US Naval Academy students are planning an amateur radio CubeSat HFsat carrying an HF transponder as well as 2m APRS.
They are working with Bill N6GHZ on the HF transponder card which will provide a bandwidth of 30 kHz, the frequencies are currently 21.4 MHz uplink and 29.42 MHz downlink. Doppler shift will be reduced to less than 2 Hz per second by using an inverting transponder.
The satellite will be gravity gradient stabilized by its long full size 10 meter band halfwave HF dipole antenna with tip masses
Read more about HFsat at http://aprs.org/hfsat.html
IARU satellite frequency coordination page http://www.amsat.org.uk/iaru/