WIRELESS and FM CIRCUITS
AM Receiver
-This is a compact three transistor, regenerative receiver with fixed feedback. It is similar in principle to the ZN414 radio IC which is now replaced by the MK484. The design is simple and sensitivity and selectivity of the receiver are good.
MW Active Antenna by David Sayles
-Finally this active antenna can be used on other bands by changing the values of the 330uH coils. To perform on multiple bands switches or relays can be used to change the value of the coils.
Q- Multiplying Loop Antenna ( David Sayles )
-This circuit is designed to be used in conjunction with the standard 4 foot square loop used in MW for long distance reception.
4 Band Double Tuned Preselector ( David Sayles )
-The circuit requires an RF input which can be from a longwire or a loop antenna.
ZN414 Portable AM Receiver
-An AM portable radio receiver made from the ZN414 IC. The ZN414 ic has now been replaced by the MK484 which is identical in performance and pinout.
SW Receiver using the ZN414
-A Short Wave Receiver based on the MK484 (formerly ZN414) that includes the tropical bands and 49 metre bands.
2 Transistor FM Transmitter
-Take care with transmitter circuits. It is illegal in most countries to operate radio transmitters without a license. Although only low power this circuit may be tuned to operate over the range 87-108MHz with a range of 20 or 30 metres.
FSM Field Strength Meter
-This is a wide band signal strength meter circuit which responds to small changes in RF energy, designed to be used for the VHF spectrum and will respond to AM or FM modulation or just a plain carrier wave.
FM Transmitter by David Sayles
A small FM voice transmitter for Band 2 VHF
FM Transmitter with Opamp by Kamram Ahmed
An low power FM Transmitter using an op-amp as the audio preamp and a single transistor as the RF amplifier.
UHF Preamplifier
This circuit is designed to work at UHF frequencies in the range 450-800MHz. It has a gain of around 10dB and is suitable for boosting weak TV signals.
AM Transmitter
Another simple audio wireless transmitter
2 Transistor Transmitter by Rob
A compact 2 transistor transmitter for use at VHF frequencies.
Bipolar Regenerative receiver by Ramon Vargas
FM transmitter by David Celestin
A portable FM transmitter that can be used to replace a wireless microphone.
30 Watt VHF Amplifier by David Celestin
The circuit is designed to cover 88-108MHz FM Broadcast Band. However, the circuit is very stable at my place and provides a clean-output through seven (7) element Butter-worth low-pass filter.
Miniature FM Transmitter
This miniature transmitter is easy to construct and it's transmissions can be picked up on any standard FM receiver. It has a range of up to 1/4 of a mile or more
Micro Power FM Broadcasting Circuits
they can be used to produce stereo modulation for mono FM transmitters
Long-range FM Transmitter
The 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 transmitter can provide reasonably good signal strength up to a distance of about 2 kilometres.
FM Wireless Mic
FM Wireless Mc can transmit voice signals to any FM Radio receiver 100 meters away. The circuit is basically a frequency modulated transmitter working at 100 MHz
Infa-Red Remote Control
This remote transmits a tone using an infa-red LED. This tone is decoded by the receiver.
IR Remote Control Jammer
This circuit does all that and more by jamming most IR remote signals.
Infra Red Switch
This is a single channel (on / off) universal switch that may be used with any Infra Red remote control using 36-38kHz.
IR Remote Switch 2
Here is a simple circuit to remotely switch on/off any electrical device through a relay using the normal TV/VCR/VCP/VCD remote control unit.
Long Range Infrared Remote
You can construct your own long range infrared (IR) wireless remote using Motorola's MC145026 emitter and MC145027 detector chips.
PC IR Remote Control
PIC16C505 IR / Wireless Remote Control
Control up to 8 devices by this easy constructable remote control. It can work as a radio or infrared remote control, depending on the components.