[Elecraft] [K2] Erratic power control with base cw K2

[Don Wilhelm]

  Al,

With the keying waveshape mod installed, you must use MCU 2.04p/KIO 1.09 
or later.  Reverting to an earlier firmware level will cause distorted 
keying waveshapes.

In addition to the parts on the Control Board, check RF board C111 (2.2 
uF) as well as C168, R98, D36 and R99.

73,
Don W3FPR

On 6/29/2011 12:37 AM, Alastair Couper wrote:
> Further testing here. I tried  changing the control board MCU to the
> previous firmware version, and no change, so that is ruled out. But... I
> do notice that my keying wave form is not right. The rise time is very
> slow, about 50ms, the falling time is about right. And the keying sounds
> like it, very mushy. So there is something in that circuit, with the
> keying bandwidth mod installed, that has changed.  Probing further...
>