[Antennas] INV_L_SWR

[Gerd]

Hi George,

I have a similar setup and spent quite some time 
to optimize it, now I am pleased
with it and it works great since a couple of 
years (160:184 countries/ /80:265/ /40:305//30:303 )

The setup is the following:

The base of the vertical part (40ft fiber-pole) 
is just indoor in the attic where it is switched (HV-relays)
to 4 different tuned circuits, one for each band, 
it is easy to optimize the circuits for each band individually
(L/C, coupling etc.) and match it to 50 Ohms. The 
50 Ohms output coupling from each band is switched
by a 6>1 remote coaxial switch (wired in parallel 
to the high impedance distribution relays).
That allows instant switching  between bands 
without any tuning procedure, SWR on all bands
is less than 1  : 1.1.   I have to add that the 
80/75 m circuit is tuned to 3790 and that an additional
capacitor is switched in on 3510 giving me a 1.1  on both frequencies.

I am planning one further improvement to extend 
the useful frequency range on 160 -which is abt 40 Khz
now- by adding a remote motor control for the 160 tuning capacitor.

good luck with
your " L"

73s
Gerd, DJ5BV (AA6TO)



At 15:26 25.11.2006, you wrote:
>I put up an inverted L antenna this past week. 
>The best I can do on SWR is 2:1 measuring at the 
>base with my MFJ analyzer and varying a variable 
>cap in series with the center conductor of the coax on 160 meters.
>If I wanted to get it down to 1:1 how can I 
>accomplish this and have it useful on 160 and 80 
>meters? I'm building a remote variable capacitor for the base.
>I don't have the exact dimensions but the best I 
>can figure are 120 feet of horizontal and 50 feet of vertical.
>By the way it works pretty good on 160 as is but 
>I'd like to get it down under 1.3:1.
>Thanks.
>George
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