4-transistor tracking transmitter

Plate Touch Sensor Circuit

This system operates on the principle that capacitance loading of an oscillator will lower its frequency. When a foreign body comes into contact with touch plate, the frequency of Ul is lowered.

50MHz Transmitter alarmer with PIC16F84

This project is about an IR-detector (Infra Red) combined with a 100mW 50MHz transmitter. The detector is sensitive to changes in IR-spectrum and is commonly used in burglar alarms. When the detector sens a person/animal/ghost/angry clown, it will transmitt a warning signal to a portable...

Single channel Transmitters and Receivers at 27MHz and 49MHz

Here is the 9 volt GS transmitter which does not use a crystal. This clever design allows only two transistors to generate both the carrier and and the modulation. Shown below at 27MHz 40MHz and 49MHz:

GSM Automatic Meter Reading

GSM based Automatic meter reading, or AMR, is the technology of automatically collecting data from energy meter and transferring that data to a central database for billing and/or analyzing. The Transmitter is connected to the meter and it counts the pulses from it and displays it over the LCD...

Gate Deep Oscillator

It`s just a variable oscillator based on a bf245 or k 161 fet. By changing the coil it can generate frequency between 0.5 and 300 MHZ. this circuit is useful to test radio circuit such as filter, receiver, transmitter and so on . It can be use for coil tuning thanks to the 100microA meter .It...

AM DSB TRANSMITTER FOR HAMS

The circuit of AM transmitter is designed to transmit (amplitude modulated) DSB (double side band) signals. A modulated AM signal consists of a carrier and two symetrically spaced side bands. The two side bands have the same amplitude and carry the same information. In fact, the carrier itself...

27Mhz and 49Mhz rf oscillator-transmitter

The modulator and oscillator consist of two NPN transistors. The base of the modulator transistor is driven by a bidirectional current source with the voltage range for the high condition limited by a saturating PNP collector to the pin 4 Vreg voltage and low condition limited by a saturating NPN...

1W-cwtransmitter

This is a little transmitter that could be put into a plastic Easter egg. It delivers approximately 1 W of measured rf output into a 50-0 dummy load, and creates no heating problems with the circuit. The crystal is a series fundamental type, and the power source provides 9 V with a 2-A supply....