Check out Jim Weir's article which appeared in Kitplanes. http://www.rst-engr.com/kitplanes/Micro760/Micro760.htm
http://www.rst-engr.com/kitplanes/Micro760/KPtext.pdf As the article mentions, the box is slightly larger than a "standard" 2 1/4" instrument hole, and the XMIT Key line voltage has to be below .4V, not the "standard" 1.5V (nominal ground, after going thru a couple of diodes in the audio switching panel, and wiring and switch contact resistance). Also, his article in this month's (Dec.) Kitplanes is on the XCOM 760, note that there are two prices, $1200 from a U.S. distributor (i.e. AS&S) and $1050 direct from the XCOM website. http://www.mcp.com.au/xcom760/ Also, Barry Kruyssen and/or John Martindale (if either is willing) might be able to get either one even cheaper, but then there would be extra for shipping. Allen G. Wiesner KR-2SS/TD S/N 1118 65 Franklin Street Ansonia, CT 06401-1240 (203) 732-0508 flash...@usadatanet.net