Topband: Shunt feed vs sloper

Bill Tippett btippett@alum.mit.edu
Tue, 11 Sep 2001 10:17:55 +0100


ZL3IX wrote:

>but there were a couple of negative comments last month.  These were mainly
>to the effect that they (slopers) act more like low dipoles. 

        Greg, 1/4 wave slopers do work but they are very dependent on the
individual installation.  K0RF has used these for years very effectively
and I assure you they work much better than low dipoles!  I believe the 
current thinking is that they act like an inverted Ground Plane so they MUST
have some sort of top-loading (usually one or more Yagi's) for them to work
properly.  If you can put one below a Yagi near the top of your tower, by
all means give it a try.  I recall from the ones I used on 80 meters that
you should begin with a length much longer (10-15%) than predicted by the
usual 234/f formula.  If you don't have a Yagi on your tower yet, don't 
waste your time trying a sloper.  

        Don't be a victim of analysis paralysis...put one up and see for
yourself if it will work for you.  Any antenna is better than no antenna!

                                                     73,  Bill  W4ZV