On Wed, 24 Oct 2007 06:39:52 -0700, Art Harris
wrote:

wrote:


I am looking for some help in understanding amplifier concepts...


Tell us what you're trying to amplify. What type of signal? AM? FM?
SSB? Other?

What frequency?

Since you mention 600 watts, this is obviously for a transmitted
signal.

AM and SSB signals require a "linear" amplifier (usually Class AB) so
that the amplitude variations aren't distorted.

FM signals can use a more efficient Class C amplifier since amplitude
variations are of no concern.

4. What is an octave when dealing with amplifiers?

An octave is a 2:1 frequency ratio (just like in music). 20 MHz is an
octave above 10 MHz.


5. Is this communication concepts HF 1000 watt amplifier a class
A, class AB, or class C amplifier?http://www.communication
concepts.com/ar347.htm

Probably Class AB. Definitely not Class C, as they mention linearity
to 800 watts.



7 Can this amplifier be "controlled" to give graded amplification less
than 1000 watts specified, or will it work only at this maximum
level?

You can vary the output by controlling how much signal you feed into
the amp. You could put a variable attenuator between whatever RF
driver you're using and the amplifier. According to the specs, 10
watts input will give 1000 watts output. Therefore, 5 watts input
would give about 500 watts output.

Art N2AH
Class A amplifiers are linear, AB are fairly linear but have
relatively high intermod distortion.