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Re: Seeking info on stacked helices



I have an array of 3 16-turn helixes for 2400 MHz. The design is similar to
the Kraus 4 helix array but does not need tapered lines because 3 helixes in
parallel are approximately 50 ohms. It does work and would be fine for
transmitting.

When comparing my helix array to a dish with a short cupped helix feed it
has one disadvantage for satellite reception. The sidelobes of the array
pick up thermal noise which reduces SNR. The dish does present a larger wind
load but the rotator can handle it.

In his book, Kraus does provide a helical antenna design with low sidelobe
levels. However, it is impractical for S band because it requires a conical
reflector which is as long as the helix.

73,

John
KD6OZH

> but I would very much like to know if anyone have
> actually built the 4 helix construction from the
> ARRL Antenna Book on 2.4 GHz with a good documented
> result.


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