Posted on Mar 31, 2013

This unit is easily tunable and stable, consumes little power, and costs less than other types of oscillators tlmt operate at the same frequencies. This unusual combination of features is made possible by a design concept that includes operation of the transistor well beyond the 3 dB frequency of its currentversus- frequency curve. The concept takes advantage of newly available crystals that resonate at frequencies up to about 1 GHz.

Click here to download the full size of the above Circuit.

The emitter of transistor Q is connected with variable capacitor Cl and series-resonant crystal X. The emitter is also connected to ground through bias resistor Rl. The base is connected to the parallel combination of inductor L and capacitor C3 through de-blocking capacitor and C4 and is forward biased with respect to the emitter by resistors R3 and R4. Impedance Z could be the 220-0 resistor shown or any small impedance that enables the extraction of the output signal through coupling capacitor C2. If Z is a tuned circuit, it is tuned to the frequency of the crystal.

Leave Comment

characters left:

New Circuits



Popular Circuits

Audio peak Indicator
Beat frequency indicator
Frequency Divider For Measurements Circuit
Dual Audio Amplifier Power Supply Circuit
Analog and digital electronic thermometer with LM35
Wire Tracer (Transmitter)
ATA5743 ATA5743 UHF ASK/FSK Receiver
Valve Tube Audio/Modulation Amplifiers 15W and 35W