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Simple but high efficiency of this circuit is a Colpitts oscillator for VHF. Ideal for higher frequencies above 50 MHz, Colpitts oscillators are used for VHF parasitic capacitance of the circuit is in parallel with the feedback capacitance desired and causes no undesired spurious resonances which may occur with the Hartley oscillator. The circuit above is a VCO FM, it is a grassroots project with grounded feedback from collector to emitter. A Colpitts oscillator is a series of designs for electronic oscillator circuits using a combination of an inductance with a capacitor to determine the frequency. Make an Oscillator 50-300 MHz Colpitts Type Circuits Diagram

Two octave wideband amplifier (covering both the civil and military airbands between 100 and 450 MHz), equipped with two MOSFET devices, which is capable of generating 250 W of output power are given on this design procedures and measurement results report. One of the two octave wideband amplifier has to use the device s with the output capacitance reduced to the utmost minimum in order to achieve a good broadband capability. It was possible to obtain a respectable power gain of more than 10 dB throughout the whole band while applying PHILIPS’ BLF548 MOSFETs. The BLF548 is a balanced N-channel enhancement mode vertical D-MOS transistor in a SOT262 package. This device is especially designed for use in wideband amplifiers up to 500 MHz. 150 W nominal output power at a supply voltage of 28 Volts can be delivered by the transistor. The attainable bandwidth will exceed 300 MHz due to the low output capacitance. Notes 1. American Technical Ceramics type 100B or capacitor of same quality. 2....

Circuit diagram This circuit is a 73 MHz Hallogene Lamp Radio-Controlled. The purpose of it is to control the power state of a hallogene lamp by a remote control. When we press the push botton of the remonte control, the power state of the lamp will be changed, so, if the lamp was turned on, it will turned off and if it was turned on, it will turned off. If we press to the button another time, the same action will be occured. When the button is pressed, a LED indicator lights on the remote control. The system is consisted by two separate circuit. One is the remote control, or the emmetor. The other is the receptor, or the hallogene lamp controller. We plug the input of the lamp controller circuit to the 120VAC source of the sector to supply it. The lamp must be pluged to the output of the circuit to be supplied and controlled. The controller circuit has also an antenna to receive the signal of the remote control. The remote control has also an antenna to transmit the signal to the cont...