[TenTec] Open Wire Line - A CASE FOR OCFD

[Mark van Wijk, PA5MW]

I might add  to that:

Choose any equal length for your open dipole which
a) suits your local environment at fysical lengths and
b) produces the 3D radiation field you need for the required bands

Note: open wire fed balanced antennas never need to be any exactly X-times 
0.5 wavelength. IMPORTANT: RF radiation does not care about radiator length. 
It will radiate anyway. The end part of your open wire feeders is the the 
only complex part which has to be matched by means of a balanced tuner.

One better calculate the total length of the balanced antenna system ; from 
the outer tip of the dipole leg, along the open wire length to the matching 
balanced tuner. That total length (dipole leg +total open wire feeder 
length) determines the condition of what you need to match.

As said by Rick; it is easy to add/remove a few feet to avoid the total 
length becoming a half wave and thereby a very high Z (at least too high for 
your balanced tuner)

There is some books showing a table about which TOTAL lengths to avoid, 
depending on the bands used.
Les Moxon was one of those describing it in his book "HF Antennas for all 
locations".

Back in '87 I started with such a balanced antenna + open wire feeders+ 
balanced tuner (Annecke home build kit). It has been the best overall 
experience for years.

73 Mark, PA5MW


-----Original Message----- 
From: Rick - DJ0IP / NJ0IP
Sent: Tuesday, October 20, 2015 9:24 PM
To: 'Discussion of Ten-Tec Equipment'
Subject: Re: [TenTec] Open Wire Line - A CASE FOR OCFD

Wade, if your tuner spits and sputters on 15m, simply add 5 ft. more
feedline to it and it will straighten up and fly right.