[BC] Nautel 2 Armstrong

[WFIFeng@aol.com]

In a message dated 02/07/2007 12:05:23 PM Eastern Standard Time, 
sbailey at nespower.com writes:

> The one thing I want to know is how to get to the negative clipper, with
>  out removing the transmitter from the rack. We have the clipping set at
>  the factory setting at 90%. I would like to bring it up to 99%. Did you
>  have the factory do this, or did you do this yourself?

Because most radios still use an ordinary diode-based envelope detector, 
you're better off *not* pushing the negative modulation to more than ~96%. Doing 
so only adds distortion, as the diode in the receiver loses the forward bias, 
thus "flat-bottoming" the audio. 

This is very easily verified with a scope on the audio output of a typical 
radio, tuned to a sine-wave modulated AM signal generator. As you approach 100% 
modulation, you'll see the audio's bottom peaks flatten-out before the sig 
generator reaches -100%.

Willie...