HP 3478A $40 BIN USA - Page 1
Forum section: electronics / general

author: Jwalling
author_rank: Unknown
timestamp: September 18, 2018, 01:26:06 pm
content: No affiliation. Damn good price...https://www.ebay.com/itm/273468509011?

author: GreyWoolfe
author_rank: Unknown
timestamp: September 18, 2018, 01:55:13 pm
content: Well that just sucks. On vacation and I don't have my eBay or PayPal login information with me. Sh!t

author: Jwalling
author_rank: Unknown
timestamp: September 18, 2018, 02:09:16 pm
content: Quote from: GreyWoolfe on September 18, 2018, 01:55:13 pmI just bought it for you. Send me a PM with your address and I'll have it drop-shipped to you. If you can't receive it, let me know and I'll ship it to myself, then forward on when you're ready for cost of postage and the original cost + shipping.EDIT: From greyeagle1 to GreyWoolfe

author: BradC
author_rank: Super Contributor
timestamp: September 18, 2018, 02:10:52 pm
content: Now that is service!

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 18, 2018, 02:29:08 pm
content: Who wants to ship a bench multimeter to me?

author: coromonadalix
author_rank: Super Contributor
timestamp: September 19, 2018, 12:02:35 am
content: me too lollIf greywoolfe doesn't take it, i will

author: Old Printer
author_rank: Frequent Contributor
timestamp: September 19, 2018, 12:14:07 am
content: Small world, that's the guy I bought my Tek 2225 scope from a couple years ago. Good unit, smooth deal - no complaints.Jwalling, nice gesture

author: Jwalling
author_rank: Unknown
timestamp: September 19, 2018, 12:50:33 pm
content: Quote from: coromonadalix on September 19, 2018, 12:02:35 amI just heard from him. Someone will be there to receive it, so it's being drop-shipped directly to him - sorry.

author: GreyWoolfe
author_rank: Unknown
timestamp: September 21, 2018, 02:41:28 am
content: Jay, I checked and the meter was delivered. FEDEX AND UPS ground in Florida is 1 day. Something awesome to come home to. Thank you so much again for your kindness. Pictures to come.

author: xrunner
author_rank: Super Contributor
timestamp: September 21, 2018, 02:47:34 am
content: Wow what a great story. Yea pics!

author: GreyWoolfe
author_rank: Unknown
timestamp: September 21, 2018, 03:04:17 am
content: Quote from: xrunner on September 21, 2018, 02:47:34 amNo worries, we will have a peek under her skirt.

author: Jwalling
author_rank: Unknown
timestamp: September 21, 2018, 09:34:20 am
content: Quote from: GreyWoolfe on September 21, 2018, 02:41:28 amYou're welcome! I hope you get many years of use out of it. After you verify that it works OK, be sure to check the battery which hold the calibration constants.

author: GreyWoolfe
author_rank: Unknown
timestamp: September 21, 2018, 01:16:03 pm
content: Quote from: Jwalling on September 21, 2018, 09:34:20 amWill do. I don't have a butane soldering iron but I do have a spare UPS that I can power one of my soldering stations on to replace it. I found a thread on how to do just that.

author: Old Printer
author_rank: Frequent Contributor
timestamp: September 21, 2018, 07:32:03 pm
content: Quote from: GreyWoolfe on September 21, 2018, 01:16:03 pmYou live in a tree?

author: Jwalling
author_rank: Unknown
timestamp: September 21, 2018, 07:58:39 pm
content: Quote from: Old Printer on September 21, 2018, 07:32:03 pmOK, I've been re-reading that sentence and the previous posts for several minutes now.I don't get it, but it's been a long day...

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 21, 2018, 08:13:34 pm
content: Quote from: Jwalling on September 21, 2018, 07:58:39 pmBoth a butane soldering iron and a UPS make it sound like GreyWoolfe is off the grid somewhere.

author: adrianarcher
author_rank: Contributor
timestamp: September 21, 2018, 08:40:57 pm
content: Here is one on auction in Vancouver, BC, Canada, right now $1!https://maxsold.maxsold.com/auction/12204/item/multimeter-and-function-generator-a-1114465/

author: Jwalling
author_rank: Unknown
timestamp: September 21, 2018, 08:50:55 pm
content: Quote from: Mr. Scram on September 21, 2018, 08:13:34 pmOK, I got it now. GreyWoolfe's using a UPS made sense to me as you don't want to GND the + with it plugged into the mains.Ehh... never-mind. I missed it.

author: GreyWoolfe
author_rank: Unknown
timestamp: September 21, 2018, 10:40:28 pm
content: Quote from: Mr. Scram on September 21, 2018, 08:13:34 pmConsidering here in Florida we have Faulty Power and light, that is not far off the mark.I have 4 big UPSs to keep everything up in my office. I had a butane iron years ago but it was horrible at holding butane. I will be better off using a UPS or my isolation transformer for my soldering station.

author: bitseeker
author_rank: Super Contributor
timestamp: September 22, 2018, 01:27:16 am
content: Since you have plenty of backup power, you can skip soldering in a standby battery and just keep the 3478A powered with a UPS while doing the replacement operation.

author: GreyWoolfe
author_rank: Unknown
timestamp: September 22, 2018, 03:24:48 am
content: Quote from: bitseeker on September 22, 2018, 01:27:16 amD'oh! Didn't think of that.The whole workbench, including the soldering stations, is on its own UPS.

author: Old Printer
author_rank: Frequent Contributor
timestamp: September 22, 2018, 03:45:03 am
content: Quote from: GreyWoolfe on September 21, 2018, 10:40:28 pmI am too much of a noob to have picked up the isolated soldering iron connection, but I have learned something, actually two things..you don't live in a treeIt's a big state, but we buy our power from the same company and I have a generator which gets used all too often. I'm in Ft. Lauderdale. Howdy neighbor!

author: GreyWoolfe
author_rank: Unknown
timestamp: September 23, 2018, 02:18:17 am
content: Quote from: Old Printer on September 22, 2018, 03:45:03 amHowdy neighbor!I live in Edgewater now but I have lived in Hollywood Beach and Hallandale Beach. The generator only has to come out after hurricanes. No, I don't live in a tree but my 80 meter full wave loop does live in the trees!!

author: GreyWoolfe
author_rank: Unknown
timestamp: September 24, 2018, 12:53:38 am
content: So I got to unbox the meter!!!As you can see, lots of bubble wrap and packing peanuts. The second pic shows the face of the meter, extra bubble wrap. The next pic shows the bezel of the meter, clean but with a broken power button, it still works. You can see that it says uncalibrated. Just a quick play shows the reading of a 1R1, 10% resistor, so it is a bit off. As a comparison, my HP 3466A shows 1R08 and my GW Instek GDM-8251A shows 1R24. I will get out my HeathKit scope calibrator for some DC voltages and get some comparisons and then I will open her up and see what is under the skirt. Too tired after 14 hours on the road Saturday and another 6 hours today with a stop in between to pick up the dogs left at my mother-in-law's house.

author: bitseeker
author_rank: Super Contributor
timestamp: September 24, 2018, 04:42:02 am
content: Good to see it was well packed. That seems rare nowadays with eBay sellers.

author: Jwalling
author_rank: Unknown
timestamp: September 24, 2018, 09:36:13 am
content: Crap. So I guess the battery has already gone flat. Are you able to do a proper cal?

author: GreyWoolfe
author_rank: Unknown
timestamp: September 24, 2018, 10:57:10 am
content: Quote from: Jwalling on September 24, 2018, 09:36:13 amUnfortunately, I do not. There is a company, express test, on eBay that will do a calibration for $75 plus shipping. After I replace the battery and any caps that might need replacing, I will probably save some coin and get it done so I have at least 1 accurate meter.

author: Jwalling
author_rank: Unknown
timestamp: September 24, 2018, 12:33:41 pm
content: Quote from: GreyWoolfe on September 24, 2018, 10:57:10 amThat sucks, more than the meter costs. I wish you had had a better outcome, sorry.Might want to check TMI and get a quote from them:https://www.tmicalibration.com/services/calibration/They're in FL so it may save you some on shipping... They're in Palm Harbor, is that close enough to drop it off?

author: GreyWoolfe
author_rank: Unknown
timestamp: September 24, 2018, 04:58:51 pm
content: Quote from: Jwalling on September 24, 2018, 12:33:41 pmNo, they aren't. They are on the other side of the state, a couple of hours drive. One thing at a time, I will get the battery replaced first.

author: Jwalling
author_rank: Unknown
timestamp: September 24, 2018, 08:22:41 pm
content: You want to send it back to the seller?They should have disclosed that it powers up with "uncalibrated"

author: xrunner
author_rank: Super Contributor
timestamp: September 24, 2018, 09:38:06 pm
content: Quote from: Jwalling on September 24, 2018, 08:22:41 pmAbsolutely. If it's "used" it is expected to work as a new one, but that it's just already used. Send it back for a refund.

author: GreyWoolfe
author_rank: Unknown
timestamp: September 25, 2018, 01:06:10 am
content: Quote from: xrunner on September 24, 2018, 09:38:06 pmSending it back is probably for the best. It was not represented properly and at the end of the day, I do not have the extra money to spend on calibration. Jay, which one of us needs to initiate the return? You bought it but had it sent to me. Who knows, maybe the seller will refund the $40 and say keep the meter.

author: xrunner
author_rank: Super Contributor
timestamp: September 25, 2018, 01:09:24 am
content: Quote from: GreyWoolfe on September 25, 2018, 01:06:10 amIt's too bad about the meter GreyWoolfe, but yes in many cases I've had the seller will just say keep it. I've had that happen for items up to about $10, might happen in this case.

author: bitseeker
author_rank: Super Contributor
timestamp: September 25, 2018, 01:30:35 am
content: Since it was purchased by Jay, the return has to be initiated from his account, AFAIK. If they want the item back, they'll send him a return label (usually via eBay), which he can then email to you (print to PDF), and you can print and affix to the package to send the item back. Some vendors don't want the added expense of return shipping and might opt to forgo the return and simply issue a refund (Amazon often does that, too, on inexpensive items).

author: GreyWoolfe
author_rank: Unknown
timestamp: September 25, 2018, 02:42:56 am
content: Quote from: xrunner on September 25, 2018, 01:09:24 amIf I can get the $40 back and keep the meter, that money can go into the cookie jar toward getting the meter calibrated. If I get to keep it, I may ask in the voltnuttery section if someone could do a basic cal for fewer shekels than a NIST calibration. I certainly don't need that level. If it doesn't work out, it doesn't work out. Let's see if Jay can work some magic on a misrepresented meter.

author: xrunner
author_rank: Super Contributor
timestamp: September 25, 2018, 02:49:51 am
content: Quote from: GreyWoolfe on September 25, 2018, 02:42:56 amWell as you are probably aware, you can get into the cal procedure easily enough per the service maual. If you keep it and replace the battery, go ahead and play with the cal. You can get some modes calibrated well enough by referencing it to your best meter for the time being. You can probably get quite a few useful parameters calibrated good enough to use, until you decide who to send it to.

author: SirAlucard
author_rank: Regular Contributor
timestamp: September 25, 2018, 03:44:45 am
content: Quote from: adrianarcher on September 21, 2018, 08:40:57 pmYea but look how crusty that looks compared to how nice the one he received looks.Quote from: GreyWoolfe on September 25, 2018, 02:42:56 amAlso I see no reason to return the meter, sure its not calibrated, but at that price even a self calibration is worth it. Eventually when I get a proper bench meter I pretty much expect it to not be correctly calibrated (cause I'll likely end up finding a cheap one that hasn't been used in a while). Where on the east side of FL are you? I myself am in Palm Beach County.

author: coromonadalix
author_rank: Super Contributor
timestamp: September 25, 2018, 04:42:14 am
content: Quote from: SirAlucard on September 25, 2018, 03:44:45 am

author: Jwalling
author_rank: Unknown
timestamp: September 25, 2018, 09:41:15 am
content: Quote from: GreyWoolfe on September 25, 2018, 01:06:10 amI'll initiate the return. I'll let you know when I hear something.Sorry about this... If there had been a picture with the meter showing "uncalibrated" I wouldn't have started this thread.

author: GreyWoolfe
author_rank: Unknown
timestamp: September 25, 2018, 10:56:06 am
content: Quote from: Jwalling on September 25, 2018, 09:41:15 amJay, no need for you to apologize, this is on the seller, not you. I'm glad that I hadn't thrown away the box yet. Let's see what the seller will do.

author: GreyWoolfe
author_rank: Unknown
timestamp: September 25, 2018, 10:20:14 pm
content: Here is an update. Jay, don't worry about the return. I just received a notice from someone who is blessing me with a DMM Check + with enclosure. I'm sure that I can do a good enough calibration with it to get rid of the uncalibrated message.I just need to get the battery and replace it.If the seller is willing to do a refund without shipping the meter back for the misrepresentation, that's fine. If he wants the meter back, let him know that I will keep it and cancel the refund.Quote from: SirAlucard on September 25, 2018, 03:44:45 amVolusia County.

author: Macbeth
author_rank: Super Contributor
timestamp: September 25, 2018, 11:16:49 pm
content: $40? No good deed goes unpunished.

author: BradC
author_rank: Super Contributor
timestamp: September 25, 2018, 11:32:37 pm
content: Quote from: GreyWoolfe on September 25, 2018, 10:20:14 pmSorry to burst your bubble but I'd be surprised if you could usefully calibrate any range on that meter with a DMM Check. The 3478a needs to calibrated at the top of each range to get close to any form of accuracy. In some cases it is required to even get it to attempt the calibration.You could dump a config into it from someone else's meter. That would make the uncalibrated message go away and it'd probably be just as accurate (ie not at all).It really does require a calibrator of some kind with the right voltages and resistances to get it vaguely within spec.

author: Jwalling
author_rank: Unknown
timestamp: September 26, 2018, 12:01:36 am
content: Quote from: BradC on September 25, 2018, 11:32:37 pmI agree with Brad. I've calibrated a few a number of years ago, and I have a EDC 521 and a Fluke 5200A (which is getting a bit flaky). For the R I used a decade box and a Keithley 2015 for accurate readings.I don't think you'll be able to get into the ranges that the meter needs. Have a look at the service manual for the calibration process.If I were you, I'd bite the bullet and have it calibrated right, or send it back. Please let me know...

author: bitseeker
author_rank: Super Contributor
timestamp: September 26, 2018, 03:02:49 am
content: Quote from: GreyWoolfe on September 25, 2018, 10:20:14 pmUnfortunately, that won't be enough to fully calibrate the DMM. It's OK for doing a sanity check of a few values to know that a meter isn't completely out of whack. At most, you might be able to calibrate a minority of ranges with it, but it'll be at less than the meter's full resolution (it'd be OK for a 3.5- or 4.5-digit DMM).Unless you already have a DMM that's an order of magnitude better than this 3478A or has recently been calibrated, I'd recommend either (1) get it properly calibrated to become your lab "reference" meter or (2) return it.If you do get it calibrated, most lab-grade DMMs will be stable enough that you won't have to calibrate it again for years, depending on conditions and your particular requirements.

author: coromonadalix
author_rank: Super Contributor
timestamp: September 26, 2018, 03:45:53 am
content: For 40$ i would gladly pay 75$ to get it calibrated, if the meter is clean, not damaged on the electronics, not tampered etc ... and need only a new batteryGo for itEven other 3478A on Ebay who sell higher priced, you don't have any certitude it will 100% on specs ?? even if they write working in the description ...

author: bitseeker
author_rank: Super Contributor
timestamp: September 26, 2018, 04:24:19 am
content: Yes, $115 for a calibrated 3478A with certificate is still a great deal.

author: Old Printer
author_rank: Frequent Contributor
timestamp: September 26, 2018, 01:24:40 pm
content: As a sometimes buyer of very inexpensive ebay deals I have a question. After putting in the battery, would you be likely to know if there are any other faults that would make calibration impossible without repair? If you send it off to the cal lab and they tell you this is the case after getting into it, are you still liable for the $75 fee? I am curious if this is a situation where you just keep getting in deeper dollar wise and still wind up without a working meter. Thanks, your neighbor to the south

author: coromonadalix
author_rank: Super Contributor
timestamp: September 26, 2018, 02:41:26 pm
content: Maybe ask Lmester for the software, it read and write calibrationhttps://www.eevblog.com/forum/testgear/free-hp3478a-multimeter-control-program/If we could take an backup of an already calibrated 3478a and push it to yours, you could do some checks if it seem working on all ranges, sure you would have some values discrepancies but it should make it work, and clear the uncalibrated warning

author: coromonadalix
author_rank: Super Contributor
timestamp: September 26, 2018, 02:48:24 pm
content: Quote from: Old Printer on September 26, 2018, 01:24:40 pmI have an Fluke calibration facility near me, they will charge minimum 75$ cad, the price will depend of the type of meter scope etc etc ...They will try to calibrate the meter, if they cant do an full calibration, they will put an NFC (not fully calibrated) with an tracking sticker on it. You'll know what doesn't work with the report ...But you wont get an refund since they will work on it ...

author: Ordinaryman1971
author_rank: Frequent Contributor
timestamp: September 26, 2018, 02:48:37 pm
content: Correct, you may end up with a "free" meter if they decide not to get it returned. I can calibrate it for you, the problem is that you would have to ship it to Chicago... or just use it uncalibrated. The message disappears after few seconds and the meter should be fine, even without the calibration present.

author: GreyWoolfe
author_rank: Unknown
timestamp: September 26, 2018, 02:56:49 pm
content: Quote from: Old Printer on September 26, 2018, 01:24:40 pmI don't know as I have never had anything calibrated before. The meter works, it's just off. The uncalibrated message seems to mean a dead battery as the general consensus suggests. The battery is cheap, under $6. Not that I ever do anything needing a NIST calibrated meter but it would be cool to have. I have decided to suck it up, keep the meter, replace the battery and work on the cash for the calibration. Time to see what I can get rid of.

author: GreyWoolfe
author_rank: Unknown
timestamp: September 26, 2018, 02:58:45 pm
content: Quote from: Ordinaryman1971 on September 26, 2018, 02:48:37 pmPM sent.

author: GreyWoolfe
author_rank: Unknown
timestamp: September 27, 2018, 01:27:35 am
content: I opened the meter to take a peek inside and found 4 RIFA capacitors, 2 .022uF Y and 2, 1000 pF Y caps. The housings all have cracks running through them so I need to replace them when I replace the battery. If I am reading correctly, these are metalized film capacitors. Would this from KEMET as an example, be a good substitution?https://www.digikey.com/product-detail/en/kemet/R76PI22204030J/399-12594-ND/5731085If not, what would I want to buy?I also plan to replace the 5 electrolytic caps. They appear to be original and the PCB is dated 9th month 1985

author: bitseeker
author_rank: Super Contributor
timestamp: September 27, 2018, 03:58:54 am
content: If those RIFA caps go across the mains (I don't recall which do in that meter), then that KEMET series is not rated for that purpose. Check the datasheets. Also, I recall seeing these replacements being discussed on the forum before. A search may get you some component recommendations.

author: GreyWoolfe
author_rank: Unknown
timestamp: September 27, 2018, 04:03:04 pm
content: Quote from: bitseeker on September 27, 2018, 03:58:54 amI did a bit more digging and have the proper replacements, the battery and electros coming from Digi-key. After that, calibration. Now to find a replacement power button. So far, the part number doesn't turn up anything. I will keep practicing my GoogleFu.

author: bitseeker
author_rank: Super Contributor
timestamp: September 27, 2018, 08:55:43 pm
content: I recall some putty-like stuff that hardens after molding and can be sanded, painted, etc. Unfortunately, I don't remember what it's called. It could be a quick fix to add the missing tip to the power switch arm.

author: GreyWoolfe
author_rank: Unknown
timestamp: September 27, 2018, 09:12:37 pm
content: Quote from: bitseeker on September 27, 2018, 08:55:43 pmMany years ago when I was into military modeling, I used a product called squadron green putty to add dirt and mud build up around and under tank bogeys and fenders. That stuff dried hard. I will have to see if it is still available. Maybe someone else could chime in on a usable product.

author: Old Printer
author_rank: Frequent Contributor
timestamp: September 27, 2018, 10:14:21 pm
content: At work (a sign shop) we use 2 part epoxy putty J-B Weld called SteelStick. It's good stuff, about six bucks at Depot. So much for your $40 meter huh?Been there enough myself, just the way it goes sometimes.

author: GreyWoolfe
author_rank: Unknown
timestamp: September 27, 2018, 11:22:56 pm
content: Quote from: Old Printer on September 27, 2018, 10:14:21 pmNo kidding. $40 plus the shipping. $25 for the battery and replacement caps with shipping. A few bucks for some sort of solution for the button, though I can still power it up the way it is. I am also thinking Delrin/plastic bar stock from the local hobby shop shaped and epoxyed onto the end might be a solution. Then the shipping both ways to ordinaryman for the calibration. Still a steal.

author: Bratster
author_rank: Frequent Contributor
timestamp: September 28, 2018, 07:22:39 am
content: For the button, a member on here designed a 3D model that I have printed and works great to replace the power and input buttons on mine.I will go find that post/thread and Link it back here in a moment.Sent from my Fi Moto x4 using Tapatalk

author: bitseeker
author_rank: Super Contributor
timestamp: September 28, 2018, 07:30:10 am
content: Thanks, Bratster. Thingiverse has some test equipment parts, but not for this meter the last time I checked. Looking forward to seeing the one you tried.

author: Bratster
author_rank: Frequent Contributor
timestamp: September 28, 2018, 07:38:09 am
content: Here is the thread.https://www.eevblog.com/forum/repair/where-to-find-a-new-power-switch-for-a-hp3478a/Sent from my Fi Moto x4 using Tapatalk

author: GreyWoolfe
author_rank: Unknown
timestamp: September 28, 2018, 12:19:46 pm
content: Quote from: Bratster on September 28, 2018, 07:22:39 amThanks for posting the the link. I don't have a 3D printer. Would you possibly be able to print a couple and I would happily relinquish coin of the realm for time/materials and postage?

author: Bratster
author_rank: Frequent Contributor
timestamp: September 29, 2018, 04:47:30 am
content: Quote from: GreyWoolfe on September 28, 2018, 12:19:46 pmYou would get a higher quality part if you order it through shapeways or one of those other 3D printing services.The member that designed it did mention in that other thread that he was going to adjust the model slightly since I had to modify the physical print to make it fit.You may want to ask them if they can print it for you.If you don't want to go that route I would be open to printing some, just PM me your ZIP code so I can figure out what shipping would be.Sent from my Fi Moto x4 using Tapatalk

author: SeanB
author_rank: Super Contributor
timestamp: September 29, 2018, 10:37:04 am
content: Otherwise Sugru is the stuff you are thinking of, though I would typically just use a big blob of 2 pack Pratley putty, and mix it together, mould roughly to shape, press onto the shaft to get the interior shape correct after making a rough large outer, then finish it off after 24 hours when it has cured, and then finally when finished cure at 60C for a day to get fully hard, and then spray it appropriately.

author: GreyWoolfe
author_rank: Unknown
timestamp: September 29, 2018, 12:06:31 pm
content: Quote from: Bratster on September 29, 2018, 04:47:30 amI sent an email to shapeways and see where that goes. I will also PM my zip code.

author: bitseeker
author_rank: Super Contributor
timestamp: September 29, 2018, 09:47:22 pm
content: Yeah, I think Sugru was it. Thanks, Sean.

author: coromonadalix
author_rank: Super Contributor
timestamp: September 30, 2018, 07:45:09 am
content: I know its a long shot, but you could / can find old defective hp mainframes modules who could give you the switchs knobs needed in the future ??

author: PaulAm
author_rank: Frequent Contributor
timestamp: October 01, 2018, 01:32:34 pm
content: They always seem to be missing the button you need. Power buttons seem to be a particular favorite to go missing. I have a couple pieces waiting for a new power button.I've used 2 part auto body filler to make up stuff on occasion. In the US there's a product called Duraglass which is epoxy filler with fiberglass, although I'm sure similar products are available elsewhere. It's waterproof, durable and does not crack. Once it gets partially set you can sculpt it with a sharp knife (if you're fast).You could also make a mold of a different button and use liquid fiberglass resin to mold one.Lately, I'm leaning toward the 3d printer route.

author: xrunner
author_rank: Super Contributor
timestamp: October 01, 2018, 02:17:00 pm
content: Quote from: GreyWoolfe on September 29, 2018, 12:06:31 pmHere it is -https://www.ebay.com/i/183300958427?chn=ps

author: GreyWoolfe
author_rank: Unknown
timestamp: October 01, 2018, 10:52:11 pm
content: Quote from: xrunner on October 01, 2018, 02:17:00 pmYou da MAN, X!!

author: xrunner
author_rank: Super Contributor
timestamp: October 01, 2018, 10:54:07 pm
content: Quote from: GreyWoolfe on October 01, 2018, 10:52:11 pmI try, I try.

author: bitseeker
author_rank: Super Contributor
timestamp: October 01, 2018, 11:06:31 pm
content: Amazing! I wasn't expecting that.

author: ArthurDent
author_rank: Super Contributor
timestamp: October 02, 2018, 02:46:44 am
content: Several weeks ago I was looking through the electronics for sale section on CraigsList and found someone who was selling a lot of used test equipment, every piece with some problem. Along with many other pieces of test equipment I ended up with about seven HP3478A, one with a very defective display that became a parts donor for the rest. Two or three had dead batteries and gave the ‘uncalibrated’ message on power up, and a couple of missing or blown input fuses, a broken power switch, and a missing power button cap. There was one that had been dropped and although there wasn’t any physical damage the connector between the main board and the front panel was broken and that took some time to repair.I have some stable power supplies and resistance standards and I also have an HP 3457A 6.5 digit meter that I have great confidence in. After I repaired the problem(s) with each meter I could use my voltage standard (EDC 330, 7 digits) to set zero and all the multiples of 3 for each D.C. voltage calibration point. If there was any small disagreement between the EDC reference and the HP 3457A, I adjusted the reference to agree with the HP 3457A, and that was the method I relied on to set the calibration points on all the HP 3478A meters. I followed the same procedure for resistance using an ESI 6 decade box and a couple of very high value resistors to calibrate all the resistance ranges, always using the HP 3457A as the final word. I used the same procedure for A.C. and D.C. amps. After running through all the calibration steps I could exit the calibration mode and every repaired meter passed self test and worked properly. Checks at random points of other references and standard resistors indicated that the meters were within specs. Although it isn't exactly a true calibration I am quite confident in the results.I was pretty please that I got all but one of them working and that they were within driving distance, and they were only $20 each.

author: GregDunn
author_rank: Frequent Contributor
timestamp: October 02, 2018, 05:19:40 am
content: If you're interested in selling any of the repaired meters.....

author: TERRA Operative
author_rank: Super Contributor
timestamp: October 02, 2018, 06:36:37 am
content: A bit of a long shot maybe, but I have one of these meters I am repairing.It all works and passes checks, but the AC current and AC voltage functions don't work.I've traced it to a faulty 1QF7-0067 (U102), so I am trying to track one down.Does anyone have one of these parts, working or not, that they are willing to sell?

author: BradC
author_rank: Super Contributor
timestamp: October 02, 2018, 07:19:15 am
content: Quote from: TERRA Operative on October 02, 2018, 06:36:37 amThey are as rare as rocking horse shit. I wonder if the same/similar hybrid from the 3457a would work? I've never looked at them that closely, but they are available. I always thought they were identical, but just noted they are different part numbers. Might have to look at the schematics to see if I can pick the difference.

author: TERRA Operative
author_rank: Super Contributor
timestamp: October 02, 2018, 10:40:23 am
content: Yeah, I would even take one from an otherwise dead unit.I want to strip it down to see if it could be reverse engineered with common parts, but I don't want to potentially sacrifice my otherwise good meter (besideds the AC ranges).Would be cool to be able to build a replacement addin board from discreet components.

author: GreyWoolfe
author_rank: Unknown
timestamp: October 03, 2018, 10:40:50 pm
content: I took a couple of pictures of the PCB since I was replacing the RIFA and electrolytics and the battery. Here is the top and bottom. You can see how clean it is. I didn't clean the PCB before I started. You can also see how bad the RIFA caps are. I did the electrolytics as I was replacing the RIFA caps anyway and they were the original electrolytics. They were replaced with proper Nichicon capacitors. Now, I am waiting for the power buttons from bratster and then it will go to ordinaryman for a basic calibration. For the record, I used my isolation transformer with my soldering station so as not to short anything out. The bezel and case cleaned up very well with some simple greenTotal cost to date (rounded to nearest dollar):meter and shipping-----$58parts and shipping------$27buttons and shipping---$15Total so far--------------$100If I can get away with under $40 shipping both ways to ordinaryman, that would make the total investment in a calibrated meter with new caps and battery for about $140 USD. I think I have done OK. They are going on evilBay right now for $100 BIN and up uncalibrated and unknown battery/cap condition. The 2 listed with calibration are $325 and up. I will be very happy at the end of the process. The next pics I post will be the buttons that I receive from bratster.

author: bitseeker
author_rank: Super Contributor
timestamp: October 04, 2018, 01:49:30 am
content: It is nice and clean inside. Glad to hear all went well with the battery change. Those RIFA caps are quite cracked — disasters waiting to happen.I didn't pay attention earlier, but seeing inside I noticed you have the earlier revision that uses toroid transformers for communicating between the analog and digital sides instead of opto-isolators. I like the enclosures that HP used for those 3478A as they have more metal, less plastic.In fact, a dead 3478A of similar vintage is on its way to me. Will it be a cinch or a disaster? Only time will tell.

author: GreyWoolfe
author_rank: Unknown
timestamp: October 04, 2018, 02:48:53 am
content: Thanks to the Blog and all the horror stories I have read about exploding RIFA caps, that was the first thing I looked for when I opened it up. Then I measured the battery and it read 70 mV--I think it might have been dead. I changed the electrolytics as the board looks like it never had any rework outside of a possible battery change in the past. There was a little flux residue near one of the pins. Hopefully, the meter will stay happy for years and I hope yours turns out to be as easy as mine has been so far.

author: bitseeker
author_rank: Super Contributor
timestamp: October 04, 2018, 05:26:23 am
content: Yep, will let you know when I get it. Looking forward to seeing your final wrap up after calibration.

author: Bratster
author_rank: Frequent Contributor
timestamp: October 05, 2018, 05:38:46 am
content: Quote from: GreyWoolfe on October 03, 2018, 10:40:50 pmWould you mind sharing the part numbers for the replacement capacitors you used?Sent from my Fi Moto x4 using Tapatalk

author: GreyWoolfe
author_rank: Unknown
timestamp: October 05, 2018, 12:27:10 pm
content: Quote from: Bratster on October 05, 2018, 05:38:46 amWould you mind sharing the part numbers for the replacement capacitors you used?Sent from my Fi Moto x4 using TapatalkBratster, I assume you mean the RIFA caps. Here are the part numbers:.022 uF Digi-key part number 399-5413-ND, manufacturer part number PME271Y522MR301000 pF Digi-Key part number399-5409-ND, manufacturer part numberPME271Y410MR30399-7491-1-ND PME271Y410MR19T0EDIT, Sorry Bratster, I was trying to go from memory. I found my invoice and have corrected the part numbers for the 1000 pF RIFA cap

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: October 05, 2018, 01:06:55 pm
content: Quote from: GreyWoolfe on September 23, 2018, 02:18:17 amHallandale! I''ve been there, summer 1979, Motel Sun Aqua :-)

author: GreyWoolfe
author_rank: Unknown
timestamp: October 05, 2018, 02:21:27 pm
content: Quote from: GeorgeOfTheJungle on October 05, 2018, 01:06:55 pmI lived there in the mid 90's. The apartment wasn't that far from the beach. Nice little beach with a boardwalk.

author: chekhov
author_rank: Regular Contributor
timestamp: October 08, 2018, 07:40:16 pm
content: Two more units:https://www.ebay.com/itm/292757399598?,with button!!!Well, probably rather good opportunity, especially when don't need to pay x3 price for delivery.

author: Mr. Scram
author_rank: Super Contributor
timestamp: October 09, 2018, 06:51:13 am
content: Quote from: chekhov on October 08, 2018, 07:40:16 pmThe nerve of some people. "Good cosmetic condition"It's hardly the worst I've ever seen, but it's certainly well used.

author: PlainName
author_rank: Super Contributor
timestamp: October 09, 2018, 10:39:21 am
content: Considering the competition going for more and in considerably worse condition, it is actually quite good!This is what you call cosmetically challenged

author: Mr. Scram
author_rank: Super Contributor
timestamp: October 09, 2018, 11:28:48 am
content: Quote from: dunkemhigh on October 09, 2018, 10:39:21 amThe fact that a turd tastes worse than your cooking doesn't make the latter haute cuisine.

author: chekhov
author_rank: Regular Contributor
timestamp: October 09, 2018, 12:15:32 pm
content: Neither two of meters above are in really bad conditions from the outside (compare to thishttps://www.ebay.com/itm/222396890942?). And, what to expect from 29-30 year old gear ?It goes without saying that you have to disassemble it and wash, at least front panel, buttons - only after that I will feel comfortable to work with such instrument.The more important are possible scratches (which may mean physical damage) and internals - here is where dust it less wanted.

author: GreyWoolfe
author_rank: Unknown
timestamp: October 10, 2018, 05:36:51 pm
content: This will probably be the last post. I received the buttons from Bratster. Brett, thank you very much. The buttons look great and are a nice tight fit on the shafts. I also added a couple of pics of the feet I used. I have a small quantity of these and they set the meter at a nice height. More importantly, they were free!! Now I need to see what I can get rid of to pay for the calibration.

author: bitseeker
author_rank: Super Contributor
timestamp: October 10, 2018, 06:02:42 pm
content: That worked out nicely, GW.

author: GreyWoolfe
author_rank: Unknown
timestamp: October 10, 2018, 07:05:32 pm
content: Quote from: dunkemhigh on October 09, 2018, 10:39:21 amBelieve it or not, I was half tempted just to have the old style label maker sticker that says Electronic Warefare.Quote from: bitseeker on October 10, 2018, 06:02:42 pmVery happy to have no borked power button.

author: GreyWoolfe
author_rank: Unknown
timestamp: November 05, 2018, 08:46:30 pm
content: UPDATE: I just got a PM from Ordinaryman1971. The calibration is done and the meter is on its way back to me. I can't thank him enough for his kindness. It took awhile because he's been very busy but I am grateful for his help. Thanks, again, OM.

author: xrunner
author_rank: Super Contributor
timestamp: November 05, 2018, 10:38:31 pm
content: Great!

author: bitseeker
author_rank: Super Contributor
timestamp: November 05, 2018, 11:58:41 pm
content: That's great news GW. I bet you can't wait to measure something.

author: Haasje93
author_rank: Contributor
timestamp: November 08, 2018, 10:46:39 pm
content: Not affiliate with the seller. It seems like it is worth looking at.https://www.ebay.com/itm/Lot-Of-2-Hewlett-Packard-3478A-Digital-Multimeter/362481326514?hash=item54659219b2:g:B8UAAOSwS4Vb42mt:rk:1:pf:0

author: Ordinaryman1971
author_rank: Frequent Contributor
timestamp: December 09, 2018, 08:46:00 pm
content: By the way... if anybody needs 5 or 6 digit meter calibrated I'm more than happy to help. I have all the gear... just little time.So, if you are in a pinch give me a pm and I can do it for you. It's completely free to all eevblog members, you just have to pay for the shipping to Chicago and back. Or if you close-by you can always drop it off.I also have some parts for those meters, I can print buttons too, lol. Color of your choice... I have black and also... black and if you really insist I have black as well.

author: coromonadalix
author_rank: Super Contributor
timestamp: December 11, 2018, 11:23:09 am
content: @OrdinaryMan i'm gonna take on your offer, just need to receive new parts ...