I have a smal RF UHF oscillator with antenna, for use like sound transmitter. It is colpits osc. How to stable it's frequency ? Because when I touch it or antenna or simply move the device it's frequency untunes. I want to be able to move with hands while it transmits my speach. Many thanx forwadly.
Because
You could try adding a buffer/amplifier stage (or two) between the oscillator and the antenna, AND mount it in a screened metal box, but even then you'll still have temperature-related drift. This became more of a problem with the advent of PLL-controlled receivers which remain dead on-frequency. Older receivers had AFC which could track a drifting transmitter. These days, you need a crystal-controlled transmitter too: either with frequency multiplier stages, or a PLL to generate the final output frequency.
I want to try simple circuit with one ampliffer stage, where to find circuit ?
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