On Tue, 4 Mar 2014 16:12:04 -0800 (PST),
wrote:

(...)

http://www.ebay.com/bhp/75mhz-am-receiver
Well, probably not sensitive enough.

If you have an aircraft receiver, that goes from 108 to 138Mhz, it
will demodulate AM. A scanner should suffice. Find a high level
mixer (such as one from MiniCiruit Labs) throw in a local oscillator
at:
120 + 72 = 192 MHz
add some front end filtering and maybe some RF gain, and you have a 72
MHz receiver. Mix well, and serve. Be sure to do some intermod
calculations to make sure you don't have any inband spurs.

Kinda sounds like you're going to be needing more than one of these
receivers. It should be easy enough to build from scratch using an
aircraft band AM receiver as the starting point, and just tweak the
frequency sensitive components.

Maybe a modified runway lights control receiver which are often
crystal controlled.

Maybe a modified 121.5 ELT receiver recrystalled and retuned to 72
Mhz.

Maybe a cheap shortware receiver with an added mixer and LO for the
front end to receive 72 MHz.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558