Number one: Tune to 144.390 and make sure you turn on the TNC and it's not it packet mode. The "D" should be after the frequency.
You should start to see positions coming in from other stations unless you are so far out in the boondocks there is no digipeater nearby.
Second: Make sure you know the 70cm frequency your Beeline GPS is tuned to. Turn on and put the Beeline GPS outside, out in the open and let it sit for 20 minutes. It needs to acquire the GPS satellites Ephemeris in order to "find out" where it's at. Make sure you have programmed the Beeline GPS to transmit a packet once every 5 seconds. You have to learn how to program the Beeline GPS to get it to work properly. Read Greg's instructions on how to do that.
First hurdle: Get the 72 decoding APRS packets on 2 meters if you have traffic on 144.390 in your area. You do that and all's you have to do is change
bands, go from 2 meters to 70cm (420 to 440Mhz) and if the BLGPS is transmitting position packets, you'll see them decoded.
You get this done, read the 72's instructions on how to get the GPS in the rig working. I think a better way though it connect up an external GPS
in the fashion of a Garmin 60Cs or 60CsX and use it for your local position. A single cable will get your rocket's position into the Garmin 60Cs(X)
from the D72A and you will have a rock steady tracking and navigation solution to track your rocket. This is the cable:
https://www.gilsson.com/garmin_gps/cables/rk.htm
Also read the FAQ Mark refers to above. It's loaded with information. You can download OSM maps for the Garmin here:
https://garmin.openstreetmap.nl/
The points of interest database isn't really good at all but the maps are and they're free. Good enough for rocket tracking. You'll have to get
a Garmin 60Cs or CsX off ebay or used someplace. A cheap Garmin legend will work:
https://buy.garmin.com/en-US/US/p/173
but it uses a different cable, the monochrome map isn't as nice and new maps aren't available for it. It will find your rocket on the cheap though.
Ebay prices $33.00 but again, there is a different cable for it. Kurt