DM10 - 2019-06-23

Tracker Details

Tracker Type: WSPR

Model: PicoTrackerWSPR1 Rev5 0.6mm thickness

Powered by 2 AAA batteries


Parameters: (set <param> <val>)
trackerId[4]            : DM10
wsprCallsignId[2]       : Q2
gpsLockTimeoutMs        : 150000 2:30
lhAltFtThreshold        : 11000
hAlt.wakeAndEvaluateMs  : 600000 10:00
lAlt.wakeAndEvaluateMs  : 60000 1:00
lAlt.stickyMs           : 86400000 24:00:00
crystalCorrectionFactor : 300
systemClockOffsetMs     : -4

Launch Parameters

Balloon and Payload

  • 36" Qualatex, unstretched
  • 21.7 gram payload
  • 2.3 grams free lift
  • Half-wave antenna.

Heat sealed neck.


  • Removed ribbon, suspend from reinforced top antenna
    • Couldn't figure out how to bond together...
  • Reduced free lift to 2.3g to avoid what was probably a high-alt pop last time
  • Using new WSPR decoding software and map Front End



Flight going very well as of 1pm (9am launch).

Slowly rose to 22,000ft max at a rate of ~5ft/sec.

Seemingly the temperature sensor isn't reporting valid data.

General Thoughts / Observations

Morning launch, around 9am. Wind relatively consistent at a few miles per hour with infrequent gusts.

Using an unattached ribbon to launch didn't work.

The balloon is rotating in the wind, which will cause the ribbon to wrap around the top antenna and cause a lot of friction on release, which I suspect will rip off the antenna.

Hand launching did work.

Laid out the tracker and antennas until lined up, held balloon in my hand, and let go.

Slight dragging of the tracker on the ground. That's not good. Happened to not catch but could have. Wouldn't have been very successful in other conditions.

The tape at the midpoint of the top antenna caused a kink purely due to the chunkiness of the tape blob, not its stickiness.

Otherwise the ribbon-less launch seems to have gone very well, no tangles beyond the single tape one.

Also I kept the water bottle weights and soldering iron in a backpack instead of the launch box. Launch box only had the tracker.

On tracker start, do a few pulses of the radio. Useful for confirming the long antenna is attached properly.

Remove midpoint tape.

How to hand launch without dragging?

Try two balloons?