[Elecraft] K2/100 Flat topping on 30m?

[kc4kgu@ENTERZONE.NET]

On Wed, 30 Oct 2002, peter barville wrote:

> 
> I wonder if any of you have looked at your K2/100 on a monitor 'scope
> with a standard (ssb) two tone test?
> 
> Mine looks very good indeed, except on 30m where it begins to flat top
> at a power level of around 75 watts. 
> 
> Dropping the power to 10 watts (ie with the 100 watt PA stage out of
> circuit, but the basic K2 running pretty much at full power) shows a
> clean trace. Therefore I have to assume that the flat topping is
> occurring in the PA stage.

I monitor my signal nearly constantly with a dual trace scope.  I monitor
RF on the top trace and the actual audio I'm sending to the rig with the
bottom trace.  I haven't seen any flat topping on any band.  Just a nice
"christmas tree on its side" like you should see with a SSB signal.  The
CW looks beutiful also.

> "Why worry about the rig's ssb performance on a band where we shouldn't
> be using ssb" I hear you ask, but that's not really the point. I would
> like to think the rig, and PA, are performing correctly.

SSB is used for PSK31, RTTY and many other soundcard digital
modes.  Perhaps I'm mistaken, someone please tell me if I am but, does "CW
& FSK Only" exclude AFSK?  

73 de John - KC4KGU
K2/100 #2490