W7QO ballon WSPR en APRS boven de EU

[Jan pa3abk]

Vandaag zag ik op 20m WSPR W7QO met een QTH in DL.
Ja hoor weer een ballonnetje opgelaten.

(bron: YahoO! groups QRP labs)

All,

I've posted before about the tiny tracker that I've made. At a high
level, it's an ARM processor running at 32mhz, with 2.5v VCC from a
switching power supply, on board solar MPPT controller and has 2 radios
that can cover a range 5khz to 1.050Ghz. Instead of a module style GPS,
it uses a chip style that is good to 50km in altitude and -40C temp to
it's specifications. It can run from a small 1S lipo battery in a
day/night configuration, or a supercap in daytime only configuration
(the later is lighter). In either configuration it uses small 19x52mm
solar cells, two of them in series. The picture below is with a 1.5F 5v
supercap installed.

The board without antennas, or supercap fully built weighs in at approx
1.3gram (on a 1.6mm thick board - I have final boards that will be .8mm
and should lower that weight to ~1gr). The board is approx the size of
a AAA battery for perspective.

Mine is a little different from others, the 2 radios can work at the
same time. In my case, it will be doing APRS on 2mtrs on one radio and
WSPR on 20mtrs on the other. Both radios are completely frequency agile
and because I used a very small VCTCXO, I can do true FM on either
radios if wanted - which APRS will be using.

In this configuration, with all wires, solar, antennas, tether, etc
attached the whole payload weighs in at just over 9grams.

It will be flying under an SBS-13 envelop from Ron and the guys at
http://www.scientificballoonsolutions.com Plan right now is for a Wed
AM launch.

It will be on 144.390mhz APRS in the US and will change frequencies
based upon geofence definitions for other geographies. On WSPR, plan
right now is to use 20mtr WSPR on a 10 minute beacon period. (APRS will
be every 2 mins). Both radios will be setup for 10mW output power.

Primary APRS tracking will be via -
http://aprs.fi/#!mt=roadmap&z=11&call=a ... ail=259200

Primary WSPR tracking will be via -
http://aprs.fi/#!mt=roadmap&z=11&call=a ... ail=259200
- yes I know that's the APRS.FI website, I've created some scripting to
push WSPR spots to APRS after I translate the telemetry.

Telemetry and telemetry graphing will be available on both links above.

Quick note about telemetry, in order to not sprinkle telemetry loaded
callsigns on the WSPRnet map, my telemetry format will place the
telemetry spot at the 4 char maidenhead of the actual balloon location.
I give up 4 chars of telemetry space to do that, but as more and more
of these telemetry type uses of WSPR start to occur (and I know of 3
more in the works from various others), I didn't want to clutter the map
any more than reasonable.

This will be a daytime only flight.

I'm watching weather and winds, so the launch window may fluctuate a
little, but plan right now is for approx 8am EDT from Atlanta.

Alan