Archive for category: RF Radio circuits

Wireless FM Transmitter Circuit

RF Radio circuits | By: Diagram mania

The wireless fm transmitter circuit described here has an extra RF power amplifier stage, after the oscillator stage, to raise the power output to 200-250 milliwatts. With a good matching 50-ohm ground plane antenna or multi-element Yagi antenna, this wireless fm transmitter can provide reasonably good signal strength up to a distance of about 2 […]

Wien Bridge Oscillator Circuit

RF Radio circuits | By: Diagram mania

THis Wien bridge oscillator is very simple and as every wien oscillator has low distorsion and the resonance frequency can be easily adjusted. This frequency depends on a pair of resistors and a pair of capacitors and is defined by the formula: F = 1/2ΠRC. In this wien oscillator circuit, R is formed by R1 […]

Wideband UHF Amplifier – Antenna TV Amplifier Circuit

RF Radio circuits | By: Diagram mania

This UHF wideband amplifier(Ultra High Frequency amplifier) has a total gain of 10 to 15 dB in the 400 – 850 MHz domain frequency so it can be used where the tv signal is weak. For this UHF antenna tv amplifier to work correctly you need to cut the components pins as short as possible. […]

Wideband Active Antenna Circuit

RF Radio circuits | By: Diagram mania

A 30 to 50 cm whip antenna provides reception from 10 MHz to over 220 MHz. T1 BF981, a dual-gate MOSFET, provides low noise, high-input impedance and high gain. The circuit is powered via the coaxial cable used to connect the antenna to a receiver. Wideband active antenna amplifier circuit

VHF to AM Converter Circuit

RF Radio circuits | By: Diagram mania

There are many people who want to listen whats going on in VHF 108 – 132 MHz. This vhf am converter converts a band between 106 and 150 MHz, so you can listen even 2m radio amateurs (144Mhz). This vhf am converter is build with an vhf amplifier, one mixer and oscillator. After the input […]

VHF Active Antenna

RF Radio circuits | By: Diagram mania

A simple vhf active antenna using a single BFG65 transistor which is a low noise type. The telescopic antenna and the wide band rf amplifier combination is known as an active antenna. The antenna is a 1.6 meter telescopic dipole which works in lambda/2 from 60 MHz to 187 MHz or as a multi-lambda dipole […]

Veronica 1W FM Transmitter Circuit

RF Radio circuits | By: Diagram mania

Veronica 1W FM transmitter is easy to build and to operate in FM. Veronica is also known for frequency stability, clean fm signal and uses no integrated circuit. You may want to check this another 1W FM transmitter circuit. Veronica transmitter is equiped with a mini-mixer and so you may forget an external mixer. This […]

UUS 65 – 73 MHz FM Transmitter

RF Radio circuits | By: Diagram mania

A basic UUS 65 73 MHz fm transmitter circuit schematic which can be used as UUS oscillator with no explanation … 65 – 73 MHz transmitter ( oscillator ) circuit components: L1 = 8 t / 0.3mm / 6mm L2 = 8-12 t / 1mm / 15mm / 1mm gap SRF = 60t / 0.2mm […]

USB FM Transmitter Circuit

RF Radio circuits | By: Diagram mania

Here is a simple USB FM transmitter that could be used to play audio files from an MP3 player or computer on a standard VHF FM radio by connecting it to an USB port. The circuit use no coils that have to be wound. This USB transmitter can be used to listen to your own […]

UPC1651 FM Transmitter

RF Radio circuits | By: Diagram mania

This fm transmitter is build with UPC1651 which is a silicon monolithic integrated circuit especially designed as a wide band amplifier covering the HF band through UHF band. UPC1651 has a high power gain: 19 dB at 500 MHz, low voltage operation 5V in a small package. The coil has 5 turns of 0.5 mm […]