[Laser] Filters for red 650nm lasers wb6igp

[Chuck Houghton]

Conc filters for 650nm lasers I have narrow band dichromic glass filters cut
to accommodate a simple cover for the photodetector diode, These are small
pieces of glass cut from a large glass plate. We have successfully used them
with inexpensive pointing lasers that were tested to be operational at 650
Nm. WE BOUGHT MANY $2 LASERS AND REJECTED THOSE THAT WERE NOT 650 N.M.
operational. Testing was done with a simple spectrometer available from
Astronomical Society of the Pacific (Project Star) For $28 (2002 cost)
www.astrosociety.org for info. The glass filters we used were installed over
the photodetectors of both Kerry N6IZW and mine WB6IGP's photo detector and
in full sunlight we made a 1KM full duplex contact with over 70 db margin
using our home built systems. Voice operation was done with 5 Khz deviation
narrow band fm converting received 40 Khz carrier and converting it up to
145.040 Mhz for reception on a 2 meter FM HT. Quality of the FM was
excellent and connecting our lap top computers sound card to rx and TX QSL
cards were sent back and forth. It works! For more info email me off
reflector directly. best 73 chuck WB6IGP