The heart of RF matrix is Station Master controllers (one per radio). RF matrix gives us freedom of selecting any possible antenna configuration for SO2R use. Might sound simple, but as said there’s 7 towers with over 20 different antenna setups including big stacks of tribanders.
With RF matrix we can expand our antenna system up to 10 towers and each of those towers can have six different antenna setups. So over all capacity of our RF system is up to 60 different kinds of antennas (stacks for example are normally counted for one antenna setup).
RF Matrix @ OH8X
The microHam Station Master device for controlling the RF Matrix
Because of limited outputs of Station Master and complexity of our RF Matrix, a special BCD switching unit was made to expand the number of control lines from Station Master to RF Matrix. Every antenna has a 3 digit address for BCD logic. Using 15 outputs from Station Master through BCD unit we do have 40 control lines per radio for RF Matrix and band pass filters. So total number of control lines for RF Matrix is 80 in our SO2R setup.
Our own station automation unit takes care of switching the power splitters allowing us to beam up to four directions simultaneously. It also makes possible to use different transmitting and receiving combinations as well as automatically scan selected RX antennas during listening period. The power splitter is custom made WX0B Array Solution design “Stack Match” with four antenna outputs.
Station automation unit also controls switching of tribanders. Using two stacks of tribanders makes switching somewhat more complicated than using just monobanders. Controlling allows flexible usage of tribanders also in cases when both radios are on high bands (like radio A on 20M and radio B on 15M). The switching logic is that new selection always wins and both tribander stacks can be used for both radios.
