What is an OCF dipole?

What is an OCF dipole?

Off-center-fed dipoles (OCFs) are 1/2-wavelength wire antennas fed at neither the center nor the end, but somewhere between–off-center. OCFs are derived from the Windom antenna, a 1929 concoction using a single- wire feed attached to the antenna element at what was believed to be the 600-ohm point.

How do you make an OCF dipole?

To build the OCF dipole (in this case 80-10m) cut a single length of wire to an overall size of 133′. The 3 additional feet of wire will be used to fine-tune the OCF after you install it. Next, cut the 133′ into two separate lengths of 85′ 2 ½“ and 47′ 9 ½”.

How does an end-fed antenna work?

In the case of an end-fed antenna fed with open-line, only one wire at the end of the feed line is connected to the half wave antenna. At the end of the other wire, current still runs into the antenna, otherwise the radiator wouldn’t do anything. So at this point there is imbalance in the feed line.

Does balanced feeder radiate?

In order for balanced feeder to operate satisfactorily, the balance between the two wires must be maintained. Any imbalance will cause it to radiate, or pick up signals.

What is OCF dipole antenna?

OCF dipole is an ungrounded dipole antenna fed with twin-conductorline, either coaxial or open wire parallel conductors. The so-called “OCF windom” is also a misnomer, for the same reasons.

Can You detune An OCF antenna?

Remember this antenna is an Off Center Fed, (OCF), dipole, and if you tune it for one band, you detune it for another band. An OCF Dipole is a very finicky item to tune, so it is best you do not change things. All the crimps on this antenna look like this one, I saw not one shallow crimp.

What is the range of the off center fed dipole (OCF) graph?

Off-Center-Fed Dipole (OCF) Graphs Even Harmonics of (f0) 3.5 MHZ (80 M Band) Second harmonic (2xf0) = 40 M Band (7 MHz) Fourth harmonic (4xf0) = 20 M Band (14 MHz) Sixth harmonic (6xf0) = 15 M Band (21 MHz) Eighth harmonic (8xf0) = 10 M Band (28 MHz) Odd Harmonics of (f0) 3.5 MHZ (80 M Band) The Third Harmonic (3xf0) of 3.5 MHz

Are ni4l’s 7 band OCF dipole antennas any good?

This review of NI4L’s 7 band OCF dipole was prompted by my needing a quick deploy multiband antenna for both field day, and for RVing. Last year on Field Day I was able to use an OCF dipole for the first time, and I enjoyed the quick bandswitching it allowed, so I thought I’d try and find a good OCF dipole for use while in the field.