hybridfree/eevblog-posts huggingface dataset:
HP 33120  confuse explanations?   - Page 1
Forum section: electronics / beginners

author: J4e8a16n
author_rank: Regular Contributor
timestamp: June 01, 2015, 12:47:21 am
content: Hi,The quote comes from:http://www.prc68.com/I/JouleThief.shtml#Fig6QuoteWhy the cal factor leads to 1.17 Volts?Where does comes from this calculation ?QuoteThe period is 36 us.Thanks for your attention.JP

author: dacman
author_rank: Frequent Contributor
timestamp: June 01, 2015, 02:48:01 am
content: 200 mA is expected, 171 mV is the reading. For a cal factor, 200 mA / 171 mV = 1.17 Amps / Volt.To correct the reading to Amps, multiply the scope reading by the correction factor.

author: J4e8a16n
author_rank: Regular Contributor
timestamp: June 02, 2015, 05:58:45 pm
content: Quote from: dacman on June 01, 2015, 02:48:01 amHe does not seem to have a picture of those 171mV on his page. Is this 171mV AC? Or is it the +171mV side of a 342mV AC?Am I dumb?(I know you cant really say yes ;-)JPD

author: J4e8a16n
author_rank: Regular Contributor
timestamp: June 04, 2015, 10:59:51 am
content: Quote from: dacman on June 01, 2015, 02:48:01 amQuoteI agree with you lthough on the page it is writen Volt/Amp... Otherwise we would have V^2/ALater in the pageQuote
HP 3325A adjust - Page 1
Forum section: electronics / beginners

author: hnjmkl
author_rank: Regular Contributor
timestamp: February 18, 2022, 11:37:37 am
content: To calibrate the 3325A, the thermal converter P / N 11050A is required, I ask if you are aware of an alternative method for this calibration step, which is impractical even if you manage to find the thermal converter 0853-0001 from Best Productis.

author: jonpaul
author_rank: Super Contributor
timestamp: February 18, 2022, 08:02:14 pm
content: Use Fluke 8920A True RMS Voltmeter or 8921AJon
HP 3325A error cal1. - Page 1
Forum section: electronics / beginners

author: hnjmkl
author_rank: Regular Contributor
timestamp: April 06, 2022, 03:24:28 pm
content: I have an HP3325A with errors cal1, cal2 and 3 pass, I have the operator-service manual, in which section does it help to investigate the defect?

author: free_electron
author_rank: Super Contributor
timestamp: April 06, 2022, 03:44:58 pm
content: page 8-31

author: hnjmkl
author_rank: Regular Contributor
timestamp: April 07, 2022, 06:24:53 am
content: thank you, found the relevant section

author: hnjmkl
author_rank: Regular Contributor
timestamp: April 11, 2022, 05:26:17 pm
content: After replacing the aborted F3, the 3325A passes the 3 tests without errors. I approached the calibration, at least in amplitude, excluding harmonics and spurious, not having an SA. I performed the D / A Converter Offset, up to punyto "e", after which I was unable to continue, point "f" I cannot execute it, at this point the explanation is not very clear.
HP 3325A power supply cal - Page 1
Forum section: electronics / beginners

author: hnjmkl
author_rank: Regular Contributor
timestamp: January 26, 2022, 09:09:02 pm
content: Service manual downloaded from Agilent is missing page. 5-2 related to power supply calibration, I ask if anyone has it available.

author: wn1fju
author_rank: Frequent Contributor
timestamp: January 26, 2022, 11:02:14 pm
content: You might try downloading the HP 3325B service manual. That has the missing page, although the potentiometer numbering might be slightly different between the A and B models. Between the 3325's procedure description and the 3325A's schematics, you should be able to figure out what to do.If I remember, the power supply is adjusted with one pot to -15V as measured at a test point.

author: SilverSolder
author_rank: Super Contributor
timestamp: January 26, 2022, 11:20:00 pm
content: I recommend purchasing the superbly scanned manual from Artek Media. It is only around $10 or so. All the Artek manuals seem to be super high quality scans - much better than the stuff on the Keysight web site.

author: hnjmkl
author_rank: Regular Contributor
timestamp: January 28, 2022, 08:09:36 am
content: Unfortunately it seems that Artek has only the operational and not the 3325A service available

author: SilverSolder
author_rank: Super Contributor
timestamp: January 28, 2022, 08:28:56 pm
content: Quote from: hnjmkl on January 28, 2022, 08:09:36 amThe manual is entitled "Operating and Service Manual" - it contains everything, including diagrams, troubleshooting steps, etc.

author: hnjmkl
author_rank: Regular Contributor
timestamp: January 29, 2022, 05:51:20 am
content: the search in artekmanuals appears downloadable only operational $ 7.50, the service cod. 90002 not purchasable, I asked for clarification directly to the site, let's see what they answer.

author: hnjmkl
author_rank: Regular Contributor
timestamp: January 29, 2022, 09:56:53 am
content: Problem solved, downloaded full $ 7.50 pdf
HP 3400A RMS Voltmeter Capacitor Replacement Question - Page 1
Forum section: electronics / beginners

author: AddisonAve1938
author_rank: Newbie
timestamp: May 13, 2024, 11:52:41 pm
content: Hello all,I have a HP 3400A and some of the capacitors are leaking electrolytic and with the unit being 60 years old, the capacitors obviously need replaced. Am I able (provided the replacements fit on the boards, etc.) use film capacitors as replacements without issue?

author: Vovk_Z
author_rank: Super Contributor
timestamp: May 14, 2024, 01:56:48 am
content: If you look at those old electrolytes more closely you'll find they have quite large capacitance. At leadt 10 uF or more. It's qute hard, I would even say impossible to replace them with film capacitors (until you don't have infinite space). So, just replace them with new capacitor of an electrolytic type and that's it.

author: factory
author_rank: Super Contributor
timestamp: May 14, 2024, 04:29:31 pm
content: Where are the leaking capacitors, as I can't see any problems in the picture?Those capacitors are usually fine, except for early ones with a cream rubber seal. Also the one wet tantalum type 109D or equivalent used on some chopper boards, they are known to leak & corrode things.The 150D is a solid tant type, with no liquid to leak.I usually check them with an ESR meter and only replace those that are high ESR or have severely dropped in capacitance, whole recapping HP TE of this age is a waste of money.David
HP 3457A Error Address 15 - Page 1
Forum section: electronics / beginners

author: sairfan1
author_rank: Frequent Contributor
timestamp: October 08, 2019, 07:23:34 pm
content: Hi I bought used HP 3457A from ebay when i first time turned it on it displayed "Address 15" on screen and beep once, after that it displayed its normal display where i can measure voltage i did not test anything else, however i turned it off and on again at least 5 times and it does same.I want to know is this error message is something i should be worried about?What other test i should do to understand if its working reasonable good (hobbyist here don't expect a lot)

author: oPossum
author_rank: Super Contributor
timestamp: October 08, 2019, 07:27:10 pm
content: It is telling you what it's GPIB address is. That is normal, not an error.

author: ArthurDent
author_rank: Super Contributor
timestamp: October 08, 2019, 09:43:57 pm
content: You should download the free 369 page operating manual fromhttps://wiki.hive13.org/images/1/1c/HP_3457A_operating_manual.pdfand maybe the 273 page service manual in PDF format fromhttps://doc.xdevs.com/doc/HP_Agilent_Keysight/HP%203457A%20Service.pdfOn page 2-2 of the operating manual and on page 2-4 , section 2-22 , of the service manual it verifies what oPossum just posted about GPIB address.

author: sairfan1
author_rank: Frequent Contributor
timestamp: October 18, 2019, 08:25:20 pm
content: One more question, I learned from different sources, first thing to do with these multi meters is check battery, when i check battery of mine its showing 3.4v and i believe its good,i want to know after how long should i check it again? or Is there any indicator that alerts battery replace is neededif i leave it un-powered for long time, does it impact battery charge?

author: ArthurDent
author_rank: Super Contributor
timestamp: October 18, 2019, 09:17:33 pm
content: The first thing you should do is check to see if it has the usual Schaffner IEC line filter that has an almost 100% failure rate over time. The caps inside explode and make a mess that is hard to clean up.Don't change the battery unless you understand the procedure otherwise you will lose calibration information.https://xdevs.com/doc/Fluke/8842A/img/paffner_1.jpg

author: sairfan1
author_rank: Frequent Contributor
timestamp: October 21, 2019, 02:46:07 pm
content: How should i test it that its workable? Or should i just replace it anyway?

author: Kleinstein
author_rank: Super Contributor
timestamp: October 21, 2019, 03:36:11 pm
content: 3.4 V looks good for a lithium cell. So no need to replace it.For the filter, if it still is the original one, just replace it. There is no easy way to see if the filter is good or one that is expected to release it's magic smoke soon. If it is old (e.g. before 2010 or so) I would replace it. The risk if the filter to blow seems to be highest for the first use after a long time in storage, a little like with electrolytic caps. Still later failure is possible / likely.
HP 3457A PC Software  - Page 1
Forum section: electronics / beginners

author: sairfan1
author_rank: Frequent Contributor
timestamp: March 05, 2021, 02:53:43 pm
content: I have 3457A and i also bought GPIB (clone) for it, I'm looking for some PC integrating software, where i can view change in current in real time and also i can save data for later use/review.I came acrossthispost andthis, i did not receive any response on the first one, this project was done with Python and i do not have any experience in Python that's why i can't get the code and compile myself.Regarding 2nd project it does not support 3457A (though i believe it does 3478A) i downloaded and tried to setup but i was not able to understand this software and looks like not gona work.Looking for help if someone is using some (Windows) PC software for HP 3457A, thanks,

author: enut11
author_rank: Super Contributor
timestamp: March 05, 2021, 06:27:52 pm
content: Contact Canadian Forum member @bud. He helped me with an XL logger for my HP3456A.

author: pwlps
author_rank: Frequent Contributor
timestamp: March 06, 2021, 07:02:09 pm
content: Here is another one:https://www.eevblog.com/forum/metrology/3458a-logging-via-windows-app-revisited/The 3457A appears in the "tested" list.The interface to select will depend on your GPIB board. What kind of "clone" is it ? There is no generic GPIB driver standard on the PC side (except Visa but not sure a clone will be recognized by Visa), different vendors provide different dlls to communicate with the driver (although clones should provide a NI-compatible library such as the gpib32.dll). Is your board compatible with Visa ? Otherwise if you give me the name of the dll(s) installed with the board I can tell you if it is compatible with the software.
HP 3468B question from novice  - Page 1
Forum section: electronics / beginners

author: KO!
author_rank: Newbie
timestamp: February 09, 2020, 05:32:37 am
content: Hello i have just purchased 2x Hp3468B from ebay i have checked resistance DC voltage and AC voltage and all functions are in spec. i have replaced the battery in both of them i used my ps2520G to keep the ROM memory [[ i watched videos on youtube lol]] and all went good i did retest both and all was good for about 2 weeks, i figured i should put them in there new home and when i was done i turned both of them on. both said self test ok but one of them have a C: after the digests so was wondering what this means? thank you for your help and sorry if this is in the wrong place.

author: Le_Bassiste
author_rank: Frequent Contributor
timestamp: February 09, 2020, 09:39:37 am
content: the one having the C after the voltage reading is in CAL mode. simply turn the cal switch off. it is a DIP-switch, located at the rear of the instrument.
HP 3582a Spectrum Analyzer trigger problems  - Page 1
Forum section: electronics / beginners

author: Mike95
author_rank: Newbie
timestamp: August 21, 2019, 05:01:16 pm
content: Hello everybody,I just purchased a HP3582a and I’m having problems with the triggering. The repetitive button will not stay in unless I hold in and when I turn the level dial to the middle position and push the arm button nothing happens unless I nudge the level dial a little. All of the controls are in the start position and I tried playing with the internal/external switch in the back of the unit. This is my first Spectrum Analyzer and don’t know if I’m missing something or this thing is defective. Any and all advice would greatly appreciated!!!Thanks Mike
HP 4192A impedance analyzer beginner help / custom test fixture - Page 1
Forum section: electronics / beginners

author: JesseLackey
author_rank: Newbie
timestamp: July 12, 2020, 05:31:47 am
content: Hello esteemed eevbloggers, I have an HP 4192A that I bought at auction a few months ago, and was recently calibrated and passes self-test, so I'm pretty sure it is working. But - I don't have any test fixtures. I bought one at another auction, but due to covid-related delays it was lost by the seller.I have a project where I need to test the inductance of coils for Qi wireless transfer at 100Khz-150Khz. This beast would be just the thing, except... no test fixture and I don't know how to use it. Looking at a 115-page scanned pdf manual (there seems to be a "long" and a "short" manual, this is the "short" one) page 83 gives a procedure, and page 76 shows the "four terminal pair DUT connections" (see attached pic.) So I made a DIY test fixture with all the shields connected and the Hcur&Hpot connected and the Lpot&Lcur connected, with a little solder post where my DUT will go. See attached pic. (the shields are connected on the underside)Following the procedure outlined, I did a "zero" with the solder posts clamped together, the "display A" set to R/G, and ... it doesn't zero. It remains something like -100 ohms. And it doesn't change when made open again.I'm a little concerned my test fixture is wrong and I've damaged something; more likely the test fixture is wrong and I'm definitely missing the concept here.I've done some googling and eevblog searching and found some discussion but of course everyone has a proper test fixture, and usually the discussion doesn't include much about the test setup / procedure because it is assumed the reader knows it already.If anyone can get me started so that I can do my coil inductance over frequency measurements that'd be greatly appreciated. Really wish there was a youtube tutorial! I'm not going to get high accuracy with this test fixture but it will be useful to compare several coils, at the least.Thanks all/anyone in advance.J

author: Pulsepowerguy
author_rank: Regular Contributor
timestamp: July 13, 2020, 12:33:14 pm
content: The connection as shown is non-optimal, but should not cause damage. As with any 4-wire measurement, the potential leads (inner set) are to be placed as close as possible to the DUT. The source, or current leads (outer set) can be a little bit further away from the DUT but should not be closer to it than the potential leads. Your leads are reasonably short for most measurements. Long leads add enough parasitic L and C to the measurement setup to limit the ability to accurately read small values of L and C.As to the inability to get a zero, I cannot comment - sorry.
HP 54503A OSCILLOSCOPE CIRCUIT DIAGRAM & PARTS LIST - Page 1
Forum section: electronics / beginners

author: markhead
author_rank: Newbie
timestamp: May 02, 2013, 02:18:42 am
content: Hello folks. I have just got myself an HP 54503a oscilloscope, and while there are manuals for this and that, one called "service manual" does not appear to have a diagrammatic or parts list included in it. Appreciate suggestions of where to find one please- I am prepared to pay if required- best effort so far seems to be a dvd available ex ebay for a collection of HP manuals but none of these have that diagram. Appreciate some help please- google isn't working on this one, nor is ebay.com- there is one in ebay.uk called 54502a and I have just bought that one even though its called service manual I doubt if there is a diagram inside it. There are diagrams for lots of other hp products, but not this one- seems weird to me. Cheers. Mark

author: amyk
author_rank: Super Contributor
timestamp: May 02, 2013, 09:37:38 am
content: The 54500 series doesn't seem to have schematics available. Maybe they were never published.You could try askingHPAgilent...

author: free_electron
author_rank: Super Contributor
timestamp: May 02, 2013, 04:28:10 pm
content: Look for the CLIP. Component Level Information Package.I believe it exists for these machines.-edit-. Bummer its for 54600 series.The way that stuff works is as follows: for newer machines they don't publish this as they are board swaps. The smd and custom asics make it very difficult to repair. There is an exception : if a machine was sold to the military then the manual does exist as it is mandated by the military ....For some out of production machines that were heavily popular they also release it. These are called the CLIP. Google for that term ( use the full string component level information package) and they pop up.

author: Unknown
author_rank: Unknown
timestamp: May 02, 2013, 09:31:02 pm
content: This is not what your looking for, it's a user manual, but it's free... the down-load is 12Mg...http://bama.edebris.com/manuals/hp/54503a/Also found this site, with five HP 54503a volumes:http://auctions.findtarget.com/detail_product/370222555324/hp_54503a/Haven't looked through EEV site archive directly, but the URL is about problems with this scope:https://www.eevblog.com/forum/chat/is-this-scope-repairable/Otherwise, it seems any service-circuit information is unavailable !
hp 54503a calibration - Page 1
Forum section: electronics / beginners

author: m3vuv
author_rank: Super Contributor
timestamp: January 08, 2022, 10:45:04 am
content: Hi all,a few weeks ago i did a full recap on the psu on this,in the manual it states set the 5v rail to 5.2v with a 2 ohm load on the rail,at the time i didnt have suitable power resistors at 2watt,so i didnt bother,just put the psu back in the scope and did a self cal,i noticed the volt readings were about 30% off measuring the cal output from another scope,cant remember if it was high or low!,some time later i decided to look at it agine when the resistors arrived,so into a 2 ohm load the rail measured about 5.9v,i adjusted it as per service manual to 5.2v,this resulted in the readings now about 50% off,so i did a recal with the rail set correctly and it reads fine now,would doing a self cal with the rail to high of caused this error,it works fine now but just wondered,i assume on a 5v square wave signal i measure from the halfway,ie centerline point and not top to bottom ie peak to peak?
hp 54503a oscilloscope x/y mode - Page 1
Forum section: electronics / beginners

author: m3vuv
author_rank: Super Contributor
timestamp: December 07, 2021, 12:10:43 pm
content: Hi is it possible to get a hp 54503a oscilloscope into xy mode?,if so how the hell do you do it??,tia de m3vuv.

author: george.b
author_rank: Frequent Contributor
timestamp: December 07, 2021, 01:59:47 pm
content: According to the manual,https://bama.edebris.com/download/hp/54503a/54503A%20User.pdf, page 9-3, it should be under the "Waveform Math" menu, "vs" operator (as in plotting one channel versus the other).
hp 54503a scope frequency measurements - Page 1
Forum section: electronics / beginners

author: m3vuv
author_rank: Super Contributor
timestamp: December 09, 2021, 01:21:40 pm
content: i am trying to measure a frequency on my scope,i have a nanovna as the source and a altai te-20D sig gen,if i set them both too approx 145mhz the scope reads about 25mhz after setting the markers from waveform peak to peak on the time markers,can anyone explaine this?,the scope self cals ok and passes all selftests!.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: December 09, 2021, 05:20:33 pm
content: I do not have your scope. I use an Agilent 54810.Have you tried to use the Lo filters?Does the scope correctly read the scope's own square wave generator?

author: m3vuv
author_rank: Super Contributor
timestamp: December 09, 2021, 06:16:57 pm
content: yes i tried the filters,i wonder if it just is measuring ,the fundamental frequency as bot the vna and sig get rely on the harmonics?

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: December 09, 2021, 07:25:14 pm
content: Maybe, figgure out how the wave should appear on the screen, how many grid markers should it have on a particular scale and compare that to the measured freq.
HP 54601A vs RIGOL DS1062CA - Page 1
Forum section: electronics / beginners

author: mateuszrjzr
author_rank: Newbie
timestamp: May 04, 2013, 02:10:33 pm
content: Hello.I'm buying used oscilloscope, and i don't know wchich i should choose. HP has better parameters, four channels, 100MHz and so on, but Rigol is younger, has connection to PC and more opcions (i think). I'm not that begginer and i will use this stuff for a long time, becouse for me it is well... expensive. Wchich do you recommends?

author: tinhead
author_rank: Super Contributor
timestamp: May 04, 2013, 02:27:08 pm
content: take RIGOL DS1062CA, there is not a single reason why you should choose 54601A instead of RIGOL DS1062CA

author: Hydrawerk
author_rank: Super Contributor
timestamp: May 04, 2013, 02:28:26 pm
content: HP 54601A is too old design from the very early 1990's. Buy it only if it's very very cheap. It's very similar to 54600B. Please check attached datasheet. It has too short memory, 20Ms/s ADC and WTF 2MHz single shot bandwidth.Buy the HP 54601A only if you-need cursors in XY mode-will use it only for periodic signals-plan to buy a better scope in future.Well, compare datasheets of these two scopes and see what you prefer.

author: Hydrawerk
author_rank: Super Contributor
timestamp: May 04, 2013, 02:37:19 pm
content: Quote from: tinhead on May 04, 2013, 02:27:08 pmWell, these were expensive and good scopes in 1990's. I would buy it for $40 or cheaper... These scopes are pleasant to use, we use them at my university...I don't like much the front panel of Rigol DS1062CA, but it has definitely better ADCs and longer memory. 2×1GS/s is standard in these days.

author: mateuszrjzr
author_rank: Newbie
timestamp: May 04, 2013, 07:01:25 pm
content: Thanks guys. I just found Tektronix TDS220. It seems to be similar to rigol. It is up to 100MHz, not 60. I couldn't findany info about memory in tektronix.

author: Hydrawerk
author_rank: Super Contributor
timestamp: May 04, 2013, 07:11:28 pm
content: Another obsolete scope from 1996 or so, but it has 1Gs/s per channel. Memory is 2500 points per channel, not much really.http://www.tek.com/datasheet/digital-storage-oscilloscopes-3

author: Unknown
author_rank: Unknown
timestamp: May 04, 2013, 07:11:42 pm
content: 2.5 kpoints per channel. Decent sampling rate, but not much memory. Not that the DS1062CA has much more, from what I recall. A usable scope in my opinion, but no competition for the more modern scopes like the Rigol DS1052E.

author: mateuszrjzr
author_rank: Newbie
timestamp: May 04, 2013, 07:53:58 pm
content: Thaks you guys so much. If not you, i would buy this HPand then(always wanted to use this emoticon)

author: Hydrawerk
author_rank: Super Contributor
timestamp: May 04, 2013, 08:41:59 pm
content: DS1062CA has record Length 10k samples for single channel, 5k samples for each channel. Not very good.

author: ddavidebor
author_rank: Super Contributor
timestamp: May 04, 2013, 09:40:44 pm
content: Quote from: mateuszrjzr on May 04, 2013, 07:53:58 pmOk, consider that you probably MUST replace the main filter.Less than 10$ on aliexpress, or 45$ original ones.
HP 6024a inop - Page 1
Forum section: electronics / beginners

author: jrh69ca
author_rank: Newbie
timestamp: February 08, 2024, 07:55:46 pm
content: Hi All: I have an HP 6024a power supply that I did a bone head thing shorting the two leads. Now there's no output. I've looked inside & don't see any obvious damaged parts. Any suggestions where start troubleshooting would be appreciated. Does anyone have access to a schematic or troubleshooting documents?Thanks in advance

author: Stray Electron
author_rank: Super Contributor
timestamp: February 09, 2024, 02:27:10 am
content: I didn't read all of it but there is already a repair thread about that model on here <https://www.eevblog.com/forum/reviews/hp-6024a-bench-supply-magic-smoke/>.I've never used that model but I have used a lot of HP PSs and they've all been well robust and well protected internally.

author: jrh69ca
author_rank: Newbie
timestamp: February 14, 2024, 04:33:32 pm
content: Thank you, I'll check it out...
Hp 6253a -40 volts DC - Page 1
Forum section: electronics / beginners

author: Johnny10
author_rank: Frequent Contributor
timestamp: December 05, 2015, 03:53:23 pm
content: Need -40 volts DCI am not sure I am clear on Power Supply series connections.On a HP 6253A can I get a -40 volt output.I can get +20 -20 and +40 but can I get -40I do have two separate HP 6253A units.

author: jeroen79
author_rank: Frequent Contributor
timestamp: December 05, 2015, 04:55:28 pm
content: A brief search for HP6253A shows a dual 20V 3A powersupply.Just connect it like this:NegA / PosA---NegB / PosB---GNDThen NegA will be at -40V relative to GND.
HP 6543A, voltage set knob issue - Page 1
Forum section: electronics / beginners

author: sairfan1
author_rank: Frequent Contributor
timestamp: May 07, 2019, 05:47:20 pm
content: Hi, I recently bought HP 6543A from ebay and received it yesterday,its voltage knob is shaky though it works, i was worried if this is something i should inform seller or i can easily fix it.thanks,

author: Berni
author_rank: Super Contributor
timestamp: May 07, 2019, 05:54:01 pm
content: Its a known issue with the encoders used in these:https://www.eevblog.com/forum/testgear/agilent-66332a-dynamic-dc-source-20v5a-repair-and-mods/msg950542/#msg950542It probably happens if the knob gets too much of a knock from the side, but the way that the encoder is built, the top of it just falls off and they can usually be put back together.

author: sairfan1
author_rank: Frequent Contributor
timestamp: May 07, 2019, 08:45:56 pm
content: what do you think in long run can it stop working? or its just a shaky knob but will work good.thanks

author: Berni
author_rank: Super Contributor
timestamp: May 08, 2019, 05:04:57 am
content: No idea. I never tried to open the encoder up to see how its made inside (In fear of possibly not being able to put it back together), so i just attached the top back down to the body and called it fixed.Im guessing trough continued knob wobbling the encoder might become even looser and stop working at some point.These HP rack mount PSUs all tend to be very easy to take apart, so you don't have to worry about opening it up, service manual probably also shows you exactly how to get to the front panel PCB. If anything its worth cleaning out the dust inside.

author: sairfan1
author_rank: Frequent Contributor
timestamp: May 13, 2019, 10:31:12 pm
content: I'm further trying to learn this unit,What is CV (constant voltage) CC (constant current) and how do we switch between, just wanted to learn in what case we need these functions.thanks,

author: Berni
author_rank: Super Contributor
timestamp: May 14, 2019, 04:45:21 am
content: Works the same as on every other lab power supply out there. The lower of the two limits is used. You might want to check Youtube for tutorials on how to use general purpose lab supplies if you don't know about these.

author: sairfan1
author_rank: Frequent Contributor
timestamp: May 14, 2019, 02:29:41 pm
content: I checked youtube and general google unfortunately did not find resources how to use these power supplies (6543A) and what are the common functions to use.

author: Berni
author_rank: Super Contributor
timestamp: May 14, 2019, 03:23:17 pm
content: I meant google how to use ANY lab power supply. This is basic functionality that all such power supplies have in some way.The only more specific features on this particular HP supply are the "OCP" and "OV" buttons that provide over current and over voltage protection, this instantly disables the output if any of them are exceeded. How to use and test those is included in Chapter 5 "Front Panel Operation" of the user manual:https://literature.cdn.keysight.com/litweb/pdf/5959-3374.pdf?id=1000000421-1:epsg:man
HP 6920B capacitor question. - Page 1
Forum section: electronics / beginners

author: Crambone
author_rank: Frequent Contributor
timestamp: November 04, 2023, 11:41:23 pm
content: I acquired an HP 6920b for free and was told it was working prior to recap of electrolytic, again if ain’t broke why fix?After it was recapped it no longer worked and he just gave up and gave away so now I am going to take a stab at it.First I looked at the caps (good Nichicon type) and checked solder job and they look really nice. I then wanted to check type of cap used compared to original. I found he must have mistakenly replaced some film caps that kind of look like electrolytic with electrolytic so I believe I may have found at least the beginning to an issue. I pulled up an old picture online from someone that posted an original board showing the original caps and orientation and compared to what I’m seeing on the unit I acquired. The electrolytic are all installed in proper polarity so I’m guessing just the film caps need to be replaced. Since he didn’t hold onto the originals my question is can I use modern caps and what’s my best choice for replacement type, all axial.http://hparchive.com/Manuals/HP-6920B-Manual.pdf

author: Xena E
author_rank: Frequent Contributor
timestamp: November 05, 2023, 12:10:40 am
content: I'm guessing that the non electrolytics that were changed in error were Sprague 56289s, they were metallised paper/plastic film types and could most suitably be replaced with a polyester film type of the same voltage as indicated in the bill of parts, they wouldn't have to be tubular types, I have used the ubiquitous radial "orange drops" before, though Vishay "yellow peril" tubular axial types are also good. There is one Arco type in there also, that I think would have to be a close tolerance polystyrene film, (marked 510pF).

author: Crambone
author_rank: Frequent Contributor
timestamp: November 05, 2023, 12:53:28 am
content: Excellent thank you

author: Crambone
author_rank: Frequent Contributor
timestamp: November 05, 2023, 09:54:31 pm
content: Made some progress today and repaired cap issue. Unit now powers up and most all functions are working. AC mode works in all ranges but needs calibration, DC mode works in all ranges with the exception of the 100V range. I decided to remove the switches and carefully clean all the contacts, check that no fingers are broken or not making contact also looked for any loose wires.The cleaning took some time but went well with no success the 100V DC still isn’t working. I should have mentioned when in DC 100V range I do hear a humm but haven’t been able to identify from where it’s coming from. I don’t want to keep it active for too long and potentially cause further issues.I’m having a hard time following the schematic and the path of the 100V DC range.Any suggestions on where to concentrate my efforts would be appreciated.
HP 8563A options 026 and/or H36 - Page 1
Forum section: electronics / beginners

author: ytterligare
author_rank: Regular Contributor
timestamp: June 18, 2021, 01:26:21 pm
content: I'm in the market for a good used one 8563A capable of working up to 26.5 Ghz, and I came across some with the two option in the subject which seem to be similar and rather confusing to me.On a well known site selling refurbished material the explanation is :H36 : up to 26.5 GHz026 : extended frequency coverage to 26.5GHzThere are some unit listed that even have both present at the same time..!!Can someone shed some light on the matter ?Tnx !A.

author: thorswait
author_rank: Contributor
timestamp: December 07, 2021, 06:22:27 pm
content: For what its worth you may experiment with your unit by adding one or the other ... You can add options to your spectrum by simply hacking in the U506 eprom adding the options according to this topic.https://groups.io/g/HP-Agilent-Keysight-equipment/topic/24792332?p=Created,,,20,2,0,0I've done it with a 22GHz model to "upgrade" it to 26.5 GHz by adding the 026 options and it is working pretty well after a calibration and some Yig and YTF adjustment.
HP 8601 Sweep Generator Drifting  - Page 1
Forum section: electronics / beginners

author: Cknob
author_rank: Newbie
timestamp: September 28, 2025, 09:38:08 pm
content: Hi all. Just getting started here. Have been working on vintage vacuum tube TVs from the late 1940s and early 1950s. I have some vintage test equipment I use and have been using the HP combo of the 8600 Digital Marker and the 8601 Sweep Generator with success. However the sweeper has developed an issue of drifting off the center frequency by a significant amount..2-3 MHz off the 21.25 MHz frequency I use as the CW. It’s fine for about an hour but then drifts. If I turn it off and immediately back on it’s dead on frequency again. Then it drifts off in a considerably shorter time frame. Any suggestions as to where I should start looking?

author: ahsrabrifat
author_rank: Regular Contributor
timestamp: September 29, 2025, 03:53:39 pm
content: Monitor the DC supply rails with a good DMM as the drift develops. If you see any sag, ripple, or slow wander, recap or check the regulator transistors.

author: Cknob
author_rank: Newbie
timestamp: September 29, 2025, 08:19:47 pm
content: Ok I’ll take a look at that. By the way this is my third HP 8601 to have developed issues over the last 2 years. I have not enjoyed the supposed reliability of HP equipment from this era.
HP 8753B VNA "Error: ADR and Error:INST" then stuck at "initializing instrument" - Page 1
Forum section: electronics / beginners

author: mike3177
author_rank: Contributor
timestamp: July 16, 2016, 01:43:02 am
content: Anyone know what these errors mean? I get them immediately upon turning on the unit.I looked in the manual but it just says to contact a technician if you get an error at startup.The weird thing is I took the cover off and blew some dust out, and tested a couple of fuses and resistors with a multimeter. After doing this, I plugged it in and it turned right on and initialized with no errors. I turned it off and on a couple of times and there were no problems.Then I turned it off, connected an S parameter test set to the unit and turned it back on only to get the errors again. Disconnecting the test set has had no effect on the errors.

author: Brumby
author_rank: Unknown
timestamp: July 16, 2016, 02:54:14 am
content: I wouldn't be worrying about the error messages as such. Sounds like you have an intermittent.My guess is, whatever you disturbed in your clean and check is where the intermittent will be found. Fixing it could be as simple as removing and re-plugging a connector to clean the contacts or resoldering a cracked solder joint.After that, the "intermittent games" begin.
HP 8753C Zero Span vs. CW Time Sweep - Page 1
Forum section: electronics / beginners

author: BrumsiSol
author_rank: Newbie
timestamp: March 12, 2021, 12:43:51 pm
content: Hello together,for my master's thesis I need to make some time measurements with a HP8753C. To do so I have 2 Options:1. CW Time Sweep2. Zero SpanParameters:- Carrier Frequency: 1 GHz- Modulation Frequency: 50 HzMy expectations: For both modes I would expect to see one sine period if I set the Sweep Time to 20 ms.Reality:In the 1st Option (CW Time Sweep) I see exactly what I thought but in the Zero Span mode I don't:Option 1:" alt="" class="bbc_img" />Option 2:" alt="" class="bbc_img" />Settings:For both Options I have the same settings:- RBW = 3 kHz- Number of Sweep Points = 11- Sweep Time 0.02sObservation:As this didn't make sence to me I startet a test series where i adapted those parameters. What I saw was that the number of displayed sine waves stays the same for adjustment of RBW and Number of Sweep Points in CW Time Sweep (makes sense to me), but they change in Zero Span (doesn't make sense to me). Here is the Zero Span test list where the yellow cells are the parameters I changed for this measurement." alt="" class="bbc_img" />To me the outcomes do not make sense at all. I don't see a pattern and do not get how there can be more than one wave displayed for a time shorter than the period.So I am looking forward to your answers

author: bob91343
author_rank: Super Contributor
timestamp: March 12, 2021, 06:35:27 pm
content: I would agree that zero span should be the same as CW. Having said that, it may be that zero span actually has some residual modulation while CW doesn't. I can't read the legends on your pictures nor understand your table so I can't comment further.

author: rfclown
author_rank: Frequent Contributor
timestamp: March 13, 2021, 01:16:13 am
content: Read the manual.CW Time Sweep (Seconds)The CW TIME softkey turns on a sweep mode similar to an oscilloscope. The analyzer is set to asingle frequency, and the data is displayed versus time. The frequency of the CW time sweep isset with CW FREQ in the stimulus menu. In this sweep mode, the data is continuously sampledat precise, uniform time intervals determined by the sweep time and the number of pointsminus 1. The entered sweep time may be automatically changed if it is less than the minimumrequired for the current instrument configuration.this is the mode you want since it describes what you are trying to do. Don't assume what you think the instrument will do when you set the span to zero in the frequency sweep mode.
HP Blade 50 volt server power supply connector questions. - Page 1
Forum section: electronics / beginners

author: Chris Wilson
author_rank: Super Contributor
timestamp: May 24, 2013, 04:05:43 pm
content: I have just bought an HP 3000 Watt (48 volts at 57 Amp) Blade typeserver PSU off Ebay here in the UK. It's for a semiconductor linearamplifier project I wish to build.Has anyone found a good means of connecting cabling to thespecial blade input and output connectors on these hotswappable supplies? Or a source for the correct connectors that mighttake a cable? Thanks.

author: metalphreak
author_rank: Frequent Contributor
timestamp: May 25, 2013, 12:36:42 pm
content: If it's one of those ones where it's just a bit of PCB sticking out with contact areas on the top and bottom, you could possibly use an edge connector (plenty of cheap ones on ebay etc).You would have to find one's of the correct size, and those server supplies don't always have a standard width that matches to any edge connector (which are typically multiples of ~4mm).Molex do some:http://www.molex.com/molex/products/family?key=extreme_poweredge_&channel=products&chanName=family&pageTitle=Introduction&parentKey=edge_card_connectorsIf you get lucky, you might find the correct one that HP has used
HP double half-rack mounting hooks and rear tab - Page 1
Forum section: electronics / beginners

author: JeepinBoone
author_rank: Newbie
timestamp: March 04, 2023, 01:01:22 am
content: I'm looking for the part number and appropriate name(s) for the hooks and tab used to mount two HP test modules such as two HP 3478A meters together to fit into a standard 19" rack. I saw these hooks and rear bracket in a YT video way back (I can't remember which video) that had two modules fastened together with front hooks and a rear screw on tab and now have a need for them. 2U is the size. Yes I left a message on that video and no I've gotten no response.

author: Tony_G
author_rank: Super Contributor
timestamp: March 04, 2023, 01:06:36 am
content: Here you go -https://www.eevblog.com/forum/testgear/hpagilent-half-width-rack-mounted-middle-bracket/I've used these and they're actually quite good - Not sure they're worth the money per se but the do a good job of turning two half-width units into a single rack width. Here is the link to the US Keysight store -https://www.keysight.com/us/en/ecom/parts/part-detail.html/5061-9694- I got mine as left over components when I got 2nd hand gear so I didn't buy the actual kit from Keysight.TonyG

author: jonpaul
author_rank: Super Contributor
timestamp: March 04, 2023, 02:40:44 am
content: may have one NIB PM me if interestedLike to swap or trade, am in USAj

author: JeepinBoone
author_rank: Newbie
timestamp: March 04, 2023, 03:32:47 am
content: Yea that's an insane price for what it is. I can punch that part out in under 3 minutes for cost of materials (<$5). I gotta lead on an OEM set. Fingers crossed.

author: JeepinBoone
author_rank: Newbie
timestamp: March 05, 2023, 12:36:21 am
content: Thank you all for your help!!! If you don't know the name or part #, searching does no good. The name of the part from HP is Lock Link and the part # is 5061-9694. This connects half rack and quarter rack gear together to build one rack width.
HP DSP-1400CB-A (P/N 733428-101) - Page 1
Forum section: electronics / beginners

author: AdyB
author_rank: Newbie
timestamp: March 21, 2022, 05:45:11 pm
content: Hi all and thank you for this wonderful place called EEVblog.I come to you for help and advice. I have bought a HP DSP 1400CB-A server power supply and I am really happy with it. It is very small, really powerful, can take a lot of abuse and also very cheap especial in UK and in current times (2022, CoVID, chip shortage).I have manage to power it up and also to increase the output voltage above 14.0V but at 14.08V the over-voltage protection kicks in and it powers off. Also at 14.0V with load on output it powers off.I have been looking every were on the logic board but I can not find anything that might look like a voltage divider of something like a over-voltage protection. Also I couldn't find no dedicate IC for over-voltage, over-current protection. I have manage to identify some of the IC's but nothing points me in the right direction. Most of the IC's are from Texas Instruments.Can someone with a lot more experience please help me out in this challenge?Thank you!

author: AdyB
author_rank: Newbie
timestamp: March 21, 2022, 06:03:42 pm
content: Hi,The IC's on the logic board are:Microchip dsPIC33FJOPA4171ST 340AUCC3895393REC, I could not find any data sheet for it.UCD3138AG6AP FDS4435BZRegards,Adrian

author: AdyB
author_rank: Newbie
timestamp: March 22, 2022, 08:38:18 pm
content: Hi all,Is it possible for an opamp to be used as an over-voltage protection?I’m still trying to figure it out but most of the IC’s around the trimpot responsible with voltage adjustment are opamps in one form or another.Regards,Adrian
HP E3611a power supply display question  - Page 1
Forum section: electronics / beginners

author: RichardM
author_rank: Frequent Contributor
timestamp: October 27, 2019, 08:15:32 am
content: Hi allI purchased this power supply off eBay as is and had to replace some of the capacitors and now it appears to function correctly except for two things1. It is low to ramp down voltage on switch off and the led display suggests it overshoots the set voltage at power on (not the case ?, see 2). At startup the display can be as much as 1.5v out at 12v and takes a few minutes before the led display drops to 0.5v above 12v. All the time my 5 1/2 dmm reports bang on 12v the whole time.2. The led display does not display the actual voltage output at the terminals. I have run through the voltage calibration and adjusted the pot on the display board at max voltage but the led is out about 0.3v at 3.3v and 0.5v at 12v etcI have checked quite a few voltages across the circuit board and the 5v, +12v and -12v values are bang on. Could it be the ten turn pot on the front panel ? Or the display circuit board ? Any suggestions appreciated.CheersRichard
HP E3630A Vs Rigol DP 832 - Page 1
Forum section: electronics / beginners

author: Gp!
author_rank: Contributor
timestamp: May 04, 2018, 01:45:32 pm
content: Hi,fishing for some expert advice.I am slowly adding pieces to my beginners lab and I've sort of stumbled on the PS.A bit undecided on the two as the HP is old but at a better price (always enticing) and the Rigol speaks for itself.I double if I'll ever need anything better so both would more than sufficient and basically would be a 'buy once and for all' situation, so I didn't want to get anything too shabby.The HP has been recently calibrated and is going for about €350 against the Rigol for €511 (the dilemma is evident).Thanks for any thoughts !

author: Nitrousoxide
author_rank: Regular Contributor
timestamp: May 04, 2018, 02:33:13 pm
content: Talking from personal experience here. I own the Rigol DP832, upgraded with software license keys.For general purpose lab work, i.e. dual supply analog circuitry, I have never found the need to use any of its advanced features.It comes down to what you do daily, or what you might need the power supply for (what kind of work). For example, LXI may be essential for automation.Besides that, specifications and user interface. One major thing I noticed, the dual supply rails can only source 500mA (For example, I ran a fan off the positive rail an this would not be enough current).The price of the HP unit seems more enticing. (Keep in mind the Rigol unit is new)

author: Gp!
author_rank: Contributor
timestamp: May 04, 2018, 07:17:48 pm
content: Double thanks !This is what I was exactly looking for.The whole dilemma is just that the price of the calibrated HP or the new tech which will probably give me more flexibility in the future...mmmhhhh food for thought.Thanks again
Hp Nixie Tube Electronic counters ideas - Page 1
Forum section: electronics / beginners

author: primegaps
author_rank: Contributor
timestamp: November 29, 2017, 09:03:08 am
content: So I've been able to grab a few of these, 5 actually. I have had a freakish fascination with nixie stuff ever since i first saw it, so this was somewhat of a holy grail find for me. I have never actually owned any other nixie tube stuff, although I have a small collection of new and used nixie tubes.I have always really really wanted a nixie multi meter, or volt meter at least.Do you guys have any ideas as to what I could do with these 5 devices? I would be open to the idea of opening these up, although i would like to save at least one, just to look at the numbers chooch.I have some electronics experience from 5 years of engineering school, but I have not ever messed around with these type of high voltage electronics. I would like to have a go at restoring one, even though they seem to work fine.What would you do? I would love to learn how to mess around with these higher voltage electronics.Thanks!

author: bd139
author_rank: Super Contributor
timestamp: November 29, 2017, 09:06:50 am
content: They've only got one HT line, about 170v. It's enough to wake you up but not kill you (disclaimer: you might be unlucky). No capacitors to hold that voltage usually either so they are quite safe to work on. Usually all you need to do is clean, clean and clean. Service manual will contain all the info you need on testing and calibration.Restoration is a good plan for these. They are lovely bits of kit. I'd like one myself but they don't appear this side of the pond that often if ever.I'm sure someone will say to build a clock or something and you probably can do that non-destructively by just hooking into the gate and count lines in the device with a microcontroller or something.

author: dzarren
author_rank: Contributor
timestamp: December 03, 2017, 02:19:45 am
content: What is a HT line? I will restore a few of these then. Two of them work flawless, and the other three have at least 1 somewhat busted tube. I have enough tubes to do something interesting, the clock project seems cool, and I have a few arduinos i have been wanting to use as well.

author: bd139
author_rank: Super Contributor
timestamp: December 03, 2017, 09:22:23 am
content: High tension. There’s a voltage applied to the Nixie tubes around the 170V mark. It’s enough to wake you up unpleasantly if you touch itThe rest of it is all low voltage.