[Antennaware] Fan dipole: similar or identical segment lengths? (Kevin Zembower)

Grant Saviers grants2 at pacbell.net
Mon Jul 27 13:31:54 EDT 2020

The "equal length" is one way to say "segments should align" which could 
be different if the fan angles are large. Aligned segments I think is 
what the math does best with.  So that takes a bit of fiddling to 
determine the divisor # of segments for each dipole.  Of course you need 
to make a good guess at the starting lengths.  Close is good enough.

3 segments are not enough IMO as the currents near the feedpoint 
junction are high.  Another rather essential trick is to have a 
transmission line between the feedpoints.  My model feedpoints were 
separated by 2" 50ohm lines and the ends by 20". This is discussed by 
Cebik in one of his modeling tutorials.  Implementation between 
feedpoints was a small Cu flat strip, unknown Z, but unimportant for my 
two 80/40/20 fans, especially since 20m is closest to the coax.

At least that is what I have done and gotten good correlation model to 
built 3 band 80/40/20 fans.

Grant KZ1W

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