Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]

LF: Re: Droitwich carrier

To: [email protected]
Subject: LF: Re: Droitwich carrier
From: "Alberto di Bene" <[email protected]>
Date: Thu, 01 Aug 2002 11:37:34 +0200
References: <[email protected]>
Reply-to: [email protected]
Sender: <[email protected]>
David Willmore wrote:

This is different from what I would expect to happen.
To start with, one takes a carrier or some power, then
one modulates its amplitude.  This process spreads some
of the energy into the symetrical side bands--taking
power out of the carrier, thus causing 'downward
modulation' of the carrier, right?

I beg to differ. A properly modulated AM signal will have
a carrier of constant amplitude, unaffected by the modulation.
That's why SSB was born, to eliminate altogether a spectral
component that didn't carry any information content.
FM is another case... Its spectrum can be computed with
the Bessel functions and shows a carrier of amplitude changing
with the modulation index, going down to zero for certain
values of it, as Jim Moritz pointed out in a past message.

73  Alberto I2PHD




<Prev in Thread] Current Thread [Next in Thread>