1975 Voltage Standard Restoration & "Improvement"? 😬 Fluke 731B

[@-MrDontCare-]

Hahaha, the Stargate dialing sound made me spit out my coffee true the nose😂

[@applecorc]

I wask like, "Why is he calling it a stargate meter? I don't remember it in the show." That gave me a good laugh.

[@reps]

[@-MrDontCare-]

😂

[@cvspvr]

pp

[@DasIllu]

I do remember having a discussion in the 90's with someone who built a lot of battery powered stuff. He mentioned that for certain types of batteries a half wave rectified 50hz transformer output is actually ideal to charge them. He also drew up a rough schematic on how to measure the charge in between the pulses to cut off the charging once it's finished. I think it was about the NiCd batteries but i can be wrong. I didn't care too much at the time because that battery technology was already fading in popularity.

[@Ckay2552]

While I studied, i had some courses in electrochemistry. Its about dentrites growth. Sharp points on the surface have a higher electric field and therefor more material gets deposited on these points. Over some charging cycles these dendrites grow more and more, until they puncture the seperator or even touch the other electrode, shortening the battery. If you vary the charging voltage, dendrites growth can be minimised. Some experiments even used shifted fullwaves to charge the batteries, so in parts of the cycle, the battery gets discharged again, but it lengthens the lifetime of the battery

[@ivolol]

I quite liked it when Mr Reps went all nerdy over the electrodynamical effects that construct the voltage reference tempcos

[@randynovick7972]

My heart gets a little fluttery every time I see vintage Amphenol componentry. Thank you for the thrill. Love this return to form. Was really looking forward to it, leaving fulfilled.

[@fredio54]

That lock out toggle switch on the front? I own a bunch of EXACTLY those. I salvaged a bunch of particle accelerator equipment from a facility that was closing down. Beautiful rack mount gear and old point to point wire wrapped boards. The quality was and is exquisite. The one on that device looks rough and neglected and abused. Mine are mint.

[@fredio54]

Ha ha ha, you hate the switch. I know why, and yours is rough, but for anything else they're gorgeous.

[@Alamagosa]

The LT1008 is an externally compensated greatly improved direct replacement for the 308 operational amplifier. The other parts in that series, the LT1012 and LT1097, have internal compensation but also an external overcompensation pin so could also be used with a minor change.

[@IanScottJohnston]

That black 3458A is a thing of beauty, so nice alongside the original…….and quite a PPM stack building above them.

[@al_lazy3519]

My opinion on that half wave rectified supply is that it keeps crystals from forming in the ni cells, or rather the pulsed current breaks them if they form. I've done some heavy treatment on old nimh batteries with unrectified ac from a low voltage transformer and it did bring them back to life, even tho my preferred method is short bursts of 15v dc.

[@ramachandran8666]

Just a relaxing pleasure to watch, listen and LEARN. You have the gift of a unique yet pleasing and often funny in a very entertaining way on such "hard to crack" subjects such as circuit theory, design, and most importantly the FORENSIC analysis of the pesky invisible yet mysterious Electrons doing their magic all around starting with our BRAINS

[@perz1val]

Would be interesting to see how (if you hypothetically made one) a replica from modern parts would compare in terms of accuracy

[@emilalmberg1096]

Regarding the charging of the batteries, there was talk around 79-80 about pulse charging of nickel-cadmium batteries, mainly among RC car people, they want to get as much as possible out of the cells. Yes, the batteries don't care, they charge fine without a smoothing capacitor. -I hope you put the old components inside the device, so future electronics guys can see them, I do that when I renovate tube radios...

[@sarahjrandomnumbers]

Can confirm, I also heard of pulse charging ni-cad's, but to stop tin whiskers and to stop the dreaded "memory effect". There's always some bullshit going with batteries, like compressing the crap out of lifepo4 cells. Sure, it can have benefits in certain applications, but like with pulse charging, if you aren't using it in that very specific application, it's pointless. But everyone will do it cause they saw someone else doing it, and then it becomes REQUIRED. 🙄

[@zyeborm]

​@@sarahjrandomnumberstbf the lifepo4 manufacturers do (sometimes) specify compression as required or recommended. Though from memory it's a great deal less than what some are advocating

[@sarahjrandomnumbers]

@@zyeborm When you do the math, for ESS usage, compression is pretty much pointless. 280ah full cycle every day is many years, then take into account you're not doing a full cycle a day, and that you're not hammering them at 1c, and shelf/storage life is more of an issue than compressing. kzbin.info/www/bejne/haTZgYyta82ifsU Again, compression is something that people saw in the datasheet, then the diy crowd went insane with it, just like pulse charging nicads. Compression can help in CERTAIN situations, but for the diy crowd, the cells will degrade naturally long before cycle life is an issue.

[@lmamakos]

@@sarahjrandomnumbers Back in the day when I was hanging out in the college ham radio club, we used to "resurrect" old Motorola HT-220 batteries we got for cheap at the hamfest by "pulse charging" them with 15 or 20 amps with very short duration pulses. The theory was that we could zap away the whiskers that were internally shorting cells in the battery pack, without actually exploding the pack in the process. We did manage to avoid the exploding part, though unclear how successful that strategy was. But we were poor college students and that was cheap fun, flirting with danger.

[@MCsCreations]

Awesome looking device indeed, Marco! Fantastic work! 😃 Stay safe there with your family! 🖖😊

[@wixybelle1048]

I did some research about 8 years ago on the affect of DC compared to DC plus various AC components, and after 2 years, multiple batttery chemesties, the conclusion was that the charging had approx. 3%-5% advartage over straight DC for lithuim & NIMH with Lead acid batteries tested but not quantified, these tests were not long enough to account for sulphation effects, but the test batteries were discharged at almost their max capacity, hope this helps, love the channel, many thanks for your hard work, regards

[@jimsvideos7201]

Some dudes hotrod cars, some dudes hotrod computers, this dude hotrods voltage references.

[@brothertheo2677]

I think you might have condemned the multiturn trimpot. It is being used in ratiometric mode. Pot values have a high tempco, but their ratios drift a lot less. Also if you look at the total divider, the pot has a tiny influence on the voltage.

[@KallePihlajasaari]

I think the contact resistance of the wiper may be what is triggering him. I would also normally not care but due to the nature of this instrument I am ok with the replacement and choice of part.

[@DanielHeineck]

That kind of circuit analysis is my monologue pretty much every day at work :D

[@azizzorba5930]

du bist DER König der mess und regelungs electronics für mich.

[@einnicernutzer]

I always get excited when u upload a nee vid, great work 👍🏻

[@samuelschwager]

that shirt brings all the girls to the yard

[@whatbee]

what is the name of the readout component at 16:48?

[@nrcha]

I came here to see U2, but I still haven’t found what I am looking for.

[@NNNILabs]

falstad simulation running smoothly with real opamp model 🥶

[@billcodey1430]

U2 was a great band.

[@benedienst]

What an overkill of precision replacement parts for a unit which was already not only more than a short term stable transfer standard when it was still in production. I still have one sitting above my desk working as such. I like it‘s construction and the fact that you can trim it to match your reference group voltage calculated from it‘s history chart and do artifact calibrations on several calibrators in a row not having to enter a awkwardly odd number into their front panels.

[@Nikolasz1173]

Based Stargate reference

[@gataness]

Great video

[@TeslaTales59]

Very cool instrument!

[@tinygriffy]

Neat little handhold DHD ... all Chephren were engaged and locked .. you should see that beautiful wormhole to Delta Resistonis :P

[@MiggyManMike]

Id be curious to see how much, if any benefit could would get my replicating the board with one made using a modern pcb fab process ?

[@discobecky9179]

babe wake up new marco

[@douro20]

I've seen that "Dickson Electronics" logo before but always thought it was an old one for Diodes Inc, which was around back then as well.

[@galaxy5am987]

We want more of your cnc videos please. 😊

[@alexcrouse]

Good god that MXO44 scope. I need to hit the lottery.

[@pranjal3727]

Yayyyyyyyy new video

[@cobalt_plated_eyeball]

What self tap screws are you using on the ADRmu references?

[@hgbugalou]

Dang. All I find at flea markets are counterfeit Gucci clothing and Chinese video game systems preloaded with pirated NES and SNES games.

[@powerwall]

Do you review 5.12Kwh, and 11.8Kwh battery?

[@cheater00]

Is that lead free solder?

[@franzliszt3195]

Carbon resistors go bad with age?

[@reps]

allan bradley style carbon composition types yes, absolutely

[@talkingdot]

ahhh NiCad batteries we try and get away from them but I don't think we ever will at this point and that is okay

[@pcrengnr1]

Marco, thx for sharing. So, the end game was to improve the tempco not the accuracy. Like one of the other commenters said the pot is used in ratiometric mode so you could and should return that to the crkt. Then you'd have the accuracy again. Also that old Fluke voltage std seemed to have been quite exceptional. Fluke does seem to know what they were doing even back then. So, today their products must be untouchable even by aliens. Again, thx for sharing.

[@KallePihlajasaari]

The pot and much of the other changes were for long term stability in the end, that is what his long term logging research is all about. At these accuracy levels everything as about stability. The exact value does not matter as you transfer the standards from one instrument to another and have to allow for some error so a bit more makes no difference.

[@DiaconescuAlexandru2024]

13:09 KDE user 🤝

[@Duracellmumus]

Because the reference is zener based I would stay with the original component set in a critical area if they are not have masive temp drift or self noise isues.

[@gsuberland]

as soon as I saw that multimeter I heard "CHEVRON SEVEN LOCKED"

[@shreeshbajpai3794]

I love these cuz I understand nothing yet feel smart asf

[@hinz1]

Mod till it breaks?

[@LoomisRex]

why is this obsession for voltage standards and ppm's, what do you use them for ?

[@jan.tichavsky]

To have firmer grip on reality, of course.

[@cvspvr]

ppms is a highly addictive drug that has destroyed the lives of many brilliant electronics engineers

[@EdwinSteiner]

He uses them to test the voltmeters he needs to check his voltage standards, obviously.

[@mikemiller4838]

Kind of Like when Rick showed Morty what true level felt like. And he was never the same again.

[@TheCommuted]

Use vinegar or hydrochloric acid because it evaporates without needing cleaning.

[@zyeborm]

If there's a base on there you will leave a salt residue. Vinegar by itself can leave solid acetic acid behind. I would normally suggest using a carbonate if there's an acid or a base to neutralize then follow up with several rinses to get rid of the salt that gets left over. Advantage of the carbonate is you don't care if it's acid or base and you can dump an excess of it on there and it won't cause additional acid/base damage.

[@mallewax]

where can I buy this silly shirt? :O

[@larry785]

I wonder if "The Trust" has anything to do with that Russian-made multimeter?

[@tuff_lover]

It was really hard to watch past 10:50, but hey, you probably know enough about this.

[@Dieseleux]

Nice video! NIMH battery dont last long with trickel current, NICD are far more tolerant in this mode. check the capacity of your battery periodictly. Lead acid, NICD and in some case, LIPOFO4 permit permant stanby current.

[@tissuepaper9962]

LiFePO4*, "lithium-iron phosphate"

[@robinc.5077]

NiMH can be trickle charged at C/50 (0.02C) indefinitely

[@TheDefpom]

LOL @17:05

[@tmmtmm]

Ah yes, my quarterly dose of stay-bility has arrived

[@MeriaDuck]

11:10 oh you youngster... 1975 is a special year to me as it was the year I came into existence 😂

[@MeriaDuck]

16:52 😍 never seen one of those! Cool potentiometer.

[@JohnScherer]

So cool!

[@YoutubeSupportServices]

Wow! All that just to swing your JBC in everyone's face?... 😅

[@neilbryan6507]

No Reps, I was just starting to enjoy the beautiful detail and then you told yourself to stop. This was suboptimal, please continue at the correct level of information exchange. Thank you.

[@vergildvb7702]

The pcb just has no metallized vias

[@Scrogan]

Nice thumbnail

[@fredio54]

CuTe

[@devjock]

Chevron 3 encoded

[@mikemines2931]

Bee utif hull.

[@hongotopiadada7574]

there is no "to much information"

[@colettekerr279]

It me, the Cu Te one

[@Scorry]

ТТ-3 has nothing in common with radiation or nuking. Bakelite bodies were usual for devices at this time range. Moreover, I guess that this design was stolen from some another western-made device. And ТТ-3 is not supposed to measure vertically, but only horizontally. See symbols on the scale.

[@mohinderkaur6671]

Now that the R&D and testing is done and you have the data, please restore this back to original along with the metal can opamp and the fluke wirewound resistors and the trimpot. Much better to keep it original.

[@michal_stefik]

Today first! 😁

[@-MrDontCare-]

Second 😅

[@k9elli]

rep rep

[@TitanOne1337]

What's up with Marco's voice? Too many recitings of dark incantations to get the blessings of the ppm gods? Sounds a bit strange to me in the first couple of seconds to me

[@reps]

What's the difference you are hearing? I had a pretty loud device right next to while voiceovering this one and used some adaptive noise filter ... thought it was practically unnoticeable?

[@TitanOne1337]

Might just be the tinnitus from a friend exploding a few (read as: literally 100) tantalum caps not far from my ear by accident messing with me, but it sounded a bit groggy to me, lol

[@zyeborm]

​@@repsit sounded fine on my phone speaker but really messed up on my headphones. Can't really give you any more info than that sorry lol

[@cvspvr]

he has just received a firmware update that improves his ability to imitate humans