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Re: RX 2.4Ghz desense



Hello This is Yoshi.

At 2001/05/07 02:53:21 Renauld Halbardier wrote:
> I tried to uplink to AO40 on 70cm without any success due to a very high
> desense of 2.4 Ghz RX.
> The 70 cm ant is a 11 ele yagi and 2.4Ghz antenna, a 60 cm dish with the
> converter fixed direcly to the reflector.

  How about to put a quarter wavelength open stub of 70cm at the feedpoint
of 2.4GHz dish?  It will trap the 70cm input.
  Or how to set the 90 degree difference of polarization between 70cm YAGI
and 2.4GHz feed?

  I also put a 30mm length of grounded short-wire at the RF input of my
Drake2880 for static-protection. I works as BPF of 2.4GHz so I think it
will be work for decrease the 70cm input.
  And if you using Helix feed ay your dish, Will it resonate with 70cm?
If so, lets adjust thhe total length of helix morew shorter or longer.

  My antenna system is tempolary, but the 8ele YAGI just beside of my 29ele
LOOP and Drake2880 is not cause any desense problem at my receiving.

  I hope these will be helpful.


Yoshihiro Imaishi JF6BCC/KH2GR
GL:PM53JV, ex KC6IY(T88IY),V63BP
mailto:jf6bcc@jarl.com or jf6bcc@jamsat.or.jp
<http://plaza16.mbn.or.jp/~palau/> Sorry, Japanese only now.
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