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Old 28th Jan 2023, 7:47 pm   #9
Philips210
Nonode
 
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,573
Default Re: Crystals for David Looser Modulator

Hello.

I was wondering about the suitability of crystal oscillator modules as opposed to just using a crystal.

The XTAL oscillator modules produce a square wave output and are commonly used in digital circuits for a clock signal. The Band 1 VHF modulator would normally use a crystal or LC resonator for the required frequency. These are sine wave oscillators.

Using an oscillator module for the vision and sound carrier could well be problematic due to all the harmonics associated with a square wave.

OT, but related to clock oscillator modules, I saw an interesting project for a RF Inductance Meter that uses crystal oscillator modules for the RF test frequency. A suitably selected capacitor on the output tames the dominant harmonics. The project was by N5ESE and can be found here: https://www.n5ese.com/l-meter.htm

Regards,
Symon
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