Here are the radio mods essential for providing the full period radio experience imo.
Japanese wartime radio pack
http://www.subsim.com/radioroom/showthread.php?t=109633
Japanese traditional radio pack
http://www.subsim.com/radioroom/showthread.php?t=109699
Tokyo Rose radio pack
http://files.filefront.com/tokyo+ros.../fileinfo.html
Tedhealys music pack
http://files.filefront.com/Music+pac.../fileinfo.html
And of course CCs Captain midnights CBS radio mod
http://www.subsim.com/radioroom/showthread.php?t=108756
There was also a Saigon radio pack, but I've never been able to find a working download.
You'll want to refer here (
http://www.subsim.com/radioroom/show...=109256&page=6) post #115 to get all these working.