Roger G3XBM's (Mainly) Amateur Radio Blog

Before my 2013 stroke I enjoyed experimenting at optical frequencies and was amazed that I could decode my QRSS CW well over the horizon wit...

Some years ago, when I was fitter, I really used to enjoy going out in the car to experiment with non line-of-sight optical beaconing. I wou...

One of the fallacies going around is that optical communication is just "line-of-site" and that both the TX and RX have to be able...

Since my 2013 stroke I have not felt fit enough to do field work. I really miss my 481THz over the horizon NLOS (non line of sight) optical ...

Before my stroke in 2013 I enjoyed building and operating optical communications gear. My stroke has rather scuppered this, for now! Altho...

Facebook reminded me that 4 years ago I was doing QRSS3 tests with light at 4.8km over the horizon. "Much better results this eveni...

There is a nice precis on Wikipedia about this. It is some time since my health has allowed me to do experiments with light. My special inte...

VK4EBP reported that he has carried out successful tests over a 10km NLOS (non line of sight) path using infra red. See Australian Optica...

The DX record for communications at optical frequencies is phenomenal these days. There is a growing interest in communications over non lin...

June's RSGB RadCom carries my article, " Over the Horizon at 481THz " describing my non line-of-sight optical experiments last...

As mentioned in an earlier post, my sensitive non line-of-sight NLOS optical (red LED at about 481THz) RX packed up when I clumsily dropped ...

I am beginning to think that ALL tests outside the house should stop until I am a lot better (stroke). The best description is I feel, all t...

Before venturing out, I have been trying to plot possible NLOS paths with the optical TX at home (inside) and the RX at a convenient roads...

Today I repeated my optical tests across the garden receiving signals on my RX with both 600 ohm phones and Spectran software with QRSS3. Th...

My attention is turning back to 481THz (red light) and slightly lower frequency (IR) light communications over the visible horizon (NLOS). ...

Reading Stuart G8CYW 's article on the history of optical communications in the latest RadCom, I am considering repeating my recent NLOS...

The schematics below are of the RX and TX used in the recent "over the horizon" NLOS 481THz optical tests. As you can see, not too...

This evening I ventured further afield with the optical kit to see if I could copy my QRSS3 beacon signal in the village of Stow-cum-Quy whi...

This morning I realised that I was 2.5 degrees out in my aim last night with my optical beacon, so this evening I repeated the over-the-hori...

This evening, in the freezing cold, I attempted a non line-of-sight (NLOS) optical test using my beacon TX (1W 10mm LED at 250mA in 100mm op...