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The Nienberge Amateur Radio Group (NW Germany) launched their first ARTOB on Sunday, 07-02-95. This is what we did:
Launch: # 1 Launch date 07-02-95 Launch time: 1217 UTC Launch site: Schoeppinger Berg (NW Germany), JO32PC Payload DLØART/am: QRGs/mod.: 145.200 MHz FM data and call sign (CW) (beacon) (six tone sigs have been transmitted after the call sign: two serve as a reference, the others show altitude, balloon and outside temperature, battery voltage) 29 MHz remote control power: 2.5 watts antennas: turnstile - 2 m lambda/4 vertical - 10 m weight: balloon: 1320 g rig: 1340 g totals 2660 g diameter balloon: 7.5 ft gas: hydrogen lift when launched: about 200 g The balloon has a gaz valve which can be opened to reduce the lift rate or start the touchdown procedure. Schematic of balloon The launch on 07-02-95: (UTC) 11:15 arrival of the team at launching site Schoeppinger Berg (NW Germany), JO32PC 11:18 aviation weather data: ground wind 100 deg / 3 knots upper wind 130 deg / 6 knots QNH 1008 hPa no clouds below 5000 ft 11:25 infalting of the balloon (...) 11:52 turning on transmitter (...) 12:17 launch 12:20 altitude: 1895 ft 12:21 altitude: 2110 ft 12:22 altitude: 2460 ft 12:23 valve opened (30 s) by control team (DF1QE, Armin) 12:28 -same- from 12:30 five ARDF teams give QTE information every 10 min. to DF coordinator Joachim, DL3YBQ. Talk back via 70 cm repeater DBØEG. 12:34 valve opened (30 s) 12:36 valve opened: 12:39 rate of climb is abt zero; the valve should be closed. The control team is in a village at that time, and somehow the remote control fails (thuogh using 150 W on 10 m). The valve stays opened another two min. till (finally) the control team succeeds with their commands. The balloon now sinks by 120 ft/min. 12:40 greatest altitude: 6200 ft 13:00 altitude: 3660 ft 13:05 altitude: 2785 ft 13:08 altitude: 2085 ft The DF teams are informed and move to the expected landing site 13:16(?) balloon lands near Metelen JO32OF 13:33 First DF teams DF1QE (Armin), DL3YBO (Ludger) and DL9QJ (Oliver) reach the balloon. All equipment is fully operational (even the teams, hi), the balloon stands (!) in a little grove and is easy to recover.
The planned flight on constant flight level did (because of the remote control failure) not happen. The batterie was almost exhausted (much to fast), because of a defect cell.
The beacon power was too high, maybe a couple hundreds mW would have done. The DF teams need directions from the coordinator where to go.
Besides that, this launch is considered to be a success, especially the (most of the time, hi) controlled landing procedure looks promising. Now the operation time is not limited by a bursting of the balloon in high altitude. It is found easy to recover all the (not yet) valuable rig.
Another launch will be performed on one the next weekends using almost the same rig. After that, data transmissing will be changed to a PR like protocol, using a (8051 or so) micro controller. A repeater 2 m / 70 cm is planned, also adding a CCD camera for ATV or FAX/SSTV.
A big thank you to anybody participating, especially to Armin (DF1QE) who did most of the technics.
Any suggestions and response are welcome (address see below). We'll announce the next launch (always on a sunday) 48 h in advance.
Best 73, Oliver
[Oliver Welp, DL9QJ, N3NSF Gustav-Freytag-Str.11 / D-48161 Muenster / GERMANY Internet: firstname.lastname@example.org / email@example.com PR: DL9QJ@DBØEA.#NRW.DEU.EU Tel./Fax: +49-2533-7312]