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Old August 3rd 09, 03:10 AM posted to rec.aviation.piloting
RST Engineering - JIm
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Default Portable/back up transceiver


"vaughn" wrote in message
...


There are various ways of measuring the output power of an AM transmitter.
One manufacturer's 1-watt transmitter may be much the same as another
manufacturer's 4-watt transmitter.


Yes. One trick that a pioneer in the field of solid state avionics design
stooped to because in the '60s to get a watt at 127 MHz was a real trick was
to measure power "peak to peak". This gives you an inflated number over the
standard CW or carrier power of about 3:1. In those days Mark 12s were
routinely putting out 10 to 12 watts and solid state "real" watts were about
1.5, which made the "peak to peak" watts somewhere around 4.5 watts, which
of course the ad department "rounded up" to 5 watts.


There are other important issues, such
as the type and quality of the modulation and the audio processing. The
devil is in the details.


Amen. Decent audio processing in the modulator will make any radio sound
good. The problem is that I can count the number of quality VHF AM
engineers around today without even taking my pants and shoes off. Not
understanding the subtleties of the AM process makes a radio sound thin and
whiny, while good processing and modulation makes a real loudenboomer.


Actually, the quality of the receiver is (in general) more important than
transmit power.


That is a question we've been debating for as long as I've been in this
game. Sure, I can give you a tenth of a microvolt receiver that crossmods
like hell when good buddy fires up his cb a mile away. Or I can do crossmod
and intermod like gangbusters and the price you pay is decreased
sensitivity. Like the old saw says, price, quality, time. Pick any two.
Crossmod, intermod, sensitivity. Pick any two.

Jim