Topband: Inverted L height vs. length.

Mike & Coreen Smith VE9AA ve9aa at nbnet.nb.ca
Sat Feb 28 13:39:46 EST 2015


de VE9AA

 

I know inverted L's have been hashed out quite a few times on this list, and
I have gleaned some knowledge.  At my previous QTH I had a 5/16th WL one
which seemed to work tons better than my current one, even though I was not
up over 40' high.

 

As it happens, on my current property I don't have any towers, nor tall
trees so I have a general question.

 

As far as a 127' inverted L goes, do I have anything to gain by sloping the
"vertical" portion of the wire slightly up to a short treetop, vs. going
nearly vertical, then the rest horizontal?

 

Example:

I have a 35-40' tree nearish to where my coax exits the ground from an
underground run.  I slope it "up" so essentially I have likely close to 50'
of "vertical" then the remainder meanders through some shorter treetops and
comes back to ground rather quickly (unfortunately it's more an inverted U
than L).  I have a few thousand feet of radials mostly in the southern
portion of the field under  the "horizontal section". A 800pf Cap is at the
base and my SWR is around 50-60Kcs at the 2.1:1 pts.  I seem to do quite
well into w1,2,3,4,8 and at times western EU/Carib.  Anything outside that
sucks.  That tells me I probably have gobs of high angle radiation.

 

Have I anything to gain by putting the coax directly under the tree, going
perfectly vertical for 37-ish feet, then, sadly, pretty much "down to the
ground" for the "horizontal" section same as the original?

 

(hope this ascii art works)

 

Ie:  This is what I am doing now (wire is around 65*-70* vertical or so_)

   ___

 /        \

/            \

/               \

 

 

but I wonder of this is any better

 

__ _ 

|        \

|          \

|            \

 

 

 

Lastly, I could go farther away from the tree and try to get 80-90' of
sloping wire (likely closer to 45*) and then have the remainder droop itself
back to Earth.

 

   _  _ _ _ 

           /             \

        /                 \  

    /                      \

/

 

Anyone have a skyhook for sale?

 

 

Thanks for any insight.

 

Mike VE9AA FN66na @ 660' ASL.rocky ridgetop.

 

Mike, Coreen & Corey

Keswick Ridge, NB

 



More information about the Topband mailing list