HamBONE-04B

Second "Micro-beacon" test flight

Since the in-flight failure of the HamBONE-04A beacon we planned to repeat the experiment. A second beacon was built (on a PC board) and tested, and the launch was set for 1700Z on Saturday, February 21 2004. The same basic components were used, but the construction was more rugged and the thermal insulation better.

UPDATE: The package flew on schedule for about a 90 minute flight, but the beacon transmitted only an unmodulated carrier. There are several possible explanations, but we still got interesting information from the frequency and amplitude of the carrier.

The payload package includes:

lithium "Ultralife" 9V battery providing system power

8-bit microcontroller (PIC 12F675 SO-8)

outside temperature sensor (DS1721S)

battery voltage sensor

CW Beacon on 28.636 MHz (clock oscillator)

Vertically polarized 10m antenna

Specs of the HamBONE-04B balloon:

Envelope: 300g latex sounding balloon inflated to 1.4 pounds free lift
Target rise rate: 1000 ft/min
Expected burst altitude: 90,000 feet
Downlink: 28.636 MHz CW, 50 mW "fireball"
Battery life expectancy: 40 hours

Telemetry format is as follows:

DE KA2QPG/BLN 04B F016 OAT NEG 20C BAT 8R5V PSE QSL AR

F 016 - Frame counter, increments on each data frame.
OAT NEG 20C - Outside air temperature, degrees Celcius.
BAT 8R5V - battery voltage in volts and tenths

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Page updated April 14, 2004