In this transmitter circuit there is an extra RF power amplifier stage using 2N3866 RF power transistor.after the oscillator stage to increase output power to 250mw.Where we are using a good matching 50-ohm ground plane antenna or multi element yagi antenna.This transmitter can provide us a reasonably Good strength signal up to a distance of 2Km.Here transmitter oscillator is built around BF494 transistor T1.It is lowe power variable frequency VHF oscillator.The varicap diode D1 is used for the tuning of frequency of the transmitter and to provide frequency modulation by audio signals.The output oscillator is about to 50mw.where is transistor(T2) 2N3866 forms a VHF class A power amplifier.which boosts the oscillator signal four to five times.Then 250mw of power is generated at the collector of transistor T2.
No comments:
Post a Comment