hybridfree/eevblog-posts huggingface dataset:
Manual for Datron (Wavetek) 4600 Autocal Transconductance Amplifier - Page 1
Forum section: electronics / testgear

author: perdrix
author_rank: Frequent Contributor
timestamp: June 18, 2018, 05:36:57 pm
content: Can be downloaded from <https://groups.io/g/Datron-Wavetek/files>I'll be uploading the manuals for the 4808 as I get them scanned over the next week or so.All the bestDavid Partridge

author: pelule
author_rank: Frequent Contributor
timestamp: June 19, 2018, 05:23:06 pm
content: Hi Davidthanks for uploading - I was searching for the DOC since a long time./PeLuLe

author: perdrix
author_rank: Frequent Contributor
timestamp: August 20, 2018, 11:48:51 am
content: I've uploaded a better version of this scan to:https://groups.io/g/Datron-Wavetek/files/Datron%204600/Datron%20Wavetek%204600%20Autocal%20Transconductance%20Amplifier%20User%27s%20Handbook.pdfand have deleted the old one.RegardsDavid Partridge

author: perdrix
author_rank: Frequent Contributor
timestamp: August 20, 2018, 03:08:08 pm
content: I just uploaded this again after reprocessing it somewhat differently so it is *much* smaller and clearer as well:https://groups.io/g/Datron-Wavetek/files/Datron%204600/Datron%20Wavetek%204600%20Autocal%20Transconductance%20Amplifier%20User%27s%20Handbook.pdfSo if you downloaded the earlier upload, please download again (new version is about 10MB rather than about 60MB).CheersDave
DG4000 bootloader 06 - Page 1
Forum section: electronics / testgear

author: pa3hfu
author_rank: Contributor
timestamp: August 10, 2018, 07:03:46 pm
content: Hi,I 'm looking for bootloader version 06 for my DG4162. The only file I could download is the new firmware (DG4000Update.GEL) but first of all I'll need the latest bootloader.Who knows where to download??Thanks in advance!

author: PA0PBZ
author_rank: Super Contributor
timestamp: August 10, 2018, 07:39:07 pm
content: I have this. I hope it is what you are looking for.
Can Fluke 287/289 do low freq noise measurement on battery ? - Page 1
Forum section: electronics / testgear

author: BravoV
author_rank: Super Contributor
timestamp: August 11, 2018, 06:43:23 pm
content: As these DMM models have logging & charting feature, with sample interval can be set from one second minimum to 100 minutes, and the logging session duration can be set from one minute up to 100 days.The DC accuracy is 0.025%+2 digits at 5 Volt range with resolution at 0.0001V or100nV100uV.Is it good enough to be used for measuring single cell battery noise ?

author: Andreas
author_rank: Super Contributor
timestamp: August 11, 2018, 07:14:15 pm
content: Hello,generally I would say: no. (depends on the cell type and the temperature of the cell).a) 0.0001V are 100uV. How do you calculate 100nV in 5V range.b) With my 1/f LNA when measuring a 9.6V NiMH batteryI typically get the noise floor of the LNA of 100-200nVpp for a 0.1-10Hz range.with best regardsAndreas

author: trobbins
author_rank: Frequent Contributor
timestamp: August 13, 2018, 06:42:40 am
content: What are you trying to measure - some characteristic of the battery by itself, or as a reaction to an external signal?

author: BravoV
author_rank: Super Contributor
timestamp: August 13, 2018, 07:25:16 am
content: Quote from: Andreas on August 11, 2018, 07:14:15 pmDamn, got brain fart, thanks for the pointing out, corrected.Looks likes no go isn't it ? Especially at nV p-p noise floor.Quote from: trobbins on August 13, 2018, 06:42:40 amThe battery it self, and my meter is not good enough, actually far from it, isn't it ?

author: trobbins
author_rank: Frequent Contributor
timestamp: August 13, 2018, 09:31:40 am
content: Relevant references:https://dalmura.com.au/static/Resistor%20noise1.pdfhttps://tf.nist.gov/general/pdf/1133.pdf
Chinese Function Generators - Page 1
Forum section: electronics / testgear

author: bitshift
author_rank: Regular Contributor
timestamp: August 09, 2018, 09:20:28 am
content: I would like to buy a cheap function generator. In 2018, would a FeelTech FY6600 still be a good buy? What is the most popular/best bang for buck cheap function generator these days?

author: Old Printer
author_rank: Frequent Contributor
timestamp: August 09, 2018, 12:52:36 pm
content: Only need to look down a few threads.https://www.eevblog.com/forum/testgear/feeltech-fy6600-60mhz-2-ch-vco-function-arbitrary-waveform-signal-generator/One of the hotter subjects here right now.

author: soundtec
author_rank: Regular Contributor
timestamp: August 10, 2018, 07:05:18 am
content: Dont get the FY6600 ,they have a new model now FY6800 . I own one of each , yeah sure if you read the posts there are some unfavourable comments ,but mostly to do with earlier software versions of the Fy6600 where there was an issue. And many other 'Knockers' getting in for a low blow on something they never even set eyes upon .Fy6800 has online update capabillities , a better keypad and a properly grounded mains connector and all the upgrades for the Fy6600 like psu, output op-amps etc work on the FY6800 too .

author: bitseeker
author_rank: Super Contributor
timestamp: August 10, 2018, 07:12:04 am
content: It's best to state what you'll be using it for or what your requirements are in a function generator. Otherwise, there are too many choices.However, if you already know that the FY6600 fits your needs, then get the FY6800 instead. As soundtec itemized, it fixes the major things that were wrong or lacking with the FY6600.

author: GregDunn
author_rank: Frequent Contributor
timestamp: August 10, 2018, 07:18:04 am
content: Considering what you get for the money, the 6800 is a stellar bargain and a step up from the 6600. Unless you need extremely low distortion or very high frequency output, it's quite capable and versatile. My use is primarily audio, where it's actually much more than I need. You'd really need to pay about 3x or 4x to get a noticeable improvement. Yes, the software is a bit quirky, but it works well enough and shouldn't keep you from using all the features.
Valhalla 2703 AC Voltage Calibrator - Help needed to identify part. - Page 1
Forum section: electronics / testgear

author: TheDefpom
author_rank: Frequent Contributor
timestamp: August 09, 2018, 05:03:55 am
content: Hi All,I picked up one of these units a few months ago, I found that there is a capacitor completely ripped off one of the boards, the vertical board on the right hand side, the capacitor is right at the front edge of that board, towards the upper section, number is C122, can someone have a look in their unit and tell me what that part is, the marking looks like an electrolytic or tantalum but the service manual says it is a different type of only 470pF, which doesn't really match up, so if someone could pop the covers and confirm both the type, voltage and value of what is actually there that would be great!I will be doing a repair video on the unit once I get enough time to dig into its issues, basically it drops into standby when higher voltages are selected, so its probably some leakage thing, I am currently waiting for new caps and a new fan to a arrive before I start working on it, I will do the basic stuff first!
'New' Keithley 177 testing idea's ? - Page 1
Forum section: electronics / testgear

author: lordvader88
author_rank: Frequent Contributor
timestamp: August 08, 2018, 11:38:23 pm
content: I got this for 70CAD(~55USD) And It seems to work, I've barely tested it tho, and don't have any precision parts or sources to test on. I have a Brymen 869 and MS5308 LR meter to compare against. I have lots ebay 1% blue resistorsThe only precision resistors and temperature calibrated references/etc/ ? stuff I can think of having, would be in my tektronics scopes, and the BM869, BM235, and maybe in a cheap Vici VC99 DMM.I have scrapped wifi modems, I have motherboards, don't if they could help.I have LM431B 0.5%, TL431 1%, LM336z 1% voltage references. I have a few computer PSU'sI took it apart and some voltages I checked where great. It's a work of art in inside. Too bad the case and screen are dinged up, the LCD is nice and bright tho.

author: lowimpedance
author_rank: Super Contributor
timestamp: August 09, 2018, 12:49:09 am
content: Quote from: lordvader88 on August 08, 2018, 11:38:23 pmIIRC this meter uses LED's for the display !.If you just do comparison measurements on various components/sources with the other meters you have you should get a good confidence level for the 177's performance.Be aware with these vintage meters that the push button switches do play up but usually come good after some 'exercising'. Also note the current ranges share the same terminals as the volts/ohms, check the interanal fuse is still intact.BTW the 177 is also known as the Racal Dana 4003 and you may find that cheaper since it does not have the Keithley brand name on it. (still 100% Keithley though).Have fun
Anritsu MD8470A Upgrade & Service Manual - Page 1
Forum section: electronics / testgear

author: ZL1CVD
author_rank: Regular Contributor
timestamp: August 08, 2018, 07:50:17 am
content: Picked up a MD8470A. Runs Windows XP & have been using it as a dedicated FT8 box. Replacement CPU arrived today Intel P4M SL6VC 2.4GHz. Works much better than original 1.7GHz SL6V6. Memory is standard DDR – 2 banks supporting 512MB each (I think). Shipped with 1x 512MB PC2100. I added another 512MB PC3200 (all I had on hand) and it works fine.As I'm not using all the Anritsu RF, I've pulled out the 2x PCI signalling cards, 2x RF modules from bottom, combiner and coax hard line. At some point, I'll put a hackRF or 2 in place of the 2x RF bottom modules. There will still be enough room for a range of BPF filters and possibly a wide band PA or 2.2x Fans is quite noisy so I simply unplugged 1x. Still works fine and temp sits nicely at 36 Deg C with replaced CPU.I'm on the hunt for a service manual. Love to figure out motherboard PCI pinout's and more about the 10MHz OCXO – specifically how its routed the RF stages. The CPU clock looses time which is a pain for FT8 so I'd like to look into that too. Any help appreciated.Some may wonder why spend $$ and time on an old dog like this. 1 – the PC is enclosed in a good RF tight case. 2 Will make a good wide band transceiver with a HackRF. 3 – its fun!73s de chris zl1cvd
Any Instek MFG-2000 series users out there? - Page 1
Forum section: electronics / testgear

author: precaud
author_rank: Frequent Contributor
timestamp: August 08, 2018, 01:06:29 pm
content: Would like to hear what users think of their MFG generator.I really want a KS 33521B but the thought of paying 2 grand for a 30MHz generator in 2018 is nauseating.Although it is missing GPIB and tracking output filters, the MFG-2130M looks like a compromise I might be able to live with.
Found this interesting... - Page 1
Forum section: electronics / testgear

author: OpenCircuit
author_rank: Regular Contributor
timestamp: August 10, 2018, 03:37:51 pm
content: This is from a GPS module manufactured by Sony, VGP-BGU1. Specifically the charging input board. Guessing they mass manufactured these with the wrong connector. The right-rear leg is ground-marked with "-" in the photo left-rear leg is marked with a "+". As you can see when the connector is moved backwards into place (removed for troubleshooting) the pos and neg terminals are directly connected through the trace on the board. Obviously it will not charge properly. Way to go Sony!
HP8568 input ports - why two?  why dc block on N only? - Page 1
Forum section: electronics / testgear

author: tkamiya
author_rank: Super Contributor
timestamp: August 05, 2018, 02:04:11 pm
content: I have recently acquired an HP8568B spectrum analyzer. On this unit, there are two input ports, one N fitting and another BNC fitting. N is dc blocked and BNC is NOT. Does anyone know why there are two, and DC block is installed on only one?

author: rob.manderson
author_rank: Regular Contributor
timestamp: August 05, 2018, 02:46:00 pm
content: Look at the frequency range for each. BNC down to 100 Hz. What kind of capacitor would you need to provide coverage down to 100 Hz at 50 ohms?

author: tkamiya
author_rank: Super Contributor
timestamp: August 07, 2018, 06:49:00 pm
content: I thought that might be the case, so I looked at it. They are both the same. (so I thought) I missed that little "K" in the spec! I'm going to put DC block or cap it. I don't need to go that low and I don't trust myself sometimes.Thank you.
agilent dmm connectivity utility - Page 1
Forum section: electronics / testgear

author: Dubbie
author_rank: Unknown
timestamp: August 07, 2018, 01:18:41 am
content: Does anyone have a copy of this floating around?I had it on my lab machine and the HDD died. I can't find it anywhere on the internet.I don't want to use BenchVue because I need to log longer than an hour and I am not Bill Gates or Jeff Bezos

author: Tony_G
author_rank: Super Contributor
timestamp: August 07, 2018, 02:32:52 am
content: Keysight has a bunch of utilities still on their site. You often have to go to the technical support page for the meter.What one do you have?TonyG

author: Dubbie
author_rank: Unknown
timestamp: August 07, 2018, 02:37:12 am
content: 34461aThey seem to have scrubbed all copies of the old free app from the net. There only remains the $690 one.For now I have just thrown together a python script to log values to a CSV file.

author: Tony_G
author_rank: Super Contributor
timestamp: August 07, 2018, 02:40:06 pm
content: They certainly seem to have done that - I've never used BenchVue because all my HPAK gear is way older than what it supports. I assume from what you're saying that the free (or trial) version of BenchVue only does an hour.I just looked at the BenchVue DMM bundle and it is available for $80 a year, still way way more than free though.TonyG

author: Dubbie
author_rank: Unknown
timestamp: August 07, 2018, 07:25:32 pm
content: Thanks for the offers for the software. I have it sorted now.
Rigol DS1054Z Extra options in Self Cal menu - Page 1
Forum section: electronics / testgear

author: Miti
author_rank: Super Contributor
timestamp: August 06, 2018, 10:12:03 pm
content: Does anyone know what are the extra options LFCal and Output in the SelfCal menu? You get those after pressing Menu-Menu-Force-Menu.

author: extronic
author_rank: Contributor
timestamp: August 07, 2018, 05:11:09 am
content: Interesting. Are there any more secret menus is DS1000z?

author: BravoV
author_rank: Super Contributor
timestamp: August 07, 2018, 05:25:11 am
content: Head to over ->HERE... and read along, also recommended to bookmark that particular whole thread.
Taking humidity readings: newbie question - Page 1
Forum section: electronics / testgear

author: midgk0
author_rank: Newbie
timestamp: August 09, 2018, 09:20:54 am
content: Hi there,I hope this question hasn't already been asked: I did search and couldn't find anything. I've just started a job that involves measuring the temperature and humidity of various spaces. I've been given a Precision Gold N21FR multimeter to take spot readings, though I am thinking of proposing we buy some recording thermohygrometers for longer-term readings. Anyway, when I use the spot meter in some of the spaces, the humidity reading just keeps dropping. Sometimes this will be quite quick and it will level out, but other times I can wait 15 minutes and it still keeps dropping by 0.1% every 30 seconds or so. I was wondering whether I should try to wait for it to stop dropping, but perhaps that won't happen? Or should I choose an amount of time with a stopwatch and take a reading after the time has elapsed, regardless of whether it is still dropping or not? Sorry if this is a daft question, I just want to make sure that the data I'm logging is actually useful!Many thanks,Katherine

author: IanB
author_rank: Super Contributor
timestamp: August 09, 2018, 09:28:20 am
content: Bear in mind that that meter is not a precision instrument, so the readings will not be highly accurate.I found what looks like the manual online and it seems that for relative humidity readings the accuracy is about plus/minus 5% and you should wait up to 15 minutes for the reading to settle before taking a measurement.https://maplindownloads.s3-eu-west-1.amazonaws.com/N21FR-8667.pdf

author: midgk0
author_rank: Newbie
timestamp: August 09, 2018, 09:54:50 am
content: That's what I thought: it would be better to use the spot meter to supplement the readings of a recording thermo-hygrometer. I will try leaving it for 15 minutes, to see if that makes a difference. Thanks for your help!

author: mzzj
author_rank: Super Contributor
timestamp: August 09, 2018, 10:10:02 am
content: Quote from: midgk0 on August 09, 2018, 09:20:54 amCheapest, crappiest humidity sensors behave pretty much like you describe, settling time can be several days! to last 1-2% vs 15 minutes with a "proper"* good humidity sensor.Low humidity is typically the problematic area for cheapest sensors/meters, your meter has NO response time specification whatsoever below 45% RH*) humidity meters from manufacturers like Vaisala, Rotronic and E+E

author: midgk0
author_rank: Newbie
timestamp: August 09, 2018, 10:49:27 am
content: Thank you, good to get some advice about a better brand! I thought as much due to the vagueness of the instruction manual and the fact that it measures *everything*, never a good sign...
FLUKE 1734 Energy Logger Live Data - Page 1
Forum section: electronics / testgear

author: poducc
author_rank: Newbie
timestamp: August 06, 2018, 03:50:57 pm
content: Hi everyone,I'm currently undertaking a project where we are taking energy readings using the FLUKE 1734 Energy Logger. The project is a trial but we want to have it looking as well as possible, so it'd be great if we could see live energy data on the application we've built.Does anybody know if it's possible to somehow get the energy data on this meter/logger to be read live and then transfer this data to a web application, rather than just being able to download historical logs?Thanks for any help you can provide.

author: threephase
author_rank: Regular Contributor
timestamp: August 06, 2018, 04:43:00 pm
content: The Fluke 1734 is Fluke Connect compatible so you can connect to it via WiFi, however it isn't particularly strong and the receiver needs to be within 10M of it, depending upon the surrounding environment. You may be able to manage a bit further if there is direct line of sight.To view live streaming of data, I believe you need the Fluke condition monitoring package which is licensed software and works through their cloud connection to send the data to share the data.You may be able to connect with the free Fluke Connect package and live stream that data through a VNC viewer.You would need to consult with your local Fluke dealer to identify what facilities are available inboxed your locale.Kind regards
What this is? - Page 1
Forum section: electronics / testgear

author: AndersJ
author_rank: Frequent Contributor
timestamp: August 05, 2018, 04:55:49 pm
content: Does anyone know what this device is/does?

author: jeroen79
author_rank: Frequent Contributor
timestamp: August 05, 2018, 05:37:55 pm
content: Something that outputs 2 times more "cavins" than you put in?Can you show some pictures of the insides?

author: glarsson
author_rank: Frequent Contributor
timestamp: August 05, 2018, 05:47:42 pm
content: Or something that reduces the signal and the user should therefore multiply readings by two. Very confusing little box.

author: iainwhite
author_rank: Unknown
timestamp: August 05, 2018, 05:53:30 pm
content: Some kind of RF attenuator ??

author: Discotech
author_rank: Regular Contributor
timestamp: August 05, 2018, 05:56:29 pm
content: Branson are/were an ultrasonic company, I wonder if cavin is their own term for measuring ultrasonic cavitation ?

author: helius
author_rank: Super Contributor
timestamp: August 05, 2018, 06:20:16 pm
content: Cavins are a measure of relative cavitation activity. Seehttps://www.mrclab.com/data/products/Cav-meter-2_OPR.pdfa cavitation meter.Still unclear on what the device in the OP does. An attenuator?

author: SeanB
author_rank: Super Contributor
timestamp: August 05, 2018, 07:08:10 pm
content: I would guess a 3dB attenuator, giving a voltage output half the input, so that you can keep a meter in range while you are having a higher voltage output from whatever detector you are using. Standard instrument box, if you undo the 4 screws and look inside there will be a simple voltage divider, probably using 3 resistors, to give the attenuation and provide the required input and output impedances constant, or there will be a small ferrite autotransformer in some cases where they have a well defined operating frequency and impedances.

author: DimitriP
author_rank: Super Contributor
timestamp: August 05, 2018, 07:40:42 pm
content: It's a patience test box. It tests the amount of time before the four screws come off to take a peek inside. You just might be holding the record so far!!

author: tomato
author_rank: Regular Contributor
timestamp: August 05, 2018, 08:00:17 pm
content: Quote from: SeanB on August 05, 2018, 07:08:10 pmThat would be 6 dB.

author: AndersJ
author_rank: Frequent Contributor
timestamp: August 06, 2018, 11:29:11 am
content: The patience test box has now been taken apart before it was turned on.Anders JProud record holder
Tektronix 7603 Oscilloscope Sweeping Issue. - Page 1
Forum section: electronics / testgear

author: jack001214
author_rank: Contributor
timestamp: August 02, 2018, 09:03:34 am
content: I found this scope inside the basement of the house and when I fired it up I noticed a problem, straight away.It has come to me that the horizontal sweeping has an issue (preferably the timing plugin failed) and where the vertical sweeping is fine.I believe it works as I rapidly shake my head i could see the signal producing on the CRT display. Any help provided would really be appreciated.

author: jack001214
author_rank: Contributor
timestamp: August 02, 2018, 09:58:30 am
content: Sorry for posting this in the wrong section

author: Gene
author_rank: Newbie
timestamp: August 04, 2018, 02:42:21 pm
content: Hi,as a very quick test of the horizontal deflection system of the Tek 7603 you canextract the vertical B and the horizontal plug ins and put them aside.Then extract the vertical A plug in (that apparently is working) and putit in the horizontal compartment (that is the rightmost one) thenconnect the calibrator signal to the input of the vertical plug inas you can see in the the first attachment (is a Tek 7854, but the conceptis the very same).Turn everything on and if the horizontal deflection system of the scope isworking then you should see two dots like in the second picture.The dots should move horizontally by moving the position knob of theplug in.If you see just one dot even cranking up (gently) the vertical scale, or ifthe dots do not move with turning the position knob, then there are veryhigh chances that is the horizontal deflection of the scope that is broken.Please, keep the luminosity lower than in the videoyou are going toburn the CRT.Cheers,GeneP.S. the blue lights of the horizontal plug-ins are very glamorous!
GW instek DSO - Page 1
Forum section: electronics / testgear

author: G7PSK
author_rank: Super Contributor
timestamp: August 04, 2018, 05:01:41 pm
content: Hi I am looking for a new DSO and am thinking about the GS instek GDS-1072-U. Are they any good and is it a wise choice compared to a sigelent or rigol of similar specs.Any thaught would be appreciated.

author: nctnico
author_rank: Super Contributor
timestamp: August 04, 2018, 05:43:48 pm
content: The GDS-1072-U is outdated. Better get the GDS-1072B which is a newer 2 channel 70MHz model with more features. In general GW Instek scopes are more expensive compared to Rigol and Siglent but they have no bugs and lots of the little features which don't make it into the datasheet but make life much easier.
EEVblog BM235 latest firmware version - Page 1
Forum section: electronics / testgear

author: onicom
author_rank: Newbie
timestamp: August 16, 2017, 07:24:20 am
content: I was going through the firmware for the multimeter which i had recently purchased and noticed that the firmware version isnt a letter but the number "9", or it could be "A". I have a screenshot of it.http://imgur.com/a/DWeLdSo far everythings working fine, just the odd firmware version.

author: EEVblog
author_rank: Unknown
timestamp: August 16, 2017, 08:51:43 am
content: I just checked the latest batch and you are right, "9"I'll ask them what the change is.

author: onicom
author_rank: Newbie
timestamp: August 17, 2017, 01:57:29 am
content: I wonder what new changes have they added in the latest revision, hopefully not a major bug.

author: markb82
author_rank: Regular Contributor
timestamp: August 17, 2017, 06:46:22 am
content: I found a small bug on my BM235 , irregular sampling, its minorly annoying:(note: auto ranging is disabled, but it happens with auto-range enabled as well)

author: Geoff_S
author_rank: Regular Contributor
timestamp: August 17, 2017, 10:46:29 pm
content: The firmware in the BM235 is not user upgradeable, correct ??

author: markb82
author_rank: Regular Contributor
timestamp: August 18, 2017, 01:32:16 am
content: The microcontroller inside the BM235 is one time programmable

author: EEVblog
author_rank: Unknown
timestamp: August 18, 2017, 07:52:28 am
content: Quote from: markb82 on August 18, 2017, 01:32:16 amMost simple lower cost meters are.

author: ExodusEffects
author_rank: Contributor
timestamp: August 04, 2018, 12:15:20 pm
content: Did we ever end up finding out what the change was to the version 9 firmware. That’s what the one I bought on Wednesday has and I’d like to know as much as possible about this particular firmwareThanks in advance Dave!
Matching Pad - Page 1
Forum section: electronics / testgear

author: Charlie86
author_rank: Regular Contributor
timestamp: August 04, 2018, 12:13:01 pm
content: Hi,Friend of mine give me Matching pad element with oscilloscope probe. Can someone please explain me for what is this element useful?Pics in att.https://ibb.co/jcEg5ehttps://ibb.co/btiKrKhttps://ibb.co/d73Vyzhttps://ibb.co/m4zEQe

author: ataradov
author_rank: Super Contributor
timestamp: August 04, 2018, 05:49:27 pm
content: It adapts 57 Ohm impedance line to 50 Ohm impedance line. Chances are that you you won't see much of 57 Ohm equipment, and it is not very useful for day to day things otherwise. Worth keeping in a tool box, just in case.

author: DaJMasta
author_rank: Super Contributor
timestamp: August 04, 2018, 06:22:27 pm
content: Probably meant 75 ohm and not 57 :pThat said, most telecom equipment is 75 ohm, so if you're probing cable TV lines or digital audio/video/whatever cables then you want a 75 ohm termination so you're seeing the signal the system is actually putting out when attached to something of the appropriate termination impedance. Since 75 ohm is higher than 50 ohm, connecting a 75 ohm driver to a 50 ohm load will mean it has to draw more current which can lead to various issues if there isn't an overspec'd driver for the line, but it will also manifest as irregularities in the signal - you'll see some distortion because of the load mismatch.To be clear, this is something you'd use directly on the input to the scope in 50 ohm termination mode, without a probe, and then you'd plug your 75 ohm system directly into the matching pad.

author: ataradov
author_rank: Super Contributor
timestamp: August 04, 2018, 06:25:07 pm
content: Quote from: DaJMasta on August 04, 2018, 06:22:27 pmWell, yes, of course.Chances are if it is your first scope, and you don't already know what this is, you don't need it. At least for the foreseeable future.

author: Charlie86
author_rank: Regular Contributor
timestamp: August 04, 2018, 10:27:54 pm
content: Hi,Thank you. Will keep it in tool box and probably not ever used
Wandel & Goltermann ANT-20 network tester - Page 1
Forum section: electronics / testgear

author: Alopezpulzovan
author_rank: Newbie
timestamp: August 02, 2018, 07:44:56 pm
content: Hi everyone!First post in the EEVblog!Recently i´ve been presented with this test equipment: an old ANT-20 Advanced Network Tester made by Wandel & Goltermann.I´m not familiar with anything network-related and, besides the manual, could not find a lot of information on the internet.It has an an integrated keyboard:It powers up and boots but seems to be missing the hard drive (and therefore the Windows-based OS that came with it).Has anyone used these? Could it be repurposed (taking advantage of it´s astonishing i486DX2 built in PC) in some way?
is this any good for referencing - Page 1
Forum section: electronics / testgear

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: July 31, 2018, 11:09:29 pm
content: is it just a gimmick or would it be usefullhttp://tinyurl.com/y9zyqag3

author: chris_leyson
author_rank: Super Contributor
timestamp: July 31, 2018, 11:10:41 pm
content: NO

author: Neilm
author_rank: Super Contributor
timestamp: August 01, 2018, 06:30:39 pm
content: First thing to see - there is no specifications. Secondly, you can't easily have a reference for an inductor - the inductance varies with the applied voltage test signal.

author: HKJ
author_rank: Super Contributor
timestamp: August 01, 2018, 06:45:18 pm
content: Quote from: Neilm on August 01, 2018, 06:30:39 pmDo it? There is no core in the inductor.It is the same as the voltage reference in a plastic box, a label with the measured values are stuck on the box.The question is how careful they are with measuring the values and writing the values.With the one I have:Marked - Keysight U1733L:166.2uH - 166.3uHC:39.612nF - 39.61nFR:3.279kOhm - 3.280kOhm

author: bugi
author_rank: Regular Contributor
timestamp: August 01, 2018, 07:44:27 pm
content: It is not only about how careful they are measuring, but how good quality components they have chosen (i.e. stability). At that price, not very good.. Compare to one type of the high quality resistors which cost alone 3-4 times as much that whole device, and those resistors are not even "calibrated" (that would cost extra, lots of it), but just very high stability.Of course, good vs bad may depend on the requirements, but if the term "reference" is mentioned...

author: threephase
author_rank: Regular Contributor
timestamp: August 01, 2018, 08:28:41 pm
content: Quote from: Neilm on August 01, 2018, 06:30:39 pmWith respect, i disagree - inductance is a measured quantity based upon the physical attributes of the circuit and does not vary with voltage applied.The current in the circuit will vary, but that will be due to the reactance of the circuit, that is in turn affected by the frequency of the signal applied to it, but the inductance will remain constant only the reactance varies.Kind regards

author: Neilm
author_rank: Super Contributor
timestamp: August 02, 2018, 06:29:44 pm
content: Quote from: threephase on August 01, 2018, 08:28:41 pmIf there is a core in the ferrite there will be affects of the BH curve. I have had experiences of this in instruments I have designed where the inductance I measured with an LCR meter was significantly different when the inductor was used at higher voltages (i.e. in the circuit I was debugging)
Rack Mount, Programmable Power Supply Recomendations - Page 1
Forum section: electronics / testgear

author: Thewafflication
author_rank: Contributor
timestamp: August 02, 2018, 07:04:59 am
content: I am looking for a power supply for at home. I move a lot. My plan is to buy one or more rackmountable power supplies, and put them in a rack similar to what gigging musicians use. (Something like this:https://www.musiciansfriend.com/accessories/gator-g-tour-rack-road-case-with-casters) My local guitar shop has used ones reasonably priced.I do not need front output jacks. I am working on a custom bench that iseasyto move. (This will likely be a thread for a later day, once it is complete.)I was considering buying a pair of HP 6632B's.http://r.ebay.com/G3UR2zI like the voltage and current range and resolution on this model, but I am all about saving money. I was wondering if anyone knows of a cheaper and/or more compact alternative.

author: tautech
author_rank: Super Contributor
timestamp: August 02, 2018, 09:04:07 am
content: If you can live with a 3A PSU there's the 3 channel models from Siglent and they offer a rackmount kit for them too:https://www.siglentamerica.com/accessory/spd3303-rmk/Full selection:https://www.siglentamerica.com/power-supplies/The 2 main channels can be used and programmed individually or used in series or parallel mode configurations.Unfortunately they only have front panel outlets.

author: nctnico
author_rank: Super Contributor
timestamp: August 02, 2018, 12:20:15 pm
content: Quote from: Thewafflication on August 02, 2018, 07:04:59 amThese are super heavy and noisy! Far from portable and nice to use. I'd go for the newer bench models which can also be rack mounted.

author: ch_scr
author_rank: Frequent Contributor
timestamp: August 02, 2018, 06:09:24 pm
content: Well, maybe consider linear supplies with analog remote voltage programming capability and use either a "Keithley 213" or a "Gossen Programmer IEC 625" for the remote control.

author: nctnico
author_rank: Super Contributor
timestamp: August 02, 2018, 06:50:30 pm
content: Quote from: ch_scr on August 02, 2018, 06:09:24 pmIn that arena you can also buy some older HP models like the 6012A and 6024A. Which are pretty light because they are switchers but they have a bit more noise on their outputs.
a good ohmmeter? - Page 1
Forum section: electronics / testgear

author: MrZwing
author_rank: Regular Contributor
timestamp: August 02, 2018, 08:39:38 am
content: Hellolest get one thing out of the way. I plan to make my own resistors for fun. no its not cheaper or better ect not the thing i want to talk about in this thread i do it "because I can" and for fun.first I have a der-ee 5000 ESR but don't know how good or precise it is.So my question is.is there any good ohmmeters out there that doesn't break the bank? (max 100$ but cheaper is nice ofc)or is the ESR as good as it gets below 100$?/MrZ

author: BravoV
author_rank: Super Contributor
timestamp: August 02, 2018, 08:44:34 am
content: Define "good" according to you, so fellows here can help.Quote from: MrZwing on August 02, 2018, 08:39:38 amImo, this is pretty decent Ohm meter compared to ordinary handheld DMMs, even some expensive ones.

author: tautech
author_rank: Super Contributor
timestamp: August 02, 2018, 09:10:54 am
content: Get a 4 wire probe setup for your 5000 and check it against some precision resistors.It's probably already quite accurate enough for you needs.If youmusthave better consider getting a good bench DMM with 4 wire capability.

author: MrZwing
author_rank: Regular Contributor
timestamp: August 02, 2018, 09:57:42 am
content: Hmm i will look into the 4-wire setup and do some experiments with precision resistors.as well look around for bench dmm that would suit my needs to save up for.but my Der-EE will suffice for now and thank you for the tips./MrZ
Measure the open voltage curve and reverse withstand voltage curve of the SCR.  - Page 1
Forum section: electronics / testgear

author: jotrinelectronics
author_rank: Contributor
timestamp: August 02, 2018, 07:50:15 am
content: First find the corresponding product specification to determine the product pin and the range of parameters to be measured, and adjust the plotter to measure. The specific turn-on voltage curve and the reverse withstand voltage curve are as follows.BUT I DONT SURE IF IT IS RIGHTTurn on the voltage curve:Reverse pressure curve:
Scan of one page from the Datron 4808 Reference Handbook? - Page 1
Forum section: electronics / testgear

author: perdrix
author_rank: Frequent Contributor
timestamp: July 27, 2018, 09:11:47 am
content: I left my copy of the Datron 4808 Reference with a company for scanning. On checking it after return, they somehow managed to lose one page of the schematics. They also hadn't scanned the page.The missing page is page 11.4-5 which is the Reference Divider Assembly Out/In Guard Interface and Watchdog schematic.I have a low res scan of the schematics which I downloaded from the xdevs.com website, but to replace the missing page I would prefer a proper scan in full size (17x11), 600 dpi, monochrome (not greyscale).Is anyone able to assist please?Many thanks, Dave

author: BNElecEng
author_rank: Regular Contributor
timestamp: July 27, 2018, 12:32:26 pm
content: The same page on the 4708 manual is in good shape and they look to be exact copies.

author: quarks
author_rank: Frequent Contributor
timestamp: July 27, 2018, 03:57:32 pm
content: I only found 4800 page (see att.), should be the same as 4808hope this helps

author: picburner
author_rank: Frequent Contributor
timestamp: July 28, 2018, 04:24:11 am
content: ManualPlus had two manuals of the Datron 4808, pn: MP-75654 (REF-SCHEM) and pn: MP-89902 (Service).After ManualPlus closing all the manuals, if I remember correctly, have been donated to:https://archive.orgPerhaps the copy of a single page can be obtained.

author: perdrix
author_rank: Frequent Contributor
timestamp: July 29, 2018, 09:04:46 am
content: Quote from: quarks on July 27, 2018, 03:57:32 pmThat looks to be identical. Please could I ask you to do a hi-res (600dpi, 17x11, Monochrome) scan and email me the TIFF or PDF file - my email is david.partridge@perdrix.co.ukIf you can get it completely flat on the platten that will help too.Thank youDavid

author: perdrix
author_rank: Frequent Contributor
timestamp: July 29, 2018, 09:22:20 am
content: Quote from: BNElecEng on July 27, 2018, 12:32:26 pmThey are pretty much - the problem is that the scan of that on xdevs has been scaled down to A4 paper thus reducing the effective resolution. If you know of a full size high res scan of that please could you give me a link.Many thanksDavid

author: perdrix
author_rank: Frequent Contributor
timestamp: July 30, 2018, 10:08:20 am
content: Thank you to quarks for sending the scan of the 4800 page. It turns out that it's a 300dpi colour scan, so much like the one I'd already downloaded from xdevs.com.So, if anyone has access to an original manual for a 4800, 4708, or 4808 (I think this particular schematic is the same for all three), I'd be most grateful for a 600dpi monochrome scan of the page at full size.Thank you again to everyone for their assistance so far.Dave

author: perdrix
author_rank: Frequent Contributor
timestamp: August 02, 2018, 04:29:22 pm
content: A hard copy of the 4805 manual has been found which has the exact same schematic and I now have a high resolution scan of it.Thanks to everyone.Dave
$50 For Schematic of HP 4338B Milliohmmeter! - Page 1
Forum section: electronics / testgear

author: Hugoneus
author_rank: Frequent Contributor
timestamp: July 29, 2018, 06:25:16 pm
content: I am working on the repair video of this unit and it is driving me crazy without the schematics.If anyone has it, I would be happy to pay you $50 for it.Please let me know!

author: Hugoneus
author_rank: Frequent Contributor
timestamp: July 29, 2018, 08:13:48 pm
content: The full datasheet of the AK9201A-VP would also help a lot...

author: Hydron
author_rank: Super Contributor
timestamp: July 29, 2018, 08:41:11 pm
content: If it helps to see the AK9201A-VP as used in a circuit, it seems that Roland used them in some synths, which _do_ have schematics available:http://www.synfo.nl/servicemanuals/Roland/DJ-70_SERVICE_NOTES.pdfhttp://www.polynominal.com/Roland-dj70/roland-dj70-kasei-9201A.jpgOther than that I can't help sorry, though I do feel your pain regarding unobtanium service info.

author: _Wim_
author_rank: Super Contributor
timestamp: July 29, 2018, 09:07:11 pm
content: Here is the service manual. No schematics however. Looking forward to your video...

author: Hugoneus
author_rank: Frequent Contributor
timestamp: July 29, 2018, 10:20:40 pm
content: Quote from: Hydron on July 29, 2018, 08:41:11 pmThanks. I had found those ones and were using them as a reference. But the HP unit seems to use this ADC differently... Or I am not able to catch all the traces on the PCB.Still a mystery...

author: Shock
author_rank: Super Contributor
timestamp: August 01, 2018, 11:37:04 am
content: Aside from contacting someone in the know at Keysight, perhaps also try in the Yahoo HP/Agilent Test Euipment group, or perhaps the manual exchange group.https://groups.yahoo.com/neo/groups/hp_agilent_equipment/infohttps://groups.yahoo.com/neo/groups/Manual_Exchange/info
Looking for alternative to Fluke 715 for handheld DC Voltage Calibrator - Page 1
Forum section: electronics / testgear

author: giaco
author_rank: Newbie
timestamp: July 31, 2018, 03:20:29 am
content: I have a "fleet" of Fluke 715 calibrators I use to field check my equipment. They are convenient and easy to use. However, the zero frequently drifts on both the 200-mV and 20-V ranges, and I get out-of-tolerance reports on the yearly calibration checks. I'm supporting a very quality-conscious industry, and OOT events are not cool.I am looking for an alternative to the Fluke 715. Ideally, it would be exactly like the Fluke 715 in every way, except it would last an entire year without losing its zeroes.The Fluke 715 costs USD1300 where I live. Pricey, yes, but I'd pay more if I could get everything I want.Anybody had good experiences with handheld DC voltage calibrators in a strict regulatory environment?[My first post on this forum.]

author: cowasaki
author_rank: Frequent Contributor
timestamp: July 31, 2018, 08:04:55 am
content: Have you queried this with Fluke? You would think that a quality calibration device wouldn't have this kind of issue.

author: The Soulman
author_rank: Super Contributor
timestamp: July 31, 2018, 09:00:56 am
content: Have you've seen the pdsv2 made be Ian Johnston?http://www.ianjohnston.com/index.php/onlineshop/handheld-precision-digital-voltage-source-v2-detailHe's also a forum member here.

author: cowasaki
author_rank: Frequent Contributor
timestamp: July 31, 2018, 09:46:07 am
content: Quote from: The Soulman on July 31, 2018, 09:00:56 amI think he needs it to be certified though.

author: mzzj
author_rank: Super Contributor
timestamp: July 31, 2018, 09:54:13 am
content: I have good experiences with Beamex MC2. More costly and complex compared to 715, but also LOT more functions.

author: giaco
author_rank: Newbie
timestamp: July 31, 2018, 02:51:21 pm
content: I have not. Since this is a commercial off-the-shelf item, it seems to be more expedient to look for a more robust product first. I could be wrong, but fixing the issue of the Fluke 715 could take years.

author: 2N3055
author_rank: Super Contributor
timestamp: July 31, 2018, 05:13:13 pm
content: Have a look at French AOIP... Good products.
Fluke 120 series Industrial Scopemeter: XY Mode ?? - Page 1
Forum section: electronics / testgear

author: RonFred2
author_rank: Contributor
timestamp: July 29, 2018, 10:52:43 pm
content: I have a Fluke 125B scopemeter. I like it for use as a scope and DMM for house electrical work. But sadly the scope does not seem to have an XY mode for use as a curve tracer.Has anyone used a Fluke 120 series Scopemeter for XY mode display?
Datron 4808 manuals - Page 1
Forum section: electronics / testgear

author: perdrix
author_rank: Frequent Contributor
timestamp: July 28, 2018, 03:23:36 pm
content: I'm in the process of scanning the Datron 4808 manuals and the first one which is for the 4808 Option 70 Wideband Source is now available from:https://groups.io/g/Datron-Wavetek/files/Datron%204808/Datron%20Wavetek%204808%20Option%2070%20Wideband%20Source%20Schematics%20&%20Parts%20List.pdfEnjoy!I'll update this post as I add additional manuals (will be a bit longer as some need to be re-done).Dave
Tektronix 6 GHz usb VNA - TTR500 - Page 1
Forum section: electronics / testgear

author: fonograph
author_rank: Frequent Contributor
timestamp: July 28, 2018, 12:49:19 pm
content: 9k $ for 3 GHz one and 12k for 6 GHz version.Keysight too have new usb VNA,theirs go to 26 GHz.Is this good? How does it compare to Keysight one? Pls somebody find a way to hack them lol
TDS 540 Power supply caps? - Page 1
Forum section: electronics / testgear

author: Spence
author_rank: Newbie
timestamp: July 22, 2018, 05:33:19 pm
content: Hello all,,, I picked up a TDS 540 for 85 bucks and it had 3 errors on the self test. I took it apart and washed the boards and did not see any damage on the PCB's. tested again and booted with out errors and I then replaced all the caps and it's working just fine.My question is,, Should I go through the power supply and replace the rest of the caps? I haven't seen much about doing that.Thanks for you time!!

author: nctnico
author_rank: Super Contributor
timestamp: July 22, 2018, 06:12:27 pm
content: Leave the PSU as it is. Only the surface mount electrolytic capacitors on the CPU board, acquisition board, RS232 board and front panel are problematic. Note that a few electrolytics on the front panel have a higher voltage on them than the capacitor is rated for (see the TDS520B component service manual).

author: Spence
author_rank: Newbie
timestamp: July 27, 2018, 09:42:08 pm
content: Thanks for the reply,,

author: snoopy
author_rank: Frequent Contributor
timestamp: July 28, 2018, 01:20:23 am
content: This might give you some ideasSMPS from a TDS420 being rebuilt.
ds4014 self-cal - Page 1
Forum section: electronics / testgear

author: lmclaren
author_rank: Newbie
timestamp: July 27, 2018, 12:29:35 pm
content: Hi,I have a new Ds4014 that I have updated to the latest firmware and made a few other tweaks.The firmware update procedure states to run a self-cal after the firmware update.Is this a good idea? The scope is brand new. Is the self-cal going to overwrite the factory calibration or does it do something different?many thanksLee

author: DaJMasta
author_rank: Super Contributor
timestamp: July 27, 2018, 03:31:53 pm
content: Self cal routines don't write over factory calibration, which is generally protected behind a password and is in a service menu. In fact, a run of the self-cal after a warm up period is the first step in the full calibration for the DS4000 series.

author: Fungus
author_rank: Super Contributor
timestamp: July 27, 2018, 03:44:19 pm
content: Quote from: lmclaren on July 27, 2018, 12:29:35 pmYes.Quote from: lmclaren on July 27, 2018, 12:29:35 pmThe "factory calibration" of machines with self-cal is probably just somebody at the factory pressing the "self-cal" button.Your manual says:Key words: "At any time" - you should really do it before any important measurement.Or ... just relax. These things are only about 3% accurate (see manual).Use it to look at wiggly lines on screen, the numbers are really just ballpark figures.

author: lmclaren
author_rank: Newbie
timestamp: July 28, 2018, 12:05:23 am
content: thank you,Off to buy some bits to make the 5-1 cable.