[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: 13 cms Antennae


Thanks - I have found what I need at WIMO I think:
http://www.wimo.com/cgi-bin/verteiler.pl?url=antdish_e.htm and Kuhne make a
2.4 GHz => 50 MHz downconverter which is exactly what I would like (works with
my IC-7800 and IC-703). I also found a 23 cms transverter which I can mount
next to the antennas - but that's for later.

I am slowly getting things sorted out now.

I wonder when P3E will be launched ?

Simon Brown
www.hb9drv.ch www.laax.ch

RSGB HF Convention: Friday 7th - Sunday 9th October 2005
Holidays: Monday 10th - Thursday 20th October 2005
  ----- Original Message -----
  From: John


  The two "Kuhne" antennae (I do not see a third) you show are not true dish
antennae. Being a GRID style, with metal rods in only one plane, they will
reflect only waves that are polarized in that plane. In the case shown in the
pictures it is HORIZONTAL polarisation. A vertical polarized wave will pass
through the grid and not be reflected into the FEED.

  The listing claims both antennae will also operate in a vertical
polarisation mode. This is true ONLY IF YOU ROTATE THE ANTENNA ASSEMBLY 90
DEGREES so that the rods (and FEED) are vertical. In this case horizontal
polarised waves will pass through the grid; only vertical polarised waves will
be reflected into the feed.

  One other geneal point:
  With a "solid" dish, whether it is a solid piece of metal or a solid sheet
with small holes in it, signals of all polarisations will be reflected into
the feed. However the FEED must support both horizontal and vertical
polarisations for the complete dish/feed assembly to respond to both
polarisations. Note in your pictures the FEED appears to be a dipole, with
reflector and that that the dipole and the rods are both in the same plane. If
the dipole only was rotated 90 degrees, the antenna assembly would (ideally)
receive NO SIGNALS!

  73s, de G3BVU SK
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org