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TopBand: Inverted-L

To: <topband@contesting.com>
Subject: TopBand: Inverted-L
From: leewical@lava.net (LEE ROGER WICAL)
Date: Sat, 31 Oct 1998 11:11:40 -0500
For All:
        To add to Earl's fine e-mail and others, you can obtain a sturdy 
variable
capacitor (3500 V) from Ten-Tec direct in either assembled or in kit form
if you wish to save several bucks. The kit comes in 10,000 pieces. Well, it
appears that way.
Judgement rules!

        Ten-Tec has an 800-number. It's located in QST, CQ, CQ Contest et.al and
the customer service manager is a K4 two letter (sorry I don't have is call
here) and he is very helpful. 

        It is one of my better investments I've made. 
        I mounted the variable at the base of the "L" in a Rubbermaid (clear)
under the bed shoe box, of appropriate size.
        It is very WX proof with the rains we have here and once the "L" is 
tuned
it works w/o more attention.
        One can remotely peak the power to the antenna with the variable and 
"the
old Florescent bulb (low wattage) tube trick".

snip........

itAt 03:34 PM 10/31/98 EST, Earl W Cunningham wrote:
>
>Hi Russell,
>
>You wrote:
>"I plan to put up an Inverted-L for 160.  Do I need a balum?  Can I feed
>it with ladder line?  Is the longer the better or should I stick to +/-
>170 feet."
>==========
>No, you don't need a balun.  Feed it with 50-ohm coax, center conductor
>to the bottom of the antenna wire and shield to your ground system (as
>with all antennas of this type, it requires a good ground radial system
>to be really efficient).
>
>Make the vertical portion as high as possible, with the horizontal
>portion long enough to make the antenna 1/4-wave resonant at the
>frequency of your choice.  A total wire length of about 140 feet is a
>good place to start, then prune the length for lowest SWR at the
>frequency of interest.
>
>If you have a variable capacitor (about 0-250 pF) that will handle the
>power level you plan to run, make the antenna longer (about 170 feet) and
>connect the capacitor in series with the wire at the feedpoint and use it
>to tune out the inductive reactance (i.e., for minimum SWR).  This will
>give a closer match to the 50-ohm feedline and allow you to QSY over the
>entire band (by retuning the capacitor, if desired).
>
>73, de Earl, K6SE
>
>
>___________________________________________________________________
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        Just a note from one visionary to another!!:-)
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        ...................................................
        Lee R. Wical, B.S. in bs; M.S. in more of the same; 
        PhD in common sense, Magna Cum Rowdy.
        ...................................................
        Living near Armpit, Idaho...it is near Hootersville! 
        Where heavy industry......is a 400-lbs AVON lady! |:o)
        ...................................................................
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                ..... hydrogen and stupidity! 
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