Hello OMs,
i am currently building and programming a simple selective call system for use on QO100.
The main advantage is that it is not nessesary to have a extrem stable RX or TX frequency because i use a "dynamic FSK" mode.
The transmitter and receiver is a cheap Arduino Nano connected to mic in (or with a small speaker held to the microphone) and on the RX side connected to the speaker of the RX.
When the RX "hears" the right code then it switches the RX NF via a small relay to the speaker.
Currently i can select up to 1000 different adresses with a maximum TX/RX frequency difference of +/- 1kHz.
Now i can let my QO100 RX run and only if someone calls my "number" then the RX audio is passed to the speaker.
Maybe someone has more ideas for improvements then i will check if i can implement them.
VY73s DB8TF
