Hi everyone,

My name is James and I have been following this thread and maybe can help, or
at least make a suggestion.
On the Maxim web page you can check out a chip called the MAX038 High-frequency
Waveform Generator, its features are:
     .1Hz to 20MHz
     Triangle, sawtooth, sine, square, and pulse waveforms
     15% to 85% Variable Duty Cycle

You can even order samples of this and other chips - they are free and come
with full documentation.  I have ordered several chips from them and have
receive them within a week.

Hope this helps and have a good day.

--
James E. Merritt N0SRB                  Iowa State University
jem@iastate.edu                         Center for Nondestructive Evaluation
Electrical Engineering student          x-ray tech/modeller/programmer