{"id":788,"date":"2025-03-30T22:01:57","date_gmt":"2025-03-31T03:01:57","guid":{"rendered":"https:\/\/stuorgs.engineering.iastate.edu\/carc\/?page_id=788"},"modified":"2026-05-02T12:58:44","modified_gmt":"2026-05-02T17:58:44","slug":"balloon-lauch","status":"publish","type":"page","link":"https:\/\/stuorgs.engineering.iastate.edu\/carc\/balloon-lauch\/","title":{"rendered":"High Altitude Balloon Linear Transponder Launch"},"content":{"rendered":"\n

Conclusion: Thank you to everybody for using the transponder! The flight was a HUGE success. We are sorry about the tracking cutting out, as it seems the GPS signal was lost to the tracker. However, everyone seemed to enjoy the balloon repeater, and it worked phenomenally. Pictures of the craft will be presented here. Thank you to everyone who tried to work us!\u00a0<\/span><\/h2>\n

The Campus Amateur Radio Club at Iowa State University will be launching a 10 kHz wide linear transponder on a high-altitude balloon from Ames, Iowa in coordination with HABET<\/a>.\u00a0<\/p>\n

Launch time: May 2nd @ 1300z (weather permitting)<\/strong><\/p>\n

Use this map to view the live location of the balloon on launch day. The ID of the balloon will be W0ISU: https:\/\/amateur.sondehub.org\/#!mt=Mapnik&mz=10&qm=12h&mc=42.09924,-93.47374<\/a>\u00a0<\/strong><\/p>\n

The linear transponder will be non-inverting (use USB or CW on both the uplink and downlink) and will have a 10m uplink and a 2m downlink. The antennas on the balloon will be vertically polarized. Please use the minimum amount of power necessary to get into the transponder (5 watts should be enough). If you are able to run full-duplex, please do so! A good setup would be to run a standard HF rig for the 10m uplink, along with a 2m all-mode transceiver or SDR dongle for the 2m downlink. Unlike traditional satellite operation, there will be no significant doppler shift.<\/strong><\/p>\n

If you are calling CQ on the transponder, announce what your downlink frequency on 2m is, as your signal may be propagated via the ionosphere as well as the balloon.<\/p>\n

There will be a telemetry beacon on 432.300 MHz USB. To decode the telemetry, pipe the audio from your radio into this website:\u00a0https:\/\/horus.sondehub.org\/<\/a><\/p>\n

Frequency summary:<\/strong><\/p>\n\n\n\n\n\n
Uplink (USB or CW)<\/strong><\/td>\n28.345 – 28.355 MHz<\/strong><\/td>\n<\/tr>\n
Downlink (USB or CW)<\/strong><\/td>\n144.345 – 144.355 MHz<\/strong><\/td>\n<\/tr>\n
Telemetry Beacon (USB – HORUS v2 telemetry)<\/strong><\/td>\n432.300 MHz<\/strong><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Note that the uplink is in the normal phone portion of the band, so Technician Class licensees may try to use the balloon transponder as well.<\/p>\n

\u00a0<\/p>\n

Updates:<\/p>\n

Predictions for the path of the balloon, as of May 2nd @ 1143z:<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

\u00a0<\/p>\n

\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"

Conclusion: Thank you to everybody for using the transponder! The flight was a HUGE success. We are sorry about the tracking cutting out, as it seems the GPS signal was lost to the tracker. However, everyone seemed to enjoy the balloon repeater, and it worked phenomenally. Pictures of the craft will be presented here. Thank […]<\/p>\n","protected":false},"author":4377,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"jetpack_post_was_ever_published":false,"footnotes":""},"class_list":["post-788","page","type-page","status-publish","hentry"],"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/P7OMin-cI","_links":{"self":[{"href":"https:\/\/stuorgs.engineering.iastate.edu\/carc\/wp-json\/wp\/v2\/pages\/788","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/stuorgs.engineering.iastate.edu\/carc\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/stuorgs.engineering.iastate.edu\/carc\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/stuorgs.engineering.iastate.edu\/carc\/wp-json\/wp\/v2\/users\/4377"}],"replies":[{"embeddable":true,"href":"https:\/\/stuorgs.engineering.iastate.edu\/carc\/wp-json\/wp\/v2\/comments?post=788"}],"version-history":[{"count":37,"href":"https:\/\/stuorgs.engineering.iastate.edu\/carc\/wp-json\/wp\/v2\/pages\/788\/revisions"}],"predecessor-version":[{"id":872,"href":"https:\/\/stuorgs.engineering.iastate.edu\/carc\/wp-json\/wp\/v2\/pages\/788\/revisions\/872"}],"wp:attachment":[{"href":"https:\/\/stuorgs.engineering.iastate.edu\/carc\/wp-json\/wp\/v2\/media?parent=788"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}