Optical Repeater successfully supports two-way digital communications
over a total path of 14 kilometers. Article by Lee Scheppmann, KD0IF,
describes linear optical repeater designed and built by Kerry Banke, N6IZW,
and installed on Mt. San Miguel (DM12mq) near San Diego. PSK31 digital mode
was used with base tone at 750 Hz and 910 nm laser diodes with PGP style
detectors. The article is in Adobe Acrobat format. (2 August 2007).

Having Fun With Through-The-Air Optical Communications, a Power Point
presentation by Kerry Banke, N6IZW to the Palomar Amateur Radio Club
on February 6, 2008. This contains excerpts from the original presentation
including block and circuit diagrams, test equipment descriptions, software
used in modulation/demodulation, and links to free software available for this
and other types of weak-signal communications. (3-17-08)