CuriousMarc - 2024-11-05
A generous Patron donated this incredible analog-electro-opto-mechanical clock that was once used to synchronize the world to a microsecond. Let's find out what makes it tick, literally. HP 115BR Playlist: https://www.youtube.com/playlist?list=PL-_93BVApb5-_7sWRxQ0on8vNy7_H-zxS Link to the HP 115BR Manual: https://bama.edebris.com/download/hp/115br/HP_115BR_frequency_divider_and_clock_op_service_manual_1967.pdf Stuff that supports the channel: - Support us on Patreon: https://www.patreon.com/curiousmarc - Amazon links for the tools I use in the lab: https://www.curiousmarc.com/amazon-links - Channel merch on Fourthwall: https://curiousmarc-shop.fourthwall.com - Legacy channel merch on Teespring (I don't have everything transferred to Fourthwall yet): https://teespring.com/stores/curiousmarcs-store "Elevator Music" Credit: Crinoline Dreams by Kevin MacLeod Our lovely sponsors - PCBWay: fast turn PCBs, https://www.pcbway.com - Electro-Rent: https://www.electrorent.com - Keysight: test instruments: https://www.keysight.com - Samtec: connectors: https://www.samtec.com - R&D Microwaves: https://rdmicrowaves.com Get more technical info on the companion site: https://www.curiousmarc.com Contact info: https://www.youtube.com/curiousmarc/about 00:00 Intro to the HP 115BR clock 01:55 The very special synchronization feature 03:05 The 1964 flying atomic clock experiment 04:10 Grand opening 06:15 First power up 07:40 The incredible principle of operation (with elevator music) 13:25 Our instrument has unexplained HP mods! 15:46 Did we just get the flying clock model? 19:08 Reverse engineering the second mod 21:59 Supporting evidence from HP doc 22:49 We understand it now, should be repairable
By this point, I feel there’s no greater human archive than that of “The Doodly-Doo”.
Every time I see one of these videos with any HP equipment I just have to marvel at how brilliant the HP engineers were!
It amazes me the things that people managed to build back in the 1950/60's with a mix of electro and mechanical components. Not only did it work as needed, we can still (well Marc anyway) repair and restore them to their original state.
Ah - regenerative dividers. I recognize that block diagram from the old 5105A + 5110A synthesizer combo. I bent my mind around that way back when this was a brandy new product in the early/mid 1960s. (1964?) The concept almost made it aboard GPS satellites but people were worried about the regeneration starting up correctly. So I broke the feedback and gave GPS a dither error that was proportional to its output frequency. At the accuracies involved here it is noticeable, in the lab if not on the signal from orbit. And it may be different on newer satellites. I worked on Phase IIB.
{^_-}
13:39 I'm not sure whether you'll like this, Marc, but I (we) enjoy when your repairs are never a piece of cake 😆The harder the better, the more nail bitey. 😬
I love the smell of old electronics in the morning. Smells like, well, old electronics.
The future of my country is being decided today. And I would much rather watch Marc and his friends.
precisely my friend
Condolences.
I hear Canada, Cuba and Mexico are all fast tracking the construction of walls.
We did it 🥲
@DrinksInHighPlaces Tyranny for all!
@@richardkaz2336yeah it’s not like there’s an absurd level of emigration from those countries to the US or anything… You are actually mentally ill
Old electronics that put up a fight makes for awesome content so i'm not complaining, though i imagine it's not the most fun for you Marc.
Can't wait for the next video.
Not to worry, it’s more fun for me too when it resists a little bit. That’s when you learn more.
Watching Marc getting curious while I have breakfast, bliss.
"It shouldn't be too hard" the famous last words :) Amazing machinery with special history. Looking forward for future episodes.
Top notch again, Marc! These restoration videos should be standard material in every electronics engineering class.
'shouldn't be too hard' famous last words
This is one of my favorite channels!
The only sad thing about this episode is having to wait to see the next one!
Ongoing outstandingness. This channel is the best! 👍👍
My mouth was hanging open during the explanation of the divider
I watch this channel regardless of my understanding of electronics. Always mesmerizing.
Yess!!!!! So today is not such a bad day after all! Thank you Marc <3
Very Very Interesting! Ill be on the lookout for the next episode!
Thanks to your video, I recognized a brief appearance of an HP115BR in today's PBS Nova program called "Decoding the Universe:Quantum". I love your videos.
No kidding! I must watch that now.
Indeed! This episode: https://www.pbs.org/wgbh/nova/video/decoding-the-universe-quantum/ . The HP 115BR appears briefly at 17:35, followed by the HP 5061A Caesium clock equipped with the later integrated Patek Phillipe divider and clock. Awesome episode by the way, they are right up there with Veritasium. Or is it the other way around?
I loved seeing the synchronous motor, and hearing the sound. I’m reminded of the synchronous motor in my Hammond Organ, which was invented after Hammond heard the 60hz sound of a clock.
Imagine my joy on learning that this particular device might have provided the 60hz reference to a power plant! Maybe even the one that powered the neighborhood where Green Onions was recorded, and thus the machine that kept that famous organ in tune.
I'm really looking forward to this series. Thanks!
Very awesome, super excited to follow along on this one! I have two predecessors to this fine instrument, the analog dial clocks. One 113BR, stock and working as expected. But also a prototype narrowly saved from demise, marked 113X. This also follows no schematics, so your journey here may prove to be extremely helpful! Story goes that it was donated to an IL College by HP (the name of which escapes me). From there I'm not entirely sure what use it served. I then acquired it about 5 years ago at a hamfest, just before it was to be parted out and lost forever. I just couldnt let that happen... Thank you again for letting us follow along with you on these projects! The time and effort you put into them are not in vain!
As always Marc you bring to light these hidden gems of HP imaginative engineering. Always a good watch your videos are. I learn so much! And I hope my meeting you in person at VCF-West didn’t disturb you. You seem to have been not yourself that day. But I really enjoyed Mike’s presentation of the DSKY display repair. Thanks for appearing.
4:49 I love it when you guys describe the smell of things! Cause we’ll never be able to smell it ourselves.
Thank you sir for doing what you do and making it available to us! These kinds of electronics are the reason I got into the field, and your content genuinely makes me emotional!
I will say, at least you don't have to first fix the oscilloscope or pen plotter that will help you fix the thing you really wanted to get running. It's encouraging!
I love these videos and vintage HP gear… thanks for posting it!!
Excellent, as always. I wish my physics classes had used elevator music explanations.
great work
I didn't get a notification for this! I'm subscribed and set to all.
Boo. The Google has failed us again.
@marc ! You have to warn us before spinning up time in the wrong direction! @6:40
Fantastic!
finally some hp stuff again!!! thats why i watch! hp is the best!!!
Can't wait for the next episode!
This has got to be one of the luckiest and unluckiest finds at the same time
Can't wait for the upcoming episodes (although I'm not as on edge since you teased a happy ending :D)
I like the way you first introduce RF wizardy to get things done analog way, then go to simple repair, just to end up with part 2 video 😀
Interesting how much corrosion is on that synchronous motor considering its sealed and the rest looks fine. I really enjoy your explanations and your ability to reverse engineer nightmares.
What a wild little unit, there's a lot of history to it's mods
If I understood even 1% of this I'm sure I'd get more out of it. But ... nonetheless I still truly enjoy this channel as much as any. Maybe you guys could do a colab with Mr. Carlson. His recent barn find is going to be a real barn burner (😉, .c 1930s frequency generator ... I think?). Anyway, great stuff Marc and keep it coming! Thanks
I would love some HP gear like that just to have standards quality devices at home
Great video, thanks! I have the dark gray version of the straight 115BR, former Air Force property. Haven't gone through it yet, still need to finish repairing my HP 105, which had a major power supply failure before I got it.
I also have the HP K22-5321B Nixie clock to run off the HP 105 once it is repaired!
Nice collection! Good luck on the all the HP repairs. Keep them going!
A problem worthy of attack, proves it's worth by fighting back. 🙂 Love your videos!
Beautiful device 😌
OHHHHH ALAN KILIAN! HEY ALAN!!!! no friggen way my friend Alan Kilian is on the Curious Marc Channel LOL! wow!
It’s a little bit of fame!
And this device landed in the one place on the planet it needed to be!
Thanks Marc.
You make it look and feel so easy. Its not :D I would really like to be an apprentice of yours one day.
The aircraft at 3:24 appears to be a Douglas DC-7, which is powered by four (piston engine) Wright 3350 turbo-compounds, not turbo props.
Thanks for the correction. That still flew with pistons? Thanks goodness they didn’t use regenerative dividers in the engines ;-)
One crazy box, what, you have to open it to start it....
Also surprised to see the HP105A, as I have a 105B (backup battery), as the video's usually feature gear I'll never come across.
Thanks for the video Marc, I love the Apollo vids, but a little palate cleanser now and again is greatly appreciated. PS. I sure hope those carbon comps are just used for setting transistor bias points and not for frequency setting.
@KaldekBoch - 2024-11-05
In this crazy time, nothing calms like some CuriousMarc.
@c1ph3rpunk - 2024-11-05
Isn’t that the truth.
@Thijs99 - 2024-11-05
The Bob Ross of electronics!
@intellix7133 - 2024-11-05
It's so... fascinating to see him tearing apart these old devices and bringing them back to life. The amount of patience and experience required is out of this world !
@Thijs99 - 2024-11-05
@ Mr Marc has the gift to explain very complex things in away that they are sound simple.
@brunoramey50 - 2024-11-05
It's a crazy time, yes, but with nanosecond accuracy !