The reason I asked the question in the first place is that I don't ever remember using a 5 watt transmitter as an example. Figuring that the July issue has been sent to subscribers, here is what I actually said:
"One of the greatest drawbacks to AM is the fact that it requires a carrier (which is the frequency you dialed up on your radio) and two “sidebands” that actually carry your voice. Each of those sidebands at best have one quarter of your radio’s power, and you can only hear at the receiver what is on one of the sidebands. Thus, your rock-crusher 10-watt radio you paid kilobucks to buy can only have the equivalent of 2.5 watts of “talk” power at the other end’s receiver. And vice versa."
At 100% AM modulation, half of the power is contained in the carrier, and the other 50% is in the sidebands, split equally between the upper and lower sidebands. That's 2.5 watts of power in each sideband.
Now, as to amplifiers, every aircraft band transmitter has to go through FCC part 87 type acceptance. (47CFR87) Type acceptance is a rather complex process involving getting your boots dirty tromping around in the cow pasture (there is a specification on how high the grass can be) with your transmitter mounted on a high platform and an equally high and well calibrated antenna a fixed distance away. You then make some very delicate measurements looking for spurious signals coming from the transmitter all the way from below the AM broadcast band up to the other side of the microwave oven/GPS frequencies. All the while with Bossy licking you on the neck.
Then you go back into the lab where you freeze the transmitter, bake it, all the while looking for the same spurious signals, and you are looking for them all the way down to below one-ten-thousandth of the transmitter rated power.(-43 dBp). With and without modulation.
Let's now talk amplifiers. I have NOT seen an amplifier that has gone through this type acceptance procedure, nor have I seen one that is usable for AM. Most of the "linears" I've seen are meant for CB use down at 27 MHz. and FM use in the amateur 2-meter (144 MHz.) band. FM, by its very nature, is designed to clip and limit the input signal to remove any residual AM. Nor is there any specification for spurious outputs other than the general "can't cause interference to another user" blanket rule.
To top things off, the FCC takes a very dim view of bogus/unaaproved devices just wired up to an approved radio ... dim to the point of $10,000 and a year in the slammer for each time you key up the transmitter and spew garbage all over the band.
I'm presuming this answered the question?
Jim