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Year archives: 2023

Dynamic speech compressor with audio preamplifier

Dynamic-compressor-with-audio-preamplifier

Dynamic speech compressor or simply audio compression is an audio signal processing operation that reduces the volume of loud sounds or amplifies quiet sounds, therefore reducing or compressing an audio signal’s dynamic range. Compression is commonly used in sound recording and reproduction, broadcasting, hearing aid, live sound reinforcement, and in some instrument amplifiers. There are …

Simple two stage transistor one watt AM transmitter

One watt AM Transmitter

One watt AM transmitter This is a simple two stage transistor ‘one watt AM transmitter’ for the HF band which gives around 1 watt in output. You can use easily available transistors like BD139, SL100, 2N3866, 2N2219 or a 2N3553 in the final stage. The output with transistor 2N3553 is approx. 1.8 watt @ 12 …

Simple series modulated AM QRP HF Transmitter

Simple series modulated AM QRP HF Transmitter

A simple series modulated AM QRP HF transmitter is a type of radio transmitter that uses amplitude modulation (AM) to transmit audio signals over a high frequency (HF) radio band. It is designed to be low-power and simple to construct, making it a good choice for beginners or those who want to build a QRP …

OXO QRP HF Transmitter

OXO-QRP-HF-Transmitter

The OXO QRP HF transmitter is a simple, low-power CW (continuous wave) transmitter designed by George Burt, GM3OXX. It is a single-band transmitter that can be built to operate on any of the amateur radio bands from 160 to 20 meters. The transmitter is built around a few standard transistors and a crystal oscillator. It …

Simple audio compressor for SSB HF Radio rigs

Simple audio compressor for SSB HF rigs - PCB Layout

Simple audio compressor for SSB HF Radio rigs An audio/speech compressor is a device that reduces the dynamic range of the audio signal. This means that it makes the loud parts of the signal quieter and the quiet parts of the signal louder. This can be useful for SSB HF radio rigs because it can …

NE555 based Microphone amplifier

NE555 based Microphone amplifier

NE555 based Microphone amplifier IC NE555 or commonly known as 555 is an IC that is well known among electronics practitioners as an IC for timers, and can be used to form monostable or bistable multivibrator circuits. But not many know that the 555 IC can also be used as an  audio signal amplifier. By …

LM324 microphone speech compressor

LM324 Microphone speech compressor-PCB layout

The circuit shown is a microphone speech compressor built around operational amplifier LM324. This amplifier circuit exhibits gain and also continually adjusts that gain to maintain a constant amplitude output signal, regardless of the amount of signal coming from the microphone. The microphone is coupled to the LM324 Operational Amplifier IC which has 4 separate …

Amateur Radio – Mike Preamplifier/Speech compressors/Audio Processors – Resources

Audio processors and speech compressors are important in SSB radio because they can help improve the transmitted signal’s quality. Here are complete resources and links available in the internet connected to Mike Preamplifier/Speech compressors/Speech Processors Dyna Audio compressor Noise Canceling Electret Microphones – WB9YBM Microphone Speech Processor Microphone Amplifier with ALC Audio compression with transistors …

Really Cheap audio compressor

Really-cheap-compressor-circuit

The Really cheap audio compressor circuit diagram from www.freestompboxes.org is a simple, yet effective compressor circuit that can be built with a handful of cheap components. The circuit consists of two op-amps, two LEDs, a LDR, a few resistors, and a capacitor. The first op-amp (U1) is configured as a unity gain amplifier. The input …