[Elecraft] CW rise time mod

[Ron D'Eau Claire]

Hi, David:

The original value for C222 was 0.01 uF. Wayne asked that it be changed to
0.1 uFd. 

I wasn't privy to the source of the comment that the rise time might be
further shortened in firmware. If Wayne plans to control the keying in
firmware, it's probably important that all the hardware be consistent with a
0.1uFd cap at C222 so the firmware works as planned. 

Ron AC7AC

-----Original Message-----

Elecraft says.....
"Some owners prefer a faster CW keying waveform rise time. The rise time 
can be reduced from about 8 milliseconds to 5 milliseconds without 
affecting the fall time by replacing capacitor C222 on the K3 main RF 
board with a 0.1 uF capacitor. This change will also allow a future 
firmware revision to further reduce rise time via a menu entry."

But the schematics of the RF Board Rev. A4 (Sheet 3 of 4), dated 
9/19/07, show C222 as being 0.1 already.  The instructions recommend 
removing the existing 0.1 and replacing it with another 0.1 !!  Surely 
to reduce the rise time the existing capacitor should be shunted with 
another one.

Or do Rev A RF boards have a lower value for C222 than that shown on the 
schematic?

73
-- 
David G4DMP
Leeds, England, UK