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Old February 21st 06, 09:04 PM posted to rec.radio.cb
james
 
Posts: n/a
Default Cobra 25LTD Classic tune up

On Tue, 21 Feb 2006 04:24:38 -0800, Jay in the Mojave
wrote:

+james wrote:
+
+ On Sun, 19 Feb 2006 15:40:53 -0800, Jay in the Mojave
+ wrote:
+
+
++Hello All:
++
++I am hearing that many guys are addeding in another modulation IC, and
++Modulation transformer to double the audio power, allowing a higher
++carrier power to be 100% modulated.
++
++Jay in the Mojave
+
+
+ ******
+ The carrier in Double Sideband Full Carrier Amplitude Modulation
+ should remain constant during modulation. If not, then you have a far
+ greater problem.
+
+ james
+
+Hello James:
+
+No thats not how AM works. The Modulation increases and decreses the
+amptitude during Modulation. Thats how double sidband full modulation
+works. Look in a old ARRL Book.
+
+
+Jay in the Mojave

*****

I think you need to go back and reread and comprehend what those old
ARRL handbooks say. Then m aybe I suggest a good university textbook
on Communications. Oh by the way you may want to brush up on y our
Calculus and Differential Equations at the same time.

AM(t) = f(t)*cos(wc*t) + A*cos(wc*t)

where AM(t) is your Amplitude modulated signal with respect to time.
f(t) is the function that mathematically describes the modulating
frequency.
wc is the carrier frequency
t is time
A is amplitude

Taking the Fourier Transform of the carrier portion (A*cos(wc*t)
yields an impulse function with amplitude A at frequency wc. The rest
of the equation is your double sideband suppressed carrier and when
the Fourier transform of this is taken it will yield a frequency that
is the audio frequency plus and minus the carrier frequency at
amplitude of half the audio power.

I hope that this helps in your understanding of what Double Sideband
Full Carrier Amplitude modulation, more commonly called AM, is.

james