Balloon Repeater

The Flight of the Lockheed Martin ARC
Amateur Radio Balloon Repeater

Photos Copyright © 2003 James Alderman, KF5WT

Have you ever wondered how neat, and how much fun, it would be to put a repeater into the stratosphere? This group does so almost every year!

The Launch Team at Hillsboro Airport

This youngster officially released the balloon.

The balloon was launched about 25 minutes ahead of schedule, at 0850 August 30, 2003.

Almost immediately, it was heard by KV5R from 85 miles 85 degrees with a 12-element yagi.

It soon became apparent that the crossband repeater was listening about 10kc high, at 445.810.
It was configured to transceive continuously, with no squelch.

The parrot repeater on 146.500 (simplex) cycled normally every 20 seconds but it heard (and parroted) very little audio, due to its receiver being severely desensed by the crossband repeater.

Hundreds of people made contacts on the crossband repeater. Stations were heard as far as Tulsa and Houston. Others reported excellent ATV during the flight.

KV5R made three contacts on the crossband repeater, at 16,800, 54,000, and 87,000 feet MSL. Other AARC members, Jim WD5GXX, and Paul N5FY made several contacts. Jim was even heard using a handie at 5 watts and a handheld yagi — not bad for 100 miles UHF! KV5R attempted a handie with a handheld sleeve dipole but was unsuccessful — the repeater was very busy with much stronger stations.

The helium balloon rose to 94,515 feet (18 miles) before bursting. It travelled generally WNW at around 15 MPH, landing about 5 miles ESE of Glen Rose, in heavy briars and woods, quite near the Brazos river. It was recovered by Melissa Rasmussen, KM5R at 11:55 AM. (Lower-center)


W5SJZ said, on the 7232 HF net, that the 35mm photos and other info would be available on their web site in 1 or 2 weeks. Check the Lockheed web site for updates:


We later heard that the video package became detached and fell from the balloon assembly at about 15,000 feet during descent, landing several miles away. Several days later, the video package was discovered and returned by a supervisor of a gravel pit. We have not heard whether the electronics survived the fall, but assume the videotape did. The package was encased in styrene foam. More info as we receive it!

The recovered video package, which fell about 15,000 feet

Many thanks to all who made the flight possible!

73, de KV5R

The article above is Copyright © 2002 by Harold Melton. All Rights Reserved.
The photos are Copyright © 2002 by James Alderman. All Rights Reserved.

The Pre-launch Announcement

© 2003 W5SJZ

The Amateur Radio community is invited to participate as the Lockheed Martin Amateur Radio Club launches their 10th ham-radio-equipped weather balloon. 

The launch will take place on Saturday, August 30, at approximately 9:15 AM from the Hillsboro airport. 

An HF informational net will begin at 8:30 AM on 7.230 Mhz.

The balloon is expected to reach an altitude of 100,000 feet during its 90 minute ascent.  After bursting, the balloon will take about 25 minutes to parachute back to earth.  During the mission, ground-based recovery teams will track the balloon using directional antennas and APRS gear.  A private plane will also be assisting with recovery efforts. 

The balloon will carry the following ham radio payloads: 

  • Crossband Repeater - Uplink 445.800 Mhz, Downlink 147.56 Mhz
  • GPS Downlink - 144.39 Mhz  using call sign KG5OA-11 squawkingposition and altitude every minute
  • Simplex record / playback repeater - 146.500 Mhz recording for 20 seconds, they playing back
  • FM ATV 1255 Mhz (switching between two video cameras) 
  • 35mm still camera snapping photos every 3.5 minutes 

From high altitude, the communications range of the balloon will be approximately 500 miles.  Hams from all over Texas, Oklahoma, Arkansas, and Kansas will be able to communicate with each other using the balloon’s crossband repeater.  Hams in east Texas will most likely be able to work it with handhelds. 

Boy Scout troops from Burleson, Ft. Worth, and Hillsboro will be participating in the mission as part of their Radio Merit Badge activities. During this mission, the Lockheed club will be evaluating how future missions can be conducted in conjunction with educational and Scouting activities. 

The general public is also invited to observe the launch at the Hillsboro Municipal Airport located just off I 35W on exit 3. 

Lockheed members are carefully monitoring high altitude wind data to insure that the balloon does not come down within the restricted airspace surrounding the President’s ranch in Crawford.  If the launch cannot proceed due to unfavorable winds, the following Saturday will be the backup launch date. 

Check the Lockheed web site for updates:

6 thoughts on “Balloon Repeater
  1. Hello. I am trying to launch a BalloonSat Repeater as well. I have tried a number of different things including connecting two UV5Rs with a 2.5mm to 3.5mm and using a SainSonic RPT 2D Two-way Radio Repeater Box with no luck. What did you use for the repeater and is there a video tutorial on it?

  2. Hello my name is Jerry Schoenborn, sect of Warren County Pa RACES. I just ran across this site and was curious about the relative logistics,costs and licensing for a balloon launch. I find it interesting for emergency county wide comm.

    What FCC & FAA restrictions, licensing are required?

    Thanks, and please, if I’ve asked too much could you point me in the right direction for resources?

    Thanks, Jerry KB3ATD

  3. Hi Mike,
    you can buy different size balloons from Space Data Corp. They arent that expensive and you can get more info on flying balloons from them. you won’t want to use a cable unliess you are doing a “Tethered” Flight; otherwisse, you just let the balloon go up and burst.


  4. I am the Rally net for 100 acre Rally in Salem, mo. Due to the terrain and lack of repeaters, I am investigating a balloon hosting a cross band, similar to what a colorado group did for a bike race. Since crossband has again showed up on HT’s, where do I determine the lifting weight of a balloon. What kind of cable system do you use for getting the balloon back. I have seen your pictures of balloons, they look like som e I have seen costing form $89 to $325.

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