This circuit was obtained in a 1975 documentation. The maximum frequency depends on the diodes and the FET. Type 1N34 diodes and a FET BF245 can be used for frequencies up to 100 MHz.
This circuit was found in an old documentation for radio amateurs, being indicated for...
The transmitter we have described, operates at a frequency between 88 and 98 MHz, with a range of the...
This circuit beeps when the sensor is triggered by the opening of the freezer door or other...