HOMEBREW HF/V/U SDR

SDR front.

SDR front view. ON/OFF switch, MIC/CW key connector and fan grill are visible.

The dream of constructing a full blown HF/V/U amateur radio transceiver goes back to when I was first licensed as an amateur radio operator. Back then, with less theoretical and practical experience and not having been introduced to software defined radios it was definitely a very daunting, laborious and costly project. The sharp rise of SDR usage among hams the last years has spawned a great variety of solutions for homebrewers. By moving hardware into software and using existing building blocks, man-hours to produce a decent performance radio are greatly reduced, as well as development costs. So the task of homebrewing a ham radio was transformed into a ‘harmonic’ integration of various building blocks. Nevertheless, it still proved to be a time consuming task and it took almost 6 months to arrive into a final working black box. There are still corners waiting to be polished and some features to be added :)

This radio is the main radio in my shack. I use it mostly on 2m and 70cm for local and DX QSOs. It is also my preferred IF radio for microwave operation (although compared to the FT-817 it is WAY bulkier). There is a pdf presentation which you can download by clicking here. It offers a general description of the construction.

Specs

Transmitter

  • 160-10m 100W
  • 2m 50W
  • 70cm 20W
  • Transmit IMD3 better than -35dBc

Receiver

  • MDS (500Hz BW)
  • 160-10m -130dBm
  • 2m -144dBm
  • 70cm -140dBm
  • Two tone dynamic range 85dB
SDR back.

SDR back view. From left to right: HF PL connector, 70cm N type connector, speaker 1/4″ jack, USB connector to PC, 2m N type connector, anderson power connector, transverter interface circular connector.