[Laser] Ramsey kit mod

[David Rea, K2THZ]

What Ramsey has done with the PWM transmitter is not inherently
difficult; most of my expertise is in embedded systems (including a
heavy emphasis on microcontroller development), and I can vouch that it
isn't terribly difficult to spin up a PWM like this.

I know it's adding to the [growing] stack of laser To-Do items on my
bench, bit I can do some preliminary investigation into developing a PWM
transmitter using the Atmel AVR series of microcontrollers. These are
easy to program, and (IF I do it) I will make the Hex files available
for all to download. A simple serial-port programmer consisting of a few
diodes, a transistor and a capacitor is all that is needed to program
the devices. This way y'all don't have to bother purchasing
"pre-programmed microcontrollers" from me or a place like FAR Circuits.

At any rate - I've just effectively turned down a Deputy Chief's
position at my ambulance corps (in large part) because of this (and
several other) unfinished project(s)... I want to get myself behind the
bench a lot more this Fall and Winter...and I expect my friends here on
the laser list to hold me to that! :)

73
Dave K2THZ 

On Tue, 2003-11-11 at 23:20, Andrew T. Flowers, K0SM wrote:
> Gosh, that was easy. 
> Just remove R2--the 100K resistor after the U1A and stick the output of 
> the PGP font end into the empty hole that connects with C9.  There you 
> go--now you can use your favorite photodiode with this TX/RX combonation 
> and gather ALL of the light your lens gives you!  It gives a BIG S/N 
> improvement wiht my PDB-V107 (digikey) and "daylight" model front-end, 
> but it's hard to quantify just how much on my kitchen table.  Of course, 
> you could just complete the RX system by making your own LP filter, but 
> this is an easy way to upgrade a piece of equipment you already built.
> 
> For those who haven't seen it, the K3PGP front-end and other good stuff 
> can be found at http://k3pgp.org
> 
> Next thing to do might be to use the built in test tone for CW mode to 
> make a multi-mode transmitter.  It might be just as easy to make a 
> simple oscillator out of a 555 timer or something and throw that into 
> the line-input....
> 
> Andy
> K0SM/2
> 
> 
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