I start this thread to investigate the opportunity for a diyer to build a real low jitter oscillator.
The great issue for a diyer is that typically he doesn't own the suitable gear to test the performance of an oscillator, so the results are uncertain.
The equipement to test the phase noise of an oscillator starts from some tens thousands dollars, and a diyer can't afford them.
The true guru in this matter, that you probably know as Jocko Homo, has demonstrated that one could build a low phase noise oscillator taking a crystal from the shelf with a simple pico gate. He did reach -122 [email protected] from the carrier for a 11.2896 MHz oscillator, that's an impressive result.
But he did a strong selection of the crystal using a phase noise measurement system that costs 30,000 USD or more.
Moreover the crystals he had used, around 0.5 USD each from Mouser or Digi-Key, are no longer manufactured, and the supplier don't have anymore in stock. They were the cylinder crystal CSA309 from Citizen.
He also tested the HC49 type, but seems it's not perform like the above type.
You have to consider also that after the selection, only a few crystals can reach similar performance when placed in the oscillator, usually not more than 5%.
The other crystals were throw out, so the cost increases.
That's the reason I believe the goal is to start from a very good crystal, with high standard and repeatable features.
I will experiment with 3 kind of oscillator circuit to implement the above crystal: the Clapp crystal oscillator, the Butler two emitters, and the Driscoll.
The first oscillator is almost ready, with its own PCB, then I'll investigate the other two.
In the second and third circuits, the crystal see a very low impedance, and this usually guarantees a very high loaded Q.
When all the circuits will be ready, I can access a university lab to test them with an Agilent phase noise measurement system.
TWTMC project. For Schematics, BOM, PCB and Assembly guide see post #1506
The Well Tempered Master Clock - Building a low phase noise/jitter crystal oscillator
Group buy thread for this project is located at
The Well Tempered Master Clock - Group buy - diyAudio
New oscillators, frequency doublers and sine to square converters from post #3008
The Well Tempered Master Clock - Building a low phase noise/jitter crystal oscillator
Semi-finished boards BOMs update at post #3482
The Well Tempered Master Clock - Building a low phase noise/jitter crystal oscillator
User manuals
The Well Tempered Master Clock - Building a low phase noise/jitter crystal oscillator
The great issue for a diyer is that typically he doesn't own the suitable gear to test the performance of an oscillator, so the results are uncertain.
The equipement to test the phase noise of an oscillator starts from some tens thousands dollars, and a diyer can't afford them.
The true guru in this matter, that you probably know as Jocko Homo, has demonstrated that one could build a low phase noise oscillator taking a crystal from the shelf with a simple pico gate. He did reach -122 [email protected] from the carrier for a 11.2896 MHz oscillator, that's an impressive result.
But he did a strong selection of the crystal using a phase noise measurement system that costs 30,000 USD or more.
Moreover the crystals he had used, around 0.5 USD each from Mouser or Digi-Key, are no longer manufactured, and the supplier don't have anymore in stock. They were the cylinder crystal CSA309 from Citizen.
He also tested the HC49 type, but seems it's not perform like the above type.
You have to consider also that after the selection, only a few crystals can reach similar performance when placed in the oscillator, usually not more than 5%.
The other crystals were throw out, so the cost increases.
That's the reason I believe the goal is to start from a very good crystal, with high standard and repeatable features.
I will experiment with 3 kind of oscillator circuit to implement the above crystal: the Clapp crystal oscillator, the Butler two emitters, and the Driscoll.
The first oscillator is almost ready, with its own PCB, then I'll investigate the other two.
In the second and third circuits, the crystal see a very low impedance, and this usually guarantees a very high loaded Q.
When all the circuits will be ready, I can access a university lab to test them with an Agilent phase noise measurement system.
TWTMC project. For Schematics, BOM, PCB and Assembly guide see post #1506
The Well Tempered Master Clock - Building a low phase noise/jitter crystal oscillator
Group buy thread for this project is located at
The Well Tempered Master Clock - Group buy - diyAudio
New oscillators, frequency doublers and sine to square converters from post #3008
The Well Tempered Master Clock - Building a low phase noise/jitter crystal oscillator
Semi-finished boards BOMs update at post #3482
The Well Tempered Master Clock - Building a low phase noise/jitter crystal oscillator
User manuals
The Well Tempered Master Clock - Building a low phase noise/jitter crystal oscillator
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