Topband: Inverted L height vs. length.

[Yuri Blanarovich]

Hi Mike,

from your description, I think you would be best off not to fold back 
the top wire, but try to "go away" horizontally as much as possible. 
Folding back in "U" manner makes the current/radiation from the top half 
cancel portion from the fed portion.

If you want to enhance vertical polarization and lower angles, try to 
use "T" loading, that cancels most of the high angle horizontal 
radiation.

You might be more efficient to use loading coil (and make it work on 80m 
as a trap) at the top and shorten the loading end of wire.

I have great results with my Inverted Vee in a Tree, top at abt 40 ft, 
with ends drooping down and going horizontal at about 10 ft. I have high 
water table. I am surprised how well it works, suspect that ends are 
acting as "radials" to the sloppy top fed vertical, no stinkin baluns, 
perfect 1:1 50 ohm match.
 
73 Yuri, VE3BMV, K3BU.us
 
 
 
 On Sat, Feb 28, 2015 at 01:39 PM, Mike & Coreen Smith VE9AA wrote:
 
 > 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
>
>
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>