[Laser] Newbie

[TWOSIG at aol.com]

Let me add my welcome.
 
With a typical laser pointer and a phototransistor (clear plastic) you  
should have no trouble getting a good demonstration of light  communication.  I 
have gotten more that 800 feet at sunset (broad daylight  makes it hard to find 
the laser beam at that distance) with the phototransistor  pointed 90 degrees 
to the beam with full quieting.  The unit was a Ramsey  laser receiver, its 
circuit is a phototransistor with a 1M collector resistor  followed by an op amp, 
gain of 2, then a band pass filter, to an audio amp.  No lenses or mirrors 
required.   I have even gotten that far  with a CdS photo resistor under similar 
light conditions.
 
 
For building circuits with ICs:
 
I have had good luck using Radio Shack General purpose Grid-Style PC Board,  
part number 276-150.  They have grouped traces for IC.  I cut out a  piece a 
little bigger than I think I will need to place a 555 timer and  switching 
transistors with the other components.  I use a small fine  toothed saw to score 
the board from hole to hole, then flex the board to break  it along the weak 
line.  Then I sand the edges (not required).  When  soldering, I use a very 
small iron and small diameter solder.
 
 
Hope you have lots of fun with them.
 
 
73
James
N5GUI
 
 
 
In a message dated 1/11/2006 8:13:55 PM Central Standard Time,  
hamfreak2002 at gmail.com writes:
hey everyone, Just started modding my lase pen  to make it into a CW 
transmitter. But school have picked up for finals and  havent had much 
time to work on it but... got most of the tx done and a good  amount of 
the RX.

Any tips?

I can use a regualr radio shack  phototransistor for the RX even though 
it says infrared? its broad band  right... Its the only one I could find...

Well have to go, I will ask  more questions when I can start owrking on 
it again, hihi. 73's