31V-10.2A-Very interesting thing for me, OVP/OCP/SENSEFUNCTION this turn off output when exceding set voltage or current.-toroidal type transformer, I sent an e-mail to fabricant.-output on off botton for each channel except 5 V fix channel.The model is : MATRIX TECHNOLOGY MPS-3005H-3attach video linkSomeone know about power supply brand?Someone has an experience with this brand?Regards.
Fnirsi DSO PRO - pocket scope 20MS/s - Page 1
Forum section: electronics / testgear

author: tunk
author_rank: Super Contributor
timestamp: June 30, 2021, 08:45:57 pm
content: Introduced at the end of 2019, but no thread about it here:- single channel, 20MS/s, claimed 5MHz bandwidth (realistically 2-3MHz)- 2.4" screen- built in battery-http://www.fnirsi.cn/productinfo/392288.htmlA couple of youtube reviews:- diodegonewild:https://youtu.be/gCI0S3Bcofc- TechCornerTV:https://youtu.be/vbV5ZndUG10

author: pcprogrammer
author_rank: Super Contributor
timestamp: July 01, 2021, 07:16:25 am
content: Wow. How does one repair smd. Use a solder pistol like diodegonewild in his video near the end (at 14:55)He did the trick, but what a hack job.
Looking for A.02.04 Firmware update for E8285A - Page 1
Forum section: electronics / testgear

author: tabajaralabs
author_rank: Regular Contributor
timestamp: January 14, 2021, 07:54:55 pm
content: Subject says all =)Looking for the BIN(image) of the 2 PCMCIA cards with the A.02.04 firmware used in the E8285AAlso if you have images of any of the accessory cards, I'd be thankfull too =)Thanks!

author: cat87
author_rank: Regular Contributor
timestamp: July 01, 2021, 06:08:43 pm
content: I think this is what you wantPosting it here just in case others also need itAttaching both the A.02.04 Firmware (2 bin images for 2 PCMCIA cards) and also the RF Tools accesory.Have fun
Axiomet 3005D PSU earth connected to positive output - Page 1
Forum section: electronics / testgear

author: aandras
author_rank: Newbie
timestamp: June 28, 2021, 07:20:51 pm
content: Hi,i have one of these devices:https://en.axiomet.eu/gb/en/product/axiomet/laboratory-power-supplies/ax-3005d/100165/Yesterday - during some testing - i have just realised, that the earth banana plug (green) and the the red positive output plugs are directly connected.Which means that the positive output is connected to AC mains earth.I wonder if that is a common thing in PSU-s or am I facing a faulty device?thank you,András

author: siggi
author_rank: Regular Contributor
timestamp: June 28, 2021, 10:22:09 pm
content: Having the ground terminal shorted to either output terminal seems unreasonable. Typically you'd want a lab PSU to be floating, with the option of tying either terminal to ground. Typically there'll be a spec as to how far away from ground you can float the supply, but there's no such spec in the manual.How did you determine that it's shorted GND to positive?

author: aandras
author_rank: Newbie
timestamp: June 29, 2021, 06:35:11 am
content: Using my multimetermeter, connected to the grean and the red terminal, having the AC plug conneted and then disconnected too.If the AC plug is conneted, than there is a short between the red + teminal and the oscilloscope's probe ground (both connected to mains, otherwise no other connection between the two instruments).Actually i was trying to measure with my scope a circuit that i powered with this PSU and there were some uncomfortable issues (almost smoke),that lead me to investigate the situation and finding this strange short.

author: Gyro
author_rank: Super Contributor
timestamp: June 29, 2021, 08:43:17 am
content: No that's not normal. It has a fault. There should be no connection between the +Ve output terminal and chassis.Only a wild guess, but it may be that the series pass transistor is shorted to the case.

author: aandras
author_rank: Newbie
timestamp: June 29, 2021, 11:08:28 am
content: Thank you for the answers. I decided to look inside and i have found the cause. One (actually more) solder points on the PCB are simply too large,and if the chassis is mounted they are touching each other. The space that they designed between the back of PCB and the metal case is too narrow.First picture, left hand side solder, that is connected to +ve output as are some of the solder points on the second picture.
Rohde & Schwarz ESIB40 disk image - Page 1
Forum section: electronics / testgear

author: pjm
author_rank: Newbie
timestamp: June 28, 2021, 07:18:39 pm
content: Hi all,I've got a poorly Rohde & Schwarz ESIB40 with an old IDE drive with the click of death, usual recovery methods have failed so far. Does anyone happen to have a disk image for this EMC RX?thanks and regards,pjm.
Wants to buy Fluke 287 LCD... - Page 1
Forum section: electronics / testgear

author: prasimix
author_rank: Unknown
timestamp: June 27, 2021, 05:45:21 pm
content: My Fluke 287 as of today:If someone have replacement LCD (new or used) to sell, please PM to me. Also any info where to buy one below the price of eBay/China replacements is very welcome.

author: BeBuLamar
author_rank: Super Contributor
timestamp: June 27, 2021, 08:11:09 pm
content: Send it to Fluke and see if they can fix it and for how much. My coworker 287 has the dial came off and the display is erratic. I sent it to Fluke they said they can't fix it so they sent us a new 287 free. In fact we just got the new replacement meter last Thursday 06/25/2021.287 is supposed to be warranted for life but since they may consider you abused your meter so the warranty doesn't cover.

author: Arhigos
author_rank: Regular Contributor
timestamp: June 28, 2021, 02:43:16 am
content: LCD is available on ebay and aliexpress, but price is about $150. There is no "cheap replacement".I think if you want to save some money the only alternative will be to part out your meter, sell PCA, case parts, battery door, etc. Another alternative would be using IR and displaying measurements on external screen
Designing Power Supplies for Valve Amplifiers By Merlin Blencowe - Page 1
Forum section: electronics / testgear

author: ZeusMC
author_rank: Contributor
timestamp: June 27, 2021, 10:14:38 am
content: Hi,Does anyone have a copy they would like to sell?Thanks.

author: tautech
author_rank: Super Contributor
timestamp: June 27, 2021, 10:36:15 am
content: Welcome to the forum.Buy/Sell/Wanted is the best place to place a WTB add:https://www.eevblog.com/forum/buysellwanted/

author: ZeusMC
author_rank: Contributor
timestamp: June 27, 2021, 12:23:51 pm
content: Ak, ok, missed that sub forum.Thanks
Coming Brymen Shortages - Page 1
Forum section: electronics / testgear

author: EEVblog
author_rank: Unknown
timestamp: June 28, 2021, 05:36:09 am
content: Just got notice that after my next batch of BM235's coming next month, any new stock after that will be Feb 2022 delivery due to the main IC shortage.BM786 similar, some coming July but after that it's late November.

author: Cymaphore
author_rank: Regular Contributor
timestamp: June 28, 2021, 12:14:12 pm
content: Quote from: EEVblog on June 28, 2021, 05:36:09 amDepressing. Same as in many other areas. Some of the electronic components for our Controllers/ECUs have absurd long delivery prognosis and it's only getting worse.I'm wondering when and how this situation will recover.

author: AVGresponding
author_rank: Super Contributor
timestamp: June 28, 2021, 04:01:24 pm
content: Ooof...Storage media (HDD, SSD etc) will be the next shortage, or so I've heard, somewhat third-hand.I don't think the recovery will be quick; even if all the people that were furloughed etc come back straight away, there must be a huge backlog of orders by now.

author: David Hess
author_rank: Super Contributor
timestamp: June 28, 2021, 04:09:31 pm
content: Maybe most here are too young to remember previous semiconductor shortages. I remember shortages in power MOSFETs in the late 80s and early 90s where over a period of months, one could observe buyers moving up the voltage chain to larger and more expensive parts as the lower voltage parts ran out and went on allocation. I have already observed the same thing with discrete parts now. Recovery took years.

author: Brumby
author_rank: Unknown
timestamp: June 28, 2021, 04:17:16 pm
content: Quote from: AVGresponding on June 28, 2021, 04:01:24 pmYou are dead right .... it won't.The world has drifted into a global Just-In-Time delivery model for all manner of manufacture and these rely on stable, predictable lead times .... and just about all of those have been shot to hell.I believe we will still be battling to get back to normal two years after the Covid situation has been relegated to secondary news status, which is still a ways off.Brace yourself for a long and frustrating future.

author: Brumby
author_rank: Unknown
timestamp: June 28, 2021, 04:18:45 pm
content: Quote from: David Hess on June 28, 2021, 04:09:31 pm... and that didn't have the global impacting factors we have at this time!

author: bd139
author_rank: Super Contributor
timestamp: June 28, 2021, 04:20:50 pm
content: IT industry is shafted as well. Amazon AWS is having consistent capacity problems now and can’t get any new hardware in.Plenty of CPUs to go around but storage and ancillary ICs are short.

author: David Hess
author_rank: Super Contributor
timestamp: June 28, 2021, 04:28:43 pm
content: Quote from: AVGresponding on June 28, 2021, 04:01:24 pmThere were several boom and bust cycles in the DRAM business, and it has happened to Flash before as well. One response was to design systems which could accept different forms of memory but I doubt that will happen this time.
Rockseed RS305 problems pushing out 30v - Page 1
Forum section: electronics / testgear

author: luddite
author_rank: Newbie
timestamp: January 19, 2021, 05:22:11 pm
content: I am setting my unit to 30v with a 1amp current (set to M1)When I switch on, it drops to 12.8v & .510amps with cc kicking in, no amount of trying let's me use the 30v (or M1)Any idea what I am doing wrong please?whilst "playing" I put it on "list" then powered it on, and it ran (changing every 5 seconds) fromM1 - 14.1v - 1ampM2 - 16.8v - 4.5ampM3 - 17.1v - 5.1amp and kept rolling round those 3 presets.I however only want 1 amp so have switched off waiting for advice.PSHi everyone.

author: wbooth.clearscene
author_rank: Contributor
timestamp: June 26, 2021, 08:34:32 pm
content: mine is similar. useless.sending it back.btw. i also get huge overshoot at turnon eg 2v over, on a set of 5v at 20ma.
50s/60s vintage gear at a garage sale Tek 524AD/Hughes Memo-scope 104 - Page 1
Forum section: electronics / testgear

author: DaJMasta
author_rank: Super Contributor
timestamp: June 26, 2021, 07:57:38 pm
content: So a mother of a student of mine told me about a garage sale in a closeby neighborhood where she spotted some equipment that 'looked like the stuff you had', and sent along some pics of a Tek 524AD and a Hughes Memo-scope 104, among other things, on their cart and looking in serviceable shape. I'm not really a 'vintage' gear guy (my oldest stuff is late 80s/early 90s and most is last 20 years), but it's unusual to see at a regular garage sale, so I stopped by. Apparently the owner of the equipment was a guy who was a materials scientist with interest in optics and electronics, and besides those there was an old Leeds & Northrup VOM, a set of 7 projector reels for a bad warner brother's movie, manuals and technical books, an all tube frequency counter that took up something like 5U of rack space, some old typesetting computers with 10" floppies, a bunch of lab glassware, and as told by one of the children cleaning out the house, apparently a bunch more scopes, oscillographs, and other things. At a cursory glance, a lot of it was in long term storage but is in generally good condition. The 524AD knobs felt just fine whereas the Hughes 104 didn't have quite the same detent and maybe could use some cleaning.Now I don't think I'm the guy to get and rehab this old equipment, but I know there is some interest in it and potentially some interest in having it for museum collections - but only museums I really know of in the US are on the west coast. Do you think it's worth me offering something for a chunk of it to resell? Do you know of a reputable collection, collector, or other I could reference the family to if they need help getting rid of the stuff? Are there any of you interested in having a look - they're just south of Rockville in Maryland and I'm happy to pass on the address, they said they would be running it as a garage sale tomorrow as well.
UNI-T UTG962 - Windows 10 - SOLVED - Page 1
Forum section: electronics / testgear

author: xcalibur
author_rank: Contributor
timestamp: June 24, 2021, 07:09:47 pm
content: Does anyone know how to get the UNI-T to work on Windows 10?Tried USB2.0 and 3.0Had had no luck using the provided driver.Tried building my own libusb driver (and forcing win10 to let me install it unsigned), but the UNI-T device manager still fails to recognise it.Any help would be appreciated.

author: xcalibur
author_rank: Contributor
timestamp: June 24, 2021, 09:20:41 pm
content: Thanks to @dakkahun, I got it to work partially.1. I installed the NI-VISA Runtime v5.4 (downloaded from ni.com)2. I installed the UNI-T Device Manager (downloaded from UNI-T)Now I can see the device in the UNI-T Device Manager and control it remotely, but I still cannot upload ARB Waveforms. {See screenshots}Any tips for getting this to work?

author: xcalibur
author_rank: Contributor
timestamp: June 25, 2021, 11:14:51 am
content: Long story short, the software does not work correctly, but there's a workaround.You cannot upload the ARB file using the "ARB WaveForm Creator" software.You have to:1. Design your waveform2. Click "Down current ARB" - This will save your waveform to a file3. Open the sig-gen virtual control panel4. Right-click on the virtual control panel and select "Send ARB File"5. Select the file you created in step 2 (above) and click "LOAD"The UTG962 will automatically switch to the ARB waveform you just uploaded.A few things that I don't like:1. Although rudimentary, the software could really have been better by allowing this simple "load" action from within the software itself.2. It should allow me to save my waveform to internal memory, it currently goes lost on power-off. The portability of this device is extremely useful, but less so if I have to drag my laptop along to load my ARB waveform each time. This is an unfortunate oversight by UNI-T. Not sure how easy this would be for them to fix via a firmware update.

author: xcalibur
author_rank: Contributor
timestamp: June 26, 2021, 02:23:07 pm
content: I resolved this before I got a reply from UNI-T, but they provided me with a new software package to download via "weTransfer", so I did.On investigation, it now includes VISA Runtime 5.4 etc.Because my Windows machine is not my dedicated "workhorse" (Mac user, but have a Windows laptop lying around for stuff like this) I formatted the machine and installed the software from scratch. This time it worked "out of the box".You still can't upload ARB files directly to the UTG962 though. Bummer.
Function generator easy freq calibration to GPSDO - Page 1
Forum section: electronics / testgear

author: Circlotron
author_rank: Super Contributor
timestamp: June 24, 2021, 04:45:57 am
content: We all know that if you shove a 10MHz reference signal from a GPSDO into your function generator then the output frequency you select will be very accurate. Does any function generator have the facility where you can set it going for several hours to completely stabilise, then in some menu push a button to tell it to trim a generated free-running 10MHZ to equal the GPSDO 10MHz, making for an easy frequency calibration? As you may guess, I don’t know anything about calibrating these things, so go easy on me.

author: bob91343
author_rank: Super Contributor
timestamp: June 24, 2021, 05:25:31 am
content: It seems to me that you are suggesting synchronizing a function generator with an external standard. The answer is, it depends on the function generator.If the generator is synthesized and uses a 10 MHz standard, say, you could in theory use the external standard and thus have what you want. If it uses something other than 10 MHz, you will have to generate that frequency from the GPS. If it doesn't work that way, you probably can't synchronize it because each frequency it generates is free running and has no standard.

author: JohnPi
author_rank: Regular Contributor
timestamp: June 26, 2021, 03:20:25 am
content: The Agilent 33220A Function Generator can do that. It's not quite 'push a button', but it is controllable from the front panel. See e.g.http://lmu.web.psi.ch/docu/manuals/bulk_manuals/Agilent/33220-90010.pdf,chapter 4 for details.

author: Circlotron
author_rank: Super Contributor
timestamp: June 26, 2021, 03:41:23 am
content: The link doesn't work.

author: picburner
author_rank: Frequent Contributor
timestamp: June 26, 2021, 04:51:09 am
content: Just remove the comma at the end of the link, then it works.
Itech IT9121 Power Meter ( BK Precision 5335B) - Page 1
Forum section: electronics / testgear

author: manytoolsmike
author_rank: Contributor
timestamp: June 25, 2021, 04:52:21 am
content: Dear EEV community,Has anyone used these instruments to measure power for high frequency drive circuits? I need to measurePower for 18 kHz to 50 kHz AC signals. The voltage ranges from 100 to 400 Vac, the power is under 10 watts.Thank everyone,Mike

author: thm_w
author_rank: Super Contributor
timestamp: June 25, 2021, 09:35:31 pm
content: Quotehttps://www.itechcanada.ca/pdfs/IT9121_9121E%20Power%20Meters.pdfShould be OK. Assuming we are talking 50kHz sine. You might want to check the accuracy spec at that low of a current though.
Rohde & Schwarz SMG lowbattery error 6 - Page 1
Forum section: electronics / testgear

author: Alexander51
author_rank: Newbie
timestamp: June 21, 2021, 07:56:34 pm
content: Dear All,My R&S SMG meets error 6. It's a low battery message.My question:What kind of battery is it?Where can I find it in my SMG?Is it easy to replace?Will I lose important data when I replace it?Thank you very much for a positive replyAlex

author: wn1fju
author_rank: Frequent Contributor
timestamp: June 23, 2021, 09:35:39 pm
content: I have neither an SMG nor the service manual, but since nobody who does has yet responded to you, I can at least offer some general advice:1. The battery most likely backs up some RAM which usually just stores things like user front-panel settings. If that's the case, it is not a big issue if it dies. However, there are cases (fortunately only a few) where a manufacturer will also store calibration constants in the RAM. In that case, a recalibration is necessary after battery replacement (but see item #4 below).2. The battery is usually on the board with the RAM and that is usually the main processor board. The board may be under a cover, so you may need to do some disassembly to get to it.3. The battery can be NiCd, NiMH, Li, etc. The main issue is whether or not it is the rechargeable type. Normally one would use the same battery, but it is possible, for instance, to use a non-rechargeable battery (two AA alkalines for instance) to replace a rechargeable type. Just throw a Schottky diode in series with the battery to prevent it from seeing voltage when the unit is turned on.4. When you finally locate the battery, measure the voltage. If it is below about 2 to 2.5 volts, your RAM has probably lost its contents. If it is above 2.5 volts, the RAM may still be alive (even though the SMG is throwing a low battery error message). In that case, you can parallel a 3V external power supply (through a 1K resistor) across the battery circuit while you replace the battery. If you are careful, this will preserve the RAM contents while you make the battery change.5. You asked, "is it easy to replace?" Usually, it is not a big deal. What you really have to fear is when the battery has leaked. Not only can this make a mess, but it can easily corrode or destroy components, leads, traces, etc. If you find any leakage, you need to scrub the board several times (alcohol) and do a very careful visual inspection. Check any suspicious areas with an ohmmeter to make sure connections haven't been eaten through.

author: Alexander51
author_rank: Newbie
timestamp: June 25, 2021, 10:18:10 am
content: Dear reader of my question,Thank you very much for your information regarding a backup battery in my SMG.I will respect your proposals and will try to repair it soon,The advise to use a Schottky diode and the idea of a parallel mounted 3 Volt battery parallel to the original backup batt.while replacing it seems me a very good idea.Thank you very much!!Alex
Datron 4700 EPROM set, in case anyone needs it... - Page 1
Forum section: electronics / testgear

author: TheDefpom
author_rank: Frequent Contributor
timestamp: June 25, 2021, 01:24:38 am
content: I have pulled and read the EPROM's from my Datron 4700 calibrator, I thought I would share them in case someone out there needs them.My unit is fully optioned with resistance, current, and high voltage output.
Hameg HM8130 DAC improvement? - Page 1
Forum section: electronics / testgear

author: rob040
author_rank: Contributor
timestamp: June 24, 2021, 08:55:18 pm
content: Hi everyone,I own two Hameg HM8130's and noticed a difference in the DAC's that have been used. I assume these DAC's "generates" the actual signal.The oldest has a Raytheon TDC1041R3C1 (10-bit, 20MSa/s) and the newest has a AD9731BR (10-bit, 170MSa/s).Will it be a (big) improvement if I replace the TDC1041 for a AD9731? Any thoughts on that?I can't find any Hameg documentation on the AD9731 version, but I can do some reverse engineering, if needed.Best regards,Rob.
Tektronix 2235 stiff time / div knob? - Page 1
Forum section: electronics / testgear

author: Mjkdar
author_rank: Newbie
timestamp: June 24, 2021, 05:46:26 pm
content: I picked up a virtually new condition 2235 tektronix oscilloscope. The time / division knob seems stiff . When I pull out the knob for the time delay, that turns quite easily. Is it normal because it's turning both sets of knobs to be quite stiff? I lubed the shaft of a little, but don't see any points inside to lubricate that would help.

author: bob91343
author_rank: Super Contributor
timestamp: June 24, 2021, 06:01:43 pm
content: The shaft may be bent, or the knob may be rubbing. The worst would be a damaged wafer.

author: Mjkdar
author_rank: Newbie
timestamp: June 24, 2021, 06:09:26 pm
content: It doesn't appear to be rubbing anywhere and it's not binding. It just seems like a cam or something inside needs to be lubed a little.
HP 10529A Logic Comparator - interesting option pod - Page 1
Forum section: electronics / testgear

author: pamphonica
author_rank: Regular Contributor
timestamp: June 24, 2021, 06:48:50 pm
content: Here's one for what our beloved Dave calls the "fanboys".I bought a nice HP10529A logic comparator and it came with an accessory I've never seen before.Simple reverse engineering shows it to be a pod that allows 5V to be fed into the comparator, and it just turns it into a large logic clip! All 16 inputs from the physical clip are pulled up with 10K resistors, and that's it. The LEDs on the comparator just show the logic state, I assume.The part number hidden under the plastic moulding is 10529-60013. It doesn't seem to appear in any of the catalogues I have.-Jeremy