UKNanowaves Group

G0EHV's lightbeam kit (from the UKNanowaves group photos)

Today I joined the UKNanowaves Group which is dedicated to optical communications.  There is a lot of useful information on this group in the postings and in the files and photos sections. Reading the membership list I noticed several local amateurs interested in optical comms, so when I get my equipment for 481THz working credibly I will have a good chance of some QSOs locally.

Today some of my optical comms electronics parts arrived so I hope to start experimenting with these on the bench shortly. Most gear built for 481THz is simple and homebrew. Apart from designs using transverters to HF or VHF, all kit is in the 0-40kHz frequency range, so easily engineered with simple test equipment. Perhaps, like VLF and LF, this is partly why it appeals to me.

The 481THz Band

My tests on 137kHz WSPR are now all but completed and I do not intend to take this work any further now I've "got the measure" of what is possible. I shall put the transverter in a box after a tidy up and use it periodically over the winter.

Now I am about to start something new: 481THz band communications! This is 623nm red light for the uninitiated. This evening I've made a start by ordering some suitable components to allow benchwork to start next week. My initial tests will be low powered beaconing with a portable receiver walking down the road. Assuming this is promising, I'll then refine the kit and organise optics to give some "antenna gain" to allow much greater range.

There are a lot of resources on the internet about light beam communication, especially using high power LEDs and there was an excellent series of inspiring articles about this in the March-May RadCom this year.