Ionut Catalin Patitoiu that's the same way we used to do the color convergence adjustment on the old analog TV sets back in the day.

+Star Gazer much better an active maser :)

+Star Gazer What do you mean by 'disciplining' the rubidium frequency? You can't "discipline" a rubidium frequency. The only thing I can think of is - not disciplining, but synchronising. You sure you're not talking about disciplining a voltage controlled crystal oscillator? The other thing is..... I haven't been able to find anywhere the meaning of a 'disciplined oscillator'. I'm assuming it means 'synchronised' or 'phase-locked to'. Pretty weird how there appears to be no formal definition of 'disciplined oscillator' out there. Not good when these two words are used blindly.

+Kenny A "disciplined" clock/frequency source is one which is actively and almost continuously adjusted in both frequency and phase to match one or more better time/frequency sources, such that the disciplined device provides a very good extrapolation of the outside time source, which may only be available some of the time. For example, the GPS radio signal provides the time and date every 1.5s, but only to the extent it actually picks up enough satellite signals to compute the radio delay from space through atmospheric disturbances and past the background noise, as a close US ally, that GPS receiver board might even be one of the classified models that sync to the secret hires part of the signal. Those GPS satellite clocks up there are themselves disciplined by adjustment commands from the relevant US military team to closely match the official US IAT reference clocks. National time labs then compare their deltas from the GPS signal to help establish the weighted average which is the official International Atomic Time. (UTC is IAT minus a whole number of leap seconds).

The output of a rubidium oscillator is typically a 10MHz signal that is phase locked to the 6.834GHz excitation frequency that is tuned to resonance with the excited rubidium gas in the physics package. While this excitation frequency is very stable once set, the resonance frequency of rubidium is variable and must be tuned by applying a magnetic field to the rubidium chamber. You have to tune a rubidium oscillator to get it 'on frequency'. You normally do this by 'disciplining' the source by periodically or continuously comparing it to another (better) source such as a cesium oscillator via GPS, learning the rate at which the rubidium changes with age and temperature, and adjusting for those changes automatically. As a practical matter, there is a voltage controlled tuning input on rubidium oscillators that varies the magnetic field applied to the chamber, and thus the frequency of the 10 MHz output. Disciplined oscillator simply means an oscillator whose output is being corrected over long time scales by comparing it to another oscillator. It is more than simply synchronizing the phase or frequency. A DO learns the rate of change of the oscillator and continues making those corrections even when the reference is no longer available. So a GPS disciplined rubidium oscillator will continue to make corrections to its rubidium even when the GPS signal is no longer available to sync to, based on the change rate it learned while GPS was available. This generally increases the stability during the 'holdover' period when the oscillator is free running. The actual oscillator being disciplined in a GPSDO can be of many different types, such as quartz based, or rubidium. Quartz having better short term stability (seconds to minutes), and rubidium having better long term stability. If the GPS signal is always available to discipline the oscillator, then quartz is fine. If you need longer term holdover characteristics, such as for cell site synchronization, then rubidium is typically used.

GPSDO without any rubidium, only with good TCXO can give 0.1ppb precision.

If you write stuff in German to an English-speaking community, at least make it understandable to native German speakers!

+Joshua Wiedekopf (LtSurgekopf) so that's complete gibberish? I'm curious cause it seems my youtube nickname is mentioned, I wonder what that is about

mrfurball​ maybe not complete gibberish, but completely without context to the video. Also, your screen name is not actually being mentioned, that's "Fussball", the German word for soccer.

mrfurball​ actually, this is pretty much gibberish. I'll try to translate: "I have no video, just TV not really you know back then more soccer, skiing, bowling 3 sport now not anymore. More light mountaineering Gotti [which I presume refers to the name]". So yeah, pretty weird stuff.

Also, I tried to be faithful to the sentence structure used by the OP, which is just horribly horribly wrong.