[Antennas] Trap for 160/80m loop ?

[patw]

Don-very clever solution you came up with.  I modeled this using Nec2Go and
  come up with some very surprising results.

   On 80m, using 100 feet of RG-8x for feedline, and tuned for 3.75 MHz,
  the SWR on the band edges is around 3:1 and with about 4 dB of loss.
   On 160m, it is resonant around 1.87 MHz, and loss around 5dB(mostly in  
the stub!).
  Loss on the band edges is > 10dB so one wouldn't want to stray to far off
  frequency on 160 meters.

   A frequency sweep going up to 22 Mhz shows it is very lossy just about
  every where else except for some 'lucky' frequencies, none of which are  
in the ham bands.
   This is a doable design and one I had never considered before.  I will
file this one away in the gray matter for future retrieval, if I can  
remember
  where I put it.
    Pat W0OPW
   PS: if anyone wants to try this, download the Nec2Go demo version, send  
me an
  email and I will send the completed antenna file.


On Mon, 18 Jun 2007 10:37:40 -0500, Donald Sanders <w4bws at comcast.net>  
wrote:

> Sam, If you use a 80 meter 1/2 wave of ladderline at the far side center
> from the feed point, and have the free end shorted, for 80 it will be
> shorted to maintain the full wave loop. On 160 it will be a 1/4 wave and
> will be an open to leave you with a 1/2 wave dipole.
> You can coax feed and have a 2 band antenna.With a tuner it will possibly
> work on 40,30 and 20 meters also.
>
> Healthfully yours,
>                           Don W4BWS

-- 
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.