View Full Version : New Ham APRS Questions

02-28-2018, 04:56 PM
Hello, I'm a new ham and also new to this forum. I got my Ham license mainly as a result of an upcoming road trip that my family is planning. We wanted to be able to communicate from vehicle to vehicle easily and without cell service.

I purchased a nice mobile rig and two Retevis (Chinese made) HT's for the trip.

Over the last week I have been looking at APRS and it interests me. Seems like a nice way to post our live location to friends at home to follow. In addition to other uses while on the road.

My mobile rig supports APRS, but it doesn't have dual receivers so it's a headache. I recently saw this video https://youtu.be/d9L_SV5Wpgo

From my thoughts I could use one of my spare Retevis radios to connect to an iphone to broadcast my GPS location on APRS. I'm hoping I can use a an old model iphone that I have that doesn't have cell service to broadcast the GPS location using the Retevis.

Does anyone else use APRS for a similar function while traveling? If anyone has experience with the method I'm thinking about using to broadcast my location, please share it with me.

03-01-2018, 05:01 PM
Hello, I'm Carl.

For APRS tracking, you need: (1) a 2m FM radio that can transmit on 144.39 MHz. I assume a Retevis (never heard of it) can do that.; (2) a GPS receiver that can output your latitude & longitude in NMEA 0183 format (Is that what you meant to use the iPhone for? I didn't know it could do that); (3) a TNC such as a Byonics TinyTracker or Kantronics KPC-3 that can accept the NMEA location data, change it to an audio signal, feed it to the radio, and control the radio; (4) a separate antenna for the APRS radio; and (5) cabling to connect it all together.

Some Kenwood radios, and probably other brands too, have all of this built into the radio -- even the antenna. I've never owned one of those, but I have built and run several trackers using simpler (read: cheaper) Kenwoods, Byonics and Kantronics TNCs, and Garmin and Byonics GPSs. There are several lying around the house (RV) someplace.

What a tracker does, whether it's all one fancy piece or several simpler pieces, is transmit an FM packet from time to time containing your callsign, location, and sometimes other info. There are APRS receiving stations almost everywhere that will receive your packet and (via Internet) send it to web sites like www.APRS.fi (it's in Helsinki). When your friends wonder where you are, they go to the web site and enter your callsign to show you on a Google Maps display. You can use www.APRS.fi in other ways, too, like displaying all the APRS stations in a particular part of the world, or displaying your track for the last, say, 24 hours. It's really slick.

03-02-2018, 08:21 PM
I downloaded pocketpacket from the iOS app store and installed on my iphone. I have a cord that goes from my phone to my radio. It broadcasts my APRS signal, but the information isn't showing up on aprs.fi. I turned my APRS modem on in my truck and received the beacon from the handheld/iphone to verify this.

I thought today that maybe the issue might be that my handheld wasn't broadcasting strong enough to reach a repeater. So on a trip into a larger town tonight I left the broadcast on for several hours in the car, but no luck. The signal was sending every minute, but none of the trip showed up on aprs.fi.

03-03-2018, 08:07 PM
When you say you "received the beacon", do you mean you were able to see a plot on a map display, or do you just mean you heard the "brrrrp" through the speaker?

I ask this because I suspect you don't have it completely set up. At a minimum, you'd have to enter your APRS ID, something like KN4JPD-1 for example. It'll be your callsign followed by a hyphen and a number, usually 1 though 15. I am totally unfamiliar with the app,but there is more to set up than just the callsign. Things like beaconing interval, corner-pegging if the app can do that, what symbol to display on maps to represent you (I use a little pic of a car for NN5I-1, a pickup for NN5I-2, and an RV for NN5I-3 if I recall correctly, which is improbable). None of my trackers are currently installed anywhere, and I actually don't know where I put'em away.

Anyway, is it fully set up?

03-19-2018, 10:36 PM
No answer, but when I look on aprs.fi you are showing up. Here's a screen shot.