DLØART/am
5th launch (18-May-1997)

[thumbnail balloon]Back to DLØART/am homepage

Don't miss the picture-gallery !!!
...and picture-gallery, part 2,
...and picture-gallery, part 3.


After quite a long break, we did it again... the 5th launch of DLØART/am was on 18-May-1997. The main issue about this flight was the transponder (mode B), which worked quite nice, and many hams took the chance to use it.


ARTOB launch 18-May-1997:

Launch:        # 5
Launch date:   18-May-1997
Launch time:   12:14 UTC 
Launch site:   Nienberge near Muenster, NW Germany, JO32SA 

Payload DLØART/am:
QRG/mod.:     (1) Telemetry beacon: 145.200 MHz  F2D & F2A
              (2) 2nd beacon:       144.991 MHz  F1A (call & info text)
              (3) Transponder  (J3E and A1A)
                    Uplink:     432.570 MHz  \ 
                    Downlink:   144.470 MHz  /    +/- 20 kHz
                    + beacon at 144.470 MHz (A1A)
              (4) RX for remote control on 70 cm and 10 m (not used)
Power:        (1) 2 W
              (2) 100 mW
              (3) 2.5 W
Antennas:     (1) groundplane
              (2) turnstile
              (3) big wheels for 2 m and 70 cm 
              (4) 70 cm: groundplane / 10 m: lambda/4 vertical
Power supply: (1) & (4): 5 D cells LiSO2 in series (=14.4 V, 6 Ah)
              (2) 1 D cell LiSO2 (3 V) and step-up to 9 V
Diameter ballon:  ca. 8.5 ft
Gas:              hydrogen
Parachute:        ca. 8 ft
Weight:           about 4700 g (over all)
Lift rate:        

The balloon has a gaz valve which can be opened to reduce the lift 
rate or start the touchdown procedure.


Schematic of balloon


Balloon Team Members:

Ground Control:  Armin (DF1QE) + Fritz (DF9XE)
DF Control:      Joachim (DL3YBQ) + Ralph (DG3YEI)
DF Teams:        Norbert (DL1YBR) + Oliver (DL9QJ)
                 Wilhelm (DG5YGF) + Kurt (DD3QQ)


Talk back of DF teams via repeater Osnabrueck, DBØCO (R 75).

(UTC)

10:30  Meeting of the team
11:15  Arrival at launch site (Muenster-Nienberge, JO32SA)
11:30  Phone call to air control Düsseldorf: launch permitted
11:40  Filling the balloon
11:50  Payload attached
12:03  Additional filling, lift rate was not sufficient
12:05  Transponder tested -> Go
12:07  Telemetry beacon switched on -> Go
12:10  Phone call to air control Düsseldorf to announce the 
       launch
12:14  LAUNCH
12:16  Altitude already 3,065 ft
12:35  Problems ocurred on decoding the telemetry; data obviously 
       invalid
(...)
13:55  Balloon bursted; telemetry data seem valid again
14:00  TOUCHDOWN (crash...) As we found out later, the balloon hit 
       the roof of a farm house nr the city of Greven (JO32TC) and 
       broke a tile (was already fixed when we came to the house... 
       but the place could still be recognized by the red color left 
       by the balloon).

       The owner was a bit surprised (only a bit, it is a 
       Muensterland farmer...!) and, since he read something about 
       "explosives" on the package, called the police. The 
       officers (almost correctly) recognized it as a weather 
       balloon and took it to the Greven police station (was it 
       arrested now?!). From there, they called Armin, DF1QE, on his 
       cellular phone, since his number was written on the boxes. 
       Shortly after that, we were able "recover" the equipment... 
       and the beacons and transponder were transmitting when we 
       arrived at the police station.


Tochdown site:         nr Greven (JO32TC)
Touchdown distance:    7 miles

Flight Data
Launch14:35 h15:55 hTouchdown MinimumMaximum
Altitude280 ft12,125 ft12,700 ft(885 ft)
Outside Temperature74 deg F22 deg F- 5 deg F46 deg F
Inside Temperature90 deg F82 deg F23 deg F22 deg F
Battery Voltage14.177 V14.311 V14.218 V14.059 V

See Reception Reports

Results:

The telemetry data were not very useful this time; since they obviously were not correct during the time period 12:35 - 13:55 UTC. We assume it was because of the very difficult flight conditions - the balloon got into a thunderstorm, which means high humidity and low temperature. We have never had problems concerning the telemetry before; on this flight, we had trouble with during final testing and during the flight... The table shown above might not tell the very truth, but we think these data we copied are at least likely.

The transponder was a big success and worked better than expected, even though we got a report (after the flight) that we were still causing some intermodulation on the 2 m band. But the device had never been tested under "real" conditions. We already were afraid that the transponder hardly would be used, since during our final test, we did not find any stations that were able to help us testing (seems not very many people have allmode equipment for 2 m and 70 cm). But we were wrong, the transponder was very busy, sometimes the QSOs sounded almost like in a contest... Among others, stations from all over Germany, from Belgium, Switzerland, the Netherlands and Great Britain were able to use it.

Here is the logbook of DL9QJ/m's transponder QSOs:
(SSB; using an Icom IC-820H w/ 30 watts and mag mount vertical antennas)

UTC  Call     RST  QTH                     Name
-----------------------------------------------------

1250 DD7LP    59   Bohmstedt       JO44MN  Christian
1252 DK6OO    59   Hildesheim      JO42XE  Hermann
1255 DG5AAE
1255 DL3KBH                                Uwe
1310 DGØODA        Thüringen               Daniel
1313 DK1QJ                                 Dieter
1315 ON6UG                                 Freddy
1320 DB7EK    59   Kleve           JO31BS  Daniel
1318 DG9BHV   59   Borgholzhausen  JO42DC  Ulrich
1325 DK1KR
1340 HB9RDE   59   Glashütten      JN37LI  Rolf
1342 DK3WG    58   Frankfurt/Oder  JO72GI  Jürgen

The balloon hulk was causing the main problem this time. I think we got a very old piece, and because of that and some not very professional handling during launch preparations, we were not able to open the gaz valve the get to balloon to land, but it bursted instead.

The time between DFing had been increased to 15 minutes (was: 10 minutes), which gave the DF teams better chances "to make more miles". But sometimes, the 15 minutes periods still were a bit short.

Our 2nd beacon (144.987 MHz) obviously again (like during our second flight) had problems with frequency stability. Its deviation caused problems on FM repeaters on R0 (input on 145.000 MHz) and kept them open (concerned: DBØUH). Again, the reason seems to be the flight conditions (see above) - we had the same weather during our second flight when the same problem ocurred. Of course, we regret any inconvenience caused by that fault!


If you heard our sigs, pse send QSL via PR / Internet / buro - all will be answered with our DLØART/am QSL cards! Any suggestion or response is always welcome!

The DLØART/am team hopes that all of youn enjoyed this experiment, as well as our previous flights. We regret that we have to terminate the project now. This is due to a substantial lack of man power (the same 2 or 3 people were always doing all the work...) and - which is the main reason - financial resources (e. g. insurance is DM 500.00 / USD 300.00 p. a.). We are just a small local amateur radio group (subdivision of DARC) and no longer able to put our money into this project.

Maybe, you will here of DLØART/am again inspite of this - he, we have a working transponder now! Possibly we will launch a captive balloon during our annual fieldday (okay, a few hundred feet is much less than what we had on this flight, but North Germany is quite flat, and it would provide a chance for some nice QSOs). An alternative would be the flight of a manned hot air balloon, on which the transponder could be a piggyback.

Anyway, we enjoyed this project and wish give our thanks to everybody who participated.

Best 73, Oliver

[Oliver Welp, DL9QJ, N3NSF
 Gustav-Freytag-Str.11 / D-48161 Muenster / GERMANY
 Internet: dl9qj@amsat.org  /  n3nsf@amsat.org
 PR:       DL9QJ@DBØEA.#NRW.DEU.EU
 Tel./Fax: +49-2533-7312]


See Reception Reports

See picture-gallery, part 1,
picture-gallery, part 2,
picture-gallery, part 3

[thumbnailBack to DLØART/am homepage


last edit 27-November-1998
© maintained by Oliver Welp, DL9QJ, N3NSF - n3nsf@amsat.org