Apr 06, 2020 09:00:00

A 60-year-old HP `` atomic clock '' looks something like this, the state of actual operation is also released in the movie

Atomic

clocks that use the atomic and molecular spectral lines to keep accurate time are extremely accurate clocks that are also used to define seconds. Mr. CuriousMarc, who is doing restoration of vintage computers etc., shows how to actually operate such an atomic clock is published on YouTube.

HP 5061A Cesium Clock-YouTube


The luggage loaded on the car ...

Atomic clock `` 5061A '' developed by

HP in the 1960s

At that time, it was used to set the time of laboratories around the world.

Einstein also predicted in a

theory of relativity that speed differences and gravity differences would cause ' time delays ' ...

An atomic clock that was also used to verify that prediction.

The 5061A is an '

atomic beam ' atomic clock using a vacuum tube.

The atom used is cesium, the only

stable isotope without radioactivity `` cesium 133 ''

It has a low boiling point of 28 ° C.

A mechanism that heats cesium atoms to create an atomic beam and measures the frequency to keep time.

CuriousMarc immediately inserted a power plug into the 5061A.

Adjust the instrument on the front panel to generate an atomic beam.

The 5061A specification should produce a 5MHz atomic beam, but measured below a value of 5MHz. 'Perhaps because we haven't been able to fully heat the cesium yet,' says CuriousMarc.

Wait a while and adjust the equipment again ...

Green lamp is on. The atomic clock has been successfully locked on the atomic clock.

The frequency exactly reaches 5MHz.

CuriousMarc decides to compare the accuracy of the

frequency with the GPS-synchronous frequency oscillator purchased on eBay to see if there is an error in the atomic clock.

Display the waveforms of the atomic clock and the GPS synchronized frequency oscillator on the

oscilloscope ...

Display

Lissajous figure . Since the Lissajous figure is stationary, the phase difference has not changed, indicating that the frequency of the atomic clock has no error with respect to the frequency of the GPS-synchronized frequency oscillator.

As with the GPS-synchronized frequency oscillator, the HP counter '5334B' also showed a strong rotation of the Lissajous figure when compared to the atomic clock. There seems to be an error in the frequency of 5334B.

Adjust the 5334B so that the Lissajous figure is still and correct the error. According to CuriousMarc, the atomic clock 'adjusted a completely crazy cheap clock'.