This crystal oscillator is indicated for the calibration of IF steps of common radio receivers. The transistor admits equivalent as 2N2222 or BF494. The circuit is from an old American publication.
This simple standing waveform (ROE or SWR) meter is used to adjust antenna matching with...
The 4046 consists in a PLL with na internal oscillator controlled by voltage (VCO). Figure bellow...
This microtransmitter operates at a frequency between 3.5 MHz and 10 MHz determined by the...