137 foot OCF 80, 40, 20 and 10 meter antenna for your 4:1 Balun


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Your wire element is manufactured using our MilSpec 19 strand 13 AWG wire with matte black polyethylene jacket. 80, 40, 20 and 10 meter coverage when used with a 4:1 Balun, and we recommend 4:1 Baluns from Balun Designs.

This customizable 137 foot OCF (Off Center Fed) antenna design has very good performance across the HF bands. The antenna covers 80, 40, 20 and 10 meters with 15 meters and WARC bands only available with an antenna tuner, where it should be limited to less than 500 watts due to elevated SWR.

To install the OCF dipole (in this case 80-10m) attach each of the S9 Antennas elements. There will be extra wire on the long side and on the shorter side, which will be used to fine-tune the OCF after you install it. Note, to determine the length of each leg, you will use the OCF design program by Walt KK1CW, which you can find on Balun Designs Support/Download page.

Alternatively, you may also use the following design located HERE.

As you begin to install the antenna, you will notice that we have already stripped and prepared the ends of each length by tinning them with solder. Next, run each end through the balun strain relief as depicted in the drawing and crimp each end to the connecter at and supplied with the balun. Now install the Balun and insulators in the location and at the height it will be deployed and used. The antenna can be installed in an inverted V configuration keeping in mind that this design changes the feedpoint impedance and will tune differently. Variances such as this or nearfield objects can change the feedpoint impedance, requiring the wire for each side of the antenna be shortened 1 inch at a time till performance is maximized.
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