[TowerTalk] Half Sloper recommendations - Results!

[RLVZ at aol.com]

Hi Guys,
 
Happy New Year!
 
Thank You to 10 people who replied concerning my questions about  
installing a 160-meter "Half Sloper" or moving my Inv. L from my 90' tower  (where it 
works poorly) over to my 60' tower.  Your comments  are much appreciated 
and gave good direction!  My original post  is shown below in case anyone 
missed it and wonder what I'm talking  about.  
 
Basically, I had two questions:
 
1) Should I install a Half Sloper on my 90' tower and if so how could I do  
so and maximize radiation efficiency?    
 
2) Since my Inv. L works poorly on my 90' tower due to  heavy tower 
interaction... should I move this Inv. L to my 60' tower  rather than use the 
Sloper at 90'?
 
RESULTS OF THE 10 REPLIES:
 
-1 VOTE TO INSTALL SLOPER ON THE 90' TOWER BUT "BE SURE TO USE  RADIALS".
 
-2 VOTES TO INSTALL INV. L ON THE 60' TOWER AND IT WILL DO BETTER THAN THE  
90' TOWER DUE TO LESS TOWER INTERACTION.
 
-2 VOTES TO INSTALL AN INVERTED VEE ON THE 90' TOWER.  (INTERESTING AS  I 
DIDN'T LIST AN INV VEE IN THE OPTIONS.  I HAVE USED INV.
    VEES AT THIS LOCATION FOR YEARS AND THEY WORK PRETTY  WELL IN THAT I 
CAN USUALLY WORK EVERYONE I CAN HEAR)
 
-5 VOTES TO "SHUNT FEED" THE 90' TOWER.  (VERY INTERESTING AS I DIDN'T  
LIST "SHUNT FEED" AS ONE OF MY OPTIONS!)
 
CONCLUSION:
 
Since 5 out of 10 responders said I should "Shunt Feed the 90' tower it's  
clear direction that my next project will be to "Shunt Feed the 90' tower.   
What really cinched it is that I didn't include "Shunt Feed" in the 2  
options I was considering and yet it got the most votes!  So for those who  are 
interested in improving their 160-m. performance like me... you might want  
to try "Shunt Feeding" one of your towers.
 
Shunt Tower Feed Questions:
 
1) My 90' tower is a self-supporting aluminum tower with a top mounted  
Tribander.  (no guy wires)  The five responders who said I should  "Shunt Feed 
that 90' tower" recommended I attach the shunt at various  heights ranging 
from 30' to 90' up on the tower and adjust as needed.   QUESTION 1: Will 
using a different attachment height and wire spacing  only effect the loading 
and bandwidth or is there an attachment height that  will provide better 
radiating efficiency?  
 
2) I'd like to try a "Slant Feed" as many old AM Broadcast  towers use.  
For one thing, it would make installation quicker and with  less climbing as 
it wouldn't need PVC insulators keeping  the shunt wire equally spaced.  
QUESTION 2: Is the "Slant Feed" likely  to tune and radiate about the same as a 
common 'Shunt Feed" with equally  spaced wire parallel to the tower?  
QUESTION 3: Is there any general  rule of thumb for where to attach a "Slant Feed" 
on a 1/4 wavelength  tower?  Such as, 25% up the tower above ground level?  
(I've  seen a couple 1/4 wave AM Broadcast towers and it seemed like  the 
Slant Feed wires were connected about 25% of the way up the tower  from 
ground... so perhaps aprx. 25% is the general rule of thumb?)  
 
Thanks again guys... you're a wonderful help!  
 
73,
Dick- K9OM
 
 
 
 
Hi Guys-

I'd appreciate your recommendations on building a Half  Sloper for  160-m.  
I realize that some folk have had excellent  results with Half  Slopers and 
others have had terrible results with  them!  That's why I'm  asking for 
advise on how to construct my  Half Sloper!

Question 1: Most antenna articles say when constructing an  Inv. Vee is  to 
keep the minimum angle between wires at 90 degrees or  greater.  Since  
Half 
Slopers almost never have a 90 degree angle  between the sloper wire and 
the  
tower is this one reason why many Half  Slopers don't work very well... 
lots 
of signal cancellation?

Question  2: I have a 90' tower with a Tribander on top which makes it very 
  
close to a 1/4 wave for 160-m.  I installed an Inverted L on this   tower 
with 85' vertical and the Inv. L radiating efficiency is very   poor due to 
heavy coupling between the Inverted L and the  tower.   (some models say 
that 
alot of RF is shorted right to  ground!)   Therefore, I am thinking of 
going 
with a Half Sloper  connected near  the top of the 90' tower with the 
sloper 
wire running  NE towards  Europe.  If I anchor the end of the sloper wire 
about 
200' from   the tower the angle is only going to be about 45 degrees.  Do 
you  think  this will work any better towards Europe than my heavily 
coupled  
and inefficient  Inv. L?  (another weakness with my Inv. L is that  I have 
a 
minimal  radial system as it must be pulled up each  Spring).

Question 3: Rather than build the Half Sloper on the 90'  tower  would an 
Inv. L on my 60' tower with 55' vertical and the rest  horizontal  running 
NE 
towards Europe likely outperform the Half Sloper  at 90' towards  Europe... 
keeping in mind that this is a temporary  antenna so I can only  put down a 
minimal radial system as the radials  need to be removed  in Spring.  

I realize that I'm likely to  get a variety of opinions on this and that is 
 
fine!  Please let  me know which of the above options you believe  is most 
likely to  provide the best 160-m. signal towards Europe.

Happy New  Year!

73,
Dick- K9OM
Edgewater,  Florida