hybridfree/eevblog-posts huggingface dataset:
PM100 Voltec IEEE488 Fail - Page 1
Forum section: electronics / testgear

author: Diamante
author_rank: Newbie
timestamp: April 20, 2018, 06:12:29 pm
content: Hello everyoneI'm new in the forumand I would need your help:I have a voltech PM100 power analyzer inserted into an automatic desk and interfaced via IEEE488.Unfortunately, due to the time spent around 30 years, the eprom on the IEEE488 interface card has been deleted.In fact, the tool works but no longer responds to GPIB commands.Voltech technical support replied that it can not help me having been given its IP to TektronixI have seen a lot of discussions about the PM100 instrument and I ask some owner of this tool to send me the eprom file of IEEE488 interface, on my tool labeled with IEEE488 1.04J.To all, however, I advise you to back up your memory before you remain on foot as the undersigned.my best regards

author: ky56
author_rank: Newbie
timestamp: September 13, 2018, 01:37:54 pm
content: Hey I don't suppose you have found a copy of the image of the EPROM because I have the exact same issue and I'm also new to the forum. I believe that my EPROM is damaged because all but 4 bytes are programmed (all the rest show as FF). Two of them are at address 0 and 1 and the other two are further down. Could you confirm if this is what your EPROM looks like as well?

author: Monolith
author_rank: Contributor
timestamp: September 14, 2018, 06:47:30 am
content: Hi,i made a backup of U42 (ST M27C256B Eprom) the last time i opened the unit. U42 has a sticker on it with "FRENCH AA80"Attached the binary of U42. Hope it helps!kind regardsMono

author: Monolith
author_rank: Contributor
timestamp: September 14, 2018, 07:04:58 am
content: Sorry, you can't use the eprom backup form my last post. It's U42 from the mainboard. I misunderstood your initial request. I don't have a GPIB addon module installed. Sorry can't help you but probably others can benefit from this backup. I hope someone else with a GPIB addon module equipped in his/her PM100 can do a backup for you.kind regardsMono
NVRAM Micro 400 Battery Tester - Page 1
Forum section: electronics / testgear

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: September 12, 2018, 08:30:29 pm
content: This battery tester was given to me to replace the LCD. That I did, without any problems. However, the display is gibberish (including several Neptune tridents) no matter which LCD is installed (standard Hitachi).All LCD modules (16x2) check good in a tester.I removed the "protective" epoxy brush painted on all the IC's.The µP is a 68HC705, and from what I see, it is loading garbage from the NVRAM, ID unknown, with a battery long ago dead (mfg. 1996).No support is available.After I removed the NVRAM, the 68HC705 loads nothing, (blank screen).Obviously the boot code was in there....So my question is this,1) Has anyone seen this tester?2) Is there any way to dump it regardless of battery?3) Did anyone ever dump their own NVRAM from this thing?Purely sentimental value for this person. Any help would be welcome.

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: September 12, 2018, 10:17:28 pm
content: De-encapsulation complete...No data, no battery voltage (.3V) Dead Dead Dead. The battery voltage can also be measured from pin 7 VBAT to 4 GND on the DS1218. Still DeadNow is the time to backup all those NVRAMs before it's too late. Tektronix calibrations come to mind....

author: CJay
author_rank: Super Contributor
timestamp: September 13, 2018, 11:34:50 am
content: Well that's a bit crap...FWIW, the DS12xx battery backed RAMs can usually be read like an EPROM, it'd be worth tracking down someone who has another one of those battery testers and explaining the problem to them before offering to 'back up' their device to make it safe.I'd suggest putting in an EPROM but I have a feeling the NVRAM is used to store calibration data aws well as boot code.

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: September 13, 2018, 02:23:08 pm
content: Now with NEW PIX!

author: ogden
author_rank: Super Contributor
timestamp: September 13, 2018, 02:45:03 pm
content: If NVRAM is dead then most likely it's end of the story. Usual buyers of such tool do not even know what NVRAM is.Quote from: Quarlo Klobrigney on September 12, 2018, 08:30:29 pmSuggest him to put that thing into display box with neat LED lights. Some ideas:http://newmediologo.me/doll-display-case/
what typical china panel meters burden voltage? <photo inside> - Page 1
Forum section: electronics / testgear

author: 001
author_rank: Super Contributor
timestamp: September 13, 2018, 07:23:33 pm
content: what typical china panel meters burden voltage?No any info

author: Wolfgang
author_rank: Super Contributor
timestamp: September 13, 2018, 07:43:46 pm
content: ... a few ten mV, normally for current meters. Why not measure it ? Apply a current, and measure voltage at the terminals with a high-impedance voltmeter.Now you got the resistance, multiply this by full range is your burden voltage.

author: 001
author_rank: Super Contributor
timestamp: September 13, 2018, 07:48:22 pm
content: Quote from: Wolfgang on September 13, 2018, 07:43:46 pmBecouse I`m only looking for meterI havent it in my hands now

author: bsfeechannel
author_rank: Super Contributor
timestamp: September 13, 2018, 07:49:30 pm
content: I have a meter that's pretty much like yours, at least in appearance, and the burden voltage is around 200mV.

author: 001
author_rank: Super Contributor
timestamp: September 13, 2018, 07:53:03 pm
content: Quote from: bsfeechannel on September 13, 2018, 07:49:30 pmThanx a lotIs Yours meter rated for 50mA too?

author: bsfeechannel
author_rank: Super Contributor
timestamp: September 13, 2018, 09:53:43 pm
content: Mine is rated for 50µA. But yours may very well be a 50µA meter with an internal shunt. In that case the burden voltage will be around that value.
Marconi 2440? - Page 1
Forum section: electronics / testgear

author: MW0CBC
author_rank: Newbie
timestamp: September 13, 2018, 10:48:07 am
content: I'm new to the forum but been doing all things electronic for 40 years now, both as a radio ham and, for 25 years, professionally.I have an opportunity to pick up a Marconi 2440 counter. Much better coverage than my existing counter but not found too much in the way of personal experiences with them on line......anyone care to comment on what they are like? I intend to use it with a Leo Bodnar 10MHz GPSDO so accuracy shouldn't be too much of an issue - it appears to have an external 10MHz reference input port.Any commentary most welcome.Thanks,Denis
R&S HMO1202 and RTC1002 ‘scope firmware - Page 1
Forum section: electronics / testgear

author: Zaphod1
author_rank: Newbie
timestamp: August 06, 2018, 09:06:45 pm
content: I bought a HMO1202 maybe a year back , good ‘scope ... I’ve blown an internal smd fuse a couple of times with residual volts on components when using the component tester, but heyI noticed the new model RTC1002 has the exact same front panel layout .... but I spotted it has a new firmware version.I’m wondering if the RTC firmware would load up on the HMO. ..... anyone been brave enough ?I can’t actually see any differences between this new model and the HMO ¿?Does anyone know ?

author: BloodyCactus
author_rank: Frequent Contributor
timestamp: September 12, 2018, 04:44:43 pm
content: My guess, internally all they changed is that the firmware no longer identifies as hameg. I have a HMO1212 and its firmware shows R&S and Hameg schizophrenia with screen showing one brand, SCPI showing anotherI have a the analyzer options, not sure I'd want to risk a cross grade firmware updatefeel free to try and post your results
Philips PM 8940 - Page 1
Forum section: electronics / testgear

author: Ranayna
author_rank: Super Contributor
timestamp: September 10, 2018, 08:52:03 am
content: Hi,recently, I got my hands on a Philips PM 8940. I was considering to get a differential probe for some time, so this thing might come in handyThe device is quite old (IC datecodes point to mid '82), but seems to be in good condition. It is clean on the inside and no obvious damage is visible in a quick teardown, though I have not yet checked the powersupply. There still were two 9V block-batteries in the probe, but they did not leakDue to my lack in experience, I have a couple of questions now:- Is this device still adequate nowadays? The bandwidth is low with it's 3db point at 1.5MHz- How can I make sure it is still save to use? I'm sure it will not meet modern safety standardsMy first application would be PoE switchmode supplies, going up to 60 Volts- The case of the main unit has become somewhat tacky. Can I reasonably clean it, or would it be better (is it even reasonably possible?) to get rid of the coating?- With a cursory search I was not able to find a service manual. Does it even exist?- There a lot of trimmer caps in the probe. With the low bandwidth the device has, can I reasonably calibrate it myself? I have a DS1054z, but no function generator yet. I know this would be hopeless without the service manual though.I can post pictures of the insides later as well if someone is interested

author: MadTux
author_rank: Frequent Contributor
timestamp: September 10, 2018, 10:02:52 am
content: You wouldn't want to use such probes in everyday application like microcontrollers and low other low voltage circuits. But if you're measuring small signals in differential mode at high voltage offset in things like SMPS, VFDs etc, they are very useful.High bandwidth isn't too important there, good CMRR is more important in differential probes.Since you don't have plugins like 7A22 and 7A13 on cheap china scopes, such a probe is especially useful to have when working on high voltages

author: Ranayna
author_rank: Super Contributor
timestamp: September 12, 2018, 07:46:51 am
content: Yeah, I know that the thing is not for use with everything. According to a page I found (in german:https://www.amplifier.cd/Test_Equipment/other/PM8940-isolation-amplifier.html) the thing guzzles batteriesThat alone disqualifies it for routine use.The unit seems to be not well known, i still was not able to find a service manualAnd on closer look it is clearly visible that someone fiddled with the trim-pots. So i'm afraid it will be way out of cal.I will take photos of the insides on the weekend. I think I will try to reverse engineer the unit as far as a can, just as a training for reverse engineering.
Siglent SDS1202X-E no time or date? - Page 1
Forum section: electronics / testgear

author: JBeale
author_rank: Frequent Contributor
timestamp: September 11, 2018, 04:52:01 pm
content: I thought any scope that could save files to a USB stick would be able to record the time and date on the file, if not display it on the screen. It is useful to know when a measurement was taken. Is this not possible with this model? I don't know what the Siglent runs internally but most any device that can handle USB and Ethernet ports will have this feature. Am I just somehow overlooking it, or was time/date removed for some reason?

author: SMB784
author_rank: Frequent Contributor
timestamp: September 11, 2018, 05:23:55 pm
content: It may be possible to accomplish this by rooting your scope and following the same procedurementioned in the SDS1104X-E/1204X-E threadfor adding timestamps to all save files. The devices are very similar so it very well might work for the 1202X-E as well as the 1104X-E/1204X-E.

author: tautech
author_rank: Super Contributor
timestamp: September 11, 2018, 08:02:33 pm
content: Quote from: JBeale on September 11, 2018, 04:52:01 pmAt this time X-E's don't have a RTC so any waveform timing info is only related to a triggered event. (+ or -)We've asked Siglent to implement a defacto clock for timestamps by way of an internet connection to NTP servers.

author: JBeale
author_rank: Frequent Contributor
timestamp: September 11, 2018, 08:12:29 pm
content: Thanks. The internet connection seems like a good workaround, plenty of system like the Raspberry Pi don't have any hardware RTC and they still manage to put time/date stamps on files that way.

author: tautech
author_rank: Super Contributor
timestamp: September 11, 2018, 08:27:02 pm
content: Quote from: JBeale on September 11, 2018, 08:12:29 pmI truly hope Siglent see the benefits and implement it in all X-E models. It was first bought to the forum attention some time back by borjam IIRC but wpwrak and bluejedi have recently enlightened us on how to achieve it.For the 4ch X-E's (1104 and 1204X-E) with their WiFi connectivity it should be easy to implement anywhere with their capability to connect to a cellphone.

author: TK
author_rank: Super Contributor
timestamp: September 11, 2018, 08:42:44 pm
content: SDS1202X-E and SDS1104X-E are based on Zinq SoC. It is my understanding that Zinq has RTC, maybe it is just a matter of adding a 32KHz crystal and battery to add RTC support?
DIY HP8568 Coax cable - Page 1
Forum section: electronics / testgear

author: tkamiya
author_rank: Super Contributor
timestamp: September 11, 2018, 05:11:21 pm
content: I am fast becoming tired of seeing high prices for HP8568B cables, so I'm starting to make my own. Here's my first attempt at COAX interconnect. I bought two connectors from eBay new, assembled it, and tested. It works fine. Plugs in much firmer with more positive feel than old 30+ year old cables. Connectors are in plastic shells as the cables are coax.If anyone wants to duplicate, search on eBay with "d-sub db rg174". Costs about 30 dollars for two. Seller is from Hong Kong so it takes a while to arrive in US.
TDS5104 unexpected error message - Page 1
Forum section: electronics / testgear

author: Kirkhaan
author_rank: Frequent Contributor
timestamp: September 10, 2018, 04:36:49 pm
content: I'm servicing a Tektronix TDS5104. Its internal display was not working (aux. display was working fine).Before opening the housing I checked all channels and they were working fine.The first thing I did after opening the housing is replacing the BIOS backup battery.Also I removed all accumulated dust inside, by using compressed air.Subsequently I started the oscilloscope (lids still open), applied the default BIOS setting and as a result the internal display is recognized and working again.But now suddenly Ch3 and Ch4 give attached error message.I found someone who had a similar issue back in 2009, after a power outage in their lab.See this forum topic.Before I start to troubleshoot the acquisition board, anyone an idea on what could have happened??I mean, nothing was connected to the channels, so any overload of the channel can be excluded.Of course the airflow inside the housing is less ideal when the lids are open. But I cannot imagine this would lead to a thermal overload (the scope was running for about 10min.)

author: nctnico
author_rank: Super Contributor
timestamp: September 10, 2018, 04:42:59 pm
content: The termination resistor is probably very need a very hot pre-amplifier. You really should NOT work on oscilloscopes like these without an abundant airflow over the acquisition board!

author: Kirkhaan
author_rank: Frequent Contributor
timestamp: September 10, 2018, 05:03:50 pm
content: Amazing, you are right!When I use an external fan to force airflow over the aquisition board, the error message dissapears!

author: DaJMasta
author_rank: Super Contributor
timestamp: September 10, 2018, 05:43:02 pm
content: Depending on how things are ducted, it can be very important to have chassis bits in place, even if the fans aren't removed. Since you sometimes have to work on them with the top off, you need something else. I remember a video of the LeCroy factory with special fixtures that were basically just a set of fans that are held over the board you're working on with the air directed downward, for work on active boards outside of the chassis. When I've done similar work, I've propped up a box fan at an angle, so that an acquisition board flat on the table has a huge amount of air directed sort of all over it - but I'm careful to check angle and placement of the fan with a thermal camera.It's windy to work like that, but it does keep you from cooking your expensive scope

author: Kirkhaan
author_rank: Frequent Contributor
timestamp: September 11, 2018, 08:18:23 am
content: Good learning, thanks. I will take this info account when servicing scopes!I would expect that such crucial thing is mentioned in theservice manual. But I couldn’t find it there...
SALE on RIGOL Europe Oscilloscopes - Page 1
Forum section: electronics / testgear

author: simone.pignatti
author_rank: Frequent Contributor
timestamp: September 11, 2018, 03:05:04 pm
content: I'm not sure if all of you based in Europe are aware about a sale of RIGOL oscilloscopes which is running till September the 30th 2018.There are limited quantities for each models.You find the list in attachment, let me know if it is interesting for you so I can provide more information and support.In case of MSO/DS1000Z all units come with free options included.I hope this message is not inappropriate, in case let me know and I will delete it.Thanks.
B&K2190 Scope shorted Dual NEC FET (Obsolete) finding a substitute??? - Page 1
Forum section: electronics / testgear

author: slbender
author_rank: Regular Contributor
timestamp: August 14, 2018, 09:24:05 pm
content: This B&K 2190 is a ~100 Mhz. 2 Channel Analog Oscilloscope that has been gathering dust for several years - due to a shorted NEC Dual Fet (unobtainium) near the input on one channel. Also lots of bad soldering that likely caused the failure... Any suggestions on the part, the soldering I can repair.Thanks,Steven

author: floobydust
author_rank: Super Contributor
timestamp: August 14, 2018, 09:36:23 pm
content: What's the part number?

author: slbender
author_rank: Regular Contributor
timestamp: September 10, 2018, 06:31:44 am
content: Quote from: floobydust on August 14, 2018, 09:36:23 pmNEC UPA71A Dual Jfet N Channel-Steven

author: tryode
author_rank: Newbie
timestamp: September 10, 2018, 09:47:38 am
content: You can try UT-Source, I've bought in the past from them some dual j-fets and were ok (I've checked them also with a curve tracer in order to be sure it is the real stuff).
Non-standard test leads? - Page 1
Forum section: electronics / testgear

author: GregDunn
author_rank: Frequent Contributor
timestamp: September 10, 2018, 01:09:56 am
content: I was sorting and storing my test leads tonight after the big DMM consistency check, and realized I had a pair (probably came as part of a bundle with my Fluke 179 pawn shop purchase) which I hadn't tested yet. They have no branding whatsoever, just the part number TL-99-1. I plugged them into one of my meters and - the plugs didn't seat fully. In fact, they wouldn't go into any of the guarded receptacles far enough to make electrical contact! I pushed pretty hard (on one of the cheaper meters, not wanting to damage an expensive one) and still nothing.Here's a picture of the plug (left) next to a Fluke plug. It sure looks like the contact pin is too large but the guard is comparably sized. Also attached is a picture of the probe end - looks properly marked but could be a fake I suppose.Is there a different sized test probe pin that I'm not aware of? I have no idea where these came from originally. All my other guarded probes, including some pretty cheap ones, have no trouble fitting any of my meters.

author: coppercone2
author_rank: Super Contributor
timestamp: September 10, 2018, 03:01:28 am
content: i have a feeling you are handling some serious trash

author: GregDunn
author_rank: Frequent Contributor
timestamp: September 10, 2018, 03:05:57 am
content: At least they were free.The sad thing is that they look and feel pretty solid - nice strain reliefs at each end, professional looking two-color molding, threaded tips. I guess the best thing I can do now is chop the plugs off and put some proper ones on, then relegate them to low voltage measurements...
PP-150 scope probes - Page 1
Forum section: electronics / testgear

author: joeqsmith
author_rank: Super Contributor
timestamp: September 10, 2018, 01:00:54 am
content: I just watched this video where they demonstrate a couple of low cost probes, including the PP150. The video shows the SA at 10dB/div and the probe is all over the place. There appears to be a few problems with their test setup. The long ground lead for example.For a comparison, I used my 3589A to sweep the PP150 from 1KHz to 150MHz, 0.2dB/div, with the probe grounded at the tip.I am still very impressed with these $9 probes.
Ebay power supply modules like this? - Page 1
Forum section: electronics / testgear

author: 001
author_rank: Super Contributor
timestamp: September 13, 2018, 11:21:42 am
content: Anybody try it?

author: Fungus
author_rank: Super Contributor
timestamp: September 13, 2018, 11:37:09 am
content: Only a whole series:

author: rjp
author_rank: Regular Contributor
timestamp: September 13, 2018, 11:46:18 am
content: if you have an old ~20v 5amp type laptop power brick around they make an excellent cheapo bench power supply.grab a jiffy box and a couple of screw terminal bannana jacks to package it all up.

author: rjp
author_rank: Regular Contributor
timestamp: September 13, 2018, 12:34:13 pm
content: These modules do the limiting.They are dc-dc converters with configurable volts and ampsThe laptop brick provides the power to it and avoids the chinese plug and ac-dc

author: Fungus
author_rank: Super Contributor
timestamp: September 13, 2018, 12:48:54 pm
content: Brain fart. I misunderstood, you meant use both together.Message removed.
Tektronix T932-T935 Parts - Page 1
Forum section: electronics / testgear

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: September 10, 2018, 12:17:55 am
content: Does anyone know where the following parts can be obtained without paying a King's ransom?107 366-1646-00 Knob With Shaft111 384-1393-00 Shaft .125"112 376-0051-00 Flex Shaft CouplingThanks
Test leads for Fluke 77 - Page 1
Forum section: electronics / testgear

author: edgelog
author_rank: Regular Contributor
timestamp: September 08, 2018, 05:17:14 pm
content: I have an original Fluke 77 but the leads needs replacing. Does anyone know where to get leads that are as close as possible to the originals? I'd like to be able to clip them into the holster like before. I've tried with the leads from the 289, but they don't fit at all; they're too thick. (They don't even fit the 289 particularly well.)

author: edgelog
author_rank: Regular Contributor
timestamp: September 08, 2018, 08:21:27 pm
content: I was wrong. The test leads from the 289 actually do fit the 77 holster. The length is different from the originals, though, so wrapping the leads doesn't work that well.

author: 001
author_rank: Super Contributor
timestamp: September 08, 2018, 08:21:47 pm
content: You need Fluke TL75-1 leads kit
Trimble not initialized - Page 1
Forum section: electronics / testgear

author: bin10
author_rank: Contributor
timestamp: August 31, 2018, 07:05:39 am
content: Good morning,I have a Trimble NTPX26-AB GPS that I use as a standard 10 MHz frequency reference for instruments.I can monitor all parameters with a notebook using the LadyHeather or Tboltmon programs.I have recently built a TSIP LCD 2x16 data display (ZL1CVD) to monitor the status of the Trimble NTPX26 without connecting it to the Notebook.I have found that the LCD display can not receive the TSIP data from the Trimble NTPX26 at startup, because it can not initialize the GPS receiver via the RS232 connection.It is necessary to connect the NTPX26 trimble to the Notebook, start one of the programs (LadyHeather or Tboltmon) to initialize the Trimble NTPX26 and then you can disconnect the RS232 cable from the notebook and connect it to the LCD display to receive the TSIP data.who managed to solve this problem?Kind Regards.Claudio

author: texaspyro
author_rank: Super Contributor
timestamp: September 02, 2018, 01:40:55 am
content: You need to send the device a BREAK condition (say 300 msecs long) to get it into TSIP mode.

author: bin10
author_rank: Contributor
timestamp: September 04, 2018, 08:05:25 pm
content: Hi,I monitored with DSO the package of commands needed to initialize my Trimble NTPX26 when I start the Tboltmon.exe program.is a complex signal that changes.An initialisation signal triggers the sending of the TSIP data to the Tboltmon.exe.When Tboltmon.exe receives the TSIP data it starts sending a new active "Hold" signal of the data.If this "hold" signal is interrupted the GPS NTPX26 returns to the initial mode and stops sending TSIP data.So the signals to be created are 2.

author: bin10
author_rank: Contributor
timestamp: September 08, 2018, 06:51:36 pm
content: My knowledge of C / C ++ language is nonexistent, but with the help of Arduino I reproduced the data package of initialization and maintenance of my Trinble NTPX26.Now everything is OK.
Case for Rigol DG1022Z? - Page 1
Forum section: electronics / testgear

author: cmumford
author_rank: Contributor
timestamp: September 08, 2018, 02:11:22 pm
content: Any soft case recommendations for my Rigol DG1022Z? I can't find one on the Rigol site. I have the Rigol case for my 1054Z scope and really love it - looking for something of similar quality for the 1022Z.
Multimeter relative accuracy check - Page 1
Forum section: electronics / testgear

author: GregDunn
author_rank: Frequent Contributor
timestamp: September 07, 2018, 07:39:34 pm
content: Rather than clutter up the TEA thread, I thought I'd make this separate. It's really nice having a handful of DMMs when troubleshooting; just last week I was fixing an audio amplifier and needed to simultaneously see line voltage (variac), PS voltage, channel DC offset and bias current. Seriously, something was defective and if I didn't monitor everything, it would have been way easy to fry something in the input diff amp stage - I did actually cook a resistor because the current got too high on one stage while the others looked within spec, so another DMM went on the test point there to monitor it. At one point I realized I had ALL my DMMs connected! Anyway, I found the problem (bad cap) and all is well.So while cleaning up the bench and getting ready for another project, I thought perhaps I should just do a spot check on my meters - I had them all out anyway, right? I know I don't have a cal source, but even relative accuracy is good to know about. I ended up testing with two separate power supplies: an old kit 5V analog supply which is pretty stable and quiet, and my newly acquired HP6236B. Results at 5, 10, 20 and 40VDC were comparable, so I'm just showing the 5VDC test.Interestingly, ALL the Fluke DMMs tracked beautifully (the 73 iii is not shown because it honestly didn't have enough resolution to compare with the others, but it was OK within the digits it was capable of displaying). I calculated about 0.02% difference among the 3 of them, even at the 40VDC level. The BK read a little lower, then the Dana, and the Ideal still lower but only about 0.1% off the Flukes. Of course, I have no idea which (if any) are close to being accurate, so the Ideal may well have been spot on.The point being that they're all close enough to each other for what I'm doing. I'd love to have some kind of traceable reference just out of curiosity, but frankly it wouldn't affect my use of the instruments. I suspect, but can't prove, that they're all within spec or darn close - but as I said, the correct voltage may have been significantly higher or lower than any of them showed. My opinion is that the Flukes are closest, but that carries no weight in the real world.Meanwhile, the search for a reasonably priced cal source continues, because I'd just like to know...

author: tautech
author_rank: Super Contributor
timestamp: September 07, 2018, 07:59:04 pm
content: https://www.eevblog.com/forum/testgear/group-buy-proposal-voltagestandard-dmmcheck-plus/

author: GregDunn
author_rank: Frequent Contributor
timestamp: September 07, 2018, 08:08:55 pm
content: Looks like they sold the last batch already, but I'll show my face in case Malone decides to make another run...
Siglent  DSO:   SDS1104X-E  Availability in INDIA? - Page 1
Forum section: electronics / testgear

author: bhishmar
author_rank: Contributor
timestamp: September 07, 2018, 10:53:20 am
content: Hi allAnybody in INDIA has purchased this Digital Oscilloscope yet ?Siglent SDS1104X-E(100Mhz, 4channel). I am not able to find this one inAliExpress.Nor in :a.Scientific Indiab.SweeyaTechAbove two sites were mentioned by another member here "karkoon" in:Another Post.These two sites were earlier selling Siglent model DSO's in India. They don't have this latest model in their sites.After the Nov-2017 release of SDS1104X-E, Siglent had about six firmware update releases, to fix bugs & add some features. Overall based on the feedback last 1 year this unit seems to be somewhat stable & Siglent seems to be responsive in bringing out updated firmware, to plug any detected bugs.Earlier I was zeroing in Rigol DS1054Z.Now seeing all the reviews & specifications & performance detailed in various posts , I am slightly gravitating towards SDS1104X-E, even though it is outside my initial budget. Costlier by another US$150 or more!But I think it is worth the extra money with its performance, extra features & interfaces.AliExpress still lists RIGOL DS1054Z.But do not list the Siglent SDS1104X-EThis model was introduced in Europe in late 2017 (November I think). Nearly 10 months back. So is it the usual delay before the new model being available in India (by international shipping from China)?Anybody has any idea?

author: tautech
author_rank: Super Contributor
timestamp: September 07, 2018, 07:10:27 pm
content: Quote from: bhishmar on September 07, 2018, 10:53:20 amSimple, factory production has not yet met demand so few sellers have stock. When they do, it does not last long.Contact suppliers and ask for lead times.You must place your order then wait.
Dmm for about 100€ - Page 1
Forum section: electronics / testgear

author: YU2
author_rank: Regular Contributor
timestamp: September 08, 2018, 07:44:50 pm
content: Hi, I am in Germany, what dmm is the best buy here for about 100 euro, is it still bm257s ?

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 08, 2018, 07:51:29 pm
content: Quote from: YU2 on September 08, 2018, 07:44:50 pmCan't go wrong with that one. It's great value for money and a proper DMM.
A okay electronic load for 300£ (Or more) - Page 1
Forum section: electronics / testgear

author: InductorbackEMF
author_rank: Regular Contributor
timestamp: September 07, 2018, 12:28:25 pm
content: Hello all after spending a lot of time messing around with power supply's i thought it was about time to get a Electronic load.If anyone knows of a good Load than can handle at least 20A 100v (good meaning the highest current/Voltage input for a given price) for about 300£ this could be a bit higher depending on if the price is close. Thanks in advance.Alex.

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 07, 2018, 03:27:04 pm
content: Quote from: InductorbackEMF on September 07, 2018, 12:28:25 pmI think the IT8512+ should be suitable for your purposes with a 120V and 30A rating at 300 watt. It might be slightly over budget depending on your sources, but not by a huge lot. There are neighbouring models that are cheaper but also slightly less capable and there are also higher voltage models.
What is better multimeter? Mastech M890C vs MY63 vs M830 - Page 1
Forum section: electronics / testgear

author: 001
author_rank: Super Contributor
timestamp: September 01, 2018, 06:03:24 am
content: What is better? M890C vs MY63 vs M830

author: Mameniac
author_rank: Newbie
timestamp: September 01, 2018, 06:27:26 pm
content: maybe I missunderstood the question, but I prefer a multimeter with a fast display and a real fast diode-tester for fast finding connections on a pcb.The M830 is a cheap, well working multimeter for the "quick and dirty" test procedures, and if its broken, just throw it away.The others are a bit more expensive, but not really better.The thing is : what do you need, what do you prefer ?Just quick reading some low voltages and check some resistors and diodes ?

author: HKJ
author_rank: Super Contributor
timestamp: September 01, 2018, 07:31:54 pm
content: Quote from: 001 on September 01, 2018, 06:03:24 amThat is not really something I would rate as good or even decent multimeters. They will all be fairly precise and with lousy safety.Add a few $ more to the pot and look for meters that at least have a fuse.

author: Kleinstein
author_rank: Super Contributor
timestamp: September 02, 2018, 08:59:16 am
content: There is a note the 20 A range is unfused. So I would expect the lower current ranges to have a a cheap 20x5 glass-fuse. At only 200 mA this may not be that bad - bad still not good for a CAT III rating much higher than 12 V.The more expensive ones have extra feature like capacitance and temperature.

author: 001
author_rank: Super Contributor
timestamp: September 02, 2018, 11:56:26 am
content: Hi again! Thanx a lot for yours answers!I NEED in DCV and R tests only ACV in some caseI prefer 830 for its great display and simplisity...I see what input impedance of dt830 is only 1M and M890 is 10MAnd ACV converter in dt830 is only simple diode (no buffers etc)Is it problem?

author: 001
author_rank: Super Contributor
timestamp: September 07, 2018, 12:22:22 pm
content: nobody cares?
Wanna see an OXCO heat up? - Page 1
Forum section: electronics / testgear

author: Ice-Tea
author_rank: Super Contributor
timestamp: September 06, 2018, 04:03:21 pm
content: OXCO heating up

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 06, 2018, 04:21:36 pm
content: So what, starting up cold and monitoring its output?Congrats on the 1000th by the wayTim

author: xrunner
author_rank: Super Contributor
timestamp: September 06, 2018, 05:15:46 pm
content: I think your spectrum analyzer has a bad drift.

author: Ice-Tea
author_rank: Super Contributor
timestamp: September 06, 2018, 05:17:11 pm
content: What 1000th? Oh, this one! Yay!Hadn't noticedYeah, turning on a boat anchor and monitor the output. Nothing earth shatering, obviously, but I thought it neat.

author: Ice-Tea
author_rank: Super Contributor
timestamp: September 06, 2018, 05:18:12 pm
content: Quote from: xrunner on September 06, 2018, 05:15:46 pmHeh, no. The SA is rock steady. This is a HP8662A cold start. Also rock steady after 15 min or so.

author: capt bullshot
author_rank: Super Contributor
timestamp: September 06, 2018, 05:24:00 pm
content: These:http://wunderkis.de/mg3633a/take an hour for their OCXO to reach the final frequency.What a coincidence, I've also used a CMU200 to watch that, so your video looked quite familiar.

author: Ice-Tea
author_rank: Super Contributor
timestamp: September 06, 2018, 05:31:46 pm
content: Heh, yeah, CMU200The Anrtisu looks and 'feels' like the same era as the HP.

author: capt bullshot
author_rank: Super Contributor
timestamp: September 06, 2018, 05:57:01 pm
content: http://hpmemoryproject.org/timeline/bob_devries/hp8662a_01.htmLooks like one can derive the block diagram from the modules arrangementThe Anritsu looks completely different inside, but in the same ballpark of specifications and features.Anyway, the CMU200 isn't good enough to see the phase noise of these beasts.

author: Ice-Tea
author_rank: Super Contributor
timestamp: September 06, 2018, 06:15:39 pm
content: Quote from: capt bullshot on September 06, 2018, 05:57:01 pmWhich should be pretty damn good if the marketing blurb is to be believed

author: texaspyro
author_rank: Super Contributor
timestamp: September 07, 2018, 02:39:09 am
content: I put an Oscilloquartz 8663 DOCXO on a Gerry Sweeny board into my HP-53132A counter. Here are plots during initial warmup, day1, day7, day30, and day60. And people wonder why OCXOs are kept powered on all the time.
Benning MM3 - $250 for manual 3 1/2 DMM? - Page 1
Forum section: electronics / testgear

author: 001
author_rank: Super Contributor
timestamp: September 06, 2018, 08:12:47 am
content: Why so expensive for 30 years old design?Any benefits?https://www.amazon.com/Benning-MM-3-Digital-multimeter/dp/B0002YZLN0

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 06, 2018, 10:43:25 am
content: Maybe it is a rebadged APPA from early 1990s.

author: Fungus
author_rank: Super Contributor
timestamp: September 06, 2018, 12:14:10 pm
content: It's only 121 Euros on their web site:https://www.benning-shop24.de/digital-multimeter-benning-mm-3-044029-p-639.html?language=enIt has "automaticand/ormanual measuring range selection".I read the manual. The grooves at top/bottom are for winding the probes around the meter.

author: 001
author_rank: Super Contributor
timestamp: September 06, 2018, 12:48:33 pm
content: No any automatix here
insertion units for urv5 - Page 1
Forum section: electronics / testgear

author: wilhe_jo
author_rank: Regular Contributor
timestamp: September 05, 2018, 08:06:23 pm
content: Hi all!Anyone ever tried to use one of these without the urv5 or diy own ones?There's a little write-up here:http://www.bymm.de/documents/15/Reparaturbericht_NRV_Z5_V1_3.pdf(sorry, it's german)Seems there's a cal eeprom in the connector which holds 4096 bytes (the unit has an 12 bit adc... what a coincitance...so reverse engineering might be feasible, but if someone has already looked into this before...regards
Racal 9905 and 9908 Counter Manuals - Page 1
Forum section: electronics / testgear

author: G0HZU
author_rank: Super Contributor
timestamp: December 20, 2015, 02:36:13 pm
content: Does anyone have a service manual for these counters? I rescued them at work as they had been red tagged for disposal to the skip. Neither of them have been used for something like a decade (apart from PAT testing) as they dropped out of the calibration system a long time ago. Both counters have been at the company since the 1980s and they have given valuable service in this time so I didn't want to see them get binned.The 9905 seems to work fine but the 9908 has issues with the front panel switches. The counter didn't work properly when first powered up and the display was very erratic. However, I've managed to get it to work reasonably well by just operating all the switches a few dozen times. So I think it needs some internal TLC.The 9908 works to >100MHz on the A input and 1200MHz on the C input and both counters have the 04A fast warmup OCXO option fitted. This oven type is supposed to warm up to a decent accuracy in about 6 minutes.Can anyone advise the best way to clean the switches? I have Servisol switch cleaner here but are there any gotchas with these switches? eg are they fragile in any way?Thanks in advance for any replies

author: Mr Smiley
author_rank: Frequent Contributor
timestamp: December 31, 2015, 08:27:53 pm
content: I have the manual for models 9901 to 9905 in pdf format. It has schematics at the end; but it's 2.5mb which is 1/2mb to big to upload. I will email as an attachment if you give me your address.

author: Pete67
author_rank: Newbie
timestamp: March 11, 2017, 11:46:15 pm
content: I've recently acquired a Racal 9905 counter, and I'd greatly appreciate a copy of the manual too if you would be so kind?

author: Telewriter
author_rank: Newbie
timestamp: September 05, 2018, 03:29:02 pm
content: I have only just joined the group (but am an active member of the Wireless 19 group) and have been involved in electronics for 70 years.Looking through the topics I noticed that Mr Smiley has (or had) a PDF of the Racal 9901 and 9905 manuals. I have a Racal 9905 but no manual. I am not sure of the protocol here but if this PDF is still available I would very much like a copy via email if it is not too much trouble.Regards Telewriter

author: G0HZU
author_rank: Super Contributor
timestamp: September 05, 2018, 03:52:55 pm
content: Hi TelewriterI've uploaded a couple of Racal 9905 PDFs to the link below. The 2.5Mb sized manual was the one I got from Mr Smiley. The other PDF is the schematic only.Try the link below. Hopefully this will allow a PDF download.https://www.qsl.net/g/g0hzu//RF%20Transistor%20data/PDF/

author: Telewriter
author_rank: Newbie
timestamp: September 05, 2018, 04:33:42 pm
content: Thanks GOHZUI managed to download and save those Ok and printed the schematic to file.I am still on the lookout for the Service Manual for the 9905. If I manage to get one I will let the Forum know.
Can you explain this o-scope reading ? - Page 1
Forum section: electronics / testgear

author: Hextejas
author_rank: Frequent Contributor
timestamp: September 04, 2018, 09:46:02 pm
content: The voltage is .627 according to the meter, the volts/div is set to 1.I expected the curve on the scope to only occupy about .62 of 1 box. I don't know what to call the gradient lines. The scope seems to see 2 volts ac. So where is it getting it ?Thanks

author: DaJMasta
author_rank: Super Contributor
timestamp: September 04, 2018, 09:51:40 pm
content: What's the source? What's your termination impedance? Does the meter you're using actually have the bandwidth required to measure the signal you're looking at?

author: xrunner
author_rank: Super Contributor
timestamp: September 04, 2018, 09:54:50 pm
content: Quote from: Hextejas on September 04, 2018, 09:46:02 pmAccording to "the meter" meaning an external DMM set to AC?If you see 2 volts peak-to peak on the scope the DMM (if that's what it is you mean by meter) would (should) read .707 RMS, so perhaps your meter is a bit off. Not sure what the set up is though ...

author: macboy
author_rank: Super Contributor
timestamp: September 05, 2018, 03:32:15 pm
content: Quote from: Hextejas on September 04, 2018, 09:46:02 pmWhat you are seeing is correct.A sine wave with 2.0 VP-P(Volts peak to peak) has a RMS value of 0.707 VRMS. Other waveforms have similar relations: e.g. a 2.0 VP-Ptriangle wave is 0.58 VRMS. You may need to study what RMS voltage means in order to understand.Your multimeter may read a little lower than the real RMS value depending on the frequency, as all multimeters have an upper limit and the response rolls off (decreases) above a certain frequency. This probably explains why it indicates 0.627 instead of 0.707. If you try a lower frequency (e.g. 50 Hz) then the reading can be trusted more.

author: Fungus
author_rank: Super Contributor
timestamp: September 05, 2018, 04:06:14 pm
content: Quote from: Hextejas on September 04, 2018, 09:46:02 pmThe meter will show "RMS" of the voltage - ie. the average, not the peaks.
Any experience about Yokogawa DL 1200A or DL 1540 ? - Page 1
Forum section: electronics / testgear

author: plazma
author_rank: Frequent Contributor
timestamp: September 05, 2018, 12:50:59 pm
content: There are some for sale for 140€. They are quite compact 4 channel scopes. Bandwidth is only 150 or 100MHz.

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 05, 2018, 01:00:56 pm
content: The front panel is not a traditional one.

author: abraxa
author_rank: Frequent Contributor
timestamp: September 05, 2018, 01:03:45 pm
content: Yokogawa has a good reputation and those scopes are worth that kind of money in my opinion. However, the CRTs need to be checked for burn-in - if they have it, I personally wouldn't buy them.Also, they may need replacement of the internal battery, described here:https://www.suwatsu.com/hobby/report/report_0002.htmbtw, if you don't have a use for two scopes, I'd look for a better deal for 280 Euro - you may get more bandwidth and samplerate this way.

author: Ice-Tea
author_rank: Super Contributor
timestamp: September 05, 2018, 01:42:29 pm
content: Yokogawa is very decent gear, owned a few over the years. But 200Msa is pretty poor for that 150MHz unit. Will probably be good for repetitive signals but for everything else your actual BW will be a *lot* less than the 150MHz advertized.

author: plazma
author_rank: Frequent Contributor
timestamp: September 05, 2018, 01:48:58 pm
content: I don't need more scopes but thought about hinting about these to local hobbyists. I already got Rigol DS1054Z, free DSOX 1102G and a free Tektronix TDS7104.
Elitech RC-4 Temperature probe: replacement? - Page 1
Forum section: electronics / testgear

author: frogblender
author_rank: Regular Contributor
timestamp: September 05, 2018, 04:27:46 am
content: I have a couple of Elitech RC-4 standalone temperature loggers (they are handy: -40 to +85°C; 16kpoints measured every x seconds; batterylife=god).They are especially useful for mission-critical applications like measuring how many times a day a toilet flushes.Or just measuring a constant 37.0°C.But alas, today I tucked the RC-4's wire probe into the bowels of the clothes dryer, where my tumbling wet banana hammocks, and excessive manhood in general, proved far too much, untucking the wire and ripping it to bits in short order. So now I need to find a replacement probe tout suite, in order to return to the pressing matter of the toilet assessments.So the question: anyone know where I can get a replacement RC-4 external probe?

author: Vgkid
author_rank: Super Contributor
timestamp: September 05, 2018, 09:06:24 am
content: Here you go:https://www.elitechustore.com/RC4-TMPROBE

author: frogblender
author_rank: Regular Contributor
timestamp: September 05, 2018, 01:02:50 pm
content: Quote from: Vgkid on September 05, 2018, 09:06:24 amEvidently my googling skills... are lacking.Thanks!
[solved] 8753 VNA - Ceramic circuit removal inside A3 source assembly - Page 1
Forum section: electronics / testgear

author: rfspezi
author_rank: Regular Contributor
timestamp: September 02, 2018, 05:06:37 pm
content: Does anybody have experience in removing the ceramic circuit modules inside a "A3 source assembly" of a 8753 VNA?I attached an image of the ceramic modules which are held in place by plastic frames.The module i want to remove to inspect the interface connections is the one on the right marked with the red frame.Things i need to know is e.g. if the ceramic board must be held down in place while lifting the frame?Thanks

author: rfspezi
author_rank: Regular Contributor
timestamp: September 04, 2018, 09:29:10 am
content: Done... no problem pulling out the frame.

author: Tony_G
author_rank: Super Contributor
timestamp: September 04, 2018, 04:29:38 pm
content: Pics or it didn't happenWas in one piece of ceramic?TonyG

author: rfspezi
author_rank: Regular Contributor
timestamp: September 04, 2018, 06:39:57 pm
content: Quote from: Tony_G on September 04, 2018, 04:29:38 pmNo problemThe contact problems clearly came from the "rubber" contact pads which were not elastic anymore and did not apply enough pressure to give reliable contact.The good thing was, that underneath the ceramic pcb, they used the same pads for contacting the gnd-plane.So I simply swapped the yellow marked ones with the red marked, did some contact cleaning with IPA and now the contacts are perfect again for the next 25 years.(pictures shows state after exchange)

author: Tony_G
author_rank: Super Contributor
timestamp: September 05, 2018, 03:04:23 am
content: Nice