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Simple QRP rigs, Transceivers with single side band direct conversion receivers, Receivers, Frequency counters for QRP

Signalprocessing for SSB - Direct Conversion Receiver using Phasemethod for Sideband Supression, does all necessary signalprocessing for Direct conversion Receivers using IQ-mixer for demodulation.

Practical and usable direct conversion receiver for the 40 m CW band

The original article of the progressive system, composed by a direct conversion receiver and multiband superetherodyne by W7ZOI and K5IRK

The Rock-Mite is a 40m CW kit offered by Small Wonder Labs . It features built-in keyer, direct conversion receiver with a crystal RF bandpass filter, 500 milliwatts of power, and switchable frequency offsets to work around QRM

Direct Conversion Receiver for Software Radio Soft66AD

The direct conversion receiver described consists of only a bandpass filter, mixer IC, VFO and audio filter. With only 22 parts, this simple circuit should take a few hours at the weekend to construct.

M1HOG Direct Conversion Experiments

A project with schematic to build a receiver for 80 meters band by VK1PK

The idea makes use of a very simple direct conversion receiver on the band of interest.

A simple direct conversion receiver for 80m. The receiver covers 3.51 MHz - 3.60 MHz and 3.64MHz - 3.71 MHZ - CW and Phone portions by M0DGQ

IK2PII describe here a simple direct conversion receiver, thinked for QRSS and DFCW communications, as companion of ARGO or SPECTRAN programs.

A schematic diagram of a homemade direct conversion receiver for 30 meters band

One-Cubic-Inch Direct-Conversion Receiver

The build was an experiment to see if a tube receiver could be stable enough to receive digital shortwave radio broadcasts. The tube acts as both an oscillator and mixer, so the receiver is a type of direct conversion receiver.

This project details the development of a modular direct conversion (DC) receiver designed for experimental flexibility in amateur radio and HF signal listening. The mainframe integrates a diplexer, DBM, and AF amplifier, supporting interchangeable local oscillator and antenna filtering setups. A tunable passive HF preselector complements QRP Labs bandpass filters for enhanced signal reception. Utilizing a NanoVNA for precise tuning, the receiver achieves improved signal-to-noise ratios across amateur and non-amateur bands, making it a versatile platform for further RF experimentation.

Direct conversion receivers (DCR) are gaining renewed interest due to advancements in semiconductor technologies and their suitability for integration in compact, low-cost, multi-standard applications. Unlike traditional superheterodyne receivers, DCR eliminates image frequencies and bulky off-chip filters but introduces challenges like DC offsets, nonlinearity, and noise issues. This tutorial explores DCR's historical development, compares it with other receiver architectures, and addresses its inherent obstacles. DCR's potential for integration and compatibility with software-defined radio highlights its role in modern communication systems despite its technical complexities.