Em406a Garbled output

Hello Guys, hopefully you are kind enough to help me here. i just bought an em406a module, connected it to max233 and into the com port for hyperterminal. it is sending garbage data and changes on increasing voltages. can you please tell me what exact voltage to use it at and any other settings that i need to know.

i will be grateful!!!

Are there any other patterns to the madness? Like relatively same size strings of garbage, periods of time, same end or start byte… ?