How can I feed an unbalanced antenna wtih coax?

[drkirkby]

Feeding a balanced antenna via coax is easy - just use a balun.

But what if the antenna is unbalanced, but in a way you don't understand. Take a look at this for example

https://obrazki.elektroda.pl/6_1332373482.png

This does appear to radiate, but I'm not sure how it could best be fed with coax.

I'm guessing there are degrees of unbalance, but I'm not sure I understand this fully

dave

 

[davenn]

in principal your drawing looks like a colinear antenna
it could be fed at the lower end of each of the red and blue sections by coax with a sleeve balun
have a look at this coaxial antenna drawing of mine that I have built in the past and see if the representation
is similar to what you are suggesting....

https://www.sydneystormcity.com/microwave.htm

scroll about 2/3 way down the page, just past the transverter and tripler
you will find a drawing of a colinear on the left and dipole on the right

cheers
Dave

 

[drkirkby]

in principal your drawing looks like a colinear antenna
it could be fed at the lower end of each of the red and blue sections by coax with a sleeve balun
have a look at this coaxial antenna drawing of mine that I have built in the past and see if the representation
is similar to what you are suggesting....

https://www.sydneystormcity.com/microwave.htm

scroll about 2/3 way down the page, just past the transverter and tripler
you will find a drawing of a colinear on the left and dipole on the right

cheers
Dave

The antenna is a variation of that coaxial collinear. I'm interested in the design on your web page - how did you get the gain figure of ~ 10 dBd?

I'm not sure how best to feed them.