RF Circuit | Next Electronics

A low-frequency oscillator (Q1) modulates a high-frequency oscillator (Q2) along with its associated timing capacitor. The output frequency varies continuously. The circuit comprises two primary components: the low-frequency oscillator (Q1) and the high-frequency oscillator (Q2). The low-frequency oscillator is responsible for...

1.5 Volt Tracking Transmitter

A 1.5 Volt tracking transmitter utilizing simple circuits. The current draw for this tracker is 3.7 mA, allowing the 1.5V button cell to have a prolonged lifespan. The 1.5 Volt tracking transmitter is designed to operate efficiently with a low current...

Small Radio Transmitters

Information about building a small radio transmitter, which has a PCB measuring 1.75" x 2.5" (45mm x 68mm) and has a range of approximately 30 yards. The documentation states that the frequency range is 100-108 MHz, but it has been...

RF Decibel Meter Circuit

A DIY RF decibel (or power) meter is an essential instrument in any radio workshop. However, accurate, wideband models can be quite costly. A DIY RF decibel meter serves as a valuable tool for measuring the power levels of radio frequency...

Beacon-transmitter

This transmitter is suitable for transmitter hunts, remote key finding, or radio telemetry in model rockets. It can be tuned to the two-meter band or other VHF bands by adjusting capacitor C1 and inductor L1. L1 consists of four turns...

modulation

A reason to modulate a message signal is to match the communication channel's frequency. This is necessary because the information to be sent over the channel is often at a relatively low frequency. For instance, the frequency range of music...

Car Wireless Alarm

This FM radio-controlled anti-theft system can be used with any device operating on a 6 to 12-volt DC power supply. The mini VHF FM transmitter is installed in the vehicle at night when it is parked in the driveway or...

Field Strength Meter

This circuit is a wideband signal strength meter designed to respond to small variations in RF energy within the VHF spectrum. It is capable of detecting AM or FM modulation as well as a simple carrier wave. The circuit measures...

MK414 SW Receiver

The original data sheet for the MK414 indicates that the maximum working frequency is approximately 4 MHz. SW transmissions are sufficiently strong that this receiver can effectively operate with signals up to about 6 or 7 MHz. A 10k resistor...