Yes, AM is measured by wattage, going into the antenna, but I also said FM was measured by signal strength from antnna.
No, the Effective Radiated Power (ERP) is what's important because the antenna won't radiate all the power sent to it, some will be released as heat.
And for god's sake, AM get's better range then FM! End of question! The best lower power FM transmitters got 200 yards witha great antenna, vs 2 miles with a good antenna and an AM transmitter. There's two forums dedicated to this, so Hero don't claim FM is better.
What frequency?
DSB SSP?
FM mono/stereo?
Sorry don't believe you, please post some references.
All things being equal (power, frequency and path) FM will go further than AM DSB.
As I said before, if you're comparing MW (530kHz to 1700kz) to VHF (88MHz to 108MHz) then there will be other factors as well as being able to bounce round the earth's curvature off the ionosphere, for example longer wavelengths will probably be able to bounce round obstacles better than shorter wavelengths but that's not a level playing field.
Compare an FM transmitter working on 150MHz with a DSB AM transmitter on the same frequency with exactly the same average ERP and the FM transmitter will go further.
FM gives better reception at a lower signal to noise ratio.
If FM wasn't so efficient then why do you think people are moving away from AM towards FM?
AM could theoretically give just as good sound quality as FM if the bandwidth were increased but notice that this has not happened and we have FM instead?
When you find as easy of a circuit as the one I posted, with the range it can get, with FM, please post it. I don't mean this negative. I'm just saying, people have made this exact circuit, put a good antenna on it, and gotten 1 1/2 miles + with great sound quality at over a mile.
The simplest solution is to buy it, which is what has already been half done in the circuit you posted. The circuit inside that little metal can is at least as complicated as the circuit I posted above: it will contain at least a few transistors and a crystal.
There are much simpler FM transmitter circuits but they all perform very poorly compared to the one I posted.
Here's an example but it's very poor quality. I say if you want to build your own transmitter then you should at least want to make a decent one.
FM Voice Transmitter