[Laser] TX Circuit for high speed data.

[Chuck Hast]

I have been working with the K3PGP TX circuit to run high speed data. I have
found that when my data speed goes much above 150Khz the data starts
getting rounded off, and by the time it I get it to 200Khz the signal driving
the gate on the IRF-510 starts looking pretty ugly. In order to drive the IRF
510 I am driving directly from the data output, which is buffered. Once I get
rid of the two 1K resistors in line between the input and the gate I am able
to run the data rate all the way up to 10Mhz with no problem. I have not put
a laser diode on the circuit  yet, I have been using LED's to test since I do
not want to put a laser in there and destroy it. I am assuming that the circ-
uit was really designed for the low speed testing that is generally being done
on the NLOS activity. Is there any problem with removing the 1K resistors
and driving the gate directly with the TTL buffered data output? I have kept
the diodes and the zener in line just jumped over the 1K resistors.

Any observations on this?

-- 
Chuck Hast  -- KP4DJT --
To paraphrase my flight instructor;
"the only dumb question is the one you DID NOT ask resulting in my going
out and having to identify your bits and pieces in the midst of torn
and twisted metal."