[Laser] Listening to the stars

[Kerry Banke]

I am in the process of modifying my optical communications equipment to 
work with Andy's (K0SM) Laserscatter program for NLOS house- to-house 
experiments.  Part of the modification includes extending the low frequency 
response of the detector to work at 20-30 Hz. In the past I have always 
intentionally rolled off the low frequency response to reduce 60 HZ 
interference.  Just for fun I took the modified receiver outside last night 
to "listen" to the night sky.  Besides the usual 60Hz from lights  and  the 
popping of airplane strobes I was surprised to hear the scintillation 
(twinkling ) of the stars. The sound is like that of wind going over a 
microphone.   I'm running a 4" glass lens using an SFH-203 Pin detector 
with K3PGP type MPF102 FET front end with no bias resistor.  I was able to 
hear a good number of stars but the pointing is quite critical.

  - Kerry N6IZW -