Like last year I’ve deployed a small beacon in a hedge about 10km from home with no Line of Sight
It uses a 850nm LED an arduino, real time clock and a sizable battery.
It switches on after dark with 15minute intervals of 1480Hz modulated carrier to the LED.
Last year i used a GPS module for frequency and timing but i wanted to reduce power consumption… It now uses an RTc and just the arduino to generate the carrier.
The Arduino ceramic resonator had to be replaced with a crystal to maintain enough stability.
