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LF: Re: Droitwich carrier

To: [email protected]
Subject: LF: Re: Droitwich carrier
From: "John Andrews" <[email protected]>
Date: Wed, 31 Jul 2002 12:06:05 -0400
References: <[email protected]>
Reply-to: [email protected]
Sender: <[email protected]>
A 'perfect' 100% modulated AM transmission carrying a sinewave should have
4.8 dB peak to mean, so what mechanism can account for 6.9dB ?  This
certainly does seem to reinforce the idea that the carrier reduces with
amplitude.

Here in the U.S., positive peak levels of 125% are allowed. The maximum
negative peak level is obviously 100%, the point at which the carrier goes
away. Not sure what the regulations are over there, but the asymmetry might
explain the readings.

And I'll echo some earlier comments, here. I used to be in charge of a 5 kW
PDM rig that had very little carrier shift with "old fashioned" audio
processing ahead of it. But with an Optimod, it used to buck quite a bit. No
amount of twiddling with the tilt or other settings on the Optimod would get
rid of it.

John Andrews, W1TAG



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