26 May 2012

My first 481THz 2-way QSO

The 481THz kit at the G3XBM/P end of the path
This evening, thanks to Bernie G4HJW, I managed my first 2-way optical QSO over a path of around 10.5km.  For the AM baseband QSO, Bernie used his Finningley transceiver with 100mm optics and I used my simple AM TX  with my modified KA7OEI receiver with unbiased BPW34 connected directly to the FET gate.  For some reason, the RX in my dual tube transceiver (the one on the larger tripod) was about 3-4dB less sensitive than the separate RX, so in the end I used this to copy Bernie at a solid 58-9 with scintillation.


Anonymous said...

Please post some recordings of the audio. I would like to hear what propagation effects have on the optical link.

Tnx & 73's, David

Roger G3XBM said...

Sorry but I did not make any recordings on this occasion. Will do on future tests. It sounds like a quite rapid flutter which I guess would be less if the day had not been so hot.