Issues From original WsprryPi code:

  Two users were reporting that the program never stops transmitting, even
  when intervals for disabled tx are programmed. The problem was in both
  cases fixed by flashing a new image on the SD card with a freshly downloaded 
  image: 2013-02-09-wheezy-raspbian.zip. No apt-get upgrade or firmware
  upgrade was performed. After this WsprryPi TX was running successfully. 

  One user reported his RPi died while in WsprryPi service caused by excessive
  RF voltage (90V) on GPIO4 created by a 100 watts AM transmitter 50ft away
  from the antenna. After the damage exessive current was consumed by RPi (1.1A
  from 5V supply), caused by short-circuiting in the 3.3V logic of the BCM2835
  SOC. On his replacement RPi, he is planning to add galvanic isolation and
  buffering.