The AnaSondeTM family of digital radiosondes has been developed as a low-cost, user-friendly means of gathering scientific measurements in the lower atmosphere up to altitudes of approximately 30, 000 feet. AnaSondes feature a modular sensor suite that can be customized by the user, including simple interfaces for user-added sensors. Digital data is transmitted as decimal numbers to the ground in Morse code format. Presently, all AnaSondes operate in the 70-cm amateur radio band, and an amateur radio license is required to use them. AnaSonde signals are received using inexpensive amateur radio receivers which must be capable of receiving continuous-wave (CW) transmissions. Technical Details. The AnaSonde-3M is a multipurpose variant of the AnaSonde-3 family. As compared to the AnaSonde-3E, one major change is an increase in the number of analog channels from two to seven. This radiosonde features seven 10-bit analog-to-digital converter channels with 0-5 volt DC inputs (referenced to the regulated 5 volt supply voltage) and one frequency-counting channel which measures frequencies up to 25 kHz with 1 Hz resolution. A 10 milliwatt CW transmitter at approximately 434 MHz transmits data at regular intervals. With pressure, temperature, and humidity sensors (as pictured on the right), it has a mass of 15.0 grams. The circuit board is 0.85 x 3.25 inches. There are two other major enhancements found in the AnaSonde-3M as compared to the AnaSonde-3E. First, the AnaSonde-3M is inherently capable of both Morse code and ASCII output � the output mode is selected by the user during configuration. Second, the AnaSonde-3M has a secondary configuration mode which makes it particularly easy to enter callsigns as compared to the standard configuration mode (presuming one is manually entering the configuration without using the associated software). Items Supplied With Each AnaSonde-3M. The AnaSonde-3M can be ordered as a kit or pre-assembled. Every AnaSonde comes complete with everything needed for flight except for a 9-volt battery and helium for the provided balloon. Sensors specified by the user are included with the kit. Pressure, temperature, and humidity sensors are all available as standard options; resistive sensors for specialized measurements are available from Anasphere as well. Additional equipment. A serial interface cable is needed to use a PC to program the sonde configuration. A connector kit can be used to build custom cables for communications and external power supplies.