Further to Andy, G4JNT's talk at the LF Forum (RSGB HF COnvention) last
weekend, and his article in RadCom,  Frank, K0BRA, mentioned a cheap source
of surplus Motorola ACS1397 8 Channel GPS modules from BG Micros
(http://www.bgmicro.com).

Anyone wanting to build a GPS locked frequency source may be interested to
know that the modules are advertised at $US14.95 and arrived here in the UK
three days after ordering over the Internet.  The only snag now is to get an
active aerial, or some work-around - presumably a circularly polarised
aerial with a MAT device - and an OSX connector.  Grateful for helpful
suggestions on the latter.

73 John, G3WKL