Mike,

The only rule I know is that doubling your power gives you a 3DB increase
in signal strength.  I suspect, however, that other factors come into
play.  For example, how weak is the signal in the first place, and how
quiet is the receiver picking it up?  Also, how much noise is there on the
band, and what type of emission are we talking about?  It's often much
easier to pick out a weak CW station than it is to do the same thing with
an SSB signal of comparable strength.  The bottom line here is that you've
asked an interesting question, but I don't think you'll get a
straightforward answer.

Steve

On Friday 8/29/03 10:05 Michael Ryan wrote:
>Hi all:
>
>Is there a rule of thumb that can be used?
>IE:  you have a perfectly resonant antenna with 100W out.  What power is
>needed to get an improvement on the signal strength?  Will 200W make much
>difference or to receive an actual increase in signal strength, a power
>gain of lets say, 500W is required? Will a power output of 800/KW give much
>improvements to a 500W signal strength?  Also, If you have an amp rated at
>400W continuous or digital mode,  what would the PEP SSB rating be?
>
>Thanks to all & 73:
>Michael VO1RYN