I just found out from Roy Hall that it is based on the Sangean WR2 radio but the sensitivity, selectivity, and voicing have been modified.
Here is a comparison:
http://www.jr.com/JRProductPage.process?Product=4028565
http://www.elusivedisc.com/prodinfo.asp?number=MHRDR-1W
Here is a comparison:
http://www.jr.com/JRProductPage.process?Product=4028565
http://www.elusivedisc.com/prodinfo.asp?number=MHRDR-1W