170 feet is a 1.3 wavelength beverage on 40... whats wrong with that.
I have a 290 ft unterminated beverage that I use on 80/160 which allows
me to hear much better than the noisy transmit antenna.
NN5K
KC1DI wrote:
>On 9/21/06, Geert Hofman <Geert_Hofman@jabil.com> wrote:
>
>
>>Folks,
>>
>>
>>
>>I have been doing some (antenna) garden work and have now installed a
>>full size vertical for 40 (again). I will be installing a half loop for
>>80 m and also a delta loop for 30 m.
>>
>>
>>
>>But especially for 30 & 40 , my RX is (and has always been) covered with
>>tremendous noise. In TX I have no problems , whatever I hear I can
>>mostly work, but I want to improve my RX. Now having admired the
>>beverage set up at ON4UN who lives about 5 miles from me, and having
>>read almost everything on RX antennas, I was wondering what you guys
>>would recommend for 30 & 40 m RX, because most of the things are aimed
>>at 80 and 160 m. I have no interest at all in top band and am not
>>expecting too much from 80 , but I like 30 & 40 .
>>
>>
>>
>>My plot is 20 m x 50 m ( 70 ft x 170 ft ), but cannot use any guying (
>>because it's also children's playground), and difficult to put things in
>>the middle. Also for additional supports/.., I am restricted to about 25
>>ft for fixed set ups of tubing. But I have 2 40 ft fibreglass masts (
>>spiderbeam ). I have been looking at a beverage about 170 ft long a
>>K9AY, a low dipole ( inv V at 25 ft apex), a horizontal rectangular
>>loop at 20 to 25 ft average height following the contours of the plot,
>>a vertical parasitic array.. but I am not quite sure what to take as a
>>good RX DX antenna specifically for 40 & 30 m. Alternatively I am
>>contemplating to install a 40/30 m dipole on top of my tribander (
>>stacking only 3' possible), and although I think this is the best
>>solution, I am concerned about windload of this configuration for my
>>mast. Also still looking for a good design of a 30/40 trapped dipole
>>with max wingspan of about 10 meters, which is not too heavy...
>>
>>
>>
>>I wonder what you would suggest me to do. BTW, I do not live an urban
>>environment and have average to good soil conductivity and in many
>>directions, especially from SW over N to SE "free sight". I am also on
>>one the highest spots of the area (albeit only 200 ft ASL !).
>>
>>
>>
>>Looking forward to your valued input !
>>
>>
>>
>>Geert - ON4IG - OQ5A
>>
>>
>>
>>Hi Geert,
>>
>>
>
>
>
>Wonder if you have tried to track down the noise source?
>It may be easier than trying to build another antenna in your situation.
>However with that said I would investigate a small rx loop of some sort..
>the beverage needs to be much longer than 170 ft in order to really work..
>and on 40 & 30 Meters needs to be quite low to the ground.
>
>With an rx loop it is often useful in nulling out local interference.
>
>Let us know what you finally come up with and how it works.
>73 Dave KC1DI
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