It uses BFQ34 transistor and stripline techniques.
http://www.mrs.bt.co.uk/dubus/8203-1.pdf
The basic circuit was a 5kV conventional rectifier with an improvised constant current source made with an GI-7 russian triode. The magnetron was a Toshiba 2M240, connected to a standard waveguide with tuning screws.
http://lea.hamradio.si/~s57uuu/mischam/magnetr/index.htm
frequency modulated, build with components of your junk box.
http://perso.orange.fr/jf.fourcadier/hyperfrequences/twist/twist_e.htm
To add an SMA connector for external antennas.
http://www.nodomainname.co.uk/SMC2632W/index.html