Jimmy wrote:
"The last description I saw of a quarter wave antenna was that of a
parallel circuit. Isn`t that basically how a capacity hat shortens an
antenna, by increasing the parallel capacitance?"

Parallel or series hardly makes any difference.

The 1/4-wave antenna is essentially a 1/2-wave antenna with the missing
1/4-wave piece replaced by a ground reflection. Terman illustrates
current distribution in a doublet on page 866 of his 1955 edition. He
says:
"These current distributions are those that would be obtained by
applying the exciting voltage in series with the wire at a current loop,
or to one end of the wire."

The series representation is conventional and comes from the distributed
nature of resistance, inductance, and capacitance along the antenna
wire.

From the generator or transmission line`s point of view, it may be more
convenient to view the antenna load as a parallel resonant circuit.
Parallel or series circuit, they are mathematically interchangeable by
using conversion formulas which appear in various books including the
ARRL Antenna Book. Use whichever form you like.

There is a difference between a length of wire and a tank circuit. The
wire has multiple harmonically related resonances. The tank circuit does
not. It has only one resonance.

Jimmy also wrote:
"Who says they are not (parallel circuits suitable to model an
antenna)?"

Yes, Art Unwin, who says they are not?

Jimmy also wrote:
"This question (is stagger tuning a parallel circuit?) being out of
context with the other questions seems to indicate you really don`t know
what stagger tuning means so I don`t know how to reply."

Art for years has hijacked threads to advertise a tuned loop conjoined
with a dipole. One of his claims is that the loop is tuned to one
frequency and the dipole is tuned to a different frequency ergo a
broadband antenna is produced. You must guess between the lines to make
sense of what Art says.

Best regards, Richard Harrison, KB5WZI