butler vco
Is it possible to make a XVCO from LC VCO like in fig.1? To get XVCO I'm going to replace the L by crystal.
Thank you!
Maybe you want to say VCXO.
XVCO doesn’t exist yet in electronics terminology.
Just replacing an L with a crystal is not enough to get a good Variable Crystal Oscillator.
Now depends by the frequency of the crystal, by the crystal cut, and not to the last by the oscillator type. From what I know, with Butler VCXO oscillator you get the most ppm variation of the frequency.
Thanks for reply,
Let say I need +/-100 ppm variation of the frequency and the freq=400 MHz. Can I use the above circuit just replacing L by crystal ? Does temp stability degrade in this circuit dramaticcaly?
Hard to tell you just from a basic oscillator schematic.
If you have all the transistor models run a simulation, replace the L with a crystal and see what variation in ppm you get.
Generally parallel tank configurations get lower ppm variation than series tank X-tal oscillator.
How can a crystal which is designed, for example, mechanicle vibration at 25MHz would resonate at 400MHz?
Are you saying the crystal is at 400MHz?
To riziahm
It could be a SAW resonator. The operation is the same.
No it is not exactly the same, and note that the L-C can handle much power but the crystal can handle only very low powers. SOme radio amateurs use more than one identical crystals in parallel.