Bob Bruninga WB4APR brings news of an around the world balloon attempt on March 5/9 that’ll carry a CW transmitter on 28.223 MHz.
It will be launched on either 5 or 9 March 2012 in Annapolis Maryland and go East towards Europe.
The balloon payload will only weigh about 50 grams. About the mass of two standard 9v batteries. It will use about 10 Mylar Party balloons to achieve constant-pressure flight level above 40,000 feet. The Telemetry will be in CW on 28.223 MHz and will contain only Battery voltage, and inside and outside temperatures.
The CW format will be something like this. It is assumed that all outside temperatures will be below zero or negative so the minus sign is not transmitted. The inside temperature might get above 0 during sunlight. So assume the I inside temperature is positive and the outside temperature is negative in Degrees C. When the inside temperature goes negative then the I will change to IN to indicate negative temps.
The outside Temp is always negative. If it goes positive, then the value will be replaced with an X.
. . . W3ADO I nn T nn APRS.ORG . . . < == inside temp positive and outside negative . . . W3ADO IN nn T X APRS.ORG . . . <== inside temp negative and outside positive The CW message will be repeated once a minute or so. The WEB page may be only send on every other beacon. TRACKING: The balloon has no GPS. All tracking will be done by HF DFing. All APRS users are assumed to know how to enter an APRS DF bearing report so that their DF bearing line shows up on global APRS maps. Check the APRS site for latest information at the http://www.aprs.org website.