I’ve found myself tinkering somewhere between the high GHz and Light Waves, long wave Infra Red.
This band’s wavelength is around 10um, a little bit longer than the nm for light.
This has been on my to-do list for a while after seeing Barry G8AGN’s demonstrations at Finningley for the last few years.
I’ve also been following this mailing list: https://groups.io/g/Amateur-30THz
Transmissions are basically modulated heat sources, picked up by thermal sensors like those used in IR Thermometer guns and PIR sensors.
Until just recently the modulation rate had to be very low because of the slow response time of the sensors, but some recent chat on the 30THz groups.io list has found alternative sensors that will work upto tens of hertz.
I ordered some of the MRT511 sensors and stuck one on the front end of one of my optical front ends, surprisingly it worked, well, sort of!
I made up a little wheel and fitted it to a stepper motor with stepper driver and an Arduino to get it spinning.
My soldering iron was placed behind the spinning wheel, giving about 15Hz modulation rate.
A soundcard and spectrumlab was used on the PC to detect the signal.
The distance between heat element and the bare sensor was only 10cm, but it was showing a signal so i was quite pleased!
The signal was strong!
