built a new 80-10, 70-30 off center fed dipole.

[nfsus]

blue line is no calibration for the vna. sees all from end to end
green line is a calibration that sees only the balun and the antenna.

not concerned for 15m all that much. 80-20 split caused too much rfi here at the house.

 

[fourstringburn]

I once used a Carolina Windom which is an OCFD that I had up at 45ft as an inverted V. It works on many HF bands without a tuner needed but RFI sometimes was an an issue due to un-equal voltages across the the antenna wires from having un-equal wire lengths.

I used a 4:1 Balun at the top and a choke Balun at the bottom of the coax vertical radiator and still had some RFI issues.

I since went with a ZS6BKW which is a G5RV variant and haven't had any RFI issues since.

The ZS6BKW works well on most HF bands but it doesn't match well on 60,30, and 15 meters. A tuner will let you works those bands though.

Good luck with your OCFD!

 

[nfsus]

trashed that one. tried a 60/40. didnt care for that too much. i decided to go back to the 70/30 split. to gain 15meters i went up on 20 meters and i have not been a big 15m fan for the most part. however i can use a tuner if i really want to.

 

[Dr. Frankenstein]

Have you tried a 90/45?