Tom Rauch wrote:
>>Excellent points, gentlemen. Even with a current
>>
>>
>balun/choke at the
>
>
>>feedpoint, the coax feedline can easily couple to the
>>
>>
>antenna & radials and
>
>
>>skew the pattern.
>>
>>
>
>It doesn't just skew the pattern, it brings RF into the
>shack and also reduces system efficiency by making lossy
>earth part of the antenna system.
>
>Small radial systems require careful installation as well as
>careful feedline decoupling.
>
>73 Tom
>
>
Another reason to decouple the feedline is to keep noise generated
inside your house from being coupled into your antenna.
You may or may not notice a noise difference from decoupling, depending
upon how much noise is picked up by your antenna from your local
neighborhood. This noise plus lots of band noise may mask the effects.
But if you're in a quiet area, and you happen to have some big noise
sources inside your shack (such as a Link Sys Router, or noisy computer)
you can see a big difference with decoupling. In the case of a low gain
antenna used for receiving, such as an EWE or similar, the effect is huge.
Jerry K4SAV
_______________________________________________
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and ask for Sherman, W2FLA.
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