Equivalent operational amplifiers can be used on this crystal-controlled oscillator. The circuit is from old documentation and can be changed to operate on other frequencies.
This circuit activates a relay when the conducting bars (probes) are held by a person. The circuit is...
Found in a February 1970 Radio Electronics magazine article describing applications for the...
The transmitter we have described, operates at a frequency between 88 and 98 MHz, with a range of the...