[TowerTalk] 160 vertical question (Top Hat)

[john at kk9a.com]

Another way to bring a vertical to 50 ohms is with a hairpin coil.

John KK9A

To:	towertalk at contesting.com
Subject: Re: [TowerTalk] 160 vertical question (Top Hat)
Date:	Sun, 4 Feb 2018 08:48:02 -0800


Jim's suggested tuning method works well for me to cover the entire band. I
short/open 3 series capacitors all the same value and can cover 1800 to 1975
< 1.5:1 swr. I use a transmission line transformer before the caps to match
the 25 ohm resonance.

Now for some propagation to EU from suffering sevens land - Redmond, WA.
It's Unobtainium.

Grant KZ1W

From:	Bill via TowerTalk <towertalk at contesting.com>
Date:	Sat, 3 Feb 2018 20:20:00 -0500

Planning on putting up a 160 vertical, but of course a 1/4 wave vertical is
out 
of the question here in HI since we have a height limitation.
 
Here's the question:  I'm putting up around 50 feet of 3 inch aluminum
tubing  
(left over from various antenna takedowns).  I plan on putting up on top of 
that around another 10 or 15 feet of smaller diameter stinger for a total 
height of around 60-65 feet.  I obviously need to make up for the lack of 
height and I was planning on making a top hat of four wires coming down from

the top of the antenna at around a 45 degree angle.  The problem is how long
to 
make each of those wires.  My guess is around 25 feet based on my past 
experience in making Tee-topped 80 meter verticals.  However, it is only a 
guess and I don't feel like yanking the 3 inch pipe up and down a bunch of 
times to get it just right.  
 
I know some trimming will be necessary since this is not an exact science.
I 
just need an educated guess for where to start with the length.  Any ideas?
 
Bill K4XS/KH7XS