hybridfree/eevblog-posts huggingface dataset:
Electronic DC Load Manufactures? - Page 1
Forum section: electronics / testgear

author: vini_i
author_rank: Regular Contributor
timestamp: September 28, 2016, 05:29:32 pm
content: I'm looking into some electronic DC loads comparing manufacturers.All the loads need to be 40V max.100W600W1200WPower requirements.So far I've looked atChromaB&K precisionAmetek/SorensonKeysight (no 1200W)GW InstekAdaptive Power Systems (APS)TDI PowerNH ReserchAre there any manufacturers that I have overlooked?

author: Macbeth
author_rank: Super Contributor
timestamp: September 28, 2016, 05:36:48 pm
content: Maynuo and Itech

author: HighVoltage
author_rank: Super Contributor
timestamp: September 28, 2016, 05:37:42 pm
content: EA = Elektro Automatikhttp://shop.elektroautomatik.de/shop/shop__DC%20electronic%20loads__1::3::12__en_GB

author: nctnico
author_rank: Super Contributor
timestamp: September 28, 2016, 05:39:01 pm
content: I'm missing Maynuo, EA elektro automatic, Array and Kikusui from the list.What do you want to do with it?

author: PartialDischarge
author_rank: Super Contributor
timestamp: September 28, 2016, 05:52:54 pm
content: You could also look at an used Transistor Devices Dynaload DLP series, many of them sold on ebay in the US, and could get one for cheap. Old but works.Last week I bought one, and I got a lab switched power supply to test it and all was going well until I hit the PULSE button, which loads the supply with pulses of constant current 500hz and upwards. Now that power supply is toasted.My rigol DP832 did survive that test though.

author: vini_i
author_rank: Regular Contributor
timestamp: September 28, 2016, 06:02:30 pm
content: The loads are for a tester. They need to be operated over GPIB or Ethernet. (i probably should have mentioned that)We are actually looking to replace a home spun system from 15+ years ago with a professional system.

author: nctnico
author_rank: Super Contributor
timestamp: September 28, 2016, 06:17:58 pm
content: FYI: for one of my customers it turned out to be more cost effective to build custom DC loads than using off-the-shelve loads but they don't need precise current control. Maybe you shouldn't write the home spun system off entirely.

author: vini_i
author_rank: Regular Contributor
timestamp: September 28, 2016, 06:36:58 pm
content: The B&K Precision MDL line and Itech IT8700 line look identical.Who is rebadging who?QuoteThe home spun loads were designed 15+ years ago. They lack any protection whatsoever. They don't have short circuit capability. They don't talk GPIB. The NRE necessary to design 600W and 1200W loads with those features would outweigh just buying pre built ones.

author: Ordinaryman1971
author_rank: Frequent Contributor
timestamp: February 22, 2018, 08:58:05 pm
content: Instek makes some too.. there is this really nice modular one

author: sstepane
author_rank: Regular Contributor
timestamp: February 22, 2018, 09:23:13 pm
content: Applent (Anbai) and Rigol.

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: February 23, 2018, 02:49:13 am
content: EPS Stromversorgunget-systemHoecherl&HacklZeal Mfg.
5in1 DSO8060 60Mhz Handheld Oscilloscope Multimeter Spectrum Analyzer Arbtrary - Page 1
Forum section: electronics / testgear

author: cowasaki
author_rank: Frequent Contributor
timestamp: February 24, 2018, 10:40:16 am
content: I found this whilst searching for something else on Ebay. I'm not planning on buying one but out of interest has anyone actually bought one of these? Anyone used one? What can they be like with all those devices stuffed into a single box?I remember in the early 90s getting a portable 10MHz scope which was absolute rubbish so always wary of stuff like that (I was comparing the 10MHz scope to a 100MHz Fluke digital storage scope which was a beast for it's time!)https://www.ebay.co.uk/itm/5in1-DSO8060-60Mhz-Handheld-Oscilloscope-Multimeter-Spectrum-Analyzer-Arbtrary/292339374500?hash=item4410c8d9a4:g:GQUAAOSwosFUWa6x
HP 54601a or Tektronix tds 210 ? - Page 1
Forum section: electronics / testgear

author: little_carlos
author_rank: Regular Contributor
timestamp: February 23, 2018, 12:23:01 am
content: Hi, I saw these 2 scopes here in México for 120 USD, both has the same price. The hp is 100MHz is 4 ch. and the tek is 60Mhz 2 ch.Which of those is better? My budget is limited, scopes in Latin America are way more expensive than in the states or europe, and the price of importing them is even higher. That's why im not getting a Rigol or Siglent.

author: KrudyZ
author_rank: Frequent Contributor
timestamp: February 23, 2018, 01:00:26 am
content: The main difference is in the sample rate.The TDS210 samples at up to 1 GSa/s meaning your 60 MHz bandwidth will give you a good view of single shot events up to that frequency.The HP only samples at 20 MSA/s, so the 100 MHz spec is only achievable for repetitive signals.If someone forced me to pick between the two I would pick the TDS210.

author: little_carlos
author_rank: Regular Contributor
timestamp: February 23, 2018, 01:08:40 am
content: Thanks! I see things way more clearer now, I'll buy the tektronix
UNI-T UT50C multimeter calibration, tests, bugs, etc. - Page 1
Forum section: electronics / testgear

author: cosmin1
author_rank: Regular Contributor
timestamp: January 08, 2018, 11:13:15 am
content: Hello.I want to calibrate my UT50C, but don't know which trimmer for which domain.LE: i identified some of them.Here is what i have:VR1 - DC voltageVR2 - CapacitanceVR3 - AC voltageVR4 - ?VR5 - ?VR6 - Temperature °FVR7 - Temperature °CVR8 - FrequencyVR9 - ?I really like this multimeter.It's really simple and i appreciate the ON\OFF button and automatic lighting. I hate the timed lighting on other models. On this one, the light is there exactly when you need it.Anyway, i don't intend to work with itmin high voltage equipments. In rare cases, maximum 230V.

author: cosmin1
author_rank: Regular Contributor
timestamp: January 10, 2018, 12:46:10 pm
content: I succeeded.

author: cosmin1
author_rank: Regular Contributor
timestamp: January 10, 2018, 09:05:39 pm
content: On the other hand, the multimeter has a bug.Measuring a 22k resistor on the 200Mohm scale, indicates 1Mohm value. Changing to a lower scale and measuring the same resistor, shows the real value.May be a model bug or just this multimeter is somehow defective?

author: Chris56000
author_rank: Frequent Contributor
timestamp: February 23, 2018, 12:06:26 am
content: Hi!I gave my Band Musician friend Mike Smith one of these models and I found it does indeed have this bug on the 200M resistance range – not only that, but the one I gave away always showed "001.0" on the 200M range even on open–circuit!I think UNI–T have made a design howler and somehow shunted a fixed 1M into the top 200M range, possibly a design defect in the DVM chip itself!Is there a schematic available?Chris WilliamsThis
No user movies in youtube for Owon ? - Page 1
Forum section: electronics / testgear

author: JanJansen
author_rank: Frequent Contributor
timestamp: February 21, 2018, 04:55:57 pm
content: Hi, why are there no user youtube movies about these Owon XDS3062A scopes ?Are they really bad that no one buys them ?, or do people still only buy the Rigol ?Bad thing is there is no serial decoding, it does have 12 bit ADC, i,m not buying a 8 bit scope.Hope Rigol will soon release the follow up for the 4 channel 1054Z scope.

author: Fungus
author_rank: Super Contributor
timestamp: February 21, 2018, 06:55:31 pm
content: Quote from: JanJansen on February 21, 2018, 04:55:57 pmYes.Quote from: JanJansen on February 21, 2018, 04:55:57 pmYou get twice the channels, more bandwidth, serial decoders, etc. for less money.What's not to like?

author: rsjsouza
author_rank: Super Contributor
timestamp: February 21, 2018, 07:21:30 pm
content: Although the 12-bit is very enticing, Dave did a teardown of one of its brothers and the production quality was quite terrible.Check:https://www.eevblog.com/forum/blog/eevblog-1004-owon-xds3202a-14bit-oscilloscope-teardown/msg1246500/#msg1246500

author: JanJansen
author_rank: Frequent Contributor
timestamp: February 22, 2018, 05:22:11 pm
content: Oh i did not see this topic when i posted this :https://www.eevblog.com/forum/testgear/owon-xds3062a-input-noise-(good)-and-glitches-(bad)/I remove it out of my head, i wont look to it again.

author: Fungus
author_rank: Super Contributor
timestamp: February 22, 2018, 06:58:48 pm
content: Quote from: JanJansen on February 22, 2018, 05:22:11 pmEvery 65536th sample in the buffer is always zero? That's a whole new level of "buggy"I knew they were bad but notthatbad.
BW settings on DS4014 only available with the right SW version - Page 1
Forum section: electronics / testgear

author: Steff_electronics
author_rank: Newbie
timestamp: February 20, 2018, 02:59:33 am
content: Hi,Is the Bandwidth upgrade from 100 MHz to 500 MHz on the DS4000 series only available for special SW-version?I have a DS4014 with decoder upgrade already done, but I am not abe to do the BW upgrade. (following the instructions on riglol)It is using SW version 00.00.04 and HW version 1.2Thanks for any help

author: hendorog
author_rank: Super Contributor
timestamp: February 20, 2018, 03:05:38 am
content: Quote from: Steff_electronics on February 20, 2018, 02:59:33 amThat SW version doesn't look right to me.Why don't you download the latest version from Rigol and upgrade, then try again?

author: Steff_electronics
author_rank: Newbie
timestamp: February 22, 2018, 01:29:36 am
content: Hi,I cecked again the SW version. It tells me the 00.00.04.Maybe messed up.... who knows.I will follow your suggestions and report if it works.Thanks.

author: CustomEngineerer
author_rank: Frequent Contributor
timestamp: February 22, 2018, 03:41:32 am
content: At least for the DS2000A series you don't enter separate codes for the bandwidth and other options. You enter the single code for all options, and that unlocks both the full bandwidth and the other options at the same time. Try uninstalling the keys (SCPI command on DS2000A, and assuming same for DS4000 is ':SYSTem:OPTion:UNINSTall'), then just installing the single key for 'all options'.

author: rsjsouza
author_rank: Super Contributor
timestamp: February 22, 2018, 04:20:19 am
content: ^^This. The DS4000 uses a single code that compounds all options and bandwidth.

author: hendorog
author_rank: Super Contributor
timestamp: February 22, 2018, 06:50:38 am
content: Quote from: Steff_electronics on February 22, 2018, 01:29:36 amThere is a key combo you need to enter to get the full SW version. I can't remember it, but you will find it if you look.You haven't really told us anything about what you have already tried, so you might already know this but:https://www.eevblog.com/forum/testgear/rigol-ds4000-option-and-bandwidth-hack/msg961229/#msg961229http://gotroot.ca/rigol/riglol/

author: hendorog
author_rank: Super Contributor
timestamp: February 22, 2018, 07:18:19 am
content: Looking at the release notes here:https://www.eevblog.com/forum/testgear/rigol-ds4000-option-and-bandwidth-hack/msg1350678/#msg1350678It seems you have a really old firmware version - presumably one which did not have the ability to upgrade the bandwidth with option codes. So upgrading the firmware should be your first step.
Oscilloscope SSD and Gotek upgrade - Page 1
Forum section: electronics / testgear

author: plazma
author_rank: Frequent Contributor
timestamp: February 22, 2018, 01:22:40 pm
content: I was thinking about upgrading the HDD and floppy drive of my TDS7104.Has anyone here tried the Gotek floppy emulator with HxC or FlashFloppy firmware?Any experience between SATA SDD with IDE adapter versus PATA SSD (like KingSpec from eBay)?
Rigol SA-DS1000Z decoder - Page 1
Forum section: electronics / testgear

author: stern0m1
author_rank: Contributor
timestamp: February 22, 2018, 02:30:20 am
content: Where can I find instructions how to use the addon to the rigol oscilloscope Rigol SA-DS1000Z thats supposed to decide serial data?Thanks

author: CustomEngineerer
author_rank: Frequent Contributor
timestamp: February 22, 2018, 03:34:34 am
content: The scope's user's guide.
Probes and other test equipment - China and other thieves - Page 1
Forum section: electronics / testgear

author: EE-digger
author_rank: Frequent Contributor
timestamp: February 03, 2018, 04:18:00 pm
content: I used to enjoy buying equipment, probes, etc. on ebay. Lately, I've hit my limit on probes and other equipment from China going for 3x what they should be. One of my favorites is certain Agilent / Keysight accessories listed at something like $1500 from the UK when I can get it delivered to my front door, tomorrow morning, NEW, for $550. What are these guys smoking?All sorts of Agilent probes which I bought new (some used) previously on ebay, on multiple occasions, for around $110 each, are now showing only Chinese listings for over $300. I know, if I check new listings late on a Sunday night, every 6 months a deal may show up. Didn't have to wait that long in the past.But life is too short

author: Chris56000
author_rank: Frequent Contributor
timestamp: February 21, 2018, 11:21:38 pm
content: Hi'I'm from the U.K. and this is one of my all–time favourite gripes!!!T & M gear/accessories have all been knocked off by sellers in the USA, China or Israel with bottomless credit–cards and pure greed – the number of times I've seen gear sold "spares or repair" by unscrupulous U.S. or Chinese sellers who either want prices several times more than new, or what you would expect to be a reasonable b.i.n. price, then add innumerable times that on for postage!Does it really cost 717.00 USD to ship a bench multimeter sold "S or R" and depicted in fragments from the USA to the UK?!Israel is another thing that makes me fume because of the outrageous customs charges and the atrocious state that T & M gear seems to end up in over there!Chris Williams

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: February 22, 2018, 01:51:35 am
content: Yeah, I noticed this too. Fortunately, right now, I'm in pretty good probe shape though. But, as you say, listings for used stuff where the price on Keysight for new is half what they are asking?Try this on eBay; search for "Agilent" and then sort results by highest price first - the first 4 or 5 items are 'buy it now' for $999,999.00, you do get free shipping though!That seems like it must be some kind of calculation error - perhaps the Taiwan poster entered a number that got translated badly by eBay?

author: bitseeker
author_rank: Super Contributor
timestamp: February 22, 2018, 02:07:10 am
content: Quote from: Gandalf_Sr on February 22, 2018, 01:51:35 amMaybe it's in VND, instead of USD (currently 22719 VND per 1 USD).
RF signal generator for AM/FM radio build ?? - Page 1
Forum section: electronics / testgear

author: isobig
author_rank: Contributor
timestamp: February 03, 2018, 10:25:13 pm
content: Hey all... getting back into doing some electroncs and I purchased a Elenco AM/FM radio kit to assemble recently. Instructions say to use a RF generator to align the IF stages and in sections it states to use modulation. I have seen many generators are able to do AM for the IF alignment on the AM side of the radio but it seems difficult to find something that does FM for a reasonable cost. The kit wants the generator to cover up to the FM band (88-108MHz) and they say to set it for 1kHz modulation with 22.5kHz deviation.Just doing this as a hobby so I don't need anything costly. I know the kit can be built without a generator but I prefer to do so if possible as to be more accurate. Already have a scope to measure the signals.Any recommendations on low cost new or used gear that would meet this need?Thanks!

author: Chris56000
author_rank: Frequent Contributor
timestamp: February 21, 2018, 10:31:39 pm
content: Hi!Whilst I've never tried one personally myself for that purpose, one of those cheap.DDS synthesised sinewave generator modules with an amplitude modulation facility might be of use, but you'd need to completely house it in a screened diecast box to prevent radiated "spurii" interfering with the alignment, with the generator o/p connected to a coil of wire about six turns as a radiator loop if the AM side has a ferrite–rod aerial.However, it may be worthwhile reading up your radio kit instructions thro' carefully, as there may be an "Alignment With No Signal Generator" procedure given – it's very often possible to do this because the IF transformers and oscillator coils are "pre–tuned" at the factory that made them and only a very slight adjustment will be needed to bring them into final alignment of the radio has been assembled correctly!If you're making a number of these kits, then a vintage valve–operated signal generator is your saviour – (please don't laugh, these instruments were made to a very good quality and stability specification and even a typical piece like an Advance E2 will be found to be surprisingly accurate, providing you allow adequate warmup time first!) – let us know how you get on with the kit instructions first!Chris WilliamsPS!If you download the March 1968 issue of "Radio Constructor" Magazine from the American Radio History Website, and turn to the "In Your Workshop" feature, "Smithy" the featured "serviceman" goes into some depth on restoration and use of a typical service workshop type RF Signal Generator.If the radio is monophonic only on FM, you can line up the FM Discriminator Transformer with a simple Unmodulated c.w. RF carrier at. FM IF frequency, two 47k matched resistors and a dmm with a low current (not more than 2mA range) – FM alignment generators tend to go for silly prices either from the States or worse, all end up in bloody Israel!!!
Advantest R3267 - Page 1
Forum section: electronics / testgear

author: redlght
author_rank: Newbie
timestamp: February 07, 2018, 06:09:04 am
content: I contacted US based Advantest they got a hold of their over seas factory and also the company they gave these units to and no one can come up with a service manual or schematic.My issue is the master 10MHz reference is 260Hz high and that is with the menu course and fine at zero and it will not pass the RBW cal. Does any know which board holds the 10MHz reference and if it is manually adjustable? If not it may need a new xtal. Or any photo of one of these tore down? If i use an external 10MHz reference it cals fine. Thanks for your time

author: jjoonathan
author_rank: Frequent Contributor
timestamp: February 07, 2018, 06:29:57 am
content: It's pretty easy to get to. Here's a view from the underside of the machine. CRT is facing to the bottom and the synthesizer deck has been hinged open to the left.https://photos.app.goo.gl/vUkOOIaIuTJxF9cU2

author: redlght
author_rank: Newbie
timestamp: February 07, 2018, 10:55:17 pm
content: Thanks for the photo, mine does not have that 10Mhz ref block , Is that an R3267 with the LCD screen?

author: jjoonathan
author_rank: Frequent Contributor
timestamp: February 08, 2018, 12:45:11 am
content: My bad, I posted a photo of a R3371A which has a similar RF deck to the R3265/R3271 but *not* the newer R3267/R3272. On the R3272, which has a much closer design to your device, the 10MHz reference is behind the 3rd converter, underneath the "3rd out" label.Since removing the RF deck is a PITA you probably want to verify this first. Start at the synthesizer card. There should be 3 or 4 cards accessible after removing a panel on the right hand side (or what would be the right hand side were it sitting in the configuration it is designed to be used in). The synthesizer is the one with ~10 SMB connectors rather than 2 or 3 SMB connectors. Start at the SMB connector nearest to the back of the device and work towards the front, looking for 10MHz with an oscilloscope. IIRC the 10MHz reference should be the 2nd or 3rd you test. You can then trace the cable and will probably find that it does in fact disappear behind the RF deck.Good luck, let us know how it goes!

author: redlght
author_rank: Newbie
timestamp: February 08, 2018, 01:34:18 am
content: I checked the signal before and it is off by 260Hz coming from under the rf deck on what seems to be a separate board also under the rf deck are maybe 2 boards it is really hard to tell. And yes it is quite intensive to remove but i need to correct that freq offset to able to not use a ext ref. So i guess i have to grin and bare it and get it apart. I was just hoping someone had done this before and had tear down pics, Thanks for your insight

author: redlght
author_rank: Newbie
timestamp: February 13, 2018, 11:58:04 pm
content: I have been busy have not yet tore it down, I will update with photos when i do.

author: redlght
author_rank: Newbie
timestamp: February 21, 2018, 10:21:41 pm
content: Getting at that 10mhz ref was a bit to much hassle so i sold it to someone that wants to mess with it
HP SpecAn EEROM - Page 1
Forum section: electronics / testgear

author: outremer
author_rank: Contributor
timestamp: September 03, 2017, 02:50:06 pm
content: Hi all !I got recently a used HP 8563E specan. The instrument works well, but there seems to be a broken EEROM (U501 on A2 control board). Error 700 shows up assoon as I activate a function involving the EEROM (I would have called this an EEPROM).This issue does not impair the instrument measurement capability but will not allow to save a power-on configuration for example. I checked fora replacement at Agilent-Keysight's but no luck, there is no support for a 20 plus year old equipment. The guy is an 28 pin socketed IC, hopefully notbut maybe an HP custom made piece.Any ideas where to get this?Best regardsPhil

author: rfdes
author_rank: Regular Contributor
timestamp: September 03, 2017, 05:32:19 pm
content: If you have access to a device reader/programmer, I would pop out that part and see if it is really faulty. The problem could reside elsewhere.Good luck -Jim

author: outremer
author_rank: Contributor
timestamp: September 03, 2017, 08:54:06 pm
content: Thanks Jim,I do not have access to a EPROM reader/programmer so far. This EEROM has to be replaced in the powered on instrument as stated in the service manual (first copy the data into RAM, then replace the EEROM, copy the data back to EEROM). This ROM probably also harbours the the device's firmware, so loosing the data would be really annoying. Apparently reading the ROM is OK but not writing . I could not find any circuit drawing of the instrument showing how the EEROM is written. I don't want to harm an instrument with less than 1600 working hours.Regards Phil FM5GB

author: outremer
author_rank: Contributor
timestamp: February 24, 2018, 04:59:11 pm
content: SolvedI got the replacement chip and changed it. Now everything works nicely on the specan.Regards
Does the Rigol DG1032's frequency counter actually work? - Page 1
Forum section: electronics / testgear

author: sebmadgwick
author_rank: Regular Contributor
timestamp: February 21, 2018, 02:28:08 am
content: I've had a Rigol DG1032 for a couple of years now and the counter has always been useless. The instrument measures it's own output brilliantly, but it won't trigger reliably for any other signal source.For example, if I setup the trigger for AC coupling with 0V trigger level, I can connect it to CH1 or CH2 outputs configured as a 0V-3.3V square wave and I get a solid frequency count. If I then connect it to an equivalent signal generated by something else (e.g. a microcontroller or my oscilloscope's square wave output), it never triggers. I must increase the trigger level to 1V to achieve temperamental triggering.This as just one of many demonstrations I can create to clearly show the counter failing. There's nothing wrong with the ground arrangements, connectors, cables, impedances, etc. I often pair the DG1032 with a scope via a BNC cable and 'T' connector to verify the signal I'm trying to 'count'. I have no issues using my dedicated counter instrument (TTi TF930). The DG1032 counter is just... useless.Has anyone else used the DG1032 Counter?

author: rf
author_rank: Newbie
timestamp: February 21, 2018, 06:54:39 pm
content: I just tried the counter on my DG1062Z. Rigol seems to have mixed up the DC and AC coupling options. If I set the trigger coupling to DC the counter triggers regardless of the DC offset.

author: sebmadgwick
author_rank: Regular Contributor
timestamp: February 21, 2018, 09:05:51 pm
content: Thanks for testing. I've had another play again assuming AC and DC are mislabeled and the instrument seems to behave correctly.
lambda LLS6000 mods? - Page 1
Forum section: electronics / testgear

author: linux-works
author_rank: Super Contributor
timestamp: February 21, 2018, 04:46:35 pm
content: just bought a used lambda LLS6018 psu. seems nice and has lots of current. small package, too.I didn't realize it did not retain settings at power-off. I'd like to 'fix' thatanyone ever look into this? wondering what ideas have been tried. battery backup of the cpu? some arduino thingie to re-enter the settings via keypresses (sloppy but could work). other ideas?losing settings is annoying; even worse if you want to be able to resume a process if power fails and comes back on again.finally, the fan is somewhat noisy. any mods for that? might consider variable speed and temp sensing. for low current needs, I wonder if I even need the fan on, at all?

author: Photon939
author_rank: Regular Contributor
timestamp: February 21, 2018, 05:44:49 pm
content: I have the chunkier version of your PSU that goes up to 24A at 18v.I'm not sure how you would do a settings backup, if it's old enough to have a microprocessor with separate SRAM you might be able to do battery backup on the SRAM. It has been a while since I had mine apart.Mine must have come from a machine shop as the inside was caked in black dust. The fan bearings were also shot so I replaced it with a standard 80mm fan from my junkpile. IIRC there are some resistors in there that get toasty even at idle so I would recommend not turning the fan off completely.
Datron 4708 Possible board swapping with 4700, 4705 and 4707?? - Page 1
Forum section: electronics / testgear

author: acts238willy
author_rank: Regular Contributor
timestamp: February 07, 2018, 11:47:56 am
content: The usual dilemma... an old machine with no available replacement boards.My 4708 (AC only) has quit on me.Will boards from the 47xx series swap with each other...Or, do I need to use only 4708 boards to repair mine?I also posted this in the metrology forum...HELP!

author: jfphp
author_rank: Regular Contributor
timestamp: February 07, 2018, 06:22:41 pm
content: You can swap most of the boards even with a 4200 (amplifier, synthesyzer...). Have a look at the part number of the boards. Options are coded in the CPU board and if there is no current, ohm... option you cannot put the option board into the slot occupied by a kind of dummy board.

author: acts238willy
author_rank: Regular Contributor
timestamp: February 07, 2018, 07:22:28 pm
content: THANK YOU!!!I was going to try to populate the 'AC only' 4708 with the DC and Ohms boards(orange and blue tabs) from the other machine.That would have driven me nuts!WillyB

author: jfphp
author_rank: Regular Contributor
timestamp: February 08, 2018, 10:45:41 am
content: If I remember but I don't know if it is indicated in the service manual, coding of the options is through dip switches. Have you got the op and the service manuals ?

author: acts238willy
author_rank: Regular Contributor
timestamp: February 08, 2018, 02:16:52 pm
content: The 4708 manual should have the codes, right?I can't get to it right now...

author: Samogon
author_rank: Frequent Contributor
timestamp: February 10, 2018, 02:34:07 pm
content: here it is

author: acts238willy
author_rank: Regular Contributor
timestamp: February 21, 2018, 02:50:17 pm
content: Just went and looked at my 4708 AC option20 only....All switches were DOWN?And, it works fine, AC volts and current.Switch levers 3 and 6 were marked with black pen,as was the switch body above them??Perhaps the board was harvested from a 10, 20, 30 machine?

author: Samogon
author_rank: Frequent Contributor
timestamp: February 21, 2018, 02:54:28 pm
content: All switches down meansyou have all boards installed and enabled

author: acts238willy
author_rank: Regular Contributor
timestamp: February 21, 2018, 03:06:06 pm
content: I just realized that the 'ohms' slot, the blue slot,is filled with a half-card in the illustration.Cards from the bottom are black, brown, red,orange (the DC board), yellow and green, the ACboards..blue, the current and ohms board, with the ohmstrimmer pots in the middle of a full-length card...and violet, the power amp.So, the illustration is an AC and DC machine, with NO ohms. (?)
Test and Measurement Obsolete Gear Teardown and Salvage - Page 1
Forum section: electronics / testgear

author: beanflying
author_rank: Super Contributor
timestamp: February 20, 2018, 05:58:01 am
content: As the rate of Technology change and time until obsolescence for some T&M equipment shortens there is a lot to be gained by us smaller users both in terms of reusable parts even just cases and power supplies or even knowledge of what's in the box and showing it off to a wider audience on the way is easy thanks to the net in it's various forms. Horse trading (in private or in the for sale section) of to be junked items is encouragedLike a lot of my generation (yep I am that old) I started scrapping old TV's Radios and even a few electro mechanical stock tickers for parts and or knowledge (still using the 50 pair looms for hookup wire now and some old caps make great spools for wire and solder).While the is some great Retro teardowns on Youtube I for one don't have the time or inclination to produce videos. There is plenty of gear out there thanks to evilbay for not a lot of money or trawl your local scrap yards for gear.If you add a post here scrapping retro 'reusable' Nixie counters to build a clock for example expect to receive the feedback you deserveSo what's in your junk pile or box for breaking down today?

author: beanflying
author_rank: Super Contributor
timestamp: February 21, 2018, 07:05:47 am
content: A peek of what was in the box approximate size of the anchor 500 x 500 x 200Weight- heavy!Seems to be fully functional on face value but I have no plans to feed it teletext.More bench clearing before commencing.

author: tautech
author_rank: Super Contributor
timestamp: February 21, 2018, 07:11:09 am
content: 'Bout time you put us out of our misery !

author: beanflying
author_rank: Super Contributor
timestamp: February 21, 2018, 07:30:22 am
content: Had to clear a couple of things to even get it on the bench.

author: bitseeker
author_rank: Super Contributor
timestamp: February 22, 2018, 02:57:57 am
content: Cool display. Hefty heat sinks. Can the GPIB be repurposed or converted to a USB interface with a µC?

author: ikrase
author_rank: Regular Contributor
timestamp: February 22, 2018, 03:24:04 am
content: Nice subrack case.

author: xrunner
author_rank: Super Contributor
timestamp: February 22, 2018, 03:38:51 am
content: That's some Big Iron for texting.
Question about shielding in power transformers of test gear - Page 1
Forum section: electronics / testgear

author: Martin.M
author_rank: Frequent Contributor
timestamp: February 20, 2018, 03:48:05 pm
content: hello friends,I want to know this:I have a repair running, HP 3456A Multimeter. The cooling fan is fried, and have shorted. This killed the primary coil of the power transformer.Here in germany the problem is possible bec. we have 230V~ and the fan is connected between the both coils. I will replace the fan by a PC fan, this can do the job.The transformer is simply to feed stabilized +/- 15V in the Aquisition board, and +5V stabilized in the control+output board.The aquisition board ist groundet to GUARD and strong isolated to the rest of the instrument.In the power transformer is a seperate shielding what is also connected to GUARD. The question: Can I put there another transformer what don`t have this shielding or will that destroy the accuracy of the instrument?thank yougreetingsMartin

author: orin
author_rank: Frequent Contributor
timestamp: February 20, 2018, 11:35:21 pm
content: Well, there are three shields in that transformer - one to chassis ground, the second to guard and the third to the Inguard ground. I can't imagine they would go to the expense of putting three shields in there without them being necessary. I'd be looking for a used transformer.As for the fan, why bother? Later units didn't have a fan - it seems that all you have to do is move the U1 regulator IC to the back panel, essentially 'undoing' the backdating changes given by change #10 in the 3456A service manual. I'd cut a plate to cover the hole and mount the regulator on the plate - or on a small heatsink bolted to the plate.
Question regarding Beckman Industrial DM97 - Page 1
Forum section: electronics / testgear

author: Geeboh
author_rank: Newbie
timestamp: February 15, 2018, 06:14:47 pm
content: Hi guys,I just joined this forum and seem like its fun place to hang out. Recently i just scored Beckman Industrial DM97 for below $20. I've been searching for its manual/schematic and can't find one. I crack it open and it supplied with glass fuse rated at 1A 250V. I dont think it proper fuse for this meter. Plus it only have 1 fused. Does the A and mA shared same fuse?

author: Geeboh
author_rank: Newbie
timestamp: February 15, 2018, 06:21:44 pm
content: Here some pictures

author: edwin4711
author_rank: Newbie
timestamp: February 16, 2018, 03:32:15 pm
content: The 10Amp shunt is not fused.FS1 should be 630mA according to the manual.

author: Geeboh
author_rank: Newbie
timestamp: February 19, 2018, 06:51:38 am
content: Quote from: edwin4711 on February 16, 2018, 03:32:15 pmAs i thought so. I check the A and mA terminal with continuity test. The 10a jack connected with the shunt and the mA is connected via the glass fuse. So this meant i wouldnt be able to do current measurement? Hmmm too bad. The meter cool tho, got dual display with the bar graphHmmm do you mind share the manual with me sir. I would be grateful if you do that. Couldnt get the manual anywhere online

author: edwin4711
author_rank: Newbie
timestamp: February 20, 2018, 07:49:28 pm
content: I have the user manual, I will scan it for you.Send me a email for your email adres and I will send you a pdf.

author: texaspyro
author_rank: Super Contributor
timestamp: February 21, 2018, 01:50:09 am
content: Also post it to ko4bb.com for the rest of the world to enjoy.

author: lowimpedance
author_rank: Super Contributor
timestamp: February 21, 2018, 01:59:12 am
content: @ GeebohAn extra pic of the front and the display when turned on would be a nice addition to the internal pictures too. When you get a moment of course. Thanks

author: Geeboh
author_rank: Newbie
timestamp: February 21, 2018, 05:25:30 am
content: Quote from: lowimpedance on February 21, 2018, 01:59:12 amSure no problem

author: Geeboh
author_rank: Newbie
timestamp: February 21, 2018, 05:27:14 am
content: Quote from: edwin4711 on February 20, 2018, 07:49:28 pmI'd already pm'ed you sir
HP 8591A OCXO coax - Page 1
Forum section: electronics / testgear

author: kc8ard
author_rank: Contributor
timestamp: February 19, 2018, 10:26:06 pm
content: Hello all, this is my first post. Simple question.... I was able to win a good condition 8591A on ebay. I even picked up an ocxo for it. Now, what is the coax connector called that goes between the spectrum analyzer and the ocxo? I have no idea what it is, as it looks like a combo between an airline qd connector and a sma.

author: xwarp
author_rank: Frequent Contributor
timestamp: February 20, 2018, 03:13:04 am
content: SMB?

author: kc8ard
author_rank: Contributor
timestamp: February 20, 2018, 05:54:33 pm
content: Aha. That's it. My googlefu was weak. Now all i need are the pinouts for the ocxo Unfortunately I still can't find a datasheet on it.

author: DaJMasta
author_rank: Super Contributor
timestamp: February 20, 2018, 06:47:39 pm
content: Are the service manuals for the analyzer available? You may be able to find the connector for the cable on the board it attaches to and figure out the pinout backwards from there.

author: kc8ard
author_rank: Contributor
timestamp: February 20, 2018, 08:14:23 pm
content: The service manual is available from keysight. The problem is that I don't see a pinout anywhere. I might have missed it. I'll have to look at the manual again, as I only saw a block diagram.

author: kc8ard
author_rank: Contributor
timestamp: February 20, 2018, 09:12:53 pm
content: I got it, header j3, pin1 +15(green), pin2 +5(red), pin3 acom, pin 4 acom(blue), pin 5 test ref, pin 3 and 5 should be jumpered. Now, i just need the pinout for the ocxo. Its a McCoy mc833x4-003w that i picked up on ebay for a song and a dance. I need to find the pinouts so i can throw it on the counter first to see how it compares to my gpsdo.

author: kc8ard
author_rank: Contributor
timestamp: February 20, 2018, 10:02:34 pm
content: I'm a moron lol. I found a picture of the actual unit yesterday. I know the ocxo pinout now.
U1461A Question - Page 1
Forum section: electronics / testgear

author: jonkers
author_rank: Newbie
timestamp: February 19, 2018, 07:49:46 pm
content: Hello all.I am an I&E Tech and am in the need of a new IR tester. I currently have a U1282A and i find the bluetooth connection with my phone super handy.So i was looking at the U1461a but i came across the thread (https://www.eevblog.com/forum/testgear/fluke-289-defective-or-not/msg1424474/#msg1424474) where blueskull was having some issues with firmware bugs and voltage issues.Was wondering if this was an isolated case or if it is an issue with the meter? All of the reviews i have read seem to be very positive.Thanks.
Testing and Review of the TSG-17 RF signal Generator - Page 1
Forum section: electronics / testgear

author: jcrubin
author_rank: Frequent Contributor
timestamp: February 05, 2018, 01:21:35 pm
content: After several requests ive gone and taken a specific look at this piece of test gear that I own to test and review its performance.

author: jcrubin
author_rank: Frequent Contributor
timestamp: February 16, 2018, 01:09:53 pm
content: Adding to this is Harmonic distortion testing off of the HP331A, within the range of that device and signal analysis off of the Hantek in FFT

author: jcrubin
author_rank: Frequent Contributor
timestamp: February 19, 2018, 01:41:26 pm
content: Finally, I compare this device to the Heathkit IG-102 using an HP331 Distortion analyzer
Recommended accessories for first DSO - Page 1
Forum section: electronics / testgear

author: gdombi
author_rank: Contributor
timestamp: February 18, 2018, 07:41:28 am
content: Hi everyone,First time posting to this forum. I recently started this new electronics hobby and it has smitten me badly.Been building things on RPi, Arduino, ESP8266 and ESP32 boards. As long as things worked fine, it was ... easy. However, as I started to add SPI, i2c and Serial interfaces it was becoming harder to troubleshoot when things were not working as expected. Was it the hardware? Was it the software? Both? You get it.So this is how I ended up learning about LAs and oscilloscopes. I narrowed down which ones to get based on the awesome information and lots of opinions I found on this forum. I will soon purchase a Rigol DS1054Z. Seems to hit the sweet spot of cost + feature + "needs" = budget. Now the question:What other accessories should I get for the Rigol DS1054Z? It comes with 4 150 MHz Passive Probes (PVP2150). I'm planning on getting a case to store it when not in use (and for potential moves). Is there anything else that I should consider for my first digital oscilloscope?Thanks for your guidance,Gaston

author: llkiwi2006
author_rank: Regular Contributor
timestamp: February 18, 2018, 07:52:51 am
content: You might want to get a logic analyzer, since the decoding in the ds1054z isn't great. As far as I can tell, it only decodes what's on screen, and doesn't work properly if I'm zoomed too far out.You might also want some micro-grabbers (preferably higher quality ones) if you want to probe multiple ic pins at once. If you get a logic analyzer, they usually come with micro-grabbers.

author: gdombi
author_rank: Contributor
timestamp: February 18, 2018, 08:47:51 pm
content: Great feedback. Yep, I added a Logic Analyzer and a JTAG debugger also to my hobby-toolkit. I will look into micro-grabbers since I had no idea they existed. Read about them and it makes sense in case I need to troubleshoot small things - SMDs.Would something like this work:https://www.tequipment.net/Pomona/72905-0/?v=0(Pomona 72905-0) ? Or thishttps://www.adafruit.com/product/2618?Not sure what is different between them.Thanks,Gaston

author: tautech
author_rank: Super Contributor
timestamp: February 19, 2018, 12:50:52 am
content: These are what most of get and if you can break up a bag with some mates they're not too pricey.https://www.ebay.com/itm/Lot-20-Tektronix-TEK-SMT-KlipChip-Adapter-Mini-Test-Clips-Grabbers-206-0364-01/261474295590?epid=1300248025&hash=item3ce1151f26:g:lPAAAOSw-ldZamqJSometimes there's small lots on the 'bay.They work OK down to SOIC but not smaller.
ds1054z doesn't decode - Page 1
Forum section: electronics / testgear

author: NH-GrizzlyBear
author_rank: Contributor
timestamp: February 16, 2018, 03:15:27 am
content: I'm sorry if this post is in the wrong place on the forum!I purchased the Rigol DS1054Z last year and within 3 weeks applied the "hack" to turn on all the options. At that time, I hadn't tried using any of the I2C or SPI triggering. Well, I think I have a problem with the scope.Recently, I have been learning how to use the I2C and SPI trigger functions. I've followed several youtube videos and I can't seem to get the decoder to work as stated. When I turn on "decode", a green line appears at the bottom of the display. I've selected hex format, but no characters like, "FF 00" etc., are displayed.If I "dehack and then rehack", will this issue be resolved?I would entertain any suggestions as to a fix for this.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: February 16, 2018, 04:01:11 am
content: Can you provide a bit more information please?What firmware revision are you running on the scope? What is your signal source for I2C or SPI? How are you connecting the scope to the signal source? Can you provide a screenshot showing what happens?It is doubtful that relocking and unlocking will resolve your difficulty, whatever it is, so you may as well hold off on that.

author: newbrain
author_rank: Super Contributor
timestamp: February 16, 2018, 02:04:58 pm
content: I have had no major problems with the I2C and SPI decoders, even with less than optimal signal integrity.Quote from: NH-GrizzlyBear on February 16, 2018, 03:15:27 amYou explicitly refer to I2C and SPItriggering, but triggering and decoding are separate and independent settings, are you sure you are setting up the decoder correctly?See chapter 5, pages 5-37 and 5-40 for triggering and chapter 7, pages 7-13, 7-17 for decoding in theuser manual.

author: Fungus
author_rank: Super Contributor
timestamp: February 19, 2018, 07:48:32 am
content: Quote from: NH-GrizzlyBear on February 16, 2018, 03:15:27 amNo.Quote from: NH-GrizzlyBear on February 16, 2018, 03:15:27 amFix for what? There's no information in your post about what the problem is.
R&S UPGR Psophometer - Page 1
Forum section: electronics / testgear

author: Messtechniker
author_rank: Frequent Contributor
timestamp: February 17, 2018, 04:37:23 pm
content: Apparently been bitten by the bug.A R&S UPGR Psophometer is on its way to me.Why? I don't really need it but since I happen to have the full service manual its worth a try.Fault description by the seller: - supply is shorted.But battery case and meter are OK.We will see. If the repair and full calibration goes well I'll be out hunting for an matching audio frequency generatorfrom the same period (ca. 1980) preferably also from R&S. Or from a different European manufacturer.

author: egonotto
author_rank: Super Contributor
timestamp: February 17, 2018, 06:46:59 pm
content: Hi,if it works you can measure how many alcohol you have drunkBest regardsegonotto

author: Messtechniker
author_rank: Frequent Contributor
timestamp: February 18, 2018, 09:05:01 am
content: Well probably not. For details on this seemingly weird term, see here:https://en.wikipedia.org/wiki/Psophometer
I brought  Hantek 6074BE Automotive scope <$200 - Page 1
Forum section: electronics / testgear

author: Dean2
author_rank: Contributor
timestamp: February 17, 2018, 07:16:49 am
content: Hi I brought this 70Mhz 1GSa/s 4 channel Automotive Scopebelow $200 ..Immediately i found some triggering problems..see the video--http://www.fastswf.com/WBhesUoChannel 1 is connected to the Car engine injector via 20:1 attunatorand Channel 2 is connected to the Ignition COP signal from ECU..I cant get the trigger to work..??Also found another issues at 500ms/time..it has data lossand App gets stuck when zooming.. Video --http://www.fastswf.com/V50mteMAnybody with Hantek Please Help me..Thanks in Advance

author: egonotto
author_rank: Super Contributor
timestamp: February 17, 2018, 06:30:41 pm
content: Hi,set trigger to normal mode should work with 20ms/div.But let the scope some time you switch to fast.The software is not very stable, so sometimes is a restart helpful.Best regardsegonotto

author: Dean2
author_rank: Contributor
timestamp: February 17, 2018, 11:58:45 pm
content: Hi It seems you haven't seen my Video properly ..i ask you to watch my video again .. Any help...Thanks..

author: nctnico
author_rank: Super Contributor
timestamp: February 18, 2018, 12:10:42 am
content: Quote from: Dean2 on February 17, 2018, 11:58:45 pmJust return it.

author: Dean2
author_rank: Contributor
timestamp: February 18, 2018, 03:19:44 am
content: Hi i brought it from AliExpress so i started an dispute but they refused it .CROOKED AliExpress
EEVBlog BM235 EOL with 121GW coming? - Page 1
Forum section: electronics / testgear

author: jayjr1105
author_rank: Regular Contributor
timestamp: February 18, 2018, 02:11:30 am
content: I keep seeing small quantities on Amazon and gouged eBay pricing plus all the buzz over the 121GW. I'm just wondering if the BM235 is going to be around for the long run.

author: Brumby
author_rank: Unknown
timestamp: February 18, 2018, 02:38:10 am
content: I don't see why not.Certainly there are more features on the 121GW - but the BM235 isn't a slouch ... and there is a notable difference in price point.

author: jayjr1105
author_rank: Regular Contributor
timestamp: February 18, 2018, 02:45:41 am
content: Thanks. I really want one but don't have the cash for it now but if they were going to fade away and just become hard to find and expensive, I would maybe splurge.

author: Brumby
author_rank: Unknown
timestamp: February 18, 2018, 02:57:50 am
content: I don't believe the BM235 has been around for too long - so it's not as if we are anywhere near EOL from the manufacturer just yet. Also, Dave has exclusive distribution rights for the BM235 in Australia - and his version carries the EEVblog branding, which you won't get from anyone else selling that model.