This high performance receiver module uses a Quadrature Sampling Detector (QSD), also known as a Tayloe Detector. The mixer is arranged as a double-balanced mixer for maximum performance. The receiver board has a socket for the standard QRP Labs Band Pass Filter kit. There is a transmit/receive switch onboard. Low noise LM4562 op-amps are used in instrumentation amplifier configuration to provide excellent common mode noise rejection. The receiver requires a local oscillator (LO) input at 4x the receive frequency. This could be generated by the QRP Labs Ultimate3S QRSS/WSPR kit, the VFO/Signal Generator kit, or ProgRock kit.

The audio output of the module is isolated using two 600:600-ohm transformers to reduce or eliminate the ground loop problems which can easily occur in SDR systems. The module is designed to directly drive a stereo input sound-card. For those situations where a PC has only a mono input (many PCs are like this, particularly laptops), there is an optional polyphase network plug-in module kit which cancels the unwanted sideband and produces a single sideband (SSB) output. 

The module is sized 80 x 37mm, exactly the same as the Ultimate3S QRSS/WSPR transmitter kit and VFO/Signal Generator kits, so that it can be bolted behind these modules if required. 

The receiver kit INCLUDES one Band Pass Filter kit for a band of your choice, from 160m to 10m.

Assembly instructions

Printed instructions are NOT supplied with the kit. You can download the kit-building instructions for your PCB from the links below. 

CLICK HERE to download the kit-building instructions for the receiver module kit. 
CLICK HERE to visit the BPF kit page and download instructions for the BPF module kit
CLICK HERE to visit the Polyphase network kit page and download the instructions for the polyphase network kit (if required)