What is the purpose of feeding an off-center-fed dipole (OCFD) between the center and one end instead of at the midpoint?
To create a similar feed point impedance on multiple bands✓پاسخ درست
To suppress off-center lobes at higher frequencies
To resonate the antenna across a wider range of frequencies
To reduce common-mode current coupling on the feed line shield
توضیح
A center-fed dipole sits at a current maximum on its fundamental but at a high-impedance voltage maximum on the even harmonics, so its feed point impedance swings wildly from band to band. Moving the feed away from the midpoint finds a location where the impedance is comparable on several harmonically related bands, so one fixed transformer can serve them all.