Re: [amsat-bb] Helix Feed for a Dish

[John Wright <g4dmf@xxxxxxxxx>]

At 07:30 06/06/01 +0000, you wrote:
>The dimesions suggested by Kraus in "Antennas" for a cylindrical cup are
>3/4-1 wavelength in diameter and the same length as the helix. Mine is 4"
>square by 2-1/4" long.
>
>73,
>
>John
>KD6OZH

Do you mean the *length* of the helix, or just of 1 turn? My helix is 3.5 
turns and 3" long. Do you mean for the cup to be as deep as the helix is 
long?. If this is so, what sort of length cup would be suitable for say a 
20 turn helix? Would it still be effective if it was say only 1" deep, this 
would make mounting the feed easier in my case.


____________________________

      G4DMF  QTHR   IO93HA
      Amsat-UK Member 5372
          g4dmf@amsat.org
      http://www.g4dmf.co.uk
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