Category Archives: Homebrew Projects

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!  

AD831 Mixer

I bought a pair of AD831 pre-assembled modules from China,  $10 each – not bad considering the price of the individual AD831 chip, the board comes ready to use “plug and play” with all ports terminated in to 50 ohms with SMA connectors – neat. Testing the mixer saw excellent results and the added bonus… Read More »

Receiver Mixer and Filter module

Having re-evaluated the receiver mixer and filter stages I have re-designed the front-end to accommodate the first and second mixers with both the roofing filter and SSB filter daughter PCB’s on one single module, this allowed easy assembly and modular testing of the filter stages. Each filter PCB has the impedance matching networks along with… Read More »

Adding AM mode – an after thought

For some reason not yet known I have decided to add an AM receiving mode to the rig, muRata 455KHz 6KHz wide filters are cheap and available so why not? Ok, so I could simply detect the AM with a diode, filter the audio and job done – well having researched various methods I have… Read More »