1. Radio setup
   • You need a radio that can do 70cm (430-440Mhz) and SSB (LSB and USB) - not all radios can do this.
   • Depending on how far away you are either a whip (for close) or a directional antenna (e.g. a yagi). This flight is low altitude so the range will be less then people are use to.
   • Tune to 434.000Mhz (may need to tune around as there could be some drift.
2. Computer setup
   • Hellschreiber can be decoded by dl-fldigi (or fldigi). As it requires you to read the data it won't upload it automatically.
   • Select which mode you want to decode:
   • Chose either Feld Hell or Slow Hell.
   • This will select the mode and change the colour of the decode window to white.
   • Find the signal in the waterfall and click on it, the telemetery will start decoding.
   • Once you've got a telemetry string decoded go to Upload page. Enter in a callsign or nickname, your latitude and longitude are optional and the telemetry string.
   • The page will parse the data, check the string is valid and upload it to the server. It will be displayed on http://spacenear.us/tracker/

• Slow Hell is a very slow mode - takes over a minute to transmit the telemetry. It will be better for long range decoding but you'll need to be careful to keep the red decoding bars over the signal.

• Much quicker mode - will be better close by (though you'll have to wait for the Slow Hell to finish!)

PICO,COUNT,TIME,LATITUDE,LONGITUDE,ALTITUDE*XOR CHECKSUM

• No decimals just to warn however the Upload page will sort all that out.

• Here is a wav file (zipped) of both Slow Hell and Feld Hell telemetry. It 'should' be possible to play this back through dl-fldigi however I found that on Mac OS X it was slight too fast so the decoding didn't work - playing it through a loopback worked fine.
• hellschreiber2.wav.zip

• Arduino Mini Pro 3.3V/8Mhz
• FSA03 Ublox 6 GPS
• RM22 Radio Module
• NCP1400 3.3V step up converter
• 2xAAA lithium energizer

• Very easy launch from Suffolk, filled balloon until ascent rate was approximately 0.5m/s. The radio signal was easily received by listeners including the Isle of Sheppy from an altitude of 358m. There were some problems with the php webpage for inputting the data which had to be fixed on the fly. The general impression was that it is possible to use a manually inputted setup, that Slow Hell worked much better then Feld Hell both for low signal situation but also it gave you enough time to input the data.

• The altitude graph shows the very unusual flight path. The initial ascent rate was 0.5m/s and reached the predicted peak of 3.4km altitude, it then begun descending but then settled down at an altitude of 2.55km, floated for a short period of time and then begun to ascend again. This peaked just over 3km and then descended again. The peak is slightly sharper which might suggest that it sprung a small leak. It became difficult to track as it descended for the second time but looking at the recovered data is that it might have floated again around 1600m but then continued its descent, the last data at 880m.

• We also got reception reports from F5APQ, F6AGV and PD3EM especially near to the end of the flight.
• Raw Data

• It is possible to fly a payload on a single balloon
• Hellschreiber payloads work, they require a lot more effort however it does mean that you can extract data in much poorer conditions. Slow Hell is probably better in these situations rather than Feld Hell.
• It seems that these foil balloons do float, its difficult to work out exactly what has occured during this flight, theories include:
  • Natural float oscillations (larger then what has been seen in super-pressured latex flights)
  • Rain causing descent
  • Self-terminating leak.

• Arduino Mini Pro 3.3V/8Mhz
• FSA03 Ublox 6 GPS
• RM22 Radio Module
• LiPower step up regulator
• 1xAAA lithium energizer
• BMP085 pressure sensor

• Try with a lighter payload to get a higher altitude
• Explore floating again especially the unsual flight path
• Annoy more people with making them manually input the data.

• Turning the GPS on and off using UBX commands didn't really work - if it didn't get lock quick enough.
• Using the power saving modes of the GPS does save some current.
  • Cyclic mode with 1s update + arduino + tx'er = 50mA
  • If it draws 50mA and we have 50% efficency with the step up circuit in theory it'll last for 10 hours ((1000mAh / 2) / 50)

• Test other updates for cyclic mode
• Build antenna
• Update php page