Being new to packet, I had a hard time figuring out how to connect my Alinco DJ160 HT to my TNC. Like many HT's Alinco has no documentation on packet hook ups. 
After experimenting I finally was able to get the connection to work. Buck Rogers book PRIME has HT connections but none for my radio. I found that if I used the connection for the ICOM 2AT it worked fine. 

At the tip connection of the 2.5mm mini plug, connect a 4.7K Ohm resistor and a .1 mfd Capacitor. Connect the lead from the resistor to the TNC PTT line and the lead from the capacitor to the TNC transmit audio line. I connected the groubd line from the 
plug to TNC ground. Receive audio is simply connected through the ext speaker jack to TNC receive audio. I run a KPC-1 TNC. 


Hope this is of some help. 73 Dick KC6TOL.