Dot wrote:
"Low impedance resonances occur every odd multiple (1,3,5, etc.) of a
quarter wavelength."

As I read from Arnold B. Bailey, he takes the opposite view. I think a
1/4-wavelength folded dipole shares some characteristics with a
short-circuited 1/4-wavelength stub; short on one end, high impedance on
the other end. Therefore, I agree with Bailey.

Arnold B. Bailey shows interest in folded dipoles in "TV ans Other
Receiving Antennas", He catalogs the first through the eighth resonances
on page 410. The odd order (1,3,5, etc.) resonances present high
drivepoint impedances. Even order resonances present low drivepoint
impedances.

Page 509 is Bailey`s catalog page for the 1/4-wave folded dipole. With a
1/4-in dia rod spaced at 1 inch between sides at 200 MHz, the antenna
has a 6000-ohm drivepoint. Cecil says this is too good to be true
because a 1/4-wave-matching-section of 600-ohm line would match the
1/4-wave dipole to 50 ohms.

Page 510 is Bailey`s catalog page for the 1/2-wave folded dipole. It has
0 dBd gain and its pattern is the same as a straight dipole. Same as the
1/4-wave folded dipole too for practical purposes.

The 1/4-wave folded dipole has only a 1/2 dB less gain than the 1/2-wave
folded dipole, but its resonance is sharper. It has only 5% bandwidth
versus 45% for the 1/2-wave folded dipole. This can be an advantage if
it prevents receiver overload when using the 1/4-wave folded dipole.

Best regards, Richard Harrison, KB5WZI