I had a a failure last weekend doing POTA where the SWR was bananas. I had a back up coax and same story. I tried a back up antenna (the OCFD) and all was well.

Doing a POTA yesterday, same story. I found that the wire had detached from the male plug but looked fine due to the heat shrink covering it up.

I used my OCFD Lite and all was well and no need to get out of the car to switch bands. Hmmmmm is this my new antenna for fast and rapid deployment at POTA and SOTA???

The OCFD is 22 and 44 feet and uses the Elecraft B1 balun as a 4:1. SWR was just how I wanted it. This aerial is primarily intended for use on the amateur bands. It covers the 40, 20, 15, 10, and 6, bands (without a matching unit), and the 30, 17, and 12m bands with one.

A conventional dipole is fed at the centre; when using coaxial cable, it is essentially a single band aerial,  although it can present a good match on its third harmonic. A 1:1 Balun is generally used at the feed point to prevent radiation from coax cable if this is used as a feeder. It is generally accepted that the OCFD works by taking a half wavelength of wire and moving the feed-point away from the centre to a position where the impedance is equal, or nearly equal, on a multiple of harmonics of the fundamental frequency.
This point is found at one-third of the length of the wire.

There are variations to the design but if we make an OCFD for the 40m band using 66ft of wire and put the feed point at 33% (25ft) from one end, then we will get harmonic points on the 20, 15, 10, and 6m amateur bands (a classical ‘Windom’ type). 

The impedance at this 1/3 point will be around 200/300Ω. Rather than bringing an open-wire feeder back to a balanced AMU, a 4:1 Balun is used to give a match to 50Ω coaxial cable. Quite often, 10ft of 50Ω coax is connected to the BALUN with the other end connected to a 1:1 common-mode choke. This length of cable hangs down and provides some vertical radiation.