Johnythree

I'm puzzled by this claim. I wouldn't call it a myth, but all the same...

I grew up on a vineyard. Each harvest time the grapes would hang down heavily and almost touch the ground. Our pet dogs would park themselves beneath and greedily consume a whole bunch.

They would also scoff any dried grapes they found on the ground.

The worst effect seemed that they all would get noticeably pudgy during the season.

AM is a type of modulation which is widely used by many different services (eg Shortwave broadcasting, CB radio, Aircraft VHF, etc).

However "Longwave and Mediumwave Broadcast" unambiguously refers to that service.

Transmitters need only be re-certified if they are to be sold in quantity.

Once-off Broadcast Transmitters need only demonstrate that they meet the relevant standards.

Many of the existing LF and MF BC transmitters were effectively custom built to meet the requirements of their transmit license (for example, the radiation pattern of the antenna were often unique for each station).

It doesn't. In both it depends on what the stations engineer chooses to transmit.

Most cheap FM receivers definitely use a PLL to detect FM. Giving automatic tuning is just a side benifit.

Most FM receivers can lock on the carrier because they have a "Phase locked loop" to cancel any tuning errors.

Many good AM receivers do exactly the same thing, especially those receivers which have "Synchronous Detectors" for AM.

It's just that the circuitry involved is simple for FM, but rather more complex for AM.

Is commonly known as "Bass Boost".

As the OP has said, it cannot give louder bass, but simulates the bass harmonics.

This is yet another myth:

The "Woolyness" of AM broadcast (at least in America) is due to the stations purposefully tailoring their audio processing to suit typical cheap AM receivers. And this in turn is because designers of cheap AM receivers fit narrow filters instead of using noise reduction techniques, eg a good outside antenna.

There was a period (in the rest of the world) where high quality AM receivers had a narrow/wide switch to give better audio response to stronger signals.

The good news is that modern SDR receivers usually have selectable bandwidth on AM so as to derive the full transmitted audio. And many of these have AM stereo decoders as well.

If you listen to a good quality AM broadcast (eg Gov AM stations in Australia) you will hear audio which are very hard to tell from FM audio.

Go back and read the many high-quality AM tuner articles in the electronic hobby magazines from the past.

Only while signals are strong. On weak signals however, AM has a considerable benefit in intelligibility over FM.

This is a myth. There is no reason that channel spacing need limit the modulation bandwidth. The only downside is that listeners to adjacent stations will hear a slight "monkey chatter" from the overlapping sidebands. In reality stations are never allocated adjacent frequencies within the same coverage area so this usually doesn't happen.

Yes, this is one of the proposed methods. It's known as "Independent Sideband".

It works, but it is a fairly expensive method to implement.

There were a number of successful AM stereo broadcasting methods proposed and trialed. These were completely compatible with conventional AM transmissions.

The conceptually simplest of course whas where the LSB and USB are used as separate channels.

Although most of the systems did work, they were not ultimately successful simply because insufficient stereo receivers reached the market.

Go search in Wikipedia on "AM Stereo".

There is no reason that the channel spacing need limit the sideband bandwidth.

The only downside to this is that listeners on adjacent stations hear a slight "monkey chatter" from the overlapping sidebands.

This is one of many reasons why station frequencies are never allocated close to stations which are physically close.

You only need glance at the waterfall display on a good SDR receiver to see that the actual audio bandwidth is often much wider than the channel spacing implies.

The pickle will shunt (steal) some signal, but the radiated power from the antenna will be very much greater than that flowing through the pickle.