Questions tagged [aprs]

Automatic Packet Reporting System is a digital protocol used to transmit GPS position reports, telemetry, weather reports and text messages between APRS compatible devices and software.

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16
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2answers
1k views

Is there a disadvantage to using a cheap HT for APRS?

Looking to build a cheap (not even inexpensive, just dirt cheap) APRS beacon transmitter. Right now you can get a dual band handheld transceiver with rechargeable battery, antenna, etc for under $31 [...
10
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2answers
2k views

How to do APRS in real wilderness?

I'm a relatively new ham (licensed a couple of years ago, occasional activity on 70cm and 2m, mostly repeaters). I'm looking to extend my ham experience and am interested in digital and packet modes. ...
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1answer
1k views

What Part 97 rule allows unattended, automated transmissions, such as APRS weather stations and beacons?

What rule allows Amateur Operators to establish and operate remote, automated stations like APRS weather stations or beacons? Are there different rules specifically for beacons, or do they all fall ...
10
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1answer
4k views

How do I discover APRS coverage?

I'm considering adding simple APRS transmitters to my vehicles. I'd rather just put one in and forget about it, but I understand there are areas of the US where a stronger transmitter would be ...
9
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3answers
1k views

When is APRS use considered commercial?

I've heard that APRS is only allowed for non-commercial use. I was thinking of a building a weather station that uploads data via APRS (so far, non-commercial). If I then include data from that ...
7
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2answers
2k views

APRS digi path for ISS digipeater?

So when I try to work the ISS digipeater, what should I set the digi path to be? My setup is a 5 W HT with a 2 m yagi connected to my phone with APRSDroid. I've tried the past few nights with ...
6
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3answers
2k views

Is there a difference between AFSK and FSK for AX.25/APRS USE?

APRS uses the AX.25 protocol which assumes the Bell 202 AFSK modulation scheme to generate the actual radio signal. Is there any reason the same signal can't be generated directly with FSK without ...
6
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1answer
1k views

What should be the modulation when transmitting APRS signal?

Is it SSB or NFM or other type of modulation?
6
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2answers
311 views

Is it possible to overload APRS?

Does APRS have a limited capacity in terms of beacons? What happens when an APRS frequency experiences a large number of packets?
6
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1answer
349 views

Using Direwolf with multiple radios?

I'd like to play around with ax.25 connections. It seems that if I have more than one radio (operating on different frequencies) that I would want to have multiple ax.25 interfaces. Direwolf creates ...
6
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1answer
3k views

Help understanding path taken by APRS packet

I'm looking at some raw APRS packets over APRS-IS. I'd like to determine which stations heard particular packets, but I'm having trouble understanding how TNC-2 paths work. Here are two examples: <...
6
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1answer
874 views

Can I still use my Kenwood TM-281A for normal communications even while I have a TinyTrak4 connected for APRS use?

I am considering buying a Byonics TinyTraK4 to connect to my Kenwood TM-281a to do APRS. However, I am wondering if I should instead buy a separate radio (I am considering a Baofeng UV-5R) as well ...
5
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2answers
5k views

Do aprs.fi and APRS-IS use the same credentials?

I have an account/profile on aprs.fi, and now I am trying to use APRSdroid, which requested my credentials. Can I use the password from aprs.fi for it? I am unable to register/submit my application ...
5
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1answer
167 views

APRS: WIDEn-N vs. TRACEn-N

The suggested APRS digipeater path is WIDE1-1,WIDE2-1 for the most use cases. According to the specs, this ensures two retransmissions by fill-in / regular ...
5
votes
1answer
341 views

Is it legal (in the US) for a server on APRS-IS to relay replies from non-HAMS to a HAM?

I've heard two sides to this. On one hand, sites that allow you to send messages into the APRS-IS network, for relay over RF, demand you enter a call, as "only licensed HAMs may cause a message to be ...
5
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1answer
487 views

Help understanding the information field in an APRS-IS message

I'm looking at the raw packet data from http://aprs.fi. I see packets such as these: ...
5
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1answer
379 views

Decoding weak APRS signals

I've recently started looking into APRS, and can easily receive some APRS signals from my station - however, I can't seem to decode them using QTMM or any similar software. Is this because they're ...
4
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1answer
1k views

AX.25 on macOS (aside from APRS)

I'd like to send raw AX.25 packets from a macOS PC using a KISS TNC (mobilinkd TNC2). I've sent APRS packets with this set up using Xastir, but I'd like to send other information besides just APRS (i....
4
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1answer
790 views

How can I generate a list of APRS IGates on 30m?

I am investigating using a Tiny Trak 4 with my portable HF radio to self-spot on SOTA activations via APRS on 30m. I usually self-spot via a text message. When I don't have any cell coverage, I can ...
4
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2answers
364 views

AX.25 to Kenwood $PKWDWPL sentence

In my vehicle, I have a Byonics TinyTrac4 paired with an AvMap G6. I also have a Kenwood TM-D710 that I'm currently using for voice. I live in a region of the US where both 2m APRS and 70cm High Speed ...
4
votes
2answers
216 views

Wireless temperature data logger in the USA on 433MHz

I'm a newly licensed ham tech. I am trying to figure out if I am doing everything correctly to setup a wireless temperature monitoring station that uses the 70cm band (specifically 433.4MHz) in the ...
4
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1answer
190 views

Using a flip-phones GPS NMEA data for the GPS in an APRS station

I have heard that it is possible to connect certain flip-phones to external devices via their Micro USB port and, through the USB port, send the NMEA location Data from their internal GPS to an ...
4
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1answer
579 views

What are the best APRS SmartBeaconing™ settings for different modes of transit?

There are a variety of websites that give sample SmartBeaconing™ settings – mostly for automobiles, but some for bicycles and pedestrians. I've tried several of these settings and had mixed results. ...
4
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1answer
290 views

ISS APRS Digipeater with Kam XL and ICOM IC-910H

I am trying to use the ISS APRS digipeater which transmits at 437.55MHz. Hardware setup consists of the following ICOM IC-910H. The transceiver has been connected to a Windows PC running a HAM ...
3
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2answers
905 views

Linux APRS client

I have an old PK-232 packet TNC which is spitting out APRS data from 144.390 to the serial port. I have confirmed this with minicom and see all sorts of data with lat long etc. I would like to view ...
3
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1answer
52 views

What's the difference between an APRS “item” and an APRS “object”?

What's the difference between an APRS "item" and an APRS "object"? A kenwood manual says Objects have timestamps, items do not. What does that mean, and how should it be used? Also in general: What ...
3
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2answers
281 views

What is the legality of data modes over UHF/VHF in the US?

Cheap & simple transceivers are readily available online that allow you to transmit serial data over UHF/VHF frequencies such as 433MHz (approximate range of 1000m). It seems that these are ...
3
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1answer
114 views

APRS: what is with stations clustered in the middle of a lake?

I just recently started using APRSdroid, and I've been just looking at maps, and I've noticed that in my area there are spots with just a cluster of stations on top of each other (in this specific ...
3
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3answers
2k views

How do I connect a GPS receiver to a radio for APRS?

I volunteer with the local search and rescue group as a team medic and a radio operator. The team is new and recently decided to go with the Garmin 64st as our go-to GPS units. Those of us with ...
3
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3answers
4k views

Setting up a Kenwood TM-D710G for APRS

If I am going to use a Kenwood TM-D710G for APRS, will I need to leave one of the VFOs on the APRS frequency of 144.390 MHz, or does the TM-D710G have a 3rd VFO built-in specifically for APRS use?
3
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2answers
402 views

Can I use my call sign in APRS tracker abroad?

I am planning a car expedition from the EU to the China, through a lot of countries in the east. I am interested in if I can use an APRS tracker with my call sign issued in the Austria.? And the ...
3
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2answers
352 views

Fox Hunting w/o yagi to find a lost High altitude balloon payload

First off, very new to ham radio. I wanted to track my High altitude balloon using APRS, and after loosing that payload in a mature cornfield for 2 months, decided to add a micro-fox from Byonics to ...
3
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1answer
908 views

What does the APRS 'to'/destination address mean?

I'm looking at incoming packets. Here's the beginning of a few messages: ...
3
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0answers
397 views

Getting Started with APRS [closed]

The APRS.org web site provides some good information but is not very well organized and does not appear to be actively maintained. What are some good resources for beginners seeking the following: ...
2
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3answers
2k views

Can I use APRS over TCPIP without ham license?

Simple question, but for me is really important. "Can I use the APRS over TCPIP without a ham license in Europe Union (especially in Austria)?" I consider yes, because I am not transmitting with radio,...
2
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1answer
370 views

Use amateur radio frequencies for commercial purpose

Can I use amateur radio frequency for commercial purpose (after acquiring ham license), expecting that it would be congestion free band and give me good broadcasting performance compared to other ...
2
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2answers
437 views

RTL-SDR dongle - what antenna should I use for APRS receive only?

I was following this guide to setup an iGate using an RTL-SDR dongle and a Raspberry Pi. It worked, and I have been able to test it by seeing some APRS packets from a separate transmitter (Arduino+...
2
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1answer
63 views

String in APRS report

Here are two messages I received: ...
2
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2answers
755 views

Building a portable APRS iGate/digipeater

I've been experimenting with APRS for the last year or so. There are a lot of areas that I go that don't have digipeaters or iGates. (Luckily, I live about three blocks from one, so around home I'm ...
2
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1answer
49 views

Resources and guidance regarding APRS

I know getting my Technician License is the place to start, however, I have in my head a clear path that I want to achieve and am looking for guidance for the most efficient way to achieve that goal. ...
2
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3answers
670 views

Connecting TNC-Pi to Kenwood TM-241A

I am looking into connecting a TNC-Pi to a Kenwood TM-241A for AMPRNet operation. I thought it was going to be fairly straightforward as each pin on the TNC-Pi seemed to have its own analogue on the ...
2
votes
1answer
411 views

APRS - using 100 Hz CTCSS for voice contacts

I've learned online some very thin information about how many hams will use 100 Hz CTCSS tones on their APRS transceivers to be able to make voice contacts with hams who are also using APRS. I've ...
2
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1answer
225 views

FET for low voltage class E amplifier

I'm building a small APRS radio for a high altitude balloon, and I'm thinking of using an Si570 (3.3 V CMOS) at 144 MHz to drive a small class E amplifier. I'm looking for about 1W output power. I'm ...
2
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1answer
144 views

Fetching data from APRS-IS.net

I would like to fetch the data transmitted by a specific radio station from APRS-IS.net servers. I've read the documentation on their site and it is not clear how you would do it, if you are fetching ...
2
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1answer
45 views

In HLDC framing/Bell202 encoding, are the flag bytes NZRI encoded?

I have previously implemented an APRS transmitter from scratch by manually generating the modulated sine wave. In this implementation, I did NZRI encoding over the entire packet (including postamble ...
2
votes
1answer
164 views

Where to pull audio for packet on an alinco DR-600

I have an old Alinco dual-band radio, the DR-600 (service manual) (manual) I want to use this radio for receiving APRS packets. The speaker audio out Works but there are too many things to go wrong ...
2
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0answers
163 views

It is allowed to have more APRS trackers with one callsign in Europe Union

I am interested if I can set up all my automatic APRS GPS trackers with one call sign in Austria (like in the US)? Are there any restrictions on usage?
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2answers
141 views

Can you receive GPS coordinates from a Garmin Astro dog collar on a handheld ham radio that has APRS?

I want to get a Garmin Astro 320 (or 430) which transmits GPS coordinates to a Garmin handheld unit on frequency 151.820-ish and 154.600-ish. But I would like to have the Garmin Astro GPS collar on ...
1
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1answer
40 views

Why does the APRS specification suggest to use 7-bit ASCII for user-defined data formats?

The APRS specification document says the following: Although there is no restriction on the nature of user-defined data, it is highly recommended that it is represented in printable 7-bit ASCII ...
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2answers
208 views

Direwolf sends APRS transmission but it isn't being picked up by local digipeaters

I'm new to APRS and trying to setup a RaspberryPi APRS GPS Tracker. I've installed Direwolf and configured it, my transceiver transmits the signal, and I've decoded it with GQRX via an RTL-SDR and I ...