End Fed 9:1 Magic Wire Lengths

The end fed longwire has become a very popular antenna for field and portable use. I wouldn’t use one for my base station as the dipoles and verticals are the preferred way to go. If i have antenna restrictions then this antenna can help you get on the air and make contacts.

Due to the nature of wavelength and impedance at various frequencies there is a magic wire length to use for this type of balun. Remember, the 9:1 balun is doing a conversion of impedance from about 450-700 ohms down to 50 ohms. The antenna cannot be an actual 1/4 wave length on any ham band. Thus 8, 16, 32, 68 lengths are ruled out. For example a 32 foot length is actually a half wave on 20m with an impedance of about 3500 ohms and requires a 50:1 balun.

The magic lengths to use with the End Fed longwire is 29, 35.5, 41, 58, 71 and 84 feet

I use a 29 foot wire with my PackTenna 9:1 balun for 40m-10m and then add a 28 foot length for better coverage on 80m when needed.


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