When you suspend an inverted L from a tower, the tower is always in play.
Using a tower of that size to hold up an inverted L will involve the
tower in at least as much current flow as the "L". To prevent
substantive current losses at the base of a tower supporting an L you
will need to strap the tower base, the "L" ground feed and the radials
all together. A lossy radial system at the tower base will lose you
plenty dB whether you directly feed the tower or not. When it's all
said and done, why bother with the "L". Do as good a radial system as
you can, and follow Herb's recommendation.
73, Guy.
On Mon, Apr 5, 2010 at 9:17 AM, Herb Schoenbohm <herbs@surfvi.com> wrote:
> Joe Dubeck wrote:
>> I know it's the wrong time of the year but I'm about to become a
>> newbie on 160 and plan to erect an Inverted-L transmit antenna of
>> the side of my 120' tower, primarily to work DX.
>>
>>
>>
>>
>>
>
> Forget about the cloud warming Inverted "L" hanging of you tall tower as you
> have plenty of top loading to make the tower with the beams on top to provide
> an excellent 1/4 plus radiator. A three wire cage is preferred but a single
> shunt wire of #8 wire spaced 24 inches and dropped to the ground (some hams
> used discard CATV cable with a large diameter than the single wire) can be
> tuned with a single series capacitor if you have a tap point that shows close
> to 50 ohms and has some inductive reactance to tune out. This is a far
> better solution as the horizontal "L' wire will not bet there to interfere
> with your beams pattern.
>
> Before you look for the sweet point on the shunt feed put down some
> radials, even 4 to 8 60 footers would be better than none.
>
>
> Herb, KV4FZ
>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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