hybridfree/eevblog-posts huggingface dataset:
Tektronix 700 series: anyone used the LA and DSO modules at the same time? - Page 1
Forum section: electronics / testgear

author: Frio
author_rank: Contributor
timestamp: April 08, 2018, 09:14:42 pm
content: As per title, I am curious to hear from anyone who used LA and DSO modules at the same time on a Tek 700 series.An example would be a combination of one (TLA7NX/TLA7NAX) board and one (TLA7DX/TLA7EX) board.Given that the 700 series is a logic analyzer, I was wondering whether the DSO modules actually work as a regular DSO, or they are somewhat different.The reason for asking is that I am trying to debug a piece of old video hardware and I would like to analyze at the same time the analog video signals coming from a VGA port and the digital logic ahead of the DAC that produces that signal.Cheers!Frio

author: nctnico
author_rank: Super Contributor
timestamp: April 08, 2018, 11:14:01 pm
content: I never used the DSO modules myself but AFAIK they are more like analog acquisition modules. Don't expect any realtime update rate to speak of.What you can do is connect one of the external signals and use it as a trigger input/output. I have done something similar myself when I wanted to look at the result of an ADC which was fed by a function generator (in my case: generator sync output to logic analyser input and start the acquisition on the external input).
Rigol DS1054Z Board Version differences. - Page 1
Forum section: electronics / testgear

author: mtx1992
author_rank: Newbie
timestamp: January 03, 2018, 08:07:54 pm
content: Hello.I want to buy Rigol's DS1054z, but in the internet I can found a few of versions of board of that oscilloscope:0.1.10.1.40.2.10.2.3 (is probably latest - see attachemnt please)Anyone know what differences they have?

author: Fungus
author_rank: Super Contributor
timestamp: January 04, 2018, 06:33:49 am
content: Quote from: mtx1992 on January 03, 2018, 08:07:54 pmIf your question is: "Are the early onesto be avoided?" the answer is "no".I'm not aware that any revisions have affected functionality. It's probably more a production/cost thing.

author: Distelzombie
author_rank: Frequent Contributor
timestamp: April 09, 2018, 04:55:12 am
content: A distributor I want to buy this from said their board version is 6.1.xThere is a how-to on the Rigol homepage on how to look versions up, and in the picture of their unit it says the board version is 4.1.1. It was a 1104Z though.https://assistly-production.s3.amazonaws.com/244097/portal_attachments/570388/102_1_original.png?AWSAccessKeyId=AKIAJNSFWOZ6ZS23BMKQ&Expires=1523335871&Signature=ejnz5VZ8lv%2B6vincxu%2BLEneVjjY%3D&response-content-disposition=filename%3D%22102_1.png%22&response-content-type=image%2FpngI am confused.

author: Fungus
author_rank: Super Contributor
timestamp: April 09, 2018, 06:10:10 am
content: It's not something to worry about.PS: All of them are secretly 1104Z models. You can unlock them to full bandwidth by pressing the right sequence of buttons.

author: Distelzombie
author_rank: Frequent Contributor
timestamp: April 09, 2018, 06:23:12 am
content: I am worrying about this because I want to know if I get the newest, which has the best probability of the lowest jitter in the 16MHz / 1GHz clock converter, doesn't it?

author: Fungus
author_rank: Super Contributor
timestamp: April 09, 2018, 07:48:55 am
content: Quote from: Distelzombie on April 09, 2018, 06:23:12 amJitter isn't a problem since about three years ago. Even when it was, a firmware update will fix it.

author: Distelzombie
author_rank: Frequent Contributor
timestamp: April 09, 2018, 08:07:13 am
content: I saw Daves review of the fix, and it wasn't a particularly good one.

author: Fungus
author_rank: Super Contributor
timestamp: April 09, 2018, 08:36:12 am
content: Quote from: Distelzombie on April 09, 2018, 08:07:13 amThe new waveformlooksugly when probed with an oscilloscope but nobody has shown that it causes any problems.(and several people here have tried)
Infinium 54825A 500MHz from ebay, worth it? needs software update? - Page 1
Forum section: electronics / testgear

author: DenJohX
author_rank: Newbie
timestamp: April 09, 2018, 04:25:25 am
content: Just got an HP Infinium 54825A for $450 including shipping from ebay, comes with keyboard, front cover, manual and original floppy disk, but without any probes or mouse.All tests passes and overall very clean and with just minor stratchesIts a very very old model, here are some specs:Brand HP (not that Agilent rubbish)Model 54825AAcquisition SystemSample Rate 2 GSa/sEquivalent Time Sample Rate 100 GSa/sMemory Depth 32K per channelVertical SystemVertical Sensitivity 1 mV/div to 5 V/divRise Time 700 psInput Impedance 1M with 8 pFVertical Resolution 8 bitsTime Base SystemTime Base Range 0.5 ns/div to 5 s/divTime Base Accuracy ±0.005%Display8.4 inch LCD 640x480VGA port for external monitor up to 1024x768This is my first scope and wanted something more powerful than the classic rigol to start with, I estudied Telecom Engineering many years ago but sadly the scopes in the labs where 100Mhz at the best (Not exactly a first world college) and always wanted to do some experiments with more freq RFI also bought a pair of cheap 200Mhz probes, and a pair of used HP 10431A Probes (500Mhz, 6.5-9pf).Total spent around $520, the scope passes all tests and is in a very good nick so... Do you think its a good "ebay score"?Now about updating it:For someone that knows about this model, its a VIN#25 with the VIA Motherboard (not the best from what I've read, time will tell) and came with software version 4:30.Investigating the last software version released for this model is the 4.50, anyone knows if its necessary? what are the benefits on upgrading it? I found some hard drives on ebay preloaded with the 4.50 version ready to install for $150, i don't think is worth investing that much money in this scope, specially when I'm searching for a not so expensive function gen.Please leave your comments, cheers!
DP832 PSU oddity - Page 1
Forum section: electronics / testgear

author: bson
author_rank: Unknown
timestamp: April 07, 2018, 05:38:49 am
content: A moment ago, with CH3 set to to 3.3V and nothing plugged in it showed 3.55V and 166mA. Only on CH3; CH2 was fine (didn't check CH1). Power cycled it and it behaved normally again.Even after turning down the voltage to 0.000V it still showed 0.358V and 0.166A. It wasn't a fixed offset. Almost like it had corrupted its calibration data...Disconcerting...

author: PartialDischarge
author_rank: Super Contributor
timestamp: April 07, 2018, 10:42:15 am
content: Looks like a software issue, never seen in mine a rare behaviour though. The current consumed was most probable never really there

author: mcinque
author_rank: Unknown
timestamp: April 07, 2018, 06:07:10 pm
content: Can you provide us details about firmware version of the unit and its calibration date?

author: bson
author_rank: Unknown
timestamp: April 07, 2018, 11:59:42 pm
content: Definitely only a firmware issue. Like it stepped on an in-memory copy of the calibration data.

author: bson
author_rank: Unknown
timestamp: April 08, 2018, 12:03:17 am
content: I haven't calibrated it in about a year, but it's off only about 1mV and less than 1mA on both set and readback, so no need to recalibrate yet.

author: mcinque
author_rank: Unknown
timestamp: April 08, 2018, 02:47:09 pm
content: I was asking the calibration date to understand when it was manufactured and so its board version; that, toghether with the firmware version, would allow to identify better the unit

author: billfernandez
author_rank: Regular Contributor
timestamp: April 08, 2018, 04:59:51 pm
content: When I first got my DP382 (a few years ago) I used the manual calibration process to attempt to calibrate it. One thing I learned is that the power generation subsystem is separate from the output metering subsystem, and each has to be calibrated separately. Thus it's possible for the unit to accurately produce output according to it's current setpoint, but for the meters to inaccurately report the output values.Give your problem statement, it's a reasonable hypothesis that you might have a problem in the metering subsystem. Since resetting the unit cleared the error, then perhaps calibration data is loaded on startup into volatile storage, and there was data corruption in the instance in question?

author: bson
author_rank: Unknown
timestamp: April 08, 2018, 09:50:20 pm
content: Nah, it worked fine for a couple of hours, then glitched out. Clearly the firmware stepped on its internal calibration data. I didn't actually check it with a DMM, I just disconnected everything, noted no change, took a pic, then power cycled it. I was in the middle of something else and didn't want to lose my focus.
China NO selector, one knob DMMs - Page 1
Forum section: electronics / testgear

author: 001
author_rank: Super Contributor
timestamp: April 08, 2018, 09:24:46 pm
content: Any opinions?https://www.ebay.com/itm/PEAKMETER-PM8247S-Auto-Range-Professional-Digital-Multimeter-Voltmeter-Ammeter-w/173015696765?hash=item28488a057d:g:iagAAOSwGW9aoA6o

author: ataradov
author_rank: Super Contributor
timestamp: April 08, 2018, 09:57:25 pm
content: No current measurement (despite "Ammeter" in the listing title). Very poor parameters. This is basically an electrician tool. But I'm not sure that actual electricians will want some sketchy tool from eBay.

author: joeqsmith
author_rank: Super Contributor
timestamp: April 09, 2018, 12:10:59 am
content: The capacitance input is separate and where the current input would normally go. Strange it would be separate in the first place but then the show the meter measuring an alum elec with the lead in the normal input and the meter displaying uF.

author: Distelzombie
author_rank: Frequent Contributor
timestamp: April 09, 2018, 02:42:55 am
content: I was about to say: "Those are probably not real photos. I you look closely you'll see that the leads are at exactly the same angle in every picture (Instead of the first one), even though the meters position is slightly different"But while editing a picture to make my point, I found that there are unexplainable differences.I don't want this to go to waste, so meh, there's the pic made of four layers on top of each other to show that there is no difference, but there is.
Keysight 1000X scope RTC design error? - Page 1
Forum section: electronics / testgear

author: TK
author_rank: Super Contributor
timestamp: March 28, 2018, 10:53:09 pm
content: I was playing with the RTC of my EDUX1002G. After removing the 32kHz crystal and resoldering it, the scope started to give me Clock HW failure errors, the crystal did not oscillate. After changing the RTC chip, it continued to give the same error. After checking the datasheet of the TI BQ32002 RTC chip (The one soldered by Keysight on the PCB), it says that if the crystal matches the load capacitance of 12pF (Which is the most common capacitance of SMD 32kHz crystal), no capacitors are required. So I desoldered the 2 capacitors and now the scope works without any errors. Can change the date and it boots back and keeps the correct date and time.The scope also includes the Sony CR2025 which is a 3V lithium coin cell battery, thinner than the CR2032. If you remove the battery and reinsert it, most of the time the positive pin holder will not make good contact, giving an error during boot that the scope was reset to factory default settings. The coin cell battery holder seems to be for the CR2032.Another oddity I found is that the firmware is writing to RTC registers 0x0C and 0x0F that are not published as valid register addresses on the BQ32002 datasheet.

author: TK
author_rank: Super Contributor
timestamp: April 07, 2018, 11:58:57 pm
content: No comments from Keysight?
Corrosion cleanup--Removing Batts from HP 204C Oscillator and Adding Volt Reg. - Page 1
Forum section: electronics / testgear

author: DanielSpokane
author_rank: Regular Contributor
timestamp: April 05, 2018, 10:43:31 pm
content: I have a HP 204C Oscillator that is behaving badly (looks to be an issue with the power supply). It's described in this thread:https://www.eevblog.com/forum/testgear/oscillator-not-working-right-(hp-204c)/msg1232971/#msg1232971edavid recommended installing a voltage regulator also described in that thread. I'm getting around to finally doing that and removing the batteries and I'm seeing some serious corrosion. See pictures.I'm thinking I will do my best to brush everything off... but wondering if I should try to actually remove the corrosion. I've read some threads on this and it seems there is a lot of conflicting information; from using products... to using vinegar... to doing nothing. I live in a pretty dry environment so I'm thinking just removing the batteries and cleaning off what I can should suffice... but I'm curious if anyone has an opinion or recommendation on this. Thoughts?

author: tautech
author_rank: Super Contributor
timestamp: April 05, 2018, 10:53:30 pm
content: From this sticky thread:https://www.eevblog.com/forum/repair/vintageclassic-renovation-techniques/https://www.eevblog.com/forum/chat/fluke-187-corroded-battery-terminals-how-to-clean/

author: DanielSpokane
author_rank: Regular Contributor
timestamp: April 06, 2018, 08:01:23 pm
content: Thanks tautech. Those are very helpful.Reading those over I've concluded since the batteries are Nickel Cadmium which I believe is an alkaline I need to neutralize the corrosion with an acid. My plan is to use an exacto knife and scrape off as much corrosive build up as I can. Then apply vinegar using a cue tip to the corrosive areas; let sit for a period then wash off using distilled water and cue tip. I am a little worried about some of the components that some corrosion (resistors, etc.). I'm thinking I will do pretty much the same with them as the contacts, etc. (ie put vinegar on them and wash off with distilled water)... the only difference is I will be only lightly rub them with a tooth brush so as not to damage. After I do all that I will let sit for a couple days to dry.Seems like a solid plan. Any input before I proceed?

author: tautech
author_rank: Super Contributor
timestamp: April 06, 2018, 10:19:00 pm
content: I wouldn't fuss over using distilled water as any is OK for flushing and cleaning purposes.I quite often use hot water (and fit a cuppa in too) and then IPA to finish.Toothbrush is good but for stubborn stuff I have a quite soft and small brass wire brush that's better again.Where the conformal coating is damaged and if you can get it really clean, you can recoat it with any sort of varnish, even finger nail polish will do or just tin it with solder to protect the copper traces.
Set gate time >10 sec on DG1022Z ? - Page 1
Forum section: electronics / testgear

author: Circlotron
author_rank: Super Contributor
timestamp: April 05, 2018, 04:48:27 am
content: The gate time menu on Rigol DG1022Z frequency counter function has options 1mS, 10mS 100mS, 1 sec, 10 sec, >10 sec. For >10 sec option there doesn't seem to be a method of setting this time. Press that button and it samples approx every 1 second. Any ideas how to set this to a long duration?

author: Circlotron
author_rank: Super Contributor
timestamp: April 06, 2018, 05:31:01 am
content: *Bump* to the front page for a new set of eyes.

author: bd139
author_rank: Super Contributor
timestamp: April 06, 2018, 07:17:25 am
content: AFAIK it doesn’t do this. I found the gate times very odd anyway. I also found the counter on mine to be not very sensitive so I bought a TTi TF930.

author: Circlotron
author_rank: Super Contributor
timestamp: April 06, 2018, 11:29:28 am
content: Quote from: bd139 on April 06, 2018, 07:17:25 amThis is what I mean.First pic shows gate time options of 1mS to 10 sec.Second pic shows >10 sec option but there doesn't seem any way of setting what thistime actually is.

author: bd139
author_rank: Super Contributor
timestamp: April 06, 2018, 12:03:52 pm
content: I think that’s just the menu overflowing and there’s nothing in the second one.
KORAD KA3005P Software update - Page 1
Forum section: electronics / testgear

author: HoracioDos
author_rank: Frequent Contributor
timestamp: April 07, 2018, 06:59:21 pm
content: HiWhile looking for a PSU in .reichelt.de yesterday I found this model "RND 320-KA3005P"https://www.reichelt.de/Laboratory-Power-Supplies/RND-320-KA3005P/3/index.html?ACTION=3&LA=2&ARTICLE=212042&GROUPID=4952&artnr=RND+320-KA3005P&trstct=pol_4It seems to be the same Korad PSU with other name, so I downloaded control software to check its version. I was pleased to find the highest version (V3.2) I could find. I tested it today in a Win7 VM and under wine 3.0 too. It works fine in both environments. It has a much better layout and it is much more stable.Hope this might help for those who own this model.https://www.reichelt.de/index.html?ACTION=7&LA=3&OPEN=0&INDEX=0&FILENAME=D400%252FSOFTWARE_RND320KA3000P.zip
Looking for a PC based digitizer - Page 1
Forum section: electronics / testgear

author: sdouble
author_rank: Frequent Contributor
timestamp: April 05, 2018, 11:31:58 am
content: Hi all,I'm looking for a high dynamics (14+ bits, SNR >60 dB , SFDR >70dB) digitizer using the PCIe posrt of a desktop PC.Moderate bandwidth : -50 MHz analog, 100 MS/s if possible.4 channels would be great, I could cope with only 2.SMA inputs at best. 50 ohms input impedance.Cost sensitive application.If you know some supplier, don't hesitate to post.CheersJu

author: simone.pignatti
author_rank: Frequent Contributor
timestamp: April 05, 2018, 06:54:04 pm
content: here is an examplehttps://www.picotech.com/download/datasheets/picoscope-6407-digitizer-data-sheet.pdf

author: simone.pignatti
author_rank: Frequent Contributor
timestamp: April 05, 2018, 06:55:41 pm
content: https://www.litepoint.com/wp-content/uploads/2014/03/z4441-Tech-Specs_031114.pdf

author: sdouble
author_rank: Frequent Contributor
timestamp: April 05, 2018, 10:46:46 pm
content: thanks.I'm actually after a PCIe board.Moreover i do need advanced triggering option.I need to filter (trapezoidal shaping) the signal and trigger on the shapped output.
Brymen BM235 Low internal battery gives false readings? - Page 1
Forum section: electronics / testgear

author: MacMeter
author_rank: Frequent Contributor
timestamp: April 03, 2018, 11:15:55 pm
content: I own the EEVBlog version of this Bremen BM235 meter, and just read HKM’s review, here:https://lygte-info.dk/review/DMMBrymen%20BM235%20UK.htmlI wasn’t aware of this low battery voltage reading “issue”. Pardon me if this has been discussed, I do monitor most of the BM235 threads and have never seen this brought up.From his misc. notes:“Reading is stable until about 1.8V where it increase significantly (5.000V -> 5.206V)”From final conclusion notes:“It has one problem and that is the behavior when the battery is nearly empty, a good DMM must never show wrong value!”Just curious has this been confirmed? Thanks.

author: EEVblog
author_rank: Unknown
timestamp: April 03, 2018, 11:52:12 pm
content: 1.8V total battery voltage?That's 0.9V per cell, you can't expect any meter to work at that voltage. The low battery warning comes on at 2.5V and effectively means "replace the batteries before taking critical readings". That's the same with every meter. That fact that it still works so far under the low battery cutout voltage is testament to the good design margin.Should it cut out completely? Yeah, ideally, but few meters on the market do that that I am aware of.

author: MacMeter
author_rank: Frequent Contributor
timestamp: April 04, 2018, 12:14:27 am
content: Quote from: EEVblog on April 03, 2018, 11:52:12 pmThanks for the confirmation Dave. I’ll respect the low battery warning. Maybe forum member HKM will read this and amend that part of his review with your feedback.

author: Whales
author_rank: Super Contributor
timestamp: April 04, 2018, 12:43:35 am
content: One of my cheap meters didn't have a low battery warning. You only noticed when the readings started looking strange.That meter is now in metrological heaven.

author: HKJ
author_rank: Super Contributor
timestamp: April 04, 2018, 04:19:51 am
content: Quote from: MacMeter on April 04, 2018, 12:14:27 amThe warning is correct, a good design will disable the meter before it shows wrong readings.
Ever Hear of Instrustar O Scopes? - Page 1
Forum section: electronics / testgear

author: MrAl
author_rank: Super Contributor
timestamp: March 26, 2018, 04:23:31 pm
content: Hi,Anyone ever hear of an Instrustar Oscilloscope?They make several different models, mostly PC scopes i think.I was wondering how the stand up to other more commonly known brand names.

author: MrAl
author_rank: Super Contributor
timestamp: April 03, 2018, 12:17:09 pm
content: Quote from: MrAl on March 26, 2018, 04:23:31 pmNobody here ever heard of this one?That is interesting in itself i guess.What kind of scope do you use, or maybe that would be a questions for a separate topic.

author: nctnico
author_rank: Super Contributor
timestamp: April 03, 2018, 01:14:58 pm
content: It looks like another Chinese Hantek clone. I would make sure to test it fully and that it can be returned for a refund if it turns out to be a lemon.

author: MrAl
author_rank: Super Contributor
timestamp: April 04, 2018, 03:51:26 pm
content: Quote from: nctnico on April 03, 2018, 01:14:58 pmHello there,The one i was looking at was the 205A which has "Data Logging" ability, something i needed.It's not that fast by today's standards, only 20MHz BW, but it's also much cheaper.
HP 4263A LCR Latest Firmware? - Page 1
Forum section: electronics / testgear

author: dkozel
author_rank: Regular Contributor
timestamp: April 03, 2018, 11:56:06 am
content: I'm starting a repair on an HP 4263A LCR Meter which displays "ADC Error" on boot. I have a new ADC to swap in, but want to rule out other faults first before doing that change. The B revision of the 4263 had multiple software updates to eliminate false ADC errors so it seems to make sense to make sure I'm on the latest firmware first.Currently my meter has V 2.00 installed. Does anyone know what the latest is, or even better have an EEPROM image of it?Thanks!

author: dkozel
author_rank: Regular Contributor
timestamp: April 04, 2018, 12:03:25 pm
content: Heard back from Keysight, the latest is Rev 2.00. I'll post up a copy of my EEPROM here and upload it to xDevs.
Service manual for Hitachi V-1585 oscilloscope - Page 1
Forum section: electronics / testgear

author: Miti
author_rank: Super Contributor
timestamp: March 10, 2018, 03:43:32 am
content: Does anyone has or knows a link to the real Hitachi V-1585 service manual? I downloaded one that pretended to be for V-1585 just to find out that it is for 1065 and older. The frequency counter is a bit off on mine.Thanks in advance!

author: Miti
author_rank: Super Contributor
timestamp: April 02, 2018, 11:53:37 pm
content: No one has it? Anybody knows how to calibrate the time base and the frequency counter?

author: StillTrying
author_rank: Super Contributor
timestamp: April 03, 2018, 01:37:03 am
content: Well this one includes circuit diagrams.https://elektrotanya.com/hitachi_v-1585-65-60-v-695_om_sch.pdf/download.html

author: Miti
author_rank: Super Contributor
timestamp: April 03, 2018, 03:50:45 am
content: Thanks, I've got that one but if you open it, there's nothing about 1585 in it. Whether is the same schematic as 1065, I don't know.

author: StillTrying
author_rank: Super Contributor
timestamp: April 03, 2018, 02:55:02 pm
content: I dunno, there's a few other possibles that might be close here.https://www.eevblog.com/forum/chat/hitachi-v-1065a-scope/msg154651/#msg154651https://www.eevblog.com/forum/repair/toppled-over-my-analog-oscilloscope-now-no-display-(hitachi-v-1565)/msg1467242/#msg1467242https://www.eevblog.com/forum/testgear/teardown-hitachi-v1065/msg375991/#msg375991
HP 3406A Sampling Voltmeter problem - Page 1
Forum section: electronics / testgear

author: LazyJack
author_rank: Frequent Contributor
timestamp: April 01, 2018, 08:05:38 am
content: Hi,I've just picked up a HP 3406A sampling voltmeter, with the intent to repair.During the troubleshooting following section 5-52 in the Service manual, I have found that the Probe Assembly is faulty. unfortunately, the manual says that the probe assembly needs to be replaced if it doesn't work. Which obviously sounds like a challenge to take.Has anyone successfully taken apart or repaired such a Probe? I'm already stuck at taking it apart, removing the grub screws makes it a bit a wiggly, but I have been unable to free the insides.Any advice? Thanks.

author: LazyJack
author_rank: Frequent Contributor
timestamp: April 01, 2018, 11:59:48 am
content: All right. Managed to take the probe apart, there was some gunk spilled on it, which made it stick, but removing the two grub screws I finally managed tp pull the internals out from the shell. So far the diode bridge seems to be ok, now on to test the rest.

author: LazyJack
author_rank: Frequent Contributor
timestamp: April 01, 2018, 12:56:49 pm
content: Hmmm. Looks like the signal cable from the sampler head is broken somewhere in the cable. I was unable to locate the break, wiggling the cable all over did not make the tester beep.Which is bad, because this is some special cable, with two shielded/coax lines and several normal wires inside a shielded jacket. I'm not sure what I could use to replace it. Maybe something like a HDMI cable?

author: LazyJack
author_rank: Frequent Contributor
timestamp: April 01, 2018, 03:12:22 pm
content: Success. Not only in having a discussion with myself in this topic :-), but with the meter too.Since cables usually break where they are most abused, I had a feeling hat it broke near the instrument. And that was the only place I could possibly shorten the cable as the other end is crimped into the probe housing.So having nothing to loose, I grabbed the inner stands of the broken wire and pulled. It came loose and about a 5cm long piece was in my hand. I cut that length from the cable, reconnected to the connector, it was a pain to strip and solder these wires. Put it all together and it works. I'm happy.

author: Jim Narem
author_rank: Contributor
timestamp: April 03, 2018, 06:23:16 am
content: Not that it matters to you now, but I have sucessfully replaced the discrete sampling diodes in the probe (the part most people break) with an HP/Avago/Broadcom bridge quad, HSMS-2828.

author: LazyJack
author_rank: Frequent Contributor
timestamp: April 03, 2018, 07:52:10 am
content: Thanks, this is good to know. I guess it is easy to destroy these in the probe.
BG7TBL phase noise comparator - Page 1
Forum section: electronics / testgear

author: jhenderson0107
author_rank: Regular Contributor
timestamp: April 02, 2018, 04:23:37 pm
content: I am interested in the NS-CMP product advertised on eBay at (https://www.ebay.com/itm/122376396168). I have not been able to locate a theory of operation (or a manual) for this product, so have inquired with the designer.I am guessing that the circuit incorporates cascaded frequency multipliers (not a mixer) to increase the input frequency by a factor of 260, thus increasing the phase noise by 20 log (260) = 48 dB. This would increase the phase noise my GPSDO by ~48 dB, raising it above the -117 dB/rHz @ 10 kHz noise floor of my Agilent 8562EC analyzer, permitting analysis.Do you think this is correct?

author: jpb
author_rank: Super Contributor
timestamp: April 02, 2018, 06:22:32 pm
content: It looks interesting. I would like to hear what you find out.Frequency multipliers other than 2, if my understanding is correct, need tight band-pass filters to get rid of the unwanted harmonics. The frequency multiplication could be done in a PLL but then that would be difficult with the wide input frequency range of 1MHz to 100MHz.EDIT: realise I read the thing too quickly - the factor is 260 not 48. This seems unlikely to be frequency multipliers as it contains the factor 13 - a 13 times multiplier would require filtering of the much higher content at 3, 5, 7, 9 and 11 times and I can't see this working over the range 1 - 100MHz.For simply multiplying the phase noise (frequency deviation) then I would have thought that a PLL approach would be cleaner as in :http://www.wriley.com/The%20PicoMult%20Frequency%20Error%20Multiplier.pdfbut that approach only works for a specific frequency input.So I am puzzled and hope you can get some further information from the designer.EDIT: my best guess is that a frequency synthesizer is used with a programmable PLL but a means of knowing the input frequency would be needed.
UNI-T UT71D Internal Data Logging Upload Working? - Page 1
Forum section: electronics / testgear

author: imk
author_rank: Regular Contributor
timestamp: April 02, 2018, 10:04:15 pm
content: Hello,There seems to be several purchase site reviews where purchasers complain that the UT71D record samples internally just fine but won't upload them to the PC software.Anyone having similar issues or does it work ok?Many thanks imk
Tek CFG280 - PAL/GAL JEDEC Files for U702 & U707? - Page 1
Forum section: electronics / testgear

author: Chris56000
author_rank: Frequent Contributor
timestamp: April 02, 2018, 11:36:09 am
content: Hi!I was reading:-https://www.eevblog.com/forum/beginners/simple-analog-function-generator-design/msg1174548/#msg1174548. . .and I was interested in the Tektronix CFG280 schematics referenced in this article, post no 31, page 2, and there's one stumbling box to trying it as a home project, namely there's two PAL/GAL's in it!Schematics:-www.davmar.org/pdf/TekCFG280-schem.pdfCan anyone tell me if the PAL/GAL devices U202/U707 used in this is available as spares, or has anybody got one of these CFG280s and can possibly attempt to read their JEDEC files for me or suggest if dumps has been posted anywhere?Chris Williams
Hitachi V1085 oscilloscope spare parts available - Page 1
Forum section: electronics / testgear

author: g3
author_rank: Newbie
timestamp: February 01, 2018, 06:34:18 pm
content: Hello,I recently disassembled a Hitachi V-1085 oscilloscope. No chance to repair, CRT has a crack and possibly the high-voltage transformer is also defective.So I thought I'll announce that I have some spare parts. Tell me if you need anything.

author: rbm
author_rank: Regular Contributor
timestamp: February 01, 2018, 08:08:41 pm
content: Where are you located? Do you ship to other geographies than your own?

author: g3
author_rank: Newbie
timestamp: February 07, 2018, 04:48:25 pm
content: I'm located in Germany. Would have to check out international shipment and customs as I haven't tried this yet. There's a minimal chance that I soon meet a U.S. citizen that at least could bring something cross the atlantic.

author: TonyLangley
author_rank: Newbie
timestamp: April 02, 2018, 02:34:54 am
content: Hello g3I have an Hitachi V-1060 Scope, The LOPT ( Fly-back high voltage transformer ) has shorted turns. I believe the V-1085 uses the same transformer. Can you give me any details on why you believe your transformer is faulty.Thank you for your time,Tony
Is this behavior normal for Rigol DS1054Z? Offset rapidly rising when changing v - Page 1
Forum section: electronics / testgear

author: john1222
author_rank: Newbie
timestamp: April 01, 2018, 11:45:24 pm
content: I purchased a Rigol DS1054Z after using a loaned model. But I don't think I saw this behavior previously. The DC offset rises rapidly when changing quickly from 100V to 10mV vertical settings. Is this normal behavior?https://ufile.io/na15jShort video of the offset rapidly rising uploaded. I want to ask for a replacement if this is not normal behavior. Thanks for your help.John

author: ataradov
author_rank: Super Contributor
timestamp: April 02, 2018, 12:09:25 am
content: Looks fine to me. It just applies software scaling to already captured data before hardware can deliver updated data.
Problem rigol ds1054z - Page 1
Forum section: electronics / testgear

author: Adrian_Arg.
author_rank: Frequent Contributor
timestamp: April 03, 2018, 05:14:06 pm
content: Hello, a few days ago I received an oscilloscope rigo ds1054z, yesterday I started to have this tip, when I turn it on when it is cold and only has a probe connected to channel 1, or even if it does not have a probe, when I prepend "AUTO" it is activated channel 3, but if five minutes or so have passed, that problem does not occur.

author: janekivi
author_rank: Frequent Contributor
timestamp: April 03, 2018, 05:19:17 pm
content: Yesterday... it is after you have hacked firmware installed?

author: Adrian_Arg.
author_rank: Frequent Contributor
timestamp: April 03, 2018, 05:25:30 pm
content: Yes, I installed the original again, and it does the same, when I just turned it on after it cooled down, it does, then everything works fine.

author: Qw3rtzuiop
author_rank: Frequent Contributor
timestamp: April 03, 2018, 05:26:57 pm
content: The standard setting of the "Auto" function will automatically turn on channels with a signal. That can also happen if there is some noise that is picked up by a probe or a cable.You can change the setting that the Auto function doesnt turn on/off channels (utility menu->auto options -> ch).

author: Adrian_Arg.
author_rank: Frequent Contributor
timestamp: April 03, 2018, 05:29:06 pm
content: ok, I'll put it into practice, thanks

author: Fungus
author_rank: Super Contributor
timestamp: April 03, 2018, 05:29:38 pm
content: Quote from: Qw3rtzuiop on April 03, 2018, 05:26:57 pmYes, I think it's probably this. The 'scope needs to warm up a bit.You can usually see a DC offset on the channel which goes towards zero over the first few minutes.If it continues to do it after 15 minutes then worry. Otherwise not.

author: Adrian_Arg.
author_rank: Frequent Contributor
timestamp: April 03, 2018, 05:37:50 pm
content: Not once it warms more or less about 5 minutes at most, the device works excellent, also when it is activated detects noise, once hot and it goes crazy, probe use opened, and it works, we will find the fault !...
[solved - delete pls] Signal bleed between channels - Page 1
Forum section: electronics / testgear

author: Bob Sava
author_rank: Regular Contributor
timestamp: April 01, 2018, 07:41:59 pm
content: I have what appears to be a signal bleed. CH1 (yellow) wave is a calibration signal, CH2 (purple) is a 10kHz square wave from external AWG. When I unplug or stop AWG yellow vertical line stops. Display is set for 5s persistence to show the motion of the vertical line. Later screenshot shows purple signal (CH2) coinciding with the movement of the yellow vertical line. If I plug AWG signal to any other channel, that are on separate ADC, ghost signal does not show.EDIT: I'm unable to delete this topic. After doing more tests I think crosstalk occurs outside of the oscilloscope, because part of the signal path on CH1 is unshielded (probe and/or calibration signal leads)
Brymen BM867S with Rechargeable Li-ion Batteries - Page 1
Forum section: electronics / testgear

author: imk
author_rank: Regular Contributor
timestamp: April 01, 2018, 02:18:34 am
content: Hello,After much debate i think i'll be buying the Brymen BM867s and well i just don't like buying single use batteries.So was wondering how the BM867s would work with rechargeable PP9 Li-ion batteries which i believe are 7.4v ?Many thanks imk
What do the FETs do in an analog meter - Page 1
Forum section: electronics / testgear

author: Beamin
author_rank: Super Contributor
timestamp: April 01, 2018, 04:31:15 pm
content: Besides being better on a desert or deserted island as we learned in the video?

author: Fungus
author_rank: Super Contributor
timestamp: April 01, 2018, 04:39:25 pm
content: I don't think the FETs will work on a desert island...
Datron 1061 refurbish AC board miss information about SU2656M JFET - Page 1
Forum section: electronics / testgear

author: xantia_99
author_rank: Contributor
timestamp: March 31, 2018, 09:38:44 pm
content: Hi,i change this from the repair part of this community, I hope You do not mind ...i have refurbish my old Datron 1061, Analog board, Digital board, power supply. Together with resistance and current board it work excellent . Put in a MAT12 and AD711 after that it worked very good. Problem with change a lot of chip, passive components sockets, drivers, optical ..Now it works and very stable.Today or shall i say the last year refurbish the AC-board. instability and not possible to make a zero calibration. To much noiseLost hfe in 2N3905, 2N214C and so on. Many measurement traditionally with diode tester ok , but no gain with curve tracer. Found 6 transistor without/low gain until now from input to TL7. The differential Q21 and Q22 did not match. Now its possible to calibrate but it's not stableNow my problem:I miss information about Teledyne double jfet SU2656M to make it possible to measure with a curve tracer to see if I have to exchange themI am on the right way. I have spend to may hours but I have retired so ..I am a bit tired of all this but want to finish with AC-board at the same level as new or better. If I will get everything to work very good I will change the display. But it cost i know that I have asked.Best RegardsS
Budget Multimeter with latching continuity test - Page 1
Forum section: electronics / testgear

author: DSkilton
author_rank: Newbie
timestamp: March 31, 2018, 08:33:25 am
content: I am seeking recommendations on a budget multimeter where the only critical function is a latching continuity test capability.I have considered building my own, but first wanted to see if I can just buy one cheaper.Many thanksDavid

author: Terry01
author_rank: Frequent Contributor
timestamp: March 31, 2018, 08:39:23 am
content: Fluke 101?

author: Electro Detective
author_rank: Super Contributor
timestamp: March 31, 2018, 09:49:21 am
content: The best cheapie multimeter I've used with good continuity test is a Fluke bare bones 114ok, so it's not that cheap but you do get a good meter that can run with the big Flukes
Rohde & Schwarz CMU200 update firmware - Page 1
Forum section: electronics / testgear

author: cmu2017
author_rank: Contributor
timestamp: March 30, 2018, 05:03:36 pm
content: How can I update the cmu from version 3.23 to the latest firmware/software. And where can I find this software. I have searched on the website of R&S. But on the download page isn’t any.

author: Qw3rtzuiop
author_rank: Frequent Contributor
timestamp: March 30, 2018, 09:27:49 pm
content: Take a look atgotroot.ca/cmu200/.

author: cmu2017
author_rank: Contributor
timestamp: March 31, 2018, 08:05:02 am
content: Thanks. But how do I install this software now. I have placed the software on the flash disks. But do not see it on the VersionManager

author: Qw3rtzuiop
author_rank: Frequent Contributor
timestamp: March 31, 2018, 08:37:26 am
content: Execute the firmware file on your PC. It will extract itself. Then place the folder on the flash disk. I think it needs to be fat16 formated. On startup press "Menu Select". If everything worked you should see an update menu.

author: cmu2017
author_rank: Contributor
timestamp: March 31, 2018, 10:38:06 am
content: Great, thanks. It works.
Electrical ratings for external trigger inputs on test equipment? - Page 1
Forum section: electronics / testgear

author: AlanR
author_rank: Regular Contributor
timestamp: March 30, 2018, 09:41:06 pm
content: For some reason I can't ever find the ratings of the external triggers on test equipment like my 34465A DMM for example. Like they never mention votlage level, max frequency before the instrument can no longer trigger due to trigger frequency being too high, what type of waveform to use to trigger the instrument to do something, duty cycle, etc....If curious why I need this data:I have a PLC that I wrote a ladder program into that need to send a signal from it's 5 volt output digital module to the external trigger inputs of my test equipment when a condition has been met that my PLC is going to measure with the 12 bit ADC analog modules I have attached to it that can read voltage levels on it's analog inputs.EDIT: Well since all of you are useless to helping me, I had to do some serious digging. It seems all external triggers are TTL from all vendors that make test equipment. Thought it was. Thanks for not helping me at all guys!!!
Philips PM3094 Z mode input - Page 1
Forum section: electronics / testgear

author: WaveyDipole
author_rank: Frequent Contributor
timestamp: March 30, 2018, 12:45:21 pm
content: I recently acquired a HP3314A signal generator and was experimenting with the sweep mode but couldn't get the marker to work. I checked the output from the Z out on the HP3314 on the oscilloscope and could clearly see a trace showing the positive blanking signal (+18vp approx) and a marker pulse (-18vp approx). I then did a test on the Z-MOD input of the PM3094 and found that aplying a positive voltage blanked the screen as expected, but applying a negative voltage did not brighten the screen. As a final test I tried the sweep generator and marker on a Tek 465 and here, accuracy aside, it worked as expected, generating a clear highlighted marker.I can just use a start and stop frequency that provides an appropriate calculable frequency per div and even add a cursor, but was wondering whether this an expected behaviour, or a fault? Has anyone used the Z-MOD input on a Philips PM3084 or PM3094 and did it work?
Very special meter find - Page 1
Forum section: electronics / testgear

author: PA4TIM
author_rank: Super Contributor
timestamp: April 01, 2018, 01:02:41 pm
content: This meter is produced during the cold war. To mislead the eastblock when they tried to build secret stuff from American stolen circuit designs, the yanks started to use imperial volts. In the same period Fluke merged with the European Philips.This leaded to problems when American and European techs had to work together.To overcome this Philips made this very special meter for internal use. The red button is there to switch between metric and imperial volts

author: igendel
author_rank: Frequent Contributor
timestamp: April 01, 2018, 01:11:34 pm
content: +1 for Imperial Volts!When Fluke and Philips merged, did it become Phluke or Filips?

author: georgd
author_rank: Regular Contributor
timestamp: April 01, 2018, 06:27:57 pm
content: Imperial electrical electrical units are quite amazing, never heard about them. The googling find no result.It's a product of cold war?

author: Vtile
author_rank: Super Contributor
timestamp: April 01, 2018, 06:42:47 pm
content: Oh!!That explains the variation of the standard kilogram at the beginning of the cold war!!!

author: HighVoltage
author_rank: Super Contributor
timestamp: April 01, 2018, 06:43:21 pm
content: Philips and Fluke merged in 1993.This meter must be at least 10 years older, I would guess early to med 80s.I thought I knew all Philips meters of that age, since our university's lab wassponsored by Philip. But I have never seen this meter before with sucha red button.Nice find.Thanks for sharing.

author: geekGee
author_rank: Unknown
timestamp: April 01, 2018, 06:53:59 pm
content: I always learn so very much on the first day of April.

author: rsjsouza
author_rank: Super Contributor
timestamp: April 01, 2018, 06:57:36 pm
content: Nice find, PA4TIM!
Should I update my lecroy 6100A's IDE HDD with a 120GB SATA SSD? - Page 1
Forum section: electronics / testgear

author: smartboy123
author_rank: Newbie
timestamp: March 30, 2018, 07:19:14 am
content: I got a good condition Lecroy waverunner 6100A, and like to update the CPU/RAM/HDD, for the lowest risk.I read many threads about the updating of Lecroy waverunner series scope, however, no one mentioned using a SATA3 SDD to replace the IDE HDD, they all use a PATA SDD. I don't know why.My scope's motherboard is Intel 865GLC chipset, I guess there should be 2 SATA ports on the board (I haven't teardown the scope yet, so I guess). I wonder whether can I update the PATA IDE with a new one SATA3 SDD.Does anyone have those kinds of experience about it?

author: nctnico
author_rank: Super Contributor
timestamp: March 30, 2018, 10:29:47 am
content: If the motherboard has Sata ports then I don't see why you can't use them. But you should check if the motherboard doesn't have hardware bugs in the Sata ports.
Siglent SVA1000X Spectrum Vector Analyzer? - Page 1
Forum section: electronics / testgear

author: TK
author_rank: Super Contributor
timestamp: March 29, 2018, 02:24:46 pm
content: Looks like Siglent announced a Spectrum Analyzer with Vector Analysis capabilities? It is called SVA1000X Spectrum Vector Analyzer...

author: Performa01
author_rank: Super Contributor
timestamp: March 29, 2018, 04:21:19 pm
content: https://www.eevblog.com/forum/testgear/siglent-sva1015x-1-5ghz-spectrum-vector-network-analyzer-(coming)/

author: TK
author_rank: Super Contributor
timestamp: March 29, 2018, 05:10:58 pm
content: The name is Spectrum & Vector Network Analyzer, better than Spectrum Vector Analyzer

author: Mechatrommer
author_rank: Super Contributor
timestamp: March 30, 2018, 06:25:56 am
content: why dont invent a new name like Spector or Vectrum Analyzer?
Tektronix 422 ac/dc power supply issues-help needed - Page 1
Forum section: electronics / testgear

author: rjdeeter
author_rank: Newbie
timestamp: March 30, 2018, 06:23:27 am
content: I recently acquired a Tek 422 AC/DC that so far has pwr sply issues. The history is it was supposedly working 20 yrs ago then put in storage. now it mine..beautiful condition, cute scope! low 8k sn I would really like to get it back in use..always wanted a tube front end!I cannot check the indicator without the supply...gee.....wish I had the AC supply too! (circuit looks so much easier!)so far-i checked all resistors/diodes/xstrs/caps in circuit as best as possible.I have found :In the DC -DC converter Q1184 (2n1899) is bad. fuse had not blown. (possibly not run long enough to cause it to go).i replaced both Q1184 and Q1174 with D1148 (appeared to be a reasonable sub, I had a matched pair, and matched fairly close to the one good xstr on my old sencore xstr tester, they are temporarily mounted just in case I can find 2n1899's). maybe my subs are a bad choice? is there a better one?questions-is there a problem with testing just the pwr sply section by defeating the DC interlock (pins 13-24)?The supply appears to be a loop in a loop, I managed to test the Start circuit, the feedback and -12 supply ( it makes -8V at C of Q1154). (using exterior +/-12 to run the circuits)Attached pwr per Calibration with 11.5V and have the oscillator functioning.the oscillator (~7 khz ) did appear to want to start and circuit wants to run.The big problem is too much current in the input circuit 4.5A at 12V input appears my sub for Q1174/84 is incorrect...they get really hot. and of course as input V rises so does current. it should not go over 2.5A (3A fuse).the start circuit appears to be good. but one needs the osc to generate the +/-12 supplies that run the osc that drives the ........well big loop.I am in need of someone who can suggest a good sub for the 2n1899.....mine is obviously wrong or possibly something else is haywire?I really need some help.thanksRenée