Topband: Vertical vs inverted L question/opinions

[Henry Pollock - K4TMC]

Dale,

I thing someone has already beat you.  Have you noticed all of those
self-supporting tapered tubular galvanized steel cell phone towers
sprouting over the country?  And they have short limbs at the top for
attachments.

I would think some enterprising 160M buff would consider parking an RV near
the base of one of them and shoot a line over the top, then pull up a wire
cage gamma rod for feeding the tower. (K4TMC idea patent pending). :-)

73,
Henry - K4TMC



On Sun, Aug 11, 2013 at 10:41 PM, DALE LONG <dale.long at prodigy.net> wrote:

>
>
> Tom, that gives me an idea..
>
> An artificial tree (metallic) about 130 feet tall.  Wonder how many of
> them I could sell.
>
> Where's the nearest patent office?
>
> 73,
>
> Dale - N3BNA
>
>
>
> ________________________________
>  From: Tom W8JI <w8ji at w8ji.com>
> To: topband at contesting.com
> Sent: Sunday, August 11, 2013 10:21 PM
> Subject: Re: Topband: Vertical vs inverted L question/opinions
>
>
> > Why is an inverted "L" apparently so popular on 160 when it wastes so
> much RF as a cloud warmer?
>
> "Wastes so much RF" is sort of subjective.
>
> Comparing an L to a T, both 65 feet high and resonant over 50 radials, the
> T has almost exactly the same average ground wave signal. There is only a
> tiny fraction of a dB difference. In some directions the L is a tiny bit
> stronger, and in some directions the T is a tiny bit stronger, but it all
> amounts to a fraction of a dB.
>
> The only real major issue is the L has about 0.4 dB front-to-back.
>
> They aren't that much different in impedance, either.
>
> I'm not sure anyone would see any difference, except perhaps the L fills
> in the deep vertical null a little bit.
>
> This changes if the L and T are not self-resonant. Even so, unless the L
> is made so long the current maximum moves out of the vertical section,
> there isn't really what most would consider a significant difference.
>
> In my opinion, the choice is mostly a matter of what best fits the
> supports. Unless you try to use Tree for an antenna, then you might be 20
> dB down.
>
> 73 Tom
> _________________
> Topband Reflector
> _________________
> Topband Reflector
>