This crystal oscillator generates a 20 MHz signal. Equivalent transistors such as BF494 and 2N2222 can be used. The stabilizing diodes can be 1N4148.
We found this circuit in the Linear Applications Handbook of the National Semiconductor of 1994....
This tone-modulated transmitter was found in recent English documentation. The circuit operates in the 27...
This very low current circuit was found in the April 1995 issue of Electronics Now magazine. The...