===== Toms TT4 to Yaesu wiring =====
DB9 pin 1 black Mic audio to Mod RJ12 pin 5 black\\
DB9 pin 6 green ground to Mod RJ12 pin 4 red\\
DB9 pin 7 blue to +12 volts\\
DB9 pin 3 red PTT to Mod RJ12 pin 6 white\\
DB9 pin 5 yellow speaker audio to center tip radio earphone plug\\
Ground of earphone plug and 12 volt ground also tied to DB9 pin6, RJ12 pin 5\\