Figure 1, below, shows the 10.58 to 10.74 MHz VFO oscillator circuit. Yes, this is the same circuit that was presented last time, but I’ve re-drawn it to show the Colpitts oscillator more clearly. “L” is approximately 1.5 uH; 19 turns in a T50-6 core (yellow). The value of C6 is found experimentally. I used [...]
With the circuit shown here you can create high frequency electromagnetic waves with very high output power. Possible applications are experiments with wireless power transmission, RFID Transponder, tesla coils and the like. Dependent on the coil, capacitor and cooling of the transistors output power in the range of 20W and more can be obtained. At [...]
This simple metal detector requires alone a scattering of apparatus and an evening’s work. Congenital about a cmos4011 IC, is actual able-bodied and versatile. The 250 kHz advertence oscillator is congenital with two gates (U1/1 and U1/2), C1, R1 and P1. The chase oscillator uses alone one aboideau (U1/3), two capacitors and the chase coil. [...]
Producing low-distortion sine waves, this oscillator operates over the range 16 to 22000 Hz. The circuit is based on two articles that have appeared earlier in Wireless World – Roger Rosens’ “Phase -Shifting Oscillator”, February 1982 pp. 38-41, and J. L. Linsley Hood’s “Wien-Bridge Oscillator with low harmonic distortion” from May 1981 pp. 51-53. This [...]
