Can someone explain a collinear antenna in detail ?

Thread Starter


Joined Nov 29, 2005
Would like to learn and understand all about single band collinear antennas ;


The elements, locations, spacing, principles of operation, dimensions, thicknesses, lenghts, how they interact, coils, their number of turns, diametres, why, what they do, bandwidht, all of it, everything, all the why's...:)

Yes, I have and can use search engines too. Prefer your explained knowledge.


Joined Aug 21, 2017
As the mid-coils are slightly tricky to produce, one very similar another collinear construction I like better.
It uses coax stubs one after previous, but in sticking place they rhythmically changes the inner wire and outer braiding with places. So, 1st stub inner wire becomes braiding in 2nd, is inner again in 3rd and is braiding again in 4th. The stub number may be limitless.

Thread Starter


Joined Nov 29, 2005
Thanks. Not about the coax stubs construction, please. Only end-fed with coils as pictured.
The coils;
- what do number of turns affect,
- what do diameter of coils affect,
- what does thickness of wire affects,
- what material as copper or iron or aluminium wire affects,
- what does the span length of each coil portion affects,
- what the wire length turned into coil affects,
- what the distance from each coil to the adyacent 'element rod' affects,
- what coil turn spacing affects ?
- what same direction of winding for all coils affects ?
- ... :confused:


Joined Apr 5, 2008

In the article I posted there is a whole section about the coil.
Keep in mind that the article is written by a HAM (radio amateur) and concerns a 2m (145 MHz) antenna.