I have a small city lot with a single 72 foot self supporting tower. I
would like to get on 160m mainly for domestic contests, but also to play
with some DXing.
I've decided that an Inverted L would be the way to go (but comments on
this decision are appreciated).
I have a metallic support already in place at the 68 foot level. So, I can
go up the side of the tower 68 feet or so, then attach (non-conductive
material) to the metal support and then I can go out about 75 feet to a 40
foot tall tree.
I have drawn this out (don't laugh at my art!) at:
http://www.qth.com/ka9fox/plot-L.gif
If you don't know, I am a proud appliance operator and will be able to
apply for QCAO status just 6 years! My questions are:
1) How long should the 'horizontal' part of the Inverted L be?
2) Because the horizontal part slopes down from about 68 ft to about 40
foot, I hear I will have some 'cancellations' -- how severe will that be?
3) For the radial system, can I attach the shield of the coax directly to
my tower grounding system? (it is VERY extensive - 8 runs of 20-40 feet
each using #2 wire, with each run having 2 to 4 ground rods) or do I have
to use a separate radial system? NOTE: as you'll see in the drawing, the
tower ground system fans out away from the tower in the OPPOSITE direction
that the 160L will run, as I have no room to put any tower or antenna
ground radials in the direction of the Inverted L. Is that a problem?
4) If I have to use separate radials for this antenna:
a) I don't have much room -- the longest run from tower to fence is 40ft.
b) I have a young child that plays in the backyard. How can I keep him
from tripping on radials while not spending time burying copper?
5) I have a big variable capacitor that says the following on it:
NATIONAL CO. INC.
TYPE TML
VOLTS 7.5M
200D MMF
If I need a capacitor at the base, will this work?
6) The wire I bought for this antenna is 150 feet of #14 stranded wire with
a green insulation on it. Will green wire as good as the white wire I have
for my 80m inverted vee? :-)
7) Will there be any 'hot points' on this antenna either at the base (child
hazard) or in the tree (fire hazard) that I should be aware of?
Thanks in advance for the assistance!
73 - Scott KA9FOX
---------------------------------------------------------------
INTERNET SOLUTIONS - Affordable web page design and hosting
Scott Neader (608)788-1234 / FAX (608)787-0100 / KA9FOX@QTH.com
3323 South 29th Street, La Crosse, WI 54601 / ICQ 12151451
Free Ham Radio Classified Ads: http://www.QTH.com/Classifieds
KA9FOX Contesting & DXing Site: http://www.QTH.com/KA9FOX
Internet Solutions Home Page: http://www.QTH.com/is
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|
