[Towertalk] Feedback on W9INN Antennas Wanted

[Tom Rauch]

> I want to change my current antenna setup for the lower frequencies
> particularly but also for the WARC bands.  Of particular interest to
> me is the W9INN broadband sloper for 160, 80 and 40.  Has anyone on
> the list used one of these?  If so, would you please give me some
> feedback, privately if you wish, concerning your thoughts on its
> performance?

1/4wl slopers ALL depend on the tower impedance at the connection 
point to be very low...otherwise you will have SWR problems you won't 
be able to cure.

Because they depend so much on whatever else is mounted on the tower 
and the tower height top work, they are mostly a matter of random 
luck in how well (or if) they work.

For example, if you have a 50-foot or so regular tower with nothing 
large on the top you will never get one to work on 80 meters unless 
you add some additional wires for a counterpoise at the top of the 
tower.

Now if you have the same tower with a fairly large grounded-element 
yagi at top (like a large tribander), a slopper would probably work 
OK on 80 but NOT on 160 meters!

Because of this, and because the pattern is often so unpredictable, 
I'd just install a good Inverted Vee dipole or some other antenna 
that works by itself predictably rather than by luck or happenstance. 

Otherwise, I would model the slopper antenna and tower as a total 
system before wasting time experimenting.73, Tom W8JI
W8JI@contesting.com