Found an interesting tidbit on TBY application. It is mentioned as emergency alternative to TBS in this report of PT-109 loss. http://www.history.navy.mil/faqs/faq60-11.htm Rob Flory robandpj at earthlink.net www.home.earthlink.net/~navyradio WWII Navy Radio www.home.earthlink.net/~robandpj Les Flory Television and Electronics