HP 547a current tracer - Page 1
Forum section: electronics / general

author: Shock
author_rank: Super Contributor
timestamp: March 20, 2014, 12:49:02 pm
content: Just picked up an HP 547a current tracer. Has anyone got one of these?I tested it on a bad circuit and quickly found which IC's were operating in seconds, amazing for 40 year old technology.Quite fun to play with, I might make a little PCB for test conditions at some stage.I'm also looking for a nice clear scan of the service manuals if anyone has them.Not my video, but for those that don't know what it does:

author: PaulAm
author_rank: Frequent Contributor
timestamp: March 20, 2014, 07:24:13 pm
content: I have one. I use it along with the 546a logic pulser to find shorted tants on power rails. Normally takes me longer to get everything set up than to identify the shorted cap.There's also a 545a logic probe to complete the set, but I think that's the least useful of three.BTW, if you go to agilent.com and put in 547a in the search box, it will get you to a scanned manual. The quality isn't the best, but it's readable. There's also an app note on using it.

author: Kilroy
author_rank: Regular Contributor
timestamp: March 21, 2014, 03:48:54 am
content: Excellent tool, especially when used in conjunction with a pulser.

author: TerraHertz
author_rank: Super Contributor
timestamp: March 21, 2014, 05:04:24 am
content: I have one. They are nice, huh?Isn't the picture of the manual yours? I have the small manuals for all the other HP probes in my pic below, except the 547A. It's on my list to buy the next time I'm doing a manuals fetch. The other ones of those little manuals all include the schematics, so I'd think the 547A one does too.

author: Shock
author_rank: Super Contributor
timestamp: March 21, 2014, 09:09:57 am
content: Is there any point in getting the HP 10525T over the HP 545A? Whats the difference?I have all 3 of the second set 545a, 546a and now a 547a, plus the comparator and other misc accessories in pristine condition.No paper manuals, I don't want the paper versions permanently either as I'm in the middle of going totally electronic.I could clean these up but they are in desperate need of being redone, the 545a is shocking.Is anyone interested in, or has access to a scanner to make some better/decent scans of these manuals in particular?I have a nice scanner, others are probably interested in a good set as well, probably even HP by the looks of itQuote from: TerraHertz on March 21, 2014, 05:04:24 amUnfortunately no, but if I did it would have been your lucky day.

author: TerraHertz
author_rank: Super Contributor
timestamp: March 21, 2014, 02:23:44 pm
content: Quote from: Shock on March 21, 2014, 09:09:57 amNo. The 10525T is older, uses a filament light bulb. That's just in that set because I collect old logic analysis tools.(Edit: for eg see pic below)QuoteA lot of the scanned HP manuals on Agilent's site are so bad I decided there has to be some kind of vindictive/sadistic motivation going on there.QuoteThere's a long list of paper manuals I have, that I plan to scan. These ones are on the list, once I get a 547A manual (which is easy.)But it will be a while before before I get to them. There are a few real unobtainium manuals I got recently, that I want to do first.Also, you'll hate me, but I refuse to package them as pdfs. I use html+images, zipped up and bundled in a RARbook.An unbundled example here:http://everist.org/archives/scans/Boonton_Q_Standard/and bundled ones:http://everist.org/archives/scans/RAR-books/Whether it's wise to go all electronic with manuals - that's another question. For myself I choose not to. If I can't find a paper copy I'll use whatever electronic form I can find. But there are many drawbacks to electronic documents. Some intrinsic, some due to almost universally crappy quality of scanning and compression, or the immature viewing tools, and some more abstract reasons to do with trust and dependability over the long term.

author: Shock
author_rank: Super Contributor
timestamp: March 21, 2014, 11:37:29 pm
content: Quote from: TerraHertz on March 21, 2014, 02:23:44 pmGood idea with the rar books and that works for me as well as I can easily create a pdf from your images (or leave them as is).I only use pdf because of convenience. The format is about 25 years old now so I don't see them as going anywhere anytime soon.I know I can always rip images out of them again if I have to. But yeah I'm techy so I know the benefits of keeping them in a somewhat original scanned format.But really why I'm doing it is convenience and space, I can access them anywhere and don't have to pull anything off the shelf. Recently I just got rid of two book shelves full of paper.As long as you have a data backup strategy then keeping electronic manuals is no problem.Good idea to use a system that can check file integrity. Cloud storage could be a good "just in case" option as well.But part of going electronic is the more people that do it the easier it is for everyone, rather than what is happening now.If your happy to share, let me know when you get them done I'll grab a copy and admire your handy work.

author: TerraHertz
author_rank: Super Contributor
timestamp: April 01, 2014, 02:10:51 am
content: Quote from: Shock on March 21, 2014, 11:37:29 pmBump to say, I bought a HP 547a manual. It's in the US post to my US reshipper, where it will sit for a while as I buy some other stuff for consolidation in one package to ship to Oz. Slowly...

author: notsob
author_rank: Frequent Contributor
timestamp: April 01, 2014, 06:41:49 am
content: just had a search and found my original 545A, 546A and 547A manuals, let me know what you need

author: Shock
author_rank: Super Contributor
timestamp: April 01, 2014, 09:21:23 am
content: Thanks for the replies guys.Notsob, TerraHertz may be able to sort me out. I'm just after some decent quality scans of the manuals as the HP ones are pretty poor.

author: notsob
author_rank: Frequent Contributor
timestamp: April 08, 2014, 04:24:11 am
content: For those who want them these are basic 300dpi manual scans - but definitely better than the crappy ones at HPhttp://www.megafileupload.com/en/file/516646/545A-Logic-Probe---300dpi-rar.htmlhttp://www.megafileupload.com/en/file/516647/547a-Current-Tracer---300dpi-rar.htmlhttp://www.megafileupload.com/en/file/516648/546A-Logic-Pulser---300dpi-rar.html

author: TerraHertz
author_rank: Super Contributor
timestamp: October 21, 2014, 11:28:49 am
content: Here's the 547a schematic anyway, nice and crisp.As often happens, I got sidetracked before I finished bundling the rest of the manual into one file.Edit: Hmm, you have to click on the image link under the pic, to get the full size file. 348KB.

author: Shock
author_rank: Super Contributor
timestamp: October 21, 2014, 11:51:52 am
content: Thanks, have thrown it in with the scans so far.

author: free_electron
author_rank: Super Contributor
timestamp: October 21, 2014, 02:17:14 pm
content: i have the paper manuals. not replicas but the real ones. i can scan em at any resolution you want.i use the current tracer in combination with the pulser quite often. short in a power rail ? pulser on it and sniff where the bulk of the current goes ... typically shot tantalums.

author: krivx
author_rank: Frequent Contributor
timestamp: October 21, 2014, 05:21:06 pm
content: How does the sensor work? Is it just a winding at the tip? I wonder if these could be easily replicated. They are surprisingly expensive on eBay.

author: electronic_eel
author_rank: Regular Contributor
timestamp: October 24, 2014, 09:05:28 pm
content: Would anyone mind to upload high quality scans of the 545a, 546a, 547a manuals again? The files as megafileupload posted above aren't available anymore. I'd recommend directly uploading them to KO4BB, then they'll be available for a long time.Quote from: krivx on October 21, 2014, 05:21:06 pmYes, I'm interested in that too. The schematics don't say anything about the tip.

author: Shock
author_rank: Super Contributor
timestamp: October 26, 2014, 06:25:41 am
content: Quote from: electronic_eel on October 24, 2014, 09:05:28 pmHere are the scans done so far by Notsob, they are cleaner than the HP versions or at least the 547a which was pretty bad. TerraHertz will do a better job than this when He gets around to it.http://www.megafileupload.com/en/file/574249/HP-545A-546A-547A-zip.htmlQuote from: krivx on October 21, 2014, 05:21:06 pmQuote from: electronic_eel on October 24, 2014, 09:05:28 pmFrom the manual it says:Current-STEP SENSOR. The Current-Step Sensor comprises a pickup core and winding, and eddy-current shield. The signal to be traced is sensed by the pickup winding and core.

author: kripton2035
author_rank: Super Contributor
timestamp: October 26, 2014, 08:53:44 am
content: just combined the jpeg pages into one pdf document for the 547 and compressed it to a reasonable sizeenjoy !

author: electronic_eel
author_rank: Regular Contributor
timestamp: October 26, 2014, 10:16:27 am
content: Quote from: kripton2035 on October 26, 2014, 08:53:44 amThanks.Quote from: kripton2035 on October 26, 2014, 08:53:44 amoh, you are the one keeping these repositories - nice site. Here are two more continuity testers:http://www.mikrocontroller.net/attachment/206936/pruefs01.pdfhttp://taco-nauert.com/datenblaetter/BS0401N_Bauanleitung.pdfBoth output a frequency proportional to resistance.

author: kripton2035
author_rank: Super Contributor
timestamp: October 26, 2014, 11:14:08 am
content: thanks for these linksthe second one is nicethe first one: do you have the caracteristics of the transformer ? will be difficult to make without a reference or an example...

author: electronic_eel
author_rank: Regular Contributor
timestamp: October 26, 2014, 12:25:06 pm
content: Quote from: kripton2035 on October 26, 2014, 11:14:08 amUnfortunately not. I don't have any more info and I don't have a working model. Just found it posted here:http://www.mikrocontroller.net/topic/323560#3523501

author: SeanB
author_rank: Super Contributor
timestamp: October 26, 2014, 03:29:26 pm
content: Probably 20 turns of 48SWG wire wound around a 3mm ceramic former, surrounded with a shield made from aluminium tape with a kapton tape laid on top so that you do not make a shorted turn. One and a half layers of shield and then the tape going for 3 turns over it. then you need to connect the shield to ground, and have your 2 coil wires leading off to the inner of a shielded cable.

author: electronic_eel
author_rank: Regular Contributor
timestamp: October 26, 2014, 04:10:28 pm
content: Quote from: SeanB on October 26, 2014, 03:29:26 pmThanks. I'm not so much into HF stuff, transformers and so on - why an air-core and not some kind of metal or ferrite core?

author: SeanB
author_rank: Super Contributor
timestamp: October 26, 2014, 04:42:38 pm
content: Low inductance......... Thus better high frequency performance. You might find some ferrite slugs that are 2mm diameter and wind a coil on them for specialised work.I did once use a ferrite bead and a 5 turn coil to make a current probe that would fit on a TO220 lead, using a 47R resistor at both ends and some really thin 50R cable to make it easier to handle. Worked at 100kHz on that switcher to see the current through the device without disturbing it much.

author: Barry Ward
author_rank: Newbie
timestamp: November 05, 2014, 02:04:48 pm
content: The complete theory of operation and design is here:www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1976-12.pdfSeems buildable if we can find some tiny ferrite U cores...I'd like to see it built as a battery powered unit using modern amps and maybe a tiny cell phone speaker. You can often tell a lot from the detected audio signature of even a complex digital, RF or microwave signal.

author: PaulAm
author_rank: Frequent Contributor
timestamp: December 11, 2014, 02:26:15 am
content: Thanks for that link. Always fun to read old HP journals.

author: babysitter
author_rank: Frequent Contributor
timestamp: December 20, 2014, 04:33:57 pm
content: I must proudly announce that I just got one as my self-bought christmax present. Together with 545 and 546 at the amazingly low price of 120 EU on ebay germany, a price at which it is hard to get even the simple brothers usuallyAlso love the morse mode selection of the pulser.Now off to see what this video and thread gives. Manual and HP Journal are fineWhat kind are these latching single-wire connectors ? Are those available today ? Not talking about the crocodile clips.

author: rastro
author_rank: Frequent Contributor
timestamp: February 11, 2015, 09:21:59 pm
content: Quote from: electronic_eel on October 24, 2014, 09:05:28 pmI'd like to second this request if someone could upload/ftp the manuals to:http://www.ko4bb.com/manuals/UploadInstructions.phpOr if someone could send these 3 files to me I'd be to post it on ko4bb.When I try to get theses files from Megafileupload it want's me to upload/install third party software - which I'm not comfortable with.Thanksrastro

author: TerraHertz
author_rank: Super Contributor
timestamp: February 12, 2015, 04:42:34 am
content: While this thread has surfaced again, does anyone have an original manual for the HP 10525H logic probe?I'd bought one recently, but it went missing in the post. Meanwhile I have surplus of one manual for the HP 10525T logic probe, and two surplus for the HP 10526T logic pulser. Would be happy to do a swap.My collection now:HP 10525T logic probe (have manual x2 )HP 10525H logic probe (WANT manual. bought 370623034892 - Lost in post, or mislabeled by artekmedia )HP 10526T logic pulser (have manual x3 )HP 1230A Logic trigger in case (have manual)HP 10529A Logic comparator (have manual + carton of 20 bare ref cards.)HP 545A logic probe (have manual)HP 546A logic pulser (qty 2) (have manual)HP 547A current tracer (have manual)HP 548A logic clip (have manual, don't have actual clip)I've been too busy with urgent life-impositions to do more manual scanning lately, but that won't go on forever.

author: kripton2035
author_rank: Super Contributor
timestamp: February 12, 2015, 06:59:09 am
content: Quote from: rastro on February 11, 2015, 09:21:59 pmfiles are on my answer here :https://www.eevblog.com/forum/reviews/hp-547a-current-tracer/msg537563/#msg537563

author: rastro
author_rank: Frequent Contributor
timestamp: February 12, 2015, 02:48:29 pm
content: Quote from: kripton2035 on February 12, 2015, 06:59:09 amHello kripton,I downloaded your 547A copy already - thank you for posting it.I guess I should clarify my request. I'm still trying to reach the 545a and 546a manuals without having to install 3rd party software from megafileupload. Would someone who has the 545A and/or 546A manual please respond with these as an attachment?Thanks

author: kripton2035
author_rank: Super Contributor
timestamp: February 12, 2015, 04:51:07 pm
content: it's too big to put on the eevforumso you can get them on my web page here :http://kripton2035.free.fr/tek-repository.html(at the bottom of the page)

author: rdl
author_rank: Super Contributor
timestamp: February 12, 2015, 10:59:37 pm
content: I downloaded that zip file from Megaupload a few days ago because I have an HP 545A. I used the link in post/reply #16. I didn't have to install anything, but it was a pretty slow download. It's not a pdf, but individual jpg scans of all the pages, which was not a problem for me.

author: kripton2035
author_rank: Super Contributor
timestamp: February 13, 2015, 07:32:32 am
content: I puut together the jpeg pages in a single pdf (one for each device)and then compact them to a reaonnable size (the original jpeg are 300dpi which if far too much for these old papers)these pdf's are on my web page.

author: qno
author_rank: Frequent Contributor
timestamp: February 15, 2015, 08:21:09 am
content: In an experiment a long time agoi used a playback head of a cassette player to trace current.

author: rastro
author_rank: Frequent Contributor
timestamp: February 15, 2015, 04:33:37 pm
content: Thanks for all the help with reposing these files. I am in the process of attempting to uploading these to ko4bb but ran into some technical problems - I've sent an email and am awaiting a response.

author: retrolefty
author_rank: Super Contributor
timestamp: February 15, 2015, 05:04:47 pm
content: Quote from: qno on February 15, 2015, 08:21:09 amAnd?

author: MindFlare
author_rank: Newbie
timestamp: November 08, 2016, 01:57:41 am
content: Hi notsob. I'm a bit late to this post, but any chance I could get those 300dpi scans from you, as the links are now dead? I just picked up a 547a and might be getting my hands on a 545a and 546a, as well, and I would love cleaner manual scans. Thanks!

author: kripton2035
author_rank: Super Contributor
timestamp: November 08, 2016, 06:59:25 am
content: the manuals are still on my web page...http://kripton2035.free.fr/tek-repository.htmlthat's the benefit of repositories !

author: notsob
author_rank: Frequent Contributor
timestamp: November 08, 2016, 09:26:34 am
content: Well its been a some time and i've moved house and the old computer died, I think the original manuals/books are it a box somewhere. I will start a search, it may take a while.

author: PolarisAT
author_rank: Contributor
timestamp: May 03, 2021, 10:17:32 am
content: I think this is a wonderful tool and it's a shame that nothing similar and compact is produced at the moment. I read the very interesting article about the function of the HP547A in the HP journal of Dec. 1976 (linked somewhere in here) and I studied the schematic. HP basically gives the design away with this extensive documentation, the only hard part is the pick up coil. They have a nice drawing that shows how it is basically done and the article explains what the designed took into consideration for optimal performance. Getting a suitable ferrite core is not easy and they also don't tell you what properties the inductor needs to have. I'm no expert on inductors or electric fields, nonetheless I tried my luck and solder a small SMD inductor with 1.5uH (TDK VLS252012T-1R5N1R4) that I had lying around together with a 47R resistor in parallel to a piece of RG178. I'm not sure if the 47R is necessary but I thought it couldn't hurt and would most likely help with refelction on the coax.I then used a scope and a signal generator to test the setup and it worked astonishingly well!I set the signal generator to generate positive pulses with 1Mhz and 2.5Vpp. I connected a short banana cable to it, forming a short circuit current path, and held the probe against the cable.It worked much better than expected! It does all the tricks you would expect from this kind of probe. It is not sensitive to e fields, it is detecting the polarity of h fields correctly (inverted output it turned 180°), it shows next to no output if turned 90°.I estimate the current in the test lead to be about 50mA - 100mA. The signal of the probe shows up as a 5mVp pulse. The input of the scope is set to 50Ohm for obvious reasons.What do you think about these results?Do you have any ideas how this setup could be improved?Best Regards!