hybridfree/eevblog-posts huggingface dataset:
Tektronix 11801 Noise When Using Large Main Position - Page 1
Forum section: electronics / testgear

author: lucasc
author_rank: Newbie
timestamp: July 21, 2020, 01:31:56 pm
content: Hello everyone,I have recently purchased a used Tektronix 11801 and I was getting acquainted and running some basic validation tests on it to make sure everything is working fairly well.So far everything seems to be fine with exception of one thing, I noticed that the noise in the signal gets significantly larger as a move the display "Main Pos" father from the trigger point. To be very clear, this "Main Pos" parameter moves the X-axis of the signal in relation to the trigger, so if the trigger happened at time = 0, and the Main Pos is set to 49ns, that means that the oscilloscope is starting to capturing and show the signal 49ns after every trigger.My understanding is that I should be able to move far away from the trigger without compromising the signal quality, but it seems that this is not happening right now. The attached pictures show a comparison between when I capture the edge as close as possible to the trigger, and another waveform where I intentionally wait for about 11us to capture the waveform.It's very clear that the more I wait to capture the more noise it gets and I believe this is due to jitter either on the scope of on the signal source. Now I'm concerned that this could be an issue with the scope, but I'm not sure if:1. This is the expected behavior of the 118012. My signal source is jittery and that is why the farther I am from the trigger, the higher the jitter.The waveforms attached were taken with the Leo Bodnar edge generator (http://www.leobodnar.com/shop/index.php?main_page=product_info&cPath=124&products_id=295) and I also tried with the scope internal clock output signal; the same thing happened.Can anyone that uses this scope tell me if you see the same behavior?Thanks in advance,Lucas
You've got a DPS5020. Great! Now how the hell do you power this thing?! - Page 1
Forum section: electronics / testgear

author: rawrs
author_rank: Contributor
timestamp: July 24, 2020, 12:30:09 pm
content: Hey all,The question really is quite simple. I've got a DPS5020, and I want to power this puppy. Because who doesn't want to try sending a full kW of DC juice through a power supply that fits in your hand?Now the problem arises. There's plenty of 24v or 48v power supplies out there that could do the job - but this thing isn't a step-up converter, as you may already know - it's step-down only.I've found approximately one power supply that's 60v, some amps, and even rated for medical use... ...it's also an order of magnitude more expensive than the bench supply itself! Seriously, this thing is about a grand. I'm kinda looking for something a bit more suitable.Maybe I don't need 60v, but 48v output would be fantastic, so I can power PoE stuff and whatnot. So...Any ideas? I've really come up short on this one. Mean Well would be my go-to here, but, no dice, it seems. I'd love to see if there's *any* solution out there. And if there is, I'm hoping this business case of a post will help other people who are looking to power their shiny new toy.Thanks!Rory

author: Mazo
author_rank: Regular Contributor
timestamp: July 24, 2020, 01:32:08 pm
content: I have 2 DPS5005,which I power from and old Eastern Block 4x22V secondaries transformer(each of the modules is powered by 2 windings in series).They don't seem to mind the 58-9V dc input unloaded and even measure it correctly.Just my 2cents,hope it helps.

author: The Soulman
author_rank: Super Contributor
timestamp: July 24, 2020, 01:45:12 pm
content: Most (all?) closed frame mean-well psu's have a output voltage adjustment pot with a limited trim range.Read the datasheets, a 48V psu maybe suitable for you after all.
Voltbot? - Page 1
Forum section: electronics / testgear

author: Inju
author_rank: Newbie
timestamp: July 20, 2020, 03:59:34 am
content: Hello all. I'm brand new here and due to the Corona virus I'm stuck at my girlfriends small apartment and wanted to build a super portable electronics lab to make some Eurorack modules. Started watching eevblog on YouTube which lead me here. Got myself a portable oscilliscope, a new digital solder iron and anywho, looking for a super portable bench power supply that goes to -12, 5 and +12 volts, .1 to 2 amps for testing. Was all set to building my own and ran into this strange device on amazon called Voltbot. No reviews on it. Does anyone own one and know anything about it to use as a stable power supply?

author: Inju
author_rank: Newbie
timestamp: July 20, 2020, 04:01:51 am
content: There's no way this thing can be any good right? I'm looking at the specs and it has 4 channels!

author: HKJ
author_rank: Super Contributor
timestamp: July 20, 2020, 04:45:07 am
content: I did review it:https://lygte-info.dk/review/USBpower%20Voltbot%20UK.htmlThe software may have been improved after my review.

author: Inju
author_rank: Newbie
timestamp: July 20, 2020, 02:45:58 pm
content: Thank you reading now!

author: alextwin007
author_rank: Contributor
timestamp: July 20, 2020, 05:01:55 pm
content: I've been in a similar situation with regards to a portable power supply when I'm away from my bench. The solution that I came up with was to get one of the RD DPS3003 modules, the case, some 18650s, and a protection/ charging board. This gives me a battery operated power supply, that does up to 2 amps and 18V.
Rohde & Schwarz HM7042-3 linear power supply - Page 1
Forum section: electronics / testgear

author: pcolbeck
author_rank: Contributor
timestamp: July 18, 2020, 07:53:32 am
content: HiI'm a beginner starting to gather equipment (did start an electronics degree 35 years ago but fell out into computer networking instead) to get started. I will be mainly working on audio equipment (old amps and radios) along with some computer stuff.I've been looking at bench power supplies and there is a vast range of prices. I have some spare cash at the moment so was wondering whether I should splash out on a good second hand one that would last or go for a cheaper new one.I have seen a used triple output Rohde&Schwarz HM7042-3 for about £500 and a new dual output CSI 3005EIII for £175 but cant find reviews of either.Is the Rohde&Schwarz really worth the extra money for a hobbyist?Many thanks for any input to help with my head scratching.

author: pcolbeck
author_rank: Contributor
timestamp: July 19, 2020, 08:16:16 am
content: Been looking at the specs for the R&S and the resolution is 100mV 1mA (0-1999mA), 10mA (>=2A) on the 30 Amp channels and 10mV 10mA on the 5v channel.Something new like a SPD3303X that I could get for the same money has 1mV and 1mA resolution. Is that extra resolution important for most uses?

author: tautech
author_rank: Super Contributor
timestamp: July 19, 2020, 08:55:42 am
content: Quote from: pcolbeck on July 19, 2020, 08:16:16 amNot really.I can't remember if I've ever sold a X model whereas the X-E continue to sell and I'm out of stock again !Sales figures like that indicate customers feel satisfied with 10 mA/mV adjustments although last time I checked 1mA/mV was available in the X-E when using the EasyPower SW package it comes with.Sure they're only a 3A PSU but you also have the option to series or parallel 2 outputs for 60V 3A or 30V 6A.

author: pcolbeck
author_rank: Contributor
timestamp: July 19, 2020, 11:18:14 am
content: It was the 100mV resolution on the R&S 30V channels that I was mainly worrying about.

author: pcolbeck
author_rank: Contributor
timestamp: July 19, 2020, 07:52:26 pm
content: I managed to bargain the Rohde & Schwarz to £400 so I bought that and a ELEKTRO-AUTOMATIK PS 3016-20B 16V 20A single channel PSU as well.That's me all sorted for power supplies for now I think.Now to mull over scopes.Thanks for the input tautech it helped me decide.
Proper FW version for TDS1002B? - Page 1
Forum section: electronics / testgear

author: beuford
author_rank: Contributor
timestamp: July 02, 2018, 06:58:36 am
content: Hello!I picked up a TDS1002B in near perfect condition for low cost. Seems to work fine, but I'm puzzled by the firmware. It claims to have FW V24.02 installed, but the highest I can find for this model on Tek's web site is V22.16.Did I get some sort of "hacked" product, or has the wrong (but functional) software been installed?Any info would be appreciated.Beuford

author: tautech
author_rank: Super Contributor
timestamp: July 02, 2018, 08:30:27 am
content: I haven't hunted through all the models but I suspect it's the latest and last for that model.If so it was would've been installed in the factory and there's not been a public release since.But there is another possible explanation, maybe it's for one of the other TDS1002 variants, for example TDS1002C-EDU uses V25.11.

author: beuford
author_rank: Contributor
timestamp: July 06, 2018, 05:30:46 am
content: Strange; it seems that this is the ORIGINAL firmware for this device.... weird since the serial number dates to 2010. Maybe it's a refurb with a replaced main board?Grainy pic, shot through rear grill:I know these cheap little scopes don't get a lot of love around here, but for a basic scope I like it. MUCH quieter than my Keysight (no fan!), MUCH lighter, and reasonable capabilities for the price.Beuford

author: tautech
author_rank: Super Contributor
timestamp: July 06, 2018, 05:55:41 am
content: Quote from: beuford on July 06, 2018, 05:30:46 amCool, that solves that question.There must be tens of thousands of these still out there in Edu labs all over the world and while they're pretty basic by todays standards they still do basic tasks just fine and are a heap better than no scope !I only ever had one and it was given to me by an EE with a dead backlight PSU oscillator, the C in the R-C push-pull primary had drifted from nF's into the pF's and stopped oscillating. That's all that was wrong with it but I had a better Tek at the time and it went to another home.So if the display goes dead just shine a light on it to check if it's only the backlight and then check component values around the oscillator.

author: Antonionavan
author_rank: Newbie
timestamp: July 18, 2020, 06:47:22 pm
content: Hi. i have an oscilloscope model TDS1002B-SC. this oscilloscope is in Chinese language, and i would like to know if is possible to change the firmware to english or spanish language. In the oscilloscope menu is possible change to english but is a limited traduction some label is showered in chinese. I try to obtain the firmware file for the official Tektronix web site but is not possible download. If you have any version seems to 22.16 please send me to antonionavan@gmail.com, i appreciate a lot.
electronic dc load kp182 kp184 anyone ? - Page 1
Forum section: electronics / testgear

author: oz2cpu
author_rank: Frequent Contributor
timestamp: October 25, 2019, 07:54:06 pm
content: check out ebay for the kp182 200Watt and kp184 400Wattlooks cheap and apealing ?anyone of you got one ? can reveal the resolution of load ?how small and hos accurate can you dial in a load current ?drift issues ? over heating issues ?is it silent if load is low ?tested the serial output available on the kp184 model ?how does it look on a terminal ?other things you can say about features ?constant current, constant resistance ? constant watt ? what can it do ?

author: BeeJee
author_rank: Newbie
timestamp: July 17, 2020, 11:16:31 pm
content: YouTube is loaded with interesting reviews of this DC-load. Search with "KP184"..
LabVIEW Home is no more, LabVIEW Community Edition is now free! - Page 1
Forum section: electronics / testgear

author: graybeard
author_rank: Frequent Contributor
timestamp: July 17, 2020, 05:04:41 pm
content: My trial period for LabVIEW Home edition expired. So I emailed NI (formerly National Instruments) today to inquire about purchasing it. This is the response I received from NI.Hi Chris,This is Pamela from our Sales team at NI. I'm following up on your inquiry regarding LabVIEW Home Edition.The LabVIEW Home Edition has been replaced with the LabVIEW Community Edition, and it is for free. You can download it from here:LabVIEW Community Edition.Best regards,Pamela GómezSales Development EngineerInside Salesni.com

author: free_electron
author_rank: Super Contributor
timestamp: July 17, 2020, 05:07:17 pm
content: Hooray !. now if they could kill of the new edition as well , and all other products ..
Fluke 8846A error charts - Page 1
Forum section: electronics / testgear

author: Baltazar
author_rank: Contributor
timestamp: July 17, 2020, 06:11:15 pm
content: Today I ordered a Fluke 8846A. I prepared error charts that show abs. error as a function of range & measured value. If anyone is interested, I have similar for GW Instek GDM-8351 too.One question: What is the maximum count the 8846A can show before switching to higher range? I saw some photos displaying 1.000604V on 1V range. At which point will it switch to 10V range? Once I get this info, I will complete the charts to show the overlap of adjacent ranges.

author: commongrounder
author_rank: Frequent Contributor
timestamp: July 17, 2020, 07:15:45 pm
content: I have a Tektronix DMM-4050, which is essentially the same as the 8846A. It will over-range up to 1.2 volts on the one volt range before up-shifting. It will down shift when the voltage settles back to 1.1 volts, so there is a bit of hysteresis there. Hope that helps.

author: bdunham7
author_rank: Super Contributor
timestamp: July 17, 2020, 07:35:21 pm
content: 1.2 million counts, so 20% overrange, but it is twitchy and sensitive to noise. You'll see the word 'Overload' a lot as it shifts ranges. If is averaging a noisy signal, it may shift down a range sooner than you'd think and may indicate 'Overload' even at much less than the full 1.2M counts. By 'error chart' do you mean a compilation of tolerances from the data sheet or from actual measurements of your unit?

author: Baltazar
author_rank: Contributor
timestamp: July 17, 2020, 09:22:45 pm
content: Thanks for the info, commongrounder & bdunham7. I updated the charts, i.e. extended every range by 20%.@bdunham7: This is a compilation of ± (% measurement + % of range) values from spec.
Using TDS HardCopy with Agilent 82357B GPIB Controller - Page 1
Forum section: electronics / testgear

author: snoopy
author_rank: Frequent Contributor
timestamp: July 17, 2020, 09:28:10 am
content: HelloI am trying to download screen shots from my Tek TDS784A to a PC using TDS HardCopy and Agilent 82357B GPIB controller but no luck with the software recognizing the scope. Apparently the software says it can support this controller but with the following caveat.Quotehttp://mkelzenb.caltech.edu/software/TDSHC/index.htmlThe Agilent software sees the scope but not TDS Hardcopy. Has anyone had any luck with using this combination ?regardsdavid

author: KE5FX
author_rank: Super Contributor
timestamp: July 17, 2020, 10:29:01 am
content: Looks like the software primarily expects to talk to a National Instruments adapter. In that case, you'll need to go into the Agilent configuration software and enable NI488.2 compatibility, if you haven't already.

author: snoopy
author_rank: Frequent Contributor
timestamp: July 17, 2020, 11:14:55 am
content: Quote from: KE5FX on July 17, 2020, 10:29:01 amThank you so much Sir, you are spot on ! Just make sure you reboot after changing this optioncheersdavidhttps://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z0000019L2jSAE&l=en-AUQuote
Keysight U1282A - Page 1
Forum section: electronics / testgear

author: targit
author_rank: Regular Contributor
timestamp: July 15, 2020, 11:20:33 am
content: 2+ years on my Keysight U1282A, got caught out in the rain yesterday and meter got a few splashes of rain, then had to totally strip it and clean PCB with isopropyl alcohol to get the thing to stop beeping for "incorrect lead" - current probe warning. I started out by cleaning out and drying the socket itself thinking that would be the source, but no joy until I stripped it and cleaned the PCB. Had completely forgotten its supposed to be IP67 rated.Anyone else had fun with theirs in the rain?

author: Bassman59
author_rank: Super Contributor
timestamp: July 15, 2020, 08:52:36 pm
content: Quote from: targit on July 15, 2020, 11:20:33 amDunno about that, but Keysight is offering 25% off handheld meters!

author: Elasia
author_rank: Frequent Contributor
timestamp: July 16, 2020, 10:28:12 am
content: 2 years? Call and complain.. 3 year warranty
YIG-Tuned Filter/Mixer (RYTHM) Adjustment in HP /aglinet 8565E - Page 1
Forum section: electronics / testgear

author: hafrse
author_rank: Regular Contributor
timestamp: July 17, 2020, 07:06:36 am
content: Hello,I have the service guide for 8564E/8565E , but it seems that the chapter for adjustment procedure of the YIG-Tuned Filter/Mixer is removed.(service guide for 8563E/8562E/8561E has that information).Any help to find that information?Thanks!
Rigol DS1062C communication through RS-232 with Ultrascope - Page 1
Forum section: electronics / testgear

author: ekiyoha@gmail.com
author_rank: Newbie
timestamp: July 15, 2020, 09:03:31 pm
content: Hello friends,I am posting this new topic in reply to Majdgh, who posted a topic, last February about this issue. As it is an old post, I was told to write a new topic, instead of reply to Majdgh.I got the same problem reported by Majdgh, trying to connect the Rigol DS1062C to laptop, using the RS-232 interface, and the Ultrascope software. As he has posted, everything works fine, including the remote control, but I can´t transfer data to see in wave mode, there is error in transfering data from scope.He has mentioned, he also tried to use the LabView, but also failed.I have contacted the Rigol deskhelp, inquiring about possibly new firmware, and also asking why the USB interface looks like dead, unfortunatelly I got nothing, as you can see the copied bellow:"There is no firmware update available for that model. The USB interface on that was designed for Win XP. I don't think it can be made to work on anything more modern.Glad it is still working. Let us know if we can help further."It is ashame, we "old" customer are abandoned, and we are in our own effort to solve this problem.I wonder to join efforts to figure out, and here are few steps those I tested, and may be can help you:1) Get this publication (see pdf attached):https://www.yumpu.com/en/document/view/38978251/ds1000ca-serie-scpi-programming-guide-batronix/9It is a very usefull book with commands to control DS1062C through RS-232 interface.2) In the LabView, open the windows Measurement & Automation Explorer.3) If the RS-232 interface is connected and recognized by your notebook, then it will appear in My System > Devices and Interfaces on the left upper corner of window.4) On the rightmost column, there is a question "What do you want to do?", there is an option "Communicate with my device" Right-click on your serial or parallel port name in the configuration tree and select Open VISA Test Panel.5) The VISA Test Panel looks like the attached image, there you can write commands (see the book in above described site), and read the feed back response from scope.6) This is the confirmation, that interface is working properly, and data is sending accordingly in block (1024 bytes).7) The command line is ::WAVeform:DATA?\sCHANnel1\nSee in the Excel sheet the data received in laptop.These are what I got so far, next step I will work on decoding the Hex data file and try to display these data on LabView "Front Panel", and forget the Ultrascope, this has sucked me long time, and no support by Rigol team.
Agilent E7495A/B => Zero span? - Page 1
Forum section: electronics / testgear

author: homem_do_saco
author_rank: Contributor
timestamp: July 14, 2020, 05:04:47 pm
content: Hi all.Does the E7495A/B do zero span? I`ve seen 2 posts by a forum user that it does, but no such reference on the datasheet.Thanks.
Can anyone identify this scope model? - Page 1
Forum section: electronics / testgear

author: Johnboy
author_rank: Regular Contributor
timestamp: July 14, 2020, 08:35:49 pm
content: This was cropped from a picture of my friend's father's workshop. I cannot tell what this is. Can you? Thanks!

author: ceoxrad
author_rank: Regular Contributor
timestamp: July 14, 2020, 08:53:16 pm
content: It vaguely reminds me of a TRIO-Kenwood model, but not sure

author: coromonadalix
author_rank: Super Contributor
timestamp: July 14, 2020, 11:21:43 pm
content: Seems the CS- xxxx series but cant find an exact photoCS-15xxCS-18xx ??ButHitachi V-202F seems almost identical, the hint seems the two big dial on the lower front frame, the Trio / Kenwood doesn't seem like this ?

author: Johnboy
author_rank: Regular Contributor
timestamp: July 15, 2020, 02:26:30 am
content: Excellent guesses! Thank you for narrowing the field. Definitely getting closer to identifying this model.The picture below is of the Hitachi V302B, a 30 MHz contender. The guy was an HF band devotee, so this seems to fit the glove. But the intensity knob is not quite right, and there seems to be another control below the trace rotation screw that doesn't appear on the V302B.
RIGOL DSG800 Any hopes to magically upgrade to fully BW and Options? - Page 1
Forum section: electronics / testgear

author: Houseman
author_rank: Regular Contributor
timestamp: July 20, 2020, 08:43:40 am
content: Hi forum.Thinking to buy the Rigol DSG800 series in specific the 815 model.Is there any hope to magically transform it to fully 836A with both options??Have searched through the web but it seems to be unknown.Best regards and thanks.Steve

author: noreply
author_rank: Frequent Contributor
timestamp: July 20, 2020, 05:42:36 pm
content: Hi Steve,Unfortunately - there is no 'magically transforming' to 836A - this is not possible!The 'A' variants - have additional IQ circuitry which is missing in the non 'A' models.With regard to 'enhancing' the 815 to 830 or 836 - this is work-in-progress and depends on many factorsI am currently Reviewing the 815 - thanks to the generosity of my Test Equipment distributor (I will BUY a device - either the Rigol or equivalent Siglent)- and been 'posting' my mini findings as I go along (another one scheduled later today) - and then a will publish a more complete summary.My specific 815 thread is here ...https://www.eevblog.com/forum/testgear/rigol-dsg815-testing-feedback-and-comments/msg3122450/#msg3122450The discussion on 'enhancing' 800 series thread is here ...https://www.eevblog.com/forum/testgear/upcoming-rigol-dsg815830/25/Despite the possible enhancements - the DSG815 is a fine instrument - although its a little dated design (back to 2015) - it performs extremely well.If you can live with the 1.5GHz limit - then its really good value - I like the compact size.Take Care & Good Luck

author: Houseman
author_rank: Regular Contributor
timestamp: July 20, 2020, 08:20:53 pm
content: Thank You noreply.Didn't know why could not find the thread before your kind reply.Will follow upcoming post.Best regards and thank You againSteve
Help needed on satellite meter - Page 1
Forum section: electronics / testgear

author: bitcom
author_rank: Newbie
timestamp: July 16, 2020, 03:45:50 am
content: Hi everyone, my apologies if this post in in the wrong section, but I could not find a better one.After owning the Birdog satellite meter for some years the manufacturer stopped supporting it.I'm ready to move on and trying to decide on either one of this two:https://cutt.ly/Rp6G89iandhttps://cutt.ly/kp6HnvOI was surprised not to find any kind of reviews either here or anywhere else on the web.This 2 units are apparently similar in functionality and they both support the new HEVC codec which is a good to have as it becomes more popular in the future, the ST-5150 has a very sleek and more elaborated design, but the KPT-716TS has a larger screen which is a big plus.I was hopping some of you here in the forum has any experience with any of this units so I can make a more informed decision.Thanks for any help
Python library for communication with Metrahit dmms - Page 1
Forum section: electronics / testgear

author: erazor
author_rank: Newbie
timestamp: January 01, 2015, 07:36:36 am
content: Hi,I got me a Gossen-Metrawatt Metrahit Ultra BT and began working on a Python extension to communicate with this device.For anyone interested:https://sourceforge.net/projects/metrahit/The advantage is that the user gets all the data in usable formats and doesn't have to fiddle around with diverging raw text output of the device.The extension could be used for data logging or for implementing test protocols.It's only tested with bluetooth connection under Linux and Python 2.6, but should also work with the serial cable and under Windows and newer Python versions.There's no official release yet, but the Git repository contains the first import which allows to get/set arbitrary informations, read out stored values, read values on demand and receive sent values.It's not feature complete yet and lacks documentation, but shows where it's going.Hope this helps someone and I'm open for discussion, improvements, ideas etc.

author: Trader
author_rank: Frequent Contributor
timestamp: July 14, 2020, 04:47:45 am
content: New updates?
Wilkinson power divider  – some basic testing - Page 1
Forum section: electronics / testgear

author: noreply
author_rank: Frequent Contributor
timestamp: July 14, 2020, 12:08:18 am
content: Wilkinson power divider – some basic testingI recently was introduced to the wonderful world of microstrip technology.Seehttps://en.wikipedia.org/wiki/Wilkinson_power_dividerfor background information if you never heard of this useful principle / implementation of dividing and combining RF power.One of the first things I wanted to experiment with was the Wilkinson power divider.To my surprise, I managed to find and purchase a small Wilkinson power divider PCB with the classic power divider / combiner implemented in microstrip technology.These were only £3.50 on amazon.co.ukSoon after I purchased 3 of these units – the seller put up their price – so your mileage might vary with Amazon.Whilst doing a review on a DSG815 RF signal Generator – I took this opportunity to make some quick basic tests, to see if the power dividers did actually work as the theory suggests (no reason why not as it’s a proven technology)See the attached screen shots belowTesting was with Rigol DSG815 as the RF signal source and Siglent SVA1032XTitle of attached image describes the test undertaken and the appropriate Spectral response.ConclusionThe Wilkinson power divider / combiner is a useful circuit element – and this cheap PCB does the job for low frequencies quite well.Your experiences and comments / further discussion on power dividers / combiners is welcome.
eBay find - RCA Voltohmyst - Page 1
Forum section: electronics / testgear

author: Bud
author_rank: Super Contributor
timestamp: July 12, 2020, 11:58:06 pm
content: Came across this when browsing eBay. Never heard of Voltohmyst name for a multimeter.Link to the auctionhttps://www.ebay.ca/itm/Vintage-Eico-Multimeter-556-Kit-w-Leads-box-books-extra-knob/362974689789

author: The Doktor
author_rank: Regular Contributor
timestamp: July 13, 2020, 01:14:21 am
content: The link you provided was for an Eico?RCA used the VoltOhmyst name for a range of volt-ohm meters. Some different models had their own names like "Junior VoltOhmyst", "Senior VoltOhmyst", "Master VoltOhmyst", etc. Most were pretty basic VTVMs, although I believe there was at least 1 solid-state VoltOhmyst model.The VoltOhmyst line were decent meters, I've got a few models I've (mostly) trash picked over the years. All worked well after replacing a small part or 2. I have some affection for the old buggers, but with limited space on my bench, a 410b is my VTVM of choice.These were designed to be affordable meters for service shops and such, not high end laboratory equipment. The didn't have the high frequency capabilities of something like the HP 410b or the accuracy of the HP 412a. Basically, they were the Rigol of their dayEd

author: Bud
author_rank: Super Contributor
timestamp: July 13, 2020, 01:47:46 am
content: Apparently the seller's lot has a mix of a meter and documentation that came from different meters. Anyways, indeed, there is a little trademark character after the Voltohmyst name, which likely indicates the name was a trademark, rather than a name for type of equipment.

author: schmitt trigger
author_rank: Super Contributor
timestamp: July 13, 2020, 12:51:17 pm
content: Remember the Voltohmist series.The Senior Voltohmist had a large, very legible meter panel. Very nice.The only thing is that it took a long time to warm up and stabilize.When RCA exited the test equipment business, a company named VIZ continued manufacturing them for a while until it went out of business. Digital meters were already becoming ubiquitous and the traditional VOM manufacturers which did not adjust simply vanished.
Manuals for BSI PSM3/2 AKA Uni-T UTP3335TD PSU - Page 1
Forum section: electronics / testgear

author: WaveyDipole
author_rank: Frequent Contributor
timestamp: July 07, 2020, 03:23:21 pm
content: Does anyone know whether and where I can get manuals, circuit diagram or service information for a BSI PSM3/2 power supply, otherwise known as a Uni-T UTP3335TD? The unit is working but needs adjustment, for example the 5vDC line is at 5.21V and the output on the two variable channels is also a bit out. I have tried contacting Uni-T by e-mail and eventually got a very short reply from them basically saying its an older model. On asking whether they had technical documentation for this older model I got a very brief one word e-mail back saying "No".

author: WaveyDipole
author_rank: Frequent Contributor
timestamp: July 14, 2020, 03:38:26 pm
content: Bump.
HP53132A with option 01 board, 53132-60004 - jumper W1 - Page 1
Forum section: electronics / testgear

author: tkamiya
author_rank: Super Contributor
timestamp: July 11, 2020, 05:39:15 pm
content: I have an HP53132A with option 01 board, 53132-60004. The OCXO is Isotemp OCX033-46. On the PCB sub assembly, there is a jumper W1 right below J1. Is it supposed to be shorted or not shorted? Please note, this is not the same board that was used in more recent 53132A which can take any OCXO.Symptom is, it can not be auto calibrated. Before I started tweaking OCXO, I'd like to make sure it is optioned correctly.Thank you.

author: tkamiya
author_rank: Super Contributor
timestamp: July 12, 2020, 02:01:58 am
content: Issue is resolved. OCXO has drifted out of range. Put it back around 10MHz and autocal works.

author: HighVoltage
author_rank: Super Contributor
timestamp: July 12, 2020, 08:13:56 am
content: Maybe the OCXO is bad with too much drift, noise and jitter, look at both.You need to watch the OCXO for a while to determine its quality.I had a similar issue and replaced the OCXO.

author: tkamiya
author_rank: Super Contributor
timestamp: July 12, 2020, 04:51:55 pm
content: That's very possible. Thanks for your reply.I bought this counter used about 2 years ago, and this is the first time I calibrate the internal oscillator. I've always used it with lab standard 10MHz so it's hard to tell if it drifted or it was misaligned at some point.I'll keep my eyes on it.

author: tkamiya
author_rank: Super Contributor
timestamp: July 12, 2020, 05:23:27 pm
content: THIS is this dis-concerting!I actually have two HP53132AUnit #1 had a "good" OCXO option 01Unit #2 I just repaired.I also have an OCXO standard that's just an ordinary OCXO 8663-01.Using house standard (GPSDO) as reference and extending gate time to 1 second so I see all 12 digits, Unit #1 is showing last 3 digit off and 2 digit fluctuating, and Unit #2 is showing 4 digits off and 3 digit fluctuating. This is right after successful calibration.It would be interesting to replace the internal ocxo with 8663, do something like Mr. Sweeney did....Another option is do away with high spec option entirely and make a new box with Rubidium standard. They just don't drift!

author: thinkfat
author_rank: Unknown
timestamp: July 12, 2020, 05:52:44 pm
content: I just recently bought a 53131A and upgraded it with a MV89A OCXO. PCB designed by this kind fellow:www.circuitvalley.com. Gerber files here:https://github.com/circuitvalley/agilent_53131A_53132A_options/tree/master/Time_Base_Oven.The parts are pretty recent, just the 5V reference was a bit hard to obtain. Found it at RS eventually.Pretty happy with the result, though the 53131A is of course not in need of such a beast of an OCXO. But it's nice that it doesn't drift a lot.

author: tkamiya
author_rank: Super Contributor
timestamp: July 13, 2020, 08:24:16 pm
content: Thank you!
Brymen BM-869S diode mode? - Page 1
Forum section: electronics / testgear

author: kgavionics
author_rank: Regular Contributor
timestamp: July 10, 2020, 03:18:09 pm
content: Hello guysI bought a Brymen BM-869S few months ago. I'm quite happy with the meter, but I have an issue which I find very frustrating which is the diode mode! I'm troubleshooting a defective TV power supply and when testing the diode in reverse bias, the meter reading keeps increasing slowly without showing OL, as opposed to my old Fluke 8060A which display the OL within a few seconds! How do I know if a diode is blocked in reverse bias if the meter reading keeps increasing without displaying Overload! Is this a bug or what?Thank you in advance

author: bdunham7
author_rank: Super Contributor
timestamp: July 10, 2020, 03:35:39 pm
content: I would guess that you are testing in circuit, that there is a capacitance (and possibly resistance) parallel to the diode and that the test current on the Brymen is lower than the Fluke.

author: kgavionics
author_rank: Regular Contributor
timestamp: July 10, 2020, 04:00:41 pm
content: Quote from: bdunham7 on July 10, 2020, 03:35:39 pmIt's totally disappointing ! I'll keep using my old Fluke for dide testing!

author: bdunham7
author_rank: Super Contributor
timestamp: July 10, 2020, 04:17:33 pm
content: It shouldn't be disappointing, it is just a characteristic. You have to know the characteristics of your test instruments in order to use and understand them properly. This is what RTFM means!Some meters have selectable test currents for the diode ranges, but if not, 1mA is somewhat standard. It appears the Brymen uses less for some reason. There is no 'correct' answer and in most applications, the lower test current would be fine.b/t/w, your 8060A is one of the best handheld DMMs in the history of test equipment, so it will be tough for new ones to "measure up".

author: HKJ
author_rank: Super Contributor
timestamp: July 10, 2020, 05:24:06 pm
content: Quote from: bdunham7 on July 10, 2020, 04:17:33 pmThere is not standard for diode test current on hand held meters, on bench meters you may be able to select test current.The problem is the protection, usually you need a few kohm between the internal circuit and the terminals, these kohms are made with PTC's that can switch to high impedance when you plug the test leds into mains while in the ohm range.For most DMM designs a acceptable compromise is in the range of 0.2mA to 2.5mA diode test current.

author: kgavionics
author_rank: Regular Contributor
timestamp: July 10, 2020, 06:05:11 pm
content: Quote from: bdunham7 on July 10, 2020, 04:17:33 pmSorry for not RTFM before, i checked the manual and it says that is uses 0.4 mA!Your right too about the 8060A which is indeed one of the best DMMs ever build!
Rigol DS1054Z voltage error fixed by autocal - Page 1
Forum section: electronics / testgear

author: Lorenzo_1
author_rank: Regular Contributor
timestamp: July 10, 2020, 09:43:17 pm
content: DS1054Z I use from time to time showed a 0.16V positive displacement on one channel relative to another. I was probing what should have been single node b/n op-amp and transistor with probes either end of PCB trace. Difference was ca 10% of node voltage - see ch2/3 lines in photo. Scope was warm/stable. Was showing identical waveforms but vertical displacement on one. Checked measurement on LeCroy using same probes and discrepancy not there. So I ran autocal from utilities menu on Rigol for first time in some months and the channel difference resolved itself nicely.Reported only because I was surprised at the size of the interchannel error - my first reaction was to think it might be real and perhaps related to bad socket connection on the opamp. Looks like more regular autocal might be needed to keep things sweet - or perhaps there’s an issue looming?
Metrawatt Metrahit 14S Multimeter ... how to calibrate Ohm range ? - Page 1
Forum section: electronics / testgear

author: KlausF
author_rank: Contributor
timestamp: January 11, 2019, 03:40:46 pm
content: HelloI sought the EEVBlog forum and googled, but no matches found.I would like to adjust (calibrate) the Ohm range of a Metrawatt Metrahit 14S (multimeter).Now I am searching for schematics, service manual or instruction how to do that.Any help welcome. Thanks.

author: nsrmagazin
author_rank: Regular Contributor
timestamp: January 11, 2019, 04:43:43 pm
content: Why do you think its calibratable. I found this manual, but I don't see calibration possibilities.https://www.utwente.nl/en/tnw/slt/documentation/Equipment/GeneralEquipment/metrahit18s.pdf

author: 2N3055
author_rank: Super Contributor
timestamp: January 11, 2019, 05:08:47 pm
content: datasheet:CalibrationThe multimeters of the METRAHit S series can be calibrated automatically via the RS-232 data interface with the aid of the multifunction calibrator METRAtop 90C and the METRAwin 91 software.Gossen doesn't publish calibration procedures, and you need RS232 cable. That's bad news. Good news is that in Germany you should be able to find a company that is able to professionally calibrate it. Trick is to get them to do it cheaply.If you don't mind me asking, why do you want to calibrate it? They are good quality instruments, they don't drift that easy. If you verified it gives incorrect readings, it is more probable it was damaged than drifted if error is large. So you would first have to repair it before checking accuracy any further ...

author: KlausF
author_rank: Contributor
timestamp: January 12, 2019, 06:21:53 pm
content: Quote from: nsrmagazin on January 11, 2019, 04:43:43 pmThat is nothing unusual. Instruction manuals rarely comprise calibration procedures. That is why I asked for schematics / service manual.

author: KlausF
author_rank: Contributor
timestamp: January 12, 2019, 06:25:40 pm
content: Quote from: 2N3055 on January 11, 2019, 05:08:47 pmMetrawatt is one of the high-end manufacturers with highest quality instruments.I asked for service manual / schematics because I got me a used Metrahit 14S and I want to profoundly check it and if necessary calibrate it.Nobody having schematics or service manual ?

author: RobinLox
author_rank: Newbie
timestamp: July 10, 2020, 02:59:40 pm
content: This meter gets calibrated just by some potentiometers. The 12S-16S share a very similar PCB. The 18S is the only 1xS series model which gets calibrated electronically.You could try to identify the correct pot by following the traces on the board.
MSO58 (Tektronix 5 series) slow/hanging up/not triggering when it should - Page 1
Forum section: electronics / testgear

author: uer166
author_rank: Super Contributor
timestamp: July 09, 2020, 11:57:24 pm
content: Does anyone else have issues with a 5-series scope having a generally very slow UI, seeing the "spinner" cursor indicating the scope is thinking about something every time I try to get a waveform, having it trigger but not actually update the screen until 5+ seconds later? Also issues with the waveform updates being extremely slow. I don't understand how such an expensive piece of equipment has worse user-friendliness than a $400 Rigol, surely it's some sort of user error but I can't figure out what the issue is. It also occasionally hangs completely and only recoverable with a power cycle, thee standby button does nothing. One thing is the "FastAcq" mode seems to accelerate the screen updates, but the sample rate is out the window.

author: 0culus
author_rank: Super Contributor
timestamp: July 10, 2020, 12:38:18 am
content: Have not used one but that is a shame for a *very* expensive scope.Tektronix has fallen long and far....

author: tv84
author_rank: Super Contributor
timestamp: July 10, 2020, 07:02:17 am
content: Read some of Sighound's posts inthisthread about the 5 and 6 series.

author: Sighound36
author_rank: Frequent Contributor
timestamp: July 10, 2020, 07:25:20 am
content: From my experience with both the 5 and 6 series Tek scopes the quirky UI, boot time and the ability for the units to crash/freeze on a regular basis were part major reasons I didn't not purchase either of them. Scopes of this calibre and cost should not have these basic issues at allWe are talking a minimum of $15k plus for the basic unit the UI is just not good at all plus the 12bit is only really 12 bits at 1GhzWhy not talk to the supplying agent and ask them for a check over and confirmation of what you feel is the issue suspect the unit is under warranty and a Tek rresentative can confirm if there is a fault or notAll I can say when performing power analysis on numerous occasions the scope would slow down and freeze the reboot time was genuinely close to 6 minutes in the two weeks I had the 6 series the time spent waiting for rebooting was just over two hours and that had the latest firmware and factory fresh calibration.Totally unacceptable on a £46k worth of test equipment
SSA3032X, DSA832E-TG - Comments? - Page 1
Forum section: electronics / testgear

author: ridgerunnersjw
author_rank: Contributor
timestamp: July 14, 2020, 08:27:46 pm
content: All....Firstly I apologize if I am in the wrong area....Initially I posted this in the HAM radio section only to see the test equipment forum....Saw much posting on the SSA3000X but that looked more like a 'how to' area than a 'get to know me'......Please see question below:Looking to purchase my first spectrum analyzer....Want to use it for IoT development work.After much deliberation (cost, value, etc.) I seem to be leaning pretty heavily towards the SSA3032X or the DSA832E-TG.I would love to hear comments, recommendations and gotcha's to look out for?Thanks

author: tautech
author_rank: Super Contributor
timestamp: July 14, 2020, 09:08:02 pm
content: Strongly suggest you look at the later released SSA3000X Plus models for their better feature set.Others will have reasons why to look at these too.
R&S FSH-Z2 Cable Pin-Out - Page 1
Forum section: electronics / testgear

author: Garnet
author_rank: Regular Contributor
timestamp: July 08, 2020, 12:11:38 pm
content: Can anyone provide me with the cable connections to the 7 pin Binder connector? There are two wires in the cable, red and white. I would like to determine what pins they connect to. TX, Garnet
Probing Tractor  - Page 1
Forum section: electronics / testgear

author: JustMeHere
author_rank: Frequent Contributor
timestamp: May 15, 2020, 12:16:26 am
content: I need to probe the electronic control unit on my tractor. We are very suspicious of the control unit. My question is can the probes absorb the nasty transients I've heard about in automotive environments? I got a micsig 20xx.The signals I want to probe are the start relay and the fuel cut off relay. There's a solenoid and of course altenator and a starter. This is a desil. So no spark plug ddischarge.

author: targit
author_rank: Regular Contributor
timestamp: May 15, 2020, 04:52:01 am
content: I use the Micsig differential probe for most automotive stuff, this is mostly because the 4mm banana jacks fit all my back probes and insulation piercing acupuncture probes so switching between DMM and scope is also easier. I have also used the x10 probes that came with the scope and they seem to cope with diesels pretty well - although they are not physically as robust as 4mm type DMM probes. You do need to keep an eye on where you are earthing the probes though, this is where the differential probe also helps as there is no chance of a high current path through your scope.

author: Chris Roubis
author_rank: Contributor
timestamp: May 16, 2020, 04:34:28 am
content: Quote from: JustMeHere on May 15, 2020, 12:16:26 amHave you done a pin out test, on the control unit first?Make sure you have correct voltages and also check you have a good ground.Then check value of sensors around the engine.Find a circuit diagram and pinout for your model.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: July 07, 2020, 03:08:50 am
content: I managed to fix the tractor somehow. Shaking the wire near the fuse box seemed to do the trick.

author: 0culus
author_rank: Super Contributor
timestamp: July 07, 2020, 03:30:08 am
content: Quote from: JustMeHere on July 07, 2020, 03:08:50 amYeah, but do you understand why it is working now? Seems like that is a necessary step to ensure it's actually fixed.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: July 08, 2020, 01:02:56 am
content: Quote from: 0culus on July 07, 2020, 03:30:08 amYes. The fusebox. I know within an inch of what to look at if it fails again. I have another tractor that uses the same electronics. I was able to rule out the relays and control box by swapping things around.
Help me find a handheld DMM with separate resistance and continuity modes - Page 1
Forum section: electronics / testgear

author: pebcac
author_rank: Contributor
timestamp: July 07, 2020, 11:32:23 pm
content: Hello, I'm looking for a new DMM.I've used the Fluke 117 and the BM235 previously, and I'm looking for a best of both worlds.I like the Fluke 117 for having separate resistance and continuity dial positions. I use both often, and I like to be able to directly go from off to continuity or off to resistance mode. The BM235 however, since the two modes are shared by one dial position, I need to go from off to resistance then press the mode button to switch to continuity, since its memory feature stores its last used mode.However, the Fluke 117 series doesn't have a dedicated mA measurement terminal and cannot measure small currents with good resolution.The Fluke 179 has the 1. separate resistance and continuity mode and 2. dedicated mA terminal mentioned above, but I'm looking for options in the $150-250 range.Thanks!(Maybe should have been posted to the Test Equipment section)
Advantest R3131 Circuit Diagrams (1st Lo. fault) - Page 1
Forum section: electronics / testgear

author: Uplink
author_rank: Newbie
timestamp: July 06, 2020, 12:45:14 pm
content: Afternoon - my first post on here but have read quite a bit over the years.Anyone know of a source of circuit diagrams for the R3131 Advantest Spectrum analyser? I have scoured the web & come up with ZERO, only the service manual which helpfully makes statements like "replace RF unit". Mine has developed a fault with the 1st LO. appearing to go out of lock/unstable - particularly when cold. All else is good on it when operating normally - passes cal , RTC etc.Looks a bit of a nightmare to fault find on also due to the frame construction.... I can see it getting scrapped as I don't have much time to FF on test kit

author: Uplink
author_rank: Newbie
timestamp: July 06, 2020, 02:08:40 pm
content: Correction, Fault with 2nd LO. 3840 Mhz IIRC. (not the YIG)

author: nctnico
author_rank: Super Contributor
timestamp: July 06, 2020, 04:26:17 pm
content: AFAIK this is a known problem. Search for R3131 on this forum and read the threads closely.

author: Uplink
author_rank: Newbie
timestamp: July 07, 2020, 01:17:28 pm
content: Thanks for the replynctnico.Yes I have trawled through many pages of 3131 posts on here (and elsewhere) but the only talk about the 2nd VCO (3.84Ghz) refers to the 3132 (although actually in the 3131 thread) & the physical look of the RF unit is quite different I think.This SA is a nightmare to work on as you need 2 x 96way extender cards/looms to check anything while it's running. I even bought some 96wy connectors to make up an extender but the logistics (time involved) have put me off. It takes some believing that no schematics are around for these thingsMany thanks