simple fm walkie talkie 11 circuit

This fairly simple circuit makes it possible to place such a wall as a conduit to locate. It is a conduit for power, no water or gas-seeker. The only requirement is that there is tension on the line. The antenna...

Precision QRP Transmitter

This compact transmitter is suitable for less demanding Doppler propagation measurements. It is designed for operation on the 80m band but can be easily adapted for the 40m or 20m bands. The output power is approximately 500mW of unmodulated carrier,...

Improved 3 Transistor Audio Amp (80 milliwatt) circuit

This circuit is similar to the previous one but employs positive feedback to enhance the amplitude delivered to the speaker. It was adapted from a small five-transistor radio that utilizes a 25-ohm speaker. In the prior circuit, the load resistor...

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...

Small IC amplifiers for speakers

A small amplifier IC circuit has been compiled. This circuit is part of an older series and is categorized as a simple OTL (Output Transformer-Less) circuit. The presented small amplifier IC circuit is designed for applications where compact size and simplicity...

Simple Short-Wave Transmitter

This low-cost short-wave transmitter is tunable from 10 to 15 MHz using a ½J gang condenser VC1, which sets the carrier frequency in conjunction with inductor L1. Frequency trimming is achieved with VC2. The carrier signal is amplified by transistor...

Audio-amplifier

C9 is necessary to filter out RF input interferences. R3 in combination with C5 is used to limit the AF frequency bandwidth. The 470-f.IF power supply decoupling capacitor is C10. C9 serves a critical role in the circuit by acting as...

Wireless Microphone

Q1 amplifies the output from an electret microphone (MIC1). The audio signal is fed into oscillator Q2, which modulates the signal. Additionally, L1 and C1 form a tank circuit designed for operation in the 88-MHz frequency range. The antenna consists...

RC Audio Oscillator

This document presents the design of an audio oscillator that operates at approximately 1 kHz. The circuit is likely sourced from EMFRD, as Wes's book contains a wealth of valuable circuits. This versatile oscillator serves as a signal source for...