Thanks, everyone, for the info and the reading material. I had the right concept on KISS mode, I just didn't state it very well. The TNC is passive in KISS mode, so I won't worry about any terminal settings for the KPC3+.
I heard about the delayed packet issue and thought that maybe it had been corrected with version 9.1 of the firmware, which is what I am running. Guess not.
It sounds like a schedule editor is the way to go. An alternative would be to put a vacation timer on the TNC power supply and shut it off at three in the morning each day. That's kind of a pain because I run the TNC and the radio off the same 12-volt supply.
I am running the TNC on a dedicated desktop PC. I am a Flex SDR user and have PCs around the shack for various projects. Actually, some desktops are less expensive than the small netbook computers, especially for refurbished or open box deals.
Anyway, I have my I-Gate/Digi up and running. I have been monitoring my raw packets and haven't seen any duplicates. I got into this whole area of amateur radio because I am an off road enthusiast. I spend a lot of time exploring the Sonoran desert near my property. APRS is one of my safety measures because I go really close to the Mexican border. There is a lot of foot traffic from border crossers and I want to make sure that after several days of walking through the desert, my Jeep doesn't look too tempting. I usually have someone looking out for me on the map when I am off road. I also carry a hand held Microtracker All in One unit.
73,
Steve
W6SDM
