Archive for category: RF Radio circuits

Wireless DIY Hardware Keylogger

RF Radio circuits | By: Diagram mania

This is a do it yourself wireless hardware keylogger project, consisting of a logging unit with a 2.4GHz transmitter, and a USB-based receiver. The project includes the schematics, PCB design, firmware, software and lots of additional files and data. A wireless keylogger is a perfect solution for monitoring user activity, at very low risk of […]

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

VOX Circuit

RF Radio circuits | By: Diagram mania

VOX is a switch ordered by voice, often used at microphones instead of the classic switch button. The vox described here may be connected to almost any type of audio equipment which has an external speaker for coupling. The threshold action is set with volume potentiometer of the audio amplifier which commands the VOX . […]

2M 144MHz Push Pull Amplifier DV28120T

RF Radio circuits | By: Diagram mania

2 meters 144MHz push pull amplifier wich can generate 200W, how does it sound Sounds delicious with 2 DV28120T transistors. DV28120T push pull amplifier circuit diagram

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 […]