Guenther, VE3CVS wrote:
"This ensure any form of errors in gain are cancelled out correctly
instead of using the typical 2.1 dbi value for a Dipole and providing a
falsely unrealistic value."

Gain is always measured with respect to some reference antenna. The
isotropic is a hypothetical antenna so the usual practice is to use a
1/2-wavelength reference antenna. Gain is a power ratio which is equal
to the voltage ratio squared. When dBd or some other reference is not
specified, dBi is presumed.

Kraus says the 1/2-wavelength resonant antenna`s gain over the isotropic
is 1.64. This appears on page 454 of the 1950 edition of "Antennas".
Terman was Kraus` consulting editor.

Terman says the same as Kraus on page 871 of the 1955 edition of
"Electronic and Radio Engineering". Directive gain ignores losses.
"Power Gain" as wsed to determine effective radiated power takes into
account loss in the antenna used. The reference antenna is considered
lossless.

The dB gain figure calculated from a 1.64 power ratio is shown on page
2-12 of the 19th edition of the ARRL Antenna Book. Gain in the
1/2-wavelength dipole`s best direction is shown as 2.14 dBi.

0 dBd is identical to 2.14 dBi. No false or unrealistic values obtain
from using either reference.

Best regards, Richard Harrison, KB5WZI