[AMRadio] AM power

[Geoff Edmonson]

On 06/18/2011 10:29 PM, Gary Schafer wrote:
> Sorry for the misspelled name Geoff.
>
> It sounds like you have your transmitter set up to never reach 100%
> modulation on positive or negative peaks. That's ok too.

No.. that's an incorrect statement.  I can crank the gain up and have 
the transmitter look like a CB radio with a pre-amplified mic and a 
leen-yer, with spikes on the positive side, and gaps in the base line 
where the negative peaks have extended far beyond the baseline.

> But there are two different 100% areas to be concerned with. The positive
> and the negative.

Right.  Maintaining just slightly less than 100% negative will keep the 
carrier and audio clean.

Let the positive peaks reach up to wherever they want.

> If you do not hit 100% modulation on positive peaks you still calculate PEP
> by the sum of the carrier voltage and the audio voltage. Yes you can run a
> higher carrier power with lower audio power and still stay under the 1500
> watt PEP limit. But the most effective level is 375 watts of carrier. Not
> higher and not lower.

A 375w carrier is a myth, for obtaining 1500w PEP output.

> If your audio is unsymmetrical then you are being penalized by not being
> able to run as much audio power as you could if it was symmetrical.

The opposite is true, Gary.  I can run 100w of Carrier with full voltage 
on the modulators, see a 4:1 ratio between positive and negative peaks.
Let me say this again;
a ratio of 2:1, with a 100w carrier, will produce a PEP level of 400w.
a ratio of 3:1, with a 100w carrier, will produce a PEP level of 800w
a ratio of 4:1, with a 100w carrier, will produce a PEP level of 1600w



> It would probably help to run a processor that turned your audio into a more
> symmetrical form.
>

Why would I want to limit the effect of 'loudness' of my audio, while 
maintaining the cleanness of my carrier?