Hi I'm at Uh here in Melbourne at Agilant Technologies and I got Peter da with us and we've got something absolutely fascinating here. Bit of uh, bit of, well, a lot of history behind this, right? Pete Yeah, Brief A Brief History of Agilant Time We um, Agilant Technology stopped making uh, atomic clocks about 10 years ago. We we sold that division off to another company. uh, our in-house standards here.

The the 50 71s have been in operation here. Uh with our company uh, at different sites since about 1994. Prior to that, we ran off uh, this atomic clock which is a 5061 Model 50 5061, 5061 Cesm beam frequency standard. It's uh, the company Plant number two Two.

So the company inherited this. Uh, this atomic clock in 1967. Yep, uh, from Roseville in the States. Prior to that, it was used uh in the flying clock experiments.

Now the fly. the flying if if you think back to the the dawn of the Space Age which was certainly before my time. Uh, well, not quite. But um, at the dawn of the space, they they needed to synchronize World Time Yep, and they had these atomic clocks.

and they sent these atomic clocks around the planet, reference to the atomic clocks that stayed in Santa Clara and a synchronized world time. But aside of because they sent the clocks in different directions around the planet and different places, they were able to do a calculation relative to um, what was in Santa Clara and they showed that there was a there was a trend that indicated that Einstein's theory of Relativity was actually valid was actually correct. So this is one of the F clock atomic clocks? No, no, this is plant number two. There was.

There was a number of them. Oh, there was a number of there, a number of them. So they flew whole pile of them. pile of them in directions and each one came back to the reference clocks.

Uh, and we measured against them. We're talking a phase difference. They they had huge batteries. You saw the first flying clocks they did.

There's some pictures on the the old HP web page. Uh, and they show a what's a strat liner I Think with a atomic clock coming off with a battery a battery pack because you have to keep it continuously running for the otherwise. Otherwise, repair it down, you lose, it becomes an unstable atomic clock and you don't want unable nuclei hanging around so well. No.

I know. But um, yeah. So what? they did What they're able to. they demonstrated that Einstein's theory of Relativity may be valid.

but unfortunately, the uncertainty of measurement was actually great than what the trend was. So even though they had a linear A linear progression, the uncertainties associated with that measurement were greater than the linear progression. So technically, they didn't prove Einstein's not so much. not so much later.

But they got a real good warm fuzzy right Because trending in the right dire was that was. that's my understanding. Good Anyway, So this particular atomic clock uh was was one of the flying clocks was one of the flying clocks. Let's take a look at it, shall we? And here it is here.

And yes, folks, we are going to take the covers off. but um. somebody I tweeted a photo of this and somebody mentioned that they haven't seen one with a dial on the front before up here. That's a that's Is that a custom? No, No, that's that's it's an option for it.

So it's um, they they were. there was the 5061a. There was a an earlier version of it, right? Um, the first. Uh, Now back in again in 1967.

H PR acquired the the license for the manufacturer or the patent for the manufacturer of the portable beam. Sean Beom Tube, right? Which is this magnetic tube here? Originally it was uh uh, manufactured in conjunction with a company called Varan In the US who? uh who were specialist in in vacuum tubes and the like. They make Chrons, they all sorts of really cool old stuff. Um, in fact L Enough Agilant.

Uh Acquired a life sciences company in 2010 and it was variant variant. So that's how you ended up with this here. Well, no, well, that's that's that. A bit of synchronicity there I Suppose.

So um, yeah, so that's just and funnily enough. one of the one of the guys from Varan um, that was the the PHD guy that helped design this thing was named Rod Daly Absolutely no relation, no relation to Peter So U Yeah so this is this is the inser. This is Hightech 196 vintage. If we look at the Uh manufacturing day, it's uh, look at that.

It was made in 1962, 1962, 1962 before I was born. So it was a good year and it's got a one pulse per second output. It's got 100 K So it's got a divider output. Yep, um the one pulse per second? it's It's derived from the the the L Now when you talk about atomic clocks and and you'll you'll hear numbers thrown out the world.

That says an atomic clock will lose 1 second in 15,000 years. Um, it's it's a great claim. Uh but unfortunately the the the season. the magnetic tube uh is good for between 20 and 30 years right? So this wouldn't be operational anymore.

No right, No, it's uh it. It was retired about 1994. I think from memory uh and our and replacement season Boom tube took over from could you refurbish them these? No, no it's just it's just out of support. If you look at the if you look at the controlling um the controlling in instrumentation associated with it.

this is all done by computer now. Uh, it's it's got its own microprocesses built into it. still functionally the same. What you have is uh is a a temperature controlled Crystal oscillator M which gives you terrific short-term stability that's driven by a Be tube which which it's pH stock loop system but the seasoning be T gives you terrific long-term stability.

Long-term Dri in conjunction in conjunction with the short-term stability of the temperature controlled. Crystal Oscillator Got it fantastic right? So it's a Cesium disciplined temperature controlled Crystal Oscillator. Ah yeah, it's it's a temperature controled Crystal Oscillator driven by a Cium Beam standard? All right. So um, the resonant frequency of the particular isotope.

You can look it up. it's it's on the web Google Your friend in this case? uh, we used to have a guy that could recite the the resonant frequency to 14 digits I think 14 digits. um uh but were his his bread and butter. So what else have we got in here? Uh so that's your your clock.

You've got power supplies. Uh, you've got the Cium Beam Tube is a vacuum tube but it's it's it's a magnetic tube. It's got a a magnetic field associated with it and what it does, it has about 7.5 7.2 to 7.5 G of cesium coated on the cathode of the tube. y so th for those of you that um remember vacuum tubes uh this the cathode is at the bottom.

what it actually does is boil that that seven half gram wor of cesium off the off the cathode over the life of the tube. so it actually gets uh gets transferred to the anode and once it's all gone, you need a new. That's it. All right.

y As they get older, they become noisier and oh noisier in what respect. Phase noise. Yeah, yeah. Phase.

And so the the phase noise is associated with that aging because it's uh, less cesium there and it's not boiling it off at the same rate. Um, over 20 30 years you start to see that noise become a problem, right? So yeah, so that's an old CL that's oh. it's got a lovely carry handle. Look at that.

How much does this suck away? Oh a lot. I'd have to look it up I'd have to look it up I'd have to get my boss lift the other, grab the other other side of it to help me lift it. That's fantastic. Thanks very much.

Pete All right, so that's good. That's it. Port Portable He portable se you to Fantastic Thanks Pete So.