[AMRadio] AM power

[Bob Macklin]

Some people don't really know what their output power is because they cannot 
measure it. It has to be measured on a known load. And there are a lot of 
people that really don't know the Z their transmitter is working into.

Bob Macklin
K5MYJ
Seattle, Wa.
"Real Radios Glow In The Dark"
----- Original Message ----- 
From: "Geoff Edmonson" <w5omr at att.net>
To: <garyschafer at comcast.net>; "Discussion of AM Radio in the Amateur 
Service" <amradio at mailman.qth.net>
Sent: Saturday, June 18, 2011 7:55 PM
Subject: Re: [AMRadio] AM power


> On 06/18/2011 09:47 PM, Gary Schafer wrote:
>> It doesn't matter what the modulation is. Single tone, two tone or voice.
>> 100% positive modulation of a 375 watt carrier still comes out to 1500 
>> watts
>> PEP.
>>
>
> 100%, yes.  But, if you've -got- natural asymmetrical audio coming out
> of your mouth, and your speech equipment, from the microphone through
> the modulator, to where the positive peaks have a Symmetry Ratio of 3 or
> 4, then keeping the PEP level DOWN to 1500w, means reducing the carrier
> by 100 or more watts.  So, in order to keep at 1500w PEP, if I have an
> SR of 4, that means 100w of carrier gives me a PEP reading of 1600w.
>
> 100% symmetrical audio is an SR of 2.  An SR of 3 means the positive
> peaks are reaching 3 to 1 on the scope, where the negative peaks are not
> pinching off the carrier.  If you start with a 100w carrer, then an SR
> of 2 = 400wpep.  The same 100w carrier with an SR of 3 = 800w PEP.  An
> SR of 4 is 1600w PEP output.
>
>
>
>
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