so ive been running APRS for a few months now with a TM-D710G and a Mobilinkd TNC hooked to my phone running APRSdroid, well actually i was using the 710 first and then switched to the Mobilinkd setup in the truck but thats beside the point. my position beacons are showing up fine on aprs.fi, people can see me moving around, path looks okay i think im using WIDE1-1,WIDE2-1 which should be fine for the area.

the problem is messages. someone tried to send me a message through aprs.fi and i never got it, and when i try to send messages from APRSdroid they show as sent but i have no idea if the other end is actually receiving them. i know APRS messaging is kind of hit or miss but this feels like something is actually broken not just network congestion. anyone run into this before? is there something specific i need to check in APRSdroid settings for the messaging side vs just beaconing?

the messaging thing is a known headache with APRS, especially when youre mixing igates and RF. a few things to check -- first make sure your SSID is consistent everywhere. if aprs.fi shows you as W1ABC-9 but your APRSdroid is set to W1ABC-5 or something, messages are going to get routed to the wrong place and just disappear. that bites people all the time.

also check whether there are any two-way igates in your area. a receive-only igate will pick up your packets and push them to the internet but it wont gate messages back down to RF, so you see yourself on the map but the return path is dead. you can kind of tell on aprs.fi by looking at which igate is hearing you and then checking if that station has two-way capability. if all the igates near you are receive only youre basically shouting into a one way pipe.

yeah what the other guy said about two-way igates is probably it honestly. i had the exact same symptom last year and spent like two weeks convinced my TNC was broken before someone in the local club pointed out there was only one igate in range and it was a raspberry pi setup that the guy never configured for downlink. once he fixed it messages started flowing fine.

one other thing -- APRSdroid has a setting for message retry, make sure its actually set to retry a few times and not just send once and give up. default might be okay but worth looking at. also if you can, try sending a message to SMSGTE or one of those gateway bots just to verify the outbound path is working, at least that way you know if the problem is sending or receiving.