[Amps] Amps Digest, Vol 43, Issue 70

[R L Measures]

On Jul 18, 2006, at 7:10 AM, Tom W8JI wrote:

>> Here's my thoughts. First, an amplifier with output
>> devices (note-
>> tubes or solid state) will have a certain absolute maximum
>> output
>> power capability. There is a point at which the tube(s)
>> cannot produce
>> additional RF. If an attempt to exceed that level is made
>> it
>> merely flat-tops and creates trash in addition to the
>> desired signal.
>
> That "trash" starts at anything over zero watts Ed, and it
> can get better and worse as power is increased. Transistors
> of course limit with a much more defined change in transfer
> characteristics than tubes, and the angle of the slope
> actually controls the  distortion....not the fact the
> transfer characteristic diverges from a straight line.

So why do tube manufacturers publish characteristic curves?  As I see  
it, when the slope of a constant-current line is changing, distortion  
is happening because the transfer characteristic is no longer constant.

> .,.,
>

R L MEASURES, AG6K. 805-386-3734
r at somis.org