Quote:
Originally Posted by behnamvp
good day
Mr.franco Italy
thank you for sharing project and helping others
don't know if someone asked or no but why you don't use ready oscillator
instead of crystal?
because running high frequency xt is a little bit hard at least at no projects i had success
so, i always use ready oscillators except projects that XT runs by microcontrollers.
i think many members that built your L.R.L also couldn't run XT but they don't know
thank you
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You are right, you could also use the "ready oscillators", but I find that the quartz version is the simplest, even most oscillates even without the capacitor between the emitter and the base of the transistor, in the range 2 - 10 Mhz in my opinion is the best choice. The same scheme also works with 20 Mhz, but it is more critical, also because we are at the frequency limit for quartzes that work in fundamental (harmonic). Furthermore it is necessary to have a waveform as distorted as possible, to have many harmonics and a signal of small amplitude in order not to radiate towards the sensor stage.