[TowerTalk] Inverted L for 160 Meters

[Tom Crothers]

Hello all,

 

There's an article in the October 2007 QST by Steve Ford entitled "Waiting
for the Sun".  For those of you who read the article, and may have some
information/answers, I have a few questions regarding the construction of
the 160 meter inverted L antenna that is shown in Figure 3 of the article:

 

 

*        Do I understand correctly, that C1 in the diagram is a simple
variable capacitor that ranges from 100 pF to 800 pF?  (I found one, and
purchased it)  

*        Is it for tuning the antenna for minimal SWR? 

*        How did the author arrive at the wire length of 165 to 175 feet?  

 

I know these are pretty basic issues/questions, but I built this antenna
today.  I want to be sure I've built it correctly, and moreover, I want to
be sure I understand how to tune it correctly.  

 

*	Right now, I can get a minimal SWR of 3:1 at 1.810 MHz by tuning the
variable capacitor for min SWR. 
*	I don't have any radials installed at present.  The coax braid is
grounded to my tower ground (three 8 ft rods bonded together) 
*	I plan on adding some radials (laid on the ground) tomorrow.  Should
they be of any particular length to perform optimally? 

 

I've emailed Steve Ford addressing the above, but I also wanted to see what
the folks at TT think.

 

Thanks all.  

 

73,

 

Tom

W8KF