Help needed to track 144.390 MHz APRS Balloons

James Cutler KF6RFX and Benjamin Longmier KF5KMP - University of Michigan

James Cutler KF6RFX and Benjamin Longmier KF5KMP University of Michigan

Benjamin Longmier KF5KMP and his team are looking for stations in the Azores and Portugal to help track their balloons.

On the UK High Altitude Society (UKHAS) group he writes:

My team (Project Aether) launched a balloon recently that did a lap around the Midwest in the US, headed East past Nova Scotia and is still floating strong. We don’t have any contacts in the Azores or Portugal, and are requesting help in contacting some of these folks that might be able to decode our APRS packets.

Tactical callsign: Aeth21-9
APRS track:!mt=terrain&z=9&call=a%2FAETH21-9&timerange=259200&tail=259200
144.390 MHz FM

We also have two more experimental balloons that will be heading into the Atlantic within ~24hrs.
Tactical callsign: Aeth22-1
APRS track:!mt=terrain&z=7&call=a%2FAETH22-1%2Ca%2FAETH22-3&timerange=259200&tail=259200
144.390 MHz FM

Tactical callsign: Aeth22-3
APRS track:!mt=terrain&z=7&call=a%2FAETH22-1%2Ca%2FAETH22-3&timerange=259200&tail=259200
144.390 MHz FM

Thanks for any help!
email: longmier at

Links to balloon beginners guides and tracking information

Diwali Return for APRS Balloon Payload

Dhruva Space Balloon Payload

Dhruva Space Balloon Payload

The payload of the Indian amateur radio APRS balloon launched on October 13, 2013 has been successfully retrieved.

The balloon payload was returned to Dhruva Space on November 3 during Diwali (Festival of Lights).

The balloon had been launched from the Indian Institute of Astrophysics, Bangalore and drifted into the Arabian sea, off the coast of Udupi. Ham radio operators in Karnataka and Goa in India, and the Middle East and Africa were able to track the APRS signal, containing real time location, altitude and other operating conditions of the flight, for over 600 km into the Arabian sea.

The payload was found about 42.6 km off the coast of Gangoli, Karnataka on October 15 at 11 AM by the sailors of the fishing boat “Suvarna Lakshmi”.

It was only possible to trace the payload because one of the sailors used the sim card that was in one of the pieces of equipment in the payload.

Indian Record for Tracking Ham Radio Balloon

High Altitude Balloon to Study Comet ISON

Ham radio operators set to help in tracking comet

Hindustan Times October 17, 2013

Hindustan Times October 17, 2013

After helping the Odisha government in disaster relief during cyclone Phailin, amateur radio operators will now help astrophysicists track a comet.

The Hindustan Times reports that astrophysics experts are joining hands with ham (amateur) radio operators to track and read data comet ISON, scheduled to pass nearest to the earth on November 28, 2013.

Scientists of Bengaluru-based Indian Institute of Astrophysics will send a balloon 40 km into the atmosphere to get data on the comet.

As the instruments drop with a parachute it will be a team of ham radio operators, who will track the APRS packet radio signal and retrieve the balloon.

Read the story at

TNC-Pi APRS packet radio review

TNC-Pi Raspberry Pi Packet Radio Board

TNC-Pi kit built by Nick Bown 2E0CGW

TNC-Pi kit built by Nick Bown 2E0CGW

The TNC-Pi is a £22 ($40) KISS TNC board which is designed to connect to the GPIO port of the £25 ($35) Raspberry Pi computer board.

It provides a low cost means of using amateur radio AX.25 Packet Radio and APRS.

Nick Bown 2E0CGW has written a well illustrated review of the board. You can download the PDF from TNC-Pi by Nick Bown 2E0CGW

The TNC-Pi kit is available from

APRS destination address for ham radio satellites

APRS LogoAPRS has standardized an ID series for amateur radio OSCAR spacecraft – APOxxx

At the request of Juan Carlos, LU9DO, AMSAT-LU wanted a series of APRS designators for uniquely identifying AMSAT APRS applications.  He suggested those beginning with the letter O for OSCARS.

ALL APRS applications include this identifier in their packets so that the source of APRS data can be known.  See the list at


APRS UK Yahoo Group

UK 434 MHz balloons over Central Europe

A Raspberry Pi computer board

A Raspberry Pi computer board

On Saturday, April 13 at 1000 UT, two balloons both carrying 434 MHz transmitters were launched from Cambridge, UK . One transmitting video images from a Rapsberry Pi computer board, the other carried a 144.800 MHz APRS beacon M0UPU-11 in addition to the 434 MHz beacon.

The first balloon PIE5 is flying a Raspberry Pi computer board which transmitted live Slow Scan Digital Video (SSDV) images back to the ground by a pair of transmitters to double the bandwidth. The data was RTTY 300 baud 8N2. The frequencies used were 434.070 and 434.074 MHz. The balloon call sign was $$PIE.

The second balloon AVA flew a 70cms tracker on 434.450 MHz 50 baud 7N2. Additionally once it entered air space where the airborne use of APRS is permitted a second APRS transmitter was enabled (the APRS frequency is 144.800 MHz) with the call sign M0UPU-11.

The balloons had been expected to head for Poland and on Saturday evening they were over Germany but by early Sunday morning PIE5 was over Switzerland and AVA was over Austria.

The 434 MHz downlinks  on the balloons are generated using Radiometrix NTX2 transmitter modules, the batteries were expected to last 24 hours.

A third balloon callsign XABEN transmitting on 434.350MHz, 470Hz shift, 7N1 was also launched. Tthis was configured to have a short lifetime, going straight-up until the balloon burst rather than floating at 30km across Europe.

Live video of the launch was streamed by the British Amateur TV Club (BATC) at

Tracks of both balloons are at

Direct link to M0UPU-11 APRS track!call=a%2FM0UPU-11&timerange=86400&tail=86400

Images from the PIE5 Raspberry Pi balloon transmitted using SSDV can be seen at

To get details of upcoming launches subscribe to the UKHAS Mailing List by sending a blank email to this address:

Twitter #ukhas

Beginners Guide to Tracking using dl-fldigi

Digital Slow Scan Video