A clock unit I came accross

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Why do you think this DIL crystal oscillator is anything special? It is as common as any other DIL encapsulated oscillator. If you are looking for some better (better = low phase noise), get a TCXO or even better an OCXO. They are usually big, 2.5 x 2.5 to 5 x 5 cm size. I bougt a Motorola TCXO an replaced the crystal in it, it was an easy job, because the metal can was fixed with screws. Narva also produces TCXOs and a lot of others, as well.
 
oshifis said:
Why do you think this DIL crystal oscillator is anything special? It is as common as any other DIL encapsulated oscillator. If you are looking for some better (better = low phase noise), get a TCXO or even better an OCXO. They are usually big, 2.5 x 2.5 to 5 x 5 cm size. I bougt a Motorola TCXO an replaced the crystal in it, it was an easy job, because the metal can was fixed with screws. Narva also produces TCXOs and a lot of others, as well.
Please, is it possible to decode the abbreviations TCXO and OCXO.
I really do not have any idea how good in phase jitter is the device I've got. I assume it would not be as bad as regular cristals because it has built in generator together with the cristal in one package and communicates with the external world with power, GND and clock out pins. At least I guess the jitter performance is limited and guaranteed, but I could not find any data about it...
 
TCXO = Temperature Compensated Crystal Oscillator
OCXO = Oven Controlled Crystal Oscillator

The temperature stability has no benefit for audio indeed. But these devices are usually built for radio communications equipment where the phase noise is critical. The small DIL (Dual In-Line) encapsulated modules are used in PC cards, digital measuring instruments and elsewhere where small size is important. Generally there is a simple Pierce oscillator inside, built around a TTL inverter 74HCU04 or a programmable divider, which is not bad, but nothing special. The crystal gets full 5V swing which is not good for low phase noise. The "big" TCXOs have one or more transistor inside, and the voltage on the crystal can be kept below a few hundred millivolts. And a single transistor is generally lower noise than a TTL gate. There are exceptions of course... Look for something designed for industrial use (broadcast, etc) on this page:

http://global.kyocera.com/prdct/electro/product/timing/hpxo.html
 
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