For those that don't python and/or don't know where to edit.

  hb = h2bin('''
  18 03 02 00 03
  01 40 00
  ''')

See that "40 00" there? That's hex and 0x4000 = 16384. Change it to something like "02 00", so it's 0x200 = 512, or 0x400 = 1024 ...or whatever you want.(But keep it at a power of 2... I assume).

http://en.wikipedia.org/wiki/Power_of_two