[Moon] offset superiority on 3cm eme

[Fausto Coletti]

Hi Eric, 

this is the antenna... 

http://www.laminas.com.pl/page_pl/as2700_pl.html 

IK2RTI using it succesfully also for 24 GHz eme. 

73, Fausto IK4NMF
  ----- Original Message ----- 
  From: Eric Van Offelen 
  To: Fausto Coletti 
  Sent: Monday, October 27, 2014 10:27 AM
  Subject: Re: [Moon] offset superiority on 3cm eme


  Hello Fausto,

  I am just curious to know who is the european manufacturer for this 270 cm offset dish.

  Thank you in advance for this info !

  Vy 73 de Eric ON5TA
    ----- Original Message ----- 
    From: Fausto Coletti 
    To: Dom DEHAYS ; moon at moonbounce.info 
    Sent: Monday, October 27, 2014 9:28 AM
    Subject: Re: [Moon] offset superiority on 3cm eme


    Hi Dom, 

    It is out of the question that offset dish under equal conditions 
    is more efficient than prime focus dish for small size antenna. 
    For large dish this difference is much smaller due to the small 
    size of the feed compared to the dish diameter. 
    A small advantage is still present in favor of the offset dishes 
    as they normally have a F/D ratio favorable to achieve a more 
    efficient illuminator. 
    The problem is that it is not easy to find a large offset dish  on surplus market. 
    Here in Europe, there is only one manufacturer of large offset dishes for 
    TV-SAT but it is not very cheap, it costs around 3000 Euros for a 270 cm dish. 

    73, Fausto IK4NMF

    ----- Original Message ----- 
      From: Dom DEHAYS 
      To: moon at moonbounce.info 
      Sent: Sunday, October 26, 2014 6:05 PM
      Subject: [Moon] offset superiority on 3cm eme


      Hello ,

      I've MEASURED here on a 1m dish , 0,6/0,7dB NF waveguide system 9,7dB of sun noise and 0.2dB of moon noise (SFI 110)
      On a 120cm offset , same system , I get 10,6dB* sun noise and 0,3dB moon noise. With the 120cm , the system is a bit below optimal , normaly 11dB of sun noise should be possible. 
      With the 1m system , I've worked 4 different stations  IN CW and heard some more.

      73
      Dom


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