KF6HHS wrote:
"I stand by my statement: 6 dB doubles your range."

The "Sommerfeld formula" is ancient and accepted. It says:
Ground-wave field strength = (A) Eo / d
Eo = field strength at the surface of the earth at a unit distance from
the transmitting antenna, neglecting earth`s losses
d = distance to the transmitting antenna
A = factor taking into account ground losses

If the earth is perfect, the above reduces to:
volts/meter = Eo / d
assuming the right scale factors.

At twice the distance, the field strength over flat earth is halved.

The resulting current is also halved. Thus, the power, their product, is
quartered. That`s a 6dB change from doubling the distance.

On the other hand, if you want to produce the same field strength at
twice the distance, you must use 4X the power by the Sommerfeld formula.

Best regards, Richard Harrison, KB5WZI