Topband: 80M (almost Topband) 4-sq loading coils

N2TK, Tony tony.kaz at verizon.net
Fri Dec 21 15:58:24 EST 2012


Well, I ran out of time. Work keeps getting in the way. I won’t get the
radials down before the ground freezes as I still need to clean out the wild
growth. 

 

Presently I have three ¼ wave radials at each elevated feedpoint. The
feedpoints are presently elevated because I have uneven terrain plus lots of
wild growth towards the West. 

It seems over the past couple of years the ice loading has stretched the
wire somewhat from the original dimensions. That affected the pattern.  Last
year I made sure all the lengths were fine again and the pattern seemed to
improve. This past winter with heavy ice loading I seemed to have some
stretching of the #14 wire. The pattern seems to be quite sensitive to the
matched lengths of the radials.

 

After reading N6LF’s info and realizing I can’t put up a plethora of ¼ wave
elevated radials I want to try some shortened elevated radials to see if
that helps the pattern. Hopefully the gain won’t be affected much. The
feedpoints are about 8’ above ground. If I make the radials 36’ long I can
put up 6 at each feedpoint with fairly close symmetry. I believe that means
I would need roughly 16-18uh at each feedpoint to resonate the radials. 

 

Instead of going with coil stock, is there any reason for not using a toroid
with a number of turns? If not, I assume I would want to use a powdered-iron
core?

 

Any issues I should be concerned about?

Any recommendations for what type of core I should use for this application?

I  plan on using #14 enameled wire. I would assume it is best to cover the
core with glass tape first?

 

Anything I am missing with this plan or am I wasting my time with the
shortened radial idea? 

 

This winter I will finish cleaning the area to the West of the tower where I
have lots of wild growth. Next year I will be able to put down ground
mounted radials in all directions. The plan then will be to put down 30
radials under each feedpoint and lower the feedpoints to the ground. Figured
going with 50’ length radials.

 

As always, all comments and suggestions are welcomed.

 

73 and Merry Christmas

N2TK, Tony 



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