[Laser] Error in G0MRF receiver circuit?

[Robo]

Hi Paolo,

I mean, that Yes.

Zener diode, moving up ground potential (floating ground), because in 
this circuits You do not have symmetrical power source. Pin 3 and 8 
is changed. Is a not good, yet.

Strange circuit!!!
I mean, that in this circuit is OPT301 degraded to single photodiode. 
Preamp in case is non-functional.
Look at this image. http://www.foton.sk/robo/opt301.htm
You must build both :-) for comparasion.

What You mean?

Robert Laszlo