[Elecraft] Small QRP antenna

[Jim Brown]

Nothing in this post is true. Optimum length for a counterpoise is a 
quarter wave. Radials are a form of counterpoise, and their optimum 
length is also a quarter wave. More radials reduce ground losses. 
Failing to provide an adequate counterpoise will cause the antenna's 
return current to flow on your coax, which makes the rig hot with RF. 
That's not much of a problem with 5W, but it can be a very big deal with 
100W or more.

Of course, it does depend on what you mean by "much" and "minimal." 
Inadequate counterpoise or radial systems can easily reduce you signal 
by 6 dB. That's an S-unit, and it reduces your 5W signal to 1.25W.  I 
wouldn't call that minimal or "not much."

73, Jim K9YC

On Thu,12/29/2016 7:30 AM, Fred Moore wrote:
> With an end fed 1/4 wave you only need a counterpoise that is about .05
> wave length.  it can be the coax or another counterpoise.  Although a
> counterpoise has some effect on radiation pattern of a quarter wave
> radiator, it is minimal.   You won't see much improvement in performance
> by going above .05 wave length..  it's not worth the trouble to increase
> the counterpoise length..