Category Archives: Homebrew Projects

DC Protection and Distribution Unit

I have designed an elaborate DC Protection and Distribution unit for the 70MHz SSB transceiver project, the purpose of this module is to provide two stage reverse polarity protection, power on/off switching, filter and a switched DC bus for transmit and receive. I have designed the 70MHz linear power amplifier (yet to be finished) to provide… Read More »

Amateur Radio Software

Impedance matching transformer calculator Please feel free to download this software and use it to aid designing toroidal and multi-aperture core transformers for matching Crystal Filters and interstage coupling transformers. The software is provided as-is with no warranty, please feel free to distribute the software to others however please make sure you give me credit… Read More »

IF Shift feature

Little bit of playing around with the IF stage today, finished the C++ code for the IF Shift feature – here is a short video listening to a QSO on 40 meters. A second video listening to Volmet on 5.450 and 5.505MHz, no BPF or preamp just random wire straight into first mixer.

IF Derived AGC Module

Some progress for the end of a Bank Holiday weekend – ran out of parts, BF245 FET was probably not the best choice when I have a stack of MPF102 devices, unfortunately the pinout is not compatible with the PCB track layout 🙁 Beer time!