[Laser] WB9AJZ laser RX problems

[Wendell Smith]

I built the transmitter/receiver from the web site of WB9AJZ/6:

http://www.psnw.com/~n7stu/cheapo.html

I am trying to get 4  units built up for roving during
the January VHF contest, and these seemed to be rather
simple. Here in Illinois the best DX is only going to be a
few miles, unless you are fortunate to live in a Chicago
hi-rise.

There is a loud raspy buzz whenever the phototransistor is
blocked.  Changing the 10Mohm resistance only changes the
pitch.  Shining the 800 Hz laser produces a 800 Hz tone,
but much weaker than the buzz.  Turned the laser TX off,
and the buzz remained. Under normal room  incandescant
lighting the buzz is gone, and the laser will still give the tone.

I built a second unit, thinking that I had a bug somewhere,
and the same result occured. Any thoughts or ideas for
getting rid of the buzz, or any other hints for these circuits?

Thanks,
Wendell N9REP