hybridfree/eevblog-posts huggingface dataset:
Oscilloscope PK for Price under 500USD  - Page 1
Forum section: electronics / testgear

author: jacklee
author_rank: Regular Contributor
timestamp: March 17, 2020, 09:20:22 am
content: Got these videos from youtube, the price of these models should all under 500USD, anyway it's more like Micsig VS Tektronix, Rigol, Siglent, UNI-T.Does anyone have all these models? I have Micsig TO1104, however, I would like to try that STO1104C now.Rigol oscilloscope VS Micsig oscilloscopeSiglent oscilloscope VS Micsig oscilloscopeUNI-T oscilloscope VS Micsig oscilloscopeTektronix oscilloscope VS Micsig oscilloscope

author: Fungus
author_rank: Super Contributor
timestamp: March 17, 2020, 12:09:49 pm
content: The Micsig is quite a bit more expensive than the others, but yeah, nobody here seems to have bad things to say about Micsigs*. They just haven't gained much traction yet.(*) Quite an achievement, this place is full of curmudgeons.

author: jacklee
author_rank: Regular Contributor
timestamp: March 23, 2020, 08:37:02 am
content: Agreed, when firms compete with each other, our consumers get the best possible prices, quantity, and quality of goods and services. So it's a good thing, and at least my TO1104 works well until now.

author: modoran
author_rank: Regular Contributor
timestamp: March 23, 2020, 09:32:15 am
content: Is there any difference between to1104 that you already have and the other Micsig STO1104C

author: pascal_sweden
author_rank: Super Contributor
timestamp: March 23, 2020, 10:59:16 am
content: How is the noise level on Micsig scopes?

author: jacklee
author_rank: Regular Contributor
timestamp: March 24, 2020, 06:35:32 am
content: STO with the Android system it's operation seems more smooth, but I don't have a budget to get one, my TO1104 still works well.

author: jacklee
author_rank: Regular Contributor
timestamp: March 24, 2020, 06:39:15 am
content: Quote from: pascal_sweden on March 23, 2020, 10:59:16 amMine is below 1mv anyway, the noise level would be affected by memory depth and sample ways, etc.
Signal Generator Modulation Circuit DIY? - Page 1
Forum section: electronics / testgear

author: Falco
author_rank: Newbie
timestamp: March 23, 2020, 11:34:11 pm
content: So I bought a FY3224S 24MHz arbitrary waveform function generator, and maybe I should've spent the extra 30 bucks on an FY6800-60M, double the frequency and it comes with all the modulation options. But here I spent my money already. It's really just for messing around and playing, and I don't really actually need modulation, but I thought it might be an interesting option to build my own thing. After all I do have two independent channels with the product I got.The way I see it, AM is sort of a multiplication:O = S1 * S2, which could be done with an op-amp. The function generator supports dc offset so I could say put it at offset +1V and just do multiplication. Or do bursts with a square wave with Vpp = 1V and Vbase = 0V, determine burst length with duty cycle etc. Of course it'd all be a bit fiddly since there is no direct control, but in theory that could work.The only issue is how do I feed the op amp? I can tie the ground of the signal gen easily enough through the BNC connector, and the signals would go onto the multiplier inputs. But the opamp needs to be fed a supply voltage, doesn't it? I can't just power it externally either, right? I'd need to have it on the same supply as the signal generator? Or can I just tie the opamp ground to the sig gen ground and be good with say an usb powered device? Everyone always only draws the opamps like it's some logic gate with 3 leads going in, but of course you need to power it, too.I found theMPY634IC, but that's a ridiculous $23. I can almost buy a new signal generator from that! When I look at stuff like this 4Q Multiplier AD534 on digikey I find chips that are like $45-$300?! What the heck is going on?Surely I can just cobble together some op-amps somehow and get it working, right? I can easily enough get +/- 12V from the signal generator housing from it's power supply, maybe hot glue/screw in some connectors for that in the front panel. But then again, an opamp like this LM7171 costs ~$3 and you'd need 3 of those if you did something likewith the PCB, resistors, connectors and everything that'd be another 15 bucks. Why is this stuff so expensive? It's just a few transistors?! It can't be that hard to get something with 2 bnc connectors in, combobulate the waveforms and put it out on a third bnc. again I don't really need that and it'd be a nice hobby project, but I'm not paying $45 for a single chip.

author: bob91343
author_rank: Super Contributor
timestamp: March 24, 2020, 04:17:37 am
content: You are a bit off track, as I see it. Your circuit will add two signals, not modulate. To modulate you will need something nonlinear. A variable gain amplifier or even just a diode.The higher frequency is called the carrier. The low frequency is the modulation frequency.To get a classic modulated wave is more complicated. So it depends on what you want. Read up on this stuff; it's been well documented for nearly a century.
Clarke Hess model 828 calibrator schematic - Page 1
Forum section: electronics / testgear

author: Jester
author_rank: Frequent Contributor
timestamp: March 24, 2020, 01:29:39 am
content: I picked up a non working Clarke-Hess model 828 ac/dc calibrator. I downloaded the user manual from the web, and it refers to the schematic in the circuit description, however the actual schematic is not included in the manual.Does anyone happen to have the schematic (figure 11)?Update:Finally found the time to do a power-up test.- It works in current mode, seems to be pretty accurate.- In voltage mode it only works with very low voltages < 400mV, exceeding 400mV appears to activate the overload circuit that disables the output after 0.5 second.Has anyone repaired one of these?Thanks,J
Tek AGF 31000 users - Page 1
Forum section: electronics / testgear

author: Sighound36
author_rank: Frequent Contributor
timestamp: March 26, 2020, 06:26:20 pm
content: Evening ChapsAnyone on EEV have any hands on experience with this Tek unit all?Any information would be helpful thankshttps://uk.tek.com/signal-generator/afg31000-function-generator

author: rodpp
author_rank: Frequent Contributor
timestamp: March 27, 2020, 07:07:26 am
content: You're lucky, The Signal Path reviewed it:

author: Sighound36
author_rank: Frequent Contributor
timestamp: March 27, 2020, 09:09:25 am
content: Hi rodppI have seen Shahriar hence my interest in the unit, any users out that would like to comment?
Tektronix TDS3000B RTC running slow - Page 1
Forum section: electronics / testgear

author: perdrix
author_rank: Frequent Contributor
timestamp: March 20, 2020, 01:09:40 pm
content: I know it's not a major issue, but has anyone hit this problem and found a resolution?I suspect it's probably a trimmer or firmware controlled varicap that needs tweaking, but ...TIA David

author: voltsandjolts
author_rank: Unknown
timestamp: March 20, 2020, 02:02:17 pm
content: The RTC is a sealed DIP module by Dallas/Maxim with internal battery and some NVRAM in it too.The battery in your module is likely failing.Some folks have hacked them open and replaced the battery.Otherwise you need to source a new one...which is a bit of fun because there are lots of fakes around.The bad news is they are soldered into the main board, I added a socket when I changed mine out.The good news is there is no critical info in the NVRAM, so you can just fit a new blank one. IIRC the operating hours gets reset to zero.https://www.eevblog.com/forum/testgear/tek-tds3000-series-and-dallas-nvram/https://www.digikey.co.uk/product-detail/en/maxim-integrated/DS1742W-150/DS1742W-150-ND/951280https://www.ebay.co.uk/sch/ds1742w
Rohde and Schwarz scope question - Page 1
Forum section: electronics / testgear

author: fitch
author_rank: Contributor
timestamp: March 12, 2020, 07:45:27 pm
content: Hello all,Just curious, does anyone know what a tag on an R&S scope with barcode and RM_ followed by a 9 digit number means?Thanks.

author: Mouse69
author_rank: Contributor
timestamp: March 17, 2020, 09:10:17 pm
content: What model is it, my RTC does not have it - so I can't help (sorry), but knowing the model number may help someone else identify it.

author: fitch
author_rank: Contributor
timestamp: March 18, 2020, 10:23:26 pm
content: Turns out it indicated calibration. Too bad it did not say “calibration”.
Rigol DP832A Firmware Updating - Whats correct Sequence - Page 1
Forum section: electronics / testgear

author: NY2KW
author_rank: Regular Contributor
timestamp: March 17, 2020, 09:14:59 pm
content: I bought my DP832A about 5 years ago and have never updated the firmware. Current sys info: Digital vers: 1.09; Analog vers: 1.02 and Boot vers: 1.06I want to upgrade to either 1.014 or most current on Rigol website 1.16. I am confused about the sequence of updating. On the Rigol firmware page--> "note 6: Firmware versions at or below 00.01.09.00.01 requires installation of a boot loader prior to firmware update. The boot loader can be found in the ZIP download". However no bootloader file was in the zip file just one Software Gel. There are notes about bricking the DP832a if updating done incorrectly. I also have Zip file for v 1.14 and that has 2 different Gel files - one for Software Bootloader (1.09) and another Software Normal (1.14). What is the correct sequence for updating Bootloader first or Software first?

author: MegaVolt
author_rank: Frequent Contributor
timestamp: March 18, 2020, 09:29:24 am
content: Bootloader first
DP832 battery charging, will it display ma into the load? - Page 1
Forum section: electronics / testgear

author: cpposteve
author_rank: Regular Contributor
timestamp: March 17, 2020, 09:21:03 pm
content: Hi allFairly New to the DP832a and was wonering will it display anywhere the ma gone into a load since turning on the channel?for example i want to charge a single cell Li-ion cell with a max cv set to 4.2v and cc set to 1 amp.how, if possible can i display the total capacity gone into the battery?cheerssteve

author: thm_w
author_rank: Super Contributor
timestamp: March 17, 2020, 09:55:57 pm
content: No.You'll have to write your own logging tool to perform this via scpi. eg 00:00 current 0.500A 00:01 current 0.499A -> use software script to add these numbers -> divide over time elapsed.RD6006 has this built in, or you can buy various "power meters" that will do this for you as well.My preference is to use a dedicated battery charger, if this is something you will do regularly, so there is no risk of overcharging/backfeeding/etc:https://lygte-info.dk/review/Review%20Charger%20LiitoKala%20Lii-500%20UK.htmlThey are about $20.
Another new Aneng - the AN82 - Page 1
Forum section: electronics / testgear

author: Fungus
author_rank: Super Contributor
timestamp: March 17, 2020, 12:59:09 pm
content: Just saw another new Aneng meter on the web:https://www.aliexpress.com/item/4000611991237.htmlFully featured, 9999 counts, dual display, bar graph, very large ranges (99mF, 99MOhm), it even comes with two spare fuses. :-)The case looks bomb-proof and it's a bit smaller than my 'beater' 860B+, I'm almost tempted...Edit: Looking at the pic of the insides it seems to have input jack alert on the current ranges (two connections on those inputs).

author: Mechatrommer
author_rank: Super Contributor
timestamp: March 17, 2020, 01:29:41 pm
content: maybe similar processor to Aneng Q1https://sea.banggood.com/ANENG-Q1-9999-Counts-True-RMS-Digital-Multimeter-AC-DC-Voltage-Current-Resistance-Capacitance-Tester-p-1302943.html?cur_warehouse=CN
Siglent SDS1104X-E UART Decoder and Trigger issues (BUG?) - Page 1
Forum section: electronics / testgear

author: TK
author_rank: Super Contributor
timestamp: March 16, 2020, 03:33:34 pm
content: Everytime I need to work on some serial decoding I end up debugging the scope instead of the project.I am generating 9600 baud, 8-N-1 UART packets (The classic "Hello World!"). My siglent SDS1104X-E scope cannot decode correctly the SPACE (0x20) character and it cannot trigger on UART. I set trigger on START and it triggers on any High to Low transition, in the middle of a packet. I set trigger on DATA 0x20 and it triggers on any character.I tried my micsig TO1102 and it works just fine.How can the SDS1104X-E can have a BUG on a so simple decoding and triggering task? Nobody is using these options on this scope?SDS1104X-E UART trigger START. That does not seem to be a START BIT or it is, but the decoder cannot recognize a valid UART streamSDS1104X-E UART Decode cannot identify a perfect 0x20 characterSDS1104X-E UART trigger DATA = 0x20. Where is 0x20?Micsig TO1102 UART trigger DATA = 0x20 and perfect decoding

author: tautech
author_rank: Super Contributor
timestamp: March 16, 2020, 06:22:30 pm
content: When claiming to have found a bug it's normal to include the firmware version used.....and you know that already.Please take a breath and add it into the OP.

author: TK
author_rank: Super Contributor
timestamp: March 17, 2020, 02:29:06 am
content: Was using 6.1.26Upgraded to 6.1.33 and it seems to decode better, but still cannot trigger on UART START, nor UART DATA = 0x20, it cannot even do a single trigger on DATA = 0xXX
Agilent 3499B - Page 1
Forum section: electronics / testgear

author: maginnovision
author_rank: Super Contributor
timestamp: March 12, 2020, 03:22:12 am
content: Does the HP/Agilent 3499B use the same bumpers as the 34401? They look similar and have pretty much the same dimensions in the datasheet but just thought I'd ask in case someone has tried them.If they don't fit I might be better off just getting a new 34970A without DMM and a couple new or used 34903A's.

author: bitseeker
author_rank: Super Contributor
timestamp: March 12, 2020, 04:17:09 am
content: I don't have a 3499B, but the 34401A bumpers do fit on a bunch of similar HP gear from the 33120A function generator to the E361xA power supplies, and even the 3478A multimeter. Despite being from different generations of design, they're all made to fit nicely in racks and stacks. I'm 99.9% sure the bumpers will fit.(Note that the rear bumper may not stay on with older gear that doesn't have the rear bezel, but the 3499B looks fine.)

author: maginnovision
author_rank: Super Contributor
timestamp: March 12, 2020, 01:51:06 pm
content: I went ahead and bought a NOS 3499B, couple cards, and a bumper kit for 34401a so hopefully when the stuff shows up it'll work.

author: maginnovision
author_rank: Super Contributor
timestamp: March 13, 2020, 01:39:35 am
content: I changed the title as I had another question maybe someone could answer. Do these require a null modem cable for RS232?

author: TheSteve
author_rank: Unknown
timestamp: March 13, 2020, 01:48:28 am
content: Quote from: maginnovision on March 13, 2020, 01:39:35 am99.9% sure you will need a null modem/gender changer to connect to a PC.

author: bitseeker
author_rank: Super Contributor
timestamp: March 13, 2020, 04:01:09 am
content: Good to see high confidence % in the posted answers.Looking forward to seeing your new (to you) gear, maginnovision.

author: maginnovision
author_rank: Super Contributor
timestamp: March 16, 2020, 10:14:22 pm
content: Ok so I received the unit(but no cards yet) today. It's new as advertised. Firmware version 4.2(unlisted in manual?) And HW version 2.0. Cert says 2012 and SN matches programmed SN. The bumpers do fit with a couple caveats. First there is no place to put the tilting bale. Second, the rear piece the holes don't match the screws and you'd have to remove them to R&I cards. One thing I hadn't seen in any pictures is that they come with feet and they have a metal bit which allows you to tilt it properly. The RS232 cable IS a null modem cable as well.

author: bitseeker
author_rank: Super Contributor
timestamp: March 16, 2020, 11:00:58 pm
content: Quote from: maginnovision on March 16, 2020, 10:14:22 pmThanks for the update and photos.QuoteAre you referring to the carrying handle? Unfortunately, not all equipment have that feature as part of the enclosure. Fortunately, the front bumper still works.QuoteAh, that's an interesting issue. I suppose you could trim the rubber so that the cards can be manipulated with the rear bumper installed.QuoteOh, it has the four feet with tilting bails on the front two like the HP 3478A, 3312A, etc. Funny how older and newer designs are intermixed.Quote
Mini-Circuits Power Sensor - Opinions? - Page 1
Forum section: electronics / testgear

author: wr4t
author_rank: Newbie
timestamp: March 31, 2020, 12:07:45 am
content: I recently purchased 5 Rohde NRP USB power sensors (which are great sensors), but I am looking at the Mini-Circuits PWR-8P-RC as a lower cost alternative (about 1/2 the price) and I need at least 10 more. I like that is supports both USB and LAN on the same sensor. R&S and Keysight are either USB or LAN not both and LAN is higher cost. The uncertainty appears about 50 % higher, but still good enough for my use below 3 GHz (primarily 0.5-1 GHz). Anyone have any opinions on this power sensor as an alternative to the NRP 8S.I have pretty much ruled out the Keysight sensors because the software is licensed (Benchvue), I have to send these all over the country and they need to work on whatever laptop is available, not messing around with license management software, even if the license is free.https://www.minicircuits.com/pdfs/PWR-8P-RC.pdf

author: DaJMasta
author_rank: Super Contributor
timestamp: March 31, 2020, 03:53:26 am
content: Haven't used them, but if the more limited frequency range is viable, they've certainly got a name in the industry and probably have a perfectly serviceable power sensor.That said, two things:Anritsu has some USB power sensor options, don't know what price is like, but they could be another competitor and have been doing power sensors for decades.Keysight does charge for their BenchVue license, but newly purchased sensors from them come with it for free (at least, so claims their product page for some sensors). It's something like $135 for a license otherwise, and there is a free utility at least for the U200X series sensors called "Agilent U200xA USB Power Sensor Virtual Panel" which is available for free to download from Keysight. Don't know how wide the support of power sensors is, but it's responsive and pretty comprehensive in terms of instrument control. The UI looks less polished and I'm sure it lacks some more advanced analysis functions, but as a basic power meter with full control over instrument settings, it does work and is free.I don't know what BenchVue looks like, but I've got an NRP as well and do like R&S's software for it - though the asking to save a log every time I close the program is tedious when not meaning to log anything in the course of its use....
Leader LAG-120B audio generator output question - Page 1
Forum section: electronics / testgear

author: scrubba
author_rank: Contributor
timestamp: March 16, 2020, 12:24:19 am
content: Old hardly used audio generator shows no waveform on my scope. If I disconnect the negative lead, scope shows a mess of gibberish waveforms unrelated to the generator setting. I was in the process of calibrating the generator ... all specified voltages check out fine, and all components look clean. When it was time to check frequencies, there arose the output problem. Any help would be appreciated. Thanks!

author: TERRA Operative
author_rank: Super Contributor
timestamp: March 16, 2020, 07:27:03 am
content: There's a troubleshooting section in the service manual I've attached if you don't already have it.
Tektronix 491 band c oscilator varactor diodes, solid state version - Page 1
Forum section: electronics / testgear

author: harrimansat
author_rank: Regular Contributor
timestamp: March 15, 2020, 08:52:20 pm
content: Hi,I´m searching for a replacement diode for a TEKTRONIX 491. Is marked as MA45601. I have replaced with a BB405, and PLL now works well, but If is possible I would like to put original ones or equivalent, ceramic body Ghz band diodes, in the MACOM catalog I don’t see it.There´s two diodes, one is unmarkedAny know where to find them?Thanks
Desperately seeking Brüel & Kjaer - Type 1047 manual - Page 1
Forum section: electronics / testgear

author: slab
author_rank: Newbie
timestamp: January 22, 2020, 09:19:51 am
content: HelloI can't find any manual about the Brüel & Kjaer - Type 1047.Any help most welcomed!

author: slab
author_rank: Newbie
timestamp: February 27, 2020, 08:12:19 am
content: Do you know another place where I could ask. This would definitely help me troubleshoot the Brüel & Kjaer - Type 1047 that I can't get to work properly.

author: larsdenmark
author_rank: Regular Contributor
timestamp: February 27, 2020, 08:15:17 am
content: You can try sending an email to info@bksv.com

author: Arkytype
author_rank: Contributor
timestamp: February 29, 2020, 11:16:41 pm
content: Don't bother to write, telephone, e-mail, telegraph or otherwise communicate with Bruel & Kjaer USA. They are generally unresponsive to offering Owner/Service information on older equipment. While there are many sellers who offer Bruel & Kjaer manuals, many models are not available. I sure need a 2811 and 1049 Service Manual. I've been looking for several years.Try this eBay listing 21689010. It has the 1027 Sine Random Generator (which I own) which has similar specifications. I'd guess they have the same power supply.For twenty bucks you can get both the Owner & Service manual. It is .pdf but I don't know if it comes as a download or printout.Most of the older B & K test equipment I own (several dozen) used Frako brand electrolytics; especially in power supplies. Yank all of those out and put in some quality replacements such as Rubycon. I've also found several 3-terminal voltage regulators going "soft".The 1049 & 1027 are heterodyne generators and you'll need a good 'scope and patience to troubleshoot non-power supply related issues.Lee

author: slab
author_rank: Newbie
timestamp: March 09, 2020, 06:53:39 am
content: Thank you for helping.How do you access a ebay listing via a ref. number like 21689010?Or better said, which ebay is it. On ebay.com or ebay.co.uk the search does not find it.

author: Arkytype
author_rank: Contributor
timestamp: March 15, 2020, 01:18:34 pm
content: www.ebay.comEnter 143488192719 in the search bar.Lee
Remote control software for Tektronix TDS3000B? - Page 1
Forum section: electronics / testgear

author: perdrix
author_rank: Frequent Contributor
timestamp: March 14, 2020, 11:03:57 pm
content: What do people use? I tried Tektronix OpenChoice Desktop, but that crashed when I tried a screen capture from the initial screen/Individual channel capture seemed to work better.Also it doesn't seem to do the whole remote control thing ...David

author: james_s
author_rank: Super Contributor
timestamp: March 15, 2020, 01:03:19 am
content: I've played around with EZGPIB, however I've never had a real need to automate any actual testing with it so I have not put a great deal of time into it.
HP 54603B Scope: Softkeys under the display don't work, locked? - Page 1
Forum section: electronics / testgear

author: marcopolo
author_rank: Regular Contributor
timestamp: March 13, 2020, 04:59:35 pm
content: Hi,I got 4 x HP 54603B digital scope from a school and the 6 softkeys under the CRT display don't work (same problem with all scopes)I think this is a special function for use in educational environment. How could I remove this protection?(or all the scope are not working)Thanks,Marc

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: March 13, 2020, 08:29:49 pm
content: This isn't a lockout (and it wouldn't make much sense anyways), it's very likely the keypad just stopped working due to dirt/age. You can get it back working by opening the sclope, removing the rubber membrane, cleaning it with alcohol and then re-paint the rubber contact domes with conductive paint (search ebay for 'remote control repair').

author: james_s
author_rank: Super Contributor
timestamp: March 13, 2020, 09:15:01 pm
content: I've repaired a LOT of rubber membrane keypads that weren't working and I've never once had to repaint anything. I simply wash the rubber membrane with warm water and a bit of liquid dish soap, give it a good scrub with my fingers, rinse it off and set it out on a towel to dry.

author: bd139
author_rank: Super Contributor
timestamp: March 13, 2020, 09:30:17 pm
content: Might be cracked. Usually the first thing to go if they are dropped. Had one of them. Repair thread herehttps://www.eevblog.com/forum/testgear/hp-54602b-oscilloscope-problems-repair/Mine was unfortunately a write off due to the main board being cracked

author: james_s
author_rank: Super Contributor
timestamp: March 14, 2020, 02:01:55 am
content: Either way what I would do is take it apart, wash the rubber membrane, and while that's drying inspect contacts carefully for damage. I fixed a cracked membrane strip on an older Tek scope with some carbon paint, I don't know what HP uses but Tek has the button pads printed on one of those thin flex PCBs that is stuck to the aluminum frame around the display.

author: marcopolo
author_rank: Regular Contributor
timestamp: March 14, 2020, 02:48:48 pm
content: Quote from: james_s on March 13, 2020, 09:15:01 pmDone, the first scope works again (no lockout)Thanks,Marc
Simpson 260P issue - Page 1
Forum section: electronics / testgear

author: moby
author_rank: Contributor
timestamp: March 13, 2020, 04:27:14 am
content: My dear old 260P has developed a fault - when on Rx10k, it reads around 100k with nothing connected.I have pulled out the protection board but that made no difference.Any dinosaur doctors out there?.Cheers, Mike

author: bob91343
author_rank: Super Contributor
timestamp: March 13, 2020, 04:52:50 am
content: There is a short somewhere. When you say it reads 100k I assume that is half way up, more or less. Check the range switch for corrosion.
BM235 - Continuity mode - turn off flashing backlight? - Page 1
Forum section: electronics / testgear

author: UZZ32
author_rank: Newbie
timestamp: March 13, 2020, 01:48:51 am
content: Hi there,I recently purchased a BM235 and use continuity mode a lot with the beeper, however I find the flashing backlight is just annoying - is it possible to switch it off in any of the settings or is just how it is?CheersMike
DC Electronic Load in series with low side driver? - Page 1
Forum section: electronics / testgear

author: nwave
author_rank: Newbie
timestamp: March 11, 2020, 12:28:53 am
content: I am wondering if it is possible to put a benchtop programmable DC load into a circuit with a low side driving module between it and ground.Like this:Power supply -> DC Load -> Low side driver -> GroundI am trying to use the load to test the low side driver for different loads. Is this possible? Is there a different/better way to do this?Thanks!

author: _Wim_
author_rank: Super Contributor
timestamp: March 11, 2020, 08:57:48 pm
content: If it is a floating electronic load (inputs not referenced to ground) than this should be possible.
Tektronix TDS5000 and TDS7000 BW upgrade...? - Page 1
Forum section: electronics / testgear

author: Gniske
author_rank: Newbie
timestamp: March 12, 2020, 02:53:39 pm
content: Hi allI have the TDS3000B scope, and I love them. Specially that its possible to upgrade a 100MHz 1.25Gs/s to a 500-600MHz 5Gs/sec. Great!!But, what about the TDS5000 and TDS7000 series? any hacks to get the BW upgrade? I can't find much info about it....Peter
TEK 5103N 120-0761-00 a TEK 577 D1 - Page 1
Forum section: electronics / testgear

author: frantisek
author_rank: Regular Contributor
timestamp: March 08, 2020, 04:59:05 pm
content: Hi. I need to quickly find out whether the TEK 5103N uses the high-voltage transformer 120-0761-00 or whether it is possible to use the display part - complete upper module - 5103N for CT TEK 577 D1. Thank you in advance!

author: frantisek
author_rank: Regular Contributor
timestamp: March 12, 2020, 12:47:19 pm
content: Solved! "Thank you" for everyone's willingness ...
Are these readings normal for the rigol dp832a  - Page 1
Forum section: electronics / testgear

author: cpposteve
author_rank: Regular Contributor
timestamp: March 05, 2020, 08:39:26 pm
content: Hi Allhope you can shed some light on this for me.just received my rigol DP832A (bloody noisy fan)just checking measurements to see how it performs.now for example (as the pictures will show) if i set the output to 30.111 volts, the top line shows 30.120 (weird) and the set at the bottom is 30.111 ( to be expected)on cheking the output with my eevblog meter it is reading the correct voltage withing a few milivolts, yet the voltage displayed at the top is showing 9mv more than it should.is this normal?cheerssteveP.S. is there anyway to turn the fan off while not under load?

author: thm_w
author_rank: Super Contributor
timestamp: March 05, 2020, 10:19:40 pm
content: You can check the manual here to see if its within specifications:http://beyondmeasure.rigoltech.com/acton/attachment/1579/f-01c9/1/-/-/-/-/file.pdfSee Readback voltage.Assuming the 121GW is perfectly calibrated as well.The fan should turn on high on power up, then ramp down after a few seconds. Some users have replaced with a quieter model.https://www.eevblog.com/forum/testgear/rigol-dp832-firmware-updates-and-bug-list/https://www.eevblog.com/forum/testgear/how-noisy-is-a-rigol-dp832/

author: NY2KW
author_rank: Regular Contributor
timestamp: March 13, 2020, 02:27:36 pm
content: I just checked on my 2+ year old DP832A and I do not find that inconsistency. Have you checked other settings?

author: JDubU
author_rank: Frequent Contributor
timestamp: March 13, 2020, 03:20:10 pm
content: It may be within specs but it can be re-calibrated for better accuracy. I've re-calibrated mine and now get one millivolt accuracy for almost all of each range. It cannot be calibrated perfectly because it acts like, internally, the set voltage has a coarser resolution than the read back voltage (difference in D/A vs A/D resolution?).If you have an appropriate benchtop DMM, you can calibrate it yourself:https://github.com/stupid-beard/dp832calhttps://www.eevblog.com/forum/testgear/rigol-dp832-firmware-updates-and-bug-list/600/

author: cpposteve
author_rank: Regular Contributor
timestamp: March 13, 2020, 03:46:13 pm
content: I have since re calibrated this and now all good. Thanks for the reply
Time Electronics LTD D.C. microvolt null meter type 202 - Page 1
Forum section: electronics / testgear

author: guenthert
author_rank: Frequent Contributor
timestamp: August 07, 2018, 10:35:32 am
content: Howdy! Does anyone have some information regarding the nullmeter from Time Electronics? As far as I can tell, it's not in there shop anymore, but neither listed among their legacy products. From the Intertubes I gather, that it was made in the 80ies, which puts its design probably well after the more common Fluke 845 / HP 419 / Keithley 14x and well before the Tegam AVM-2000. By that it hopefully is in the sweet-spot where a hobbyist can repair or recreate (something like) it and parts are still available.If someone knows a bit about its inner working, then please share! I'm a bit confused about it'stwosets of U and I offset trimmers as can be seen inaround 3'50".

author: threephase
author_rank: Regular Contributor
timestamp: August 07, 2018, 02:35:45 pm
content: Have you tried contacting this fella, he was also looking but don't know if he ever found out anything;https://www.vintage-radio.net/forum/showthread.php?t=137897A later thread on the PSU inside;https://www.vintage-radio.net/forum/showthread.php?t=145533Alternatively have you tried Transmille direct, if they have the meter, they may have more info. They have always been very helpful when I have contacted them.Kind regards

author: MegaVolt
author_rank: Frequent Contributor
timestamp: March 12, 2020, 10:59:48 am
content: He ran very quickly on ebay and I got only pictures
Feedback SFG606 - Page 1
Forum section: electronics / testgear

author: JKKDev
author_rank: Regular Contributor
timestamp: March 11, 2020, 05:53:46 am
content: Hey guys,I've been eyeing a Feedback SFG606 on eBay but I can't decide how much an old function generator with sweep and TTL logic output is worth when comparing to some cheap new crappy chinesium ones.I've come to terms with shipping costs of over 20€ for any piece of old test equipment so my question to you guy is: Is this kind of equipment worth aroud 50€ in todays day and age (it's in untested condition).When comparing to a 40€+40€ ppt working Gould 4074 it doesn't feel like it but I guess I could be wrong.Feel free to tell me why I should get it or not. It would join the ranks of the Gould 4074 scope and the Kepco ATE 15-6 PSU. I might dabble with audio equipment repair and that's why I went with low frequency generator.
HP 3458A/HFL User Keys - Page 1
Forum section: electronics / testgear

author: Grandchuck
author_rank: Super Contributor
timestamp: March 10, 2020, 05:34:17 pm
content: I tried all the user key program settings and all work but one:SCALE(2): SMATH11,1E6;MATH 13,T3;SMATH 11;T1The instruction sheet can be found athttp://assets.fluke.com/manuals/3458ahfliseng0000.pdfThanks!

author: Dr. Frank
author_rank: Super Contributor
timestamp: March 10, 2020, 05:48:41 pm
content: The command line is SMATH 11,1E6; ... don't omit the blank before 11.You have to measure something, like 10V or 10kOhm before you engage this function, or you get an overflow, and Offset should be zero, I suppose.It did never work well, nor was it of any use. I programmed TEMP? instead, and NSAMP? instead of LFILTER OFF.Frank

author: Grandchuck
author_rank: Super Contributor
timestamp: March 10, 2020, 06:19:34 pm
content: Thanks Dr. Frank! I chose TEMP? and RMATH 6, as you suggested.Much more useful!
Agilent 8648A 100khz-1000mhz Sig Gen - Page 1
Forum section: electronics / testgear

author: squ1d_ink
author_rank: Newbie
timestamp: March 10, 2020, 03:41:04 am
content: Bought(absurdly cheap) from a friend who got this from a production enviorment. It boots up goes through self test and appears to be functioning..BUT..the front panel is completely non responsive. I went through the manual and found that it has a mode that completely disables the front panel so everything has to be done through HP-IB(I already tried hitting local button and holding down delete while booting). Is there any way to get it back in local mode without a HP-IB adapter? I can buy a GPIB module (which cost a lot more than I paid)if thats the only way but was hoping for a work around.PS-Anyone have experience with this gear? Is it worth the trouble?Thanks

author: 0culus
author_rank: Super Contributor
timestamp: March 10, 2020, 04:35:51 am
content: My first suggestion would be to open the front panel and make sure the ribbon cable(s) are seated. Troubleshooting step zero with anything HP should always be open it up and make sure everything is seated. Failing that, GPIB adapters are fairly easy to get. I have an Agilent branded one, but NI adapters should work as well.

author: bitseeker
author_rank: Super Contributor
timestamp: March 10, 2020, 06:50:43 am
content: Welcome to the forum, squ1d_ink.Pressing theLOCALbutton returns the instrument to local operation, no GPIB adapter necessary. If that isn't working, then start with Oculus's suggestion to check for loose connections to/in the front panel. The display seems to work, so the panel isn't completely dead.

author: squ1d_ink
author_rank: Newbie
timestamp: March 10, 2020, 08:55:27 pm
content: Thanks for the responses. I went through and cleaned all the ribbon contacts with IPA and tested the contacts for continuity-all good and made sure they where seeded correctly. I talked with the guy I got it from and was told that he had hooked it up through GPIB and everything worked fine but he never looked into why the front panel didn't work. I pulled this from the manualLocal LockoutLOCAL LOCKOUT can be used with REMOTE to disable the front panel Local key. With the Local keydisabled, only the controller (or a hard reset by the line power switch) can restore local control.I have cycled power many times(assuming thats what this means ie unplug from wall) and local controll has not been restored. Unless I am misssing somthing the I need to hook up to GPIB and return local controll via command....or it has other problems.

author: james_s
author_rank: Super Contributor
timestamp: March 11, 2020, 12:19:07 am
content: You can build a USB to GPIB adapter for under $10, the bulk of that cost is the connector itself.https://www.eevblog.com/forum/projects/ar488-arduino-based-gpib-adapter/

author: bitseeker
author_rank: Super Contributor
timestamp: March 11, 2020, 12:43:49 am
content: Quote from: squ1d_ink on March 10, 2020, 08:55:27 pmIn which manual did you find this? I didn't see a remote lockout command in the 8648A command set.
DE-5000 LCR Characteristic Impedance Measurement - Page 1
Forum section: electronics / testgear

author: debounce
author_rank: Newbie
timestamp: March 10, 2020, 04:00:37 am
content: Hi Guys,I just got a DE-5000 LCR. I apologize if this is a basic question, but I am new to LCR's and was wondering if this device is capable of measuring the characteristic impedance of a transmission line (say coax or similar) or if I could use some of the readings it gives out to back calculate the line impedance? I know Z= SQRT(L/C), but is it really as simple as measuring L and C and plugging it in?My understanding is that impedance will change a bit based on the frequency that is sent out. For my educational purposes that is OK as I understand I am limited to the frequencies supported by the LCR.I see the LCR gives A/C resistance and DC resistance, but not impedance.Thanks for your time in advance!

author: octillion
author_rank: Contributor
timestamp: March 10, 2020, 04:26:40 am
content: You can take a segment of cable and measure the capacitance with the opposite end open, then inductance with the opposite end shorted. This will give you impedance at the frequency tested. For a short segment of cable (few meters), the inductance in particular will be very small and may be at the lower limit of what a handheld LCR can measure, limiting accuracy. Measuring a spool of coax would be more reasonable.
Keithley DD-51 display differences - Page 1
Forum section: electronics / testgear

author: volvo_nut_v70
author_rank: Regular Contributor
timestamp: March 09, 2020, 05:27:30 pm
content: While replacing the dim display on my Keithley 2002 I have discovered that the DD-51 display as used in the Keithley meters were made by two different manufacturers (BOE and Itron) with different lead configurations. Since the 7001 is the most likely donor of a replacement display it is beneficial to know which display is in your meter and the donor meter.It appears that there is a K2002 serial number break which appears to be a change from a 11XXXXX (old) to a 060XXX (new). My donor meter was a Keithley 7001, the serial numbers on it seem to follow the same pattern. In my case the donor 7001 was serial 111XXXX while the Itron 7001 I have is serial 065XXXX. Also of note, my K2002 had the large mesh fan grill, where the newer K2002s have the small mesh grill.The older display was made by Zhejiang BOE Display Technology Co., Ltd (BOE)http://www.zboe.cn/index_en.aspThe newer displays are made by Noritake-Itronhttps://www.noritake-elec.com/products/vfd-display-module(Itron).

author: TheSteve
author_rank: Unknown
timestamp: March 09, 2020, 05:34:33 pm
content: The new old stock DD-51's I bought were the really old ones with the single row of pins. When I had to install one into a K2400 that used the staggered offset version I made a jig to bend the leads. It turned out pretty well. It would be even more of a pain to have to try to bend(or unbend) the leads of a display that was desoldered though. Just another fun challenge that comes with equipment repair.

author: volvo_nut_v70
author_rank: Regular Contributor
timestamp: March 09, 2020, 08:04:43 pm
content: The leads on the Itron DD-51 that I took out were way too short to make it if they were bent to fit the old staggered geometry.Which suggests that they were made with longer leads and clipped during install. I know on the HP Laserjet 4/5 printers that I had bought some NOS VFD displays, all the displays came with longer leads that required trimming after install.

author: TheSteve
author_rank: Unknown
timestamp: March 10, 2020, 01:55:59 am
content: Ahh, that is even more of a pain.I have attached a pic showing the lead length on a new VFD with the single row of pins.
NI SignalExpress Tektronix Edition for DMM4040/DMM4050 - Page 1
Forum section: electronics / testgear

author: garrettm
author_rank: Frequent Contributor
timestamp: March 05, 2020, 02:10:47 am
content: So I have a Tektronix DMM4050 and wanted to install the SignalExpress software on my new laptop but quickly realized I don't have a optical drive on any of my new computers... Okay. Fine, I'll just download it. After making an account on Tektronix's website and scouring the downloads section I noticed that Tektronix doesn't make the SignalExpress software available for download anymore. Oh boy. What to do? Well, luckily a family member actually had a USB DVD drive floating around (LOL). So to do everyone a big favor I ripped the two CDs that came with the multimeter using InfraRecorder and uploaded them to my Mediafire account. So without further rambling I present to you and anyone interested the ISOs of the original discs (NI LabVIEW SignalExpress Tektronix Edition 2.51 Setup and the DMM4040/DMM4050 Documentation and Installation Files Browser).If providing these ISOs is against some sort of policy here or with Tektronix/NI just let me know and I'll take down the link. Otherwise, just click the link below to get the ISOs and enjoy.http://www.mediafire.com/folder/qbj5zj2hyf0b8/Tektronix_DMM4050

author: Alex P
author_rank: Contributor
timestamp: March 07, 2020, 11:29:43 pm
content: My CD has version 2.5.1 - is that the same as your 2.51?

author: garrettm
author_rank: Frequent Contributor
timestamp: March 10, 2020, 02:02:47 am
content: Quote from: Alex P on March 07, 2020, 11:29:43 pmMy original disc also shows 2.5.1 (its the CD to the right in the photo attached to my first post). So 2.51 was simply a typo on my part.
HP8590 series reference in/out - Page 1
Forum section: electronics / testgear

author: Miti
author_rank: Super Contributor
timestamp: March 07, 2020, 06:38:43 pm
content: I have a question about the reference in/out of the HP8590 series spectrum analysers. Can I split the 10MHz using a simple T adapter? I want to use it for an external tracking generator. By my measurements, the input is not 50 Ohm anyway and the frequency is low enough. What do you think?

author: ps
author_rank: Regular Contributor
timestamp: March 08, 2020, 10:40:37 am
content: In the counterlock assemby (A25) the reference signal is AC coupled (47 nF) and clamped to 0.6 V before driving the OSCIN input of a MC145146 PLL. Reference Output is driven by a NE5212 RF OpAmp, also AC coupled (10 nF). So I assume there will be enough power available to drive a second input, and there is definitely no 50 Ohm matching present.

author: Miti
author_rank: Super Contributor
timestamp: March 09, 2020, 12:32:05 am
content: Quote from: ps on March 08, 2020, 10:40:37 amGood info, thanks ps! I will use it as reference to an AD4350.
Anritsu 3654B (V Cal Kit) Floppy - Page 1
Forum section: electronics / testgear

author: jjoonathan
author_rank: Frequent Contributor
timestamp: March 06, 2020, 02:59:26 pm
content: Hi all! I'm trying to use an Anritsu 3654B cal kit that's missing its floppy disk with an HP 8510C VNA.First thing's first: does anyone know where I might look to find the 3654B cal constants? For HP cal kits I can find typical values on keysight.com and in the relevant manuals, but that doesn't seem to be the case for the 3654B. Any leads would be appreciatedFrom there, I expect this will require a bit of fooling around. At worst, I suspect it will mean extracting delay and parasitic params from the Anritsu cal kit definitions and thinking about how those map to the HP LC parasitic polynomial models. If the kit includes .s1p files, the mapping is theoretically straightforward and I believe I've even seen a script to do it automatically somewhere, but my understanding is that .s1p files were an optional extra on 3654B cal kits so I can't count on it.If I get really desperate, I've got some 3.5mm airline offsets so I can probably create a 2.4mm -> 3.5mm -> airlines -> 3.5mm -> 2.4mm -> short abomination and do a SSS calibration in python or something, but I can't say I'm looking forward to it. Ideas from people more experienced in the dark arts of VNA calibration would be welcome

author: octillion
author_rank: Contributor
timestamp: March 07, 2020, 04:51:59 pm
content: I don't have the 3654B kit, but I have an Anritsu 3652 K kit with the floppy, which may give you an idea of what you're missing. The floppy has four files which are only a few bytes each, and I'm not sure what they represent or how to use them. Attached are the four files on the floppy, along with scans of two sheets of paper that came along with the kit. I'm not sure if anything else ever came with the kit and went missing.

author: jjoonathan
author_rank: Frequent Contributor
timestamp: March 08, 2020, 10:43:25 pm
content: Ooh, those pieces of paper have everything that would be needed to use the kit with an 8510C -- no (more) model fitting necessary! The 0s for the L constants further suggest that the low-loss approximation is good to 40GHz, which gives me confidence in using a SSS cal out to 50GHz. Thanks for sharing!

author: hendorog
author_rank: Super Contributor
timestamp: March 08, 2020, 11:21:40 pm
content: Quote from: octillion on March 07, 2020, 04:51:59 pmJust for interests sake, I had a go at decoding the files. I used 010 Editor (Hex editor)Taking the first file I opened - Kit_info.kmo (Last two chars of extension = Male Open)First 8 bytes are 4.6E-15 in Double Precision floating point - which matches the pdf for Male Open naming it after the gender of the port, not the gender of the cal standard.Second 8 bytes are 9E-26Next 8 bytes -7E-36Next 8 bytes 2.6E-46Next 8 bytes 0.005Final 7 bytes serial #071025 in ASCIISo there is no more info than you already have hiding in there.
HP 1141A probe attenuator HF response adjustment questions - Page 1
Forum section: electronics / testgear

author: hasc
author_rank: Newbie
timestamp: March 09, 2020, 10:36:16 pm
content: I have several 1141A probes and attenuators bought from different sources. The manual says the CMRR and HF response of an attenuator needs to be adjusted with the specific probe it will be used with. Without having made any adjustments yet, just trying different combinations of attenuators and probes, the performance generally looks reasonably good (roughly 1000:1 CMRR, step response flatness well under 10%) but there is a fair amount of variation across probe/attenuator combos which I think indicates that probe-specific adjustment could help.However I am a little worried about attempting the HF response part of the adjustment because the two surface-mount trimmer caps have been filled/locked with what appears to be RTV silicone. I don't see the silicone mentioned in the manual but it is on all the attenuators I have and is also visible in the photo in this thread:https://www.eevblog.com/forum/reviews/agilent-(hp)-1141a-differential-probe-and-power-module-1142a/Does anyone have experience adjusting these attenuators? Is the silicone just there to prevent casual twiddling or could there be some other reason, like sealing against contamination? (The manual does say not to do the adjustment as part of normal maintenance because the attenuators are delicate...) Should I risk picking out the silicone and messing with the trimmers? Or just do the LF CMRR part of the adjustment only, leave the HF alone, and swap around attenuators/probes to find the best combinations as-is?