Understanding Yagi antenna

Hi Mike,

That is a very complex subject. I would go to the library and check out a good book on antenna theory. "The ARRL Antenna Book", while aimed at amateur radio operators would still provide you with more theory than you're likely to even need to know. An excellent book!

yes, it was made on a moonday.

noise reduction ferrite beads or toroids Line filters get rid of RF travelling along the outer surface of the coax's shield and avoid, consequently, any TVI/BCI. The best performance can be seen when connected right into the feed line at the antenna base!

hard not to be cynic. w.

Do you mean a cynic, as in ; a faultfinding captious critic; especially : one who believes that human conduct is motivated wholly by self-interest. Well yes, I ask the questions because (I) want to know, but if someone else learns from the answers, I don't care. "Moonday" hurumpf ;-} Mike

Hi Mike,

It is simply a function of the mechanical connection of the line at that point (the inner conductor needs the cut-out and the shield has a closer point of attachment).

the distance between the closest points of contact before the line was installed - i.e. the thickness of the inner conductor's insulation (true for absolutely every antenna built).

Not sure that matters if in fact it has been designed to be a Z transformer. If so, then you have one of several dimensions possible n/4 wavelength or n/2 wavelength where n is odd.

Decoupling.

I had to go back and look at the picture, but that's interesting, the cutout makes for a good fit for the mechanical connection to the coax. And I'll use that,

for the gap in the antenna I'm building. Thanks

To learn specifically about Yagi antennas, it's hard to beat Lawson's _Yagi Antenna Design_.

Roy Lewallen, W7EL