[AMRadio] Re:Reactor Wanted


Geoff/W5OMR ars.w5omr at gmail.com
Sun Nov 11 20:02:02 EST 2007


Thomas Adams wrote:
> and maybe even make the legal limit output for AM (375 watts of carrier).

Hi, Tom.

This is an incorrect statement.  There is no -legal limit carrier level- 
for AM.

The legal limit on -any- mode is 1,500 watts -PEP -output-.  Period.

If you have a transmitter that has it's audio at the base-line on 
negative peaks and positive peaks that reach beyond a 2:1 ratio, then 
your 375w carrier is producing more than 1,500 watts PEP output.

This function has been defined by John/WA5BXO (with the help of 
Don/K4KYV, Bob (Bacon) WA3WDR and Tim, W5TOB.) as SR, for Symmetry Ratio.

What it means, in a very much simplified manner, is that if your audio 
equipment (from microphone through modulator) has the ability to 
faithfully reproduce your natural voice, then the typical male-pattern 
speech characteristics will modulate the rig in an asymmetrical manner.

In the case specified (and mine) the SR ratios are 3:1 and 4:1, 
respectively. 

With a 100w carrier, an SR of 3 would mean that the PEP (which is 4x the 
carrier, for 100%, or an SR of 2) would equal 800w PEP.

See www.qsl.net/*wa5bxo*/asyam/aam3.html for more info.

-- 
Driving your AM Rig without a scope, 
is like driving your car at night, without headlights. (K4KYV)

--
73 = Best Regards,
-Geoff/W5OMR



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