[Moon] 3 cm circular polarisation

[SM6CKU]

Dom,
My preamp (DB6NT) has a NF of 0,75 dB, the SMA to SMA male connector is 0,1 dB, the isolation relay is 0,15 dB and the coax between relay and LNA is 0,15 dB. A total of 1,15 dB which has been confirmed by measurements. I agree that a WG version will improve these figures, but I prefer not to use WG pieces. I can accept the 0,5 dB loss compared to that solution. 2,5 dB of moon noise instead of 2.
But this has nothing to do with linear or CP.... 
I will try to take some photos tomorrow.

73 de Ben
  ----- Original Message ----- 
  From: Dom DEHAYS 
  To: SM6CKU ; Moon-Net ; moon at moonbounce.info 
  Sent: Sunday, September 21, 2014 12:15 PM
  Subject: Re: [Moon] 3 cm circular polarisation


  Hi all ,

  I have no personnal objection to go CP on 3cm eme BUT it should be done with a waveguide access on the RX side of the feed.Most feeds with a polarizer I have seen yet use an SMA connector on the RX side , it is a problem as we need to use a coaxial sma relay for isolation and a cable ( and/or adapter(s)) to connect a coaxial preamp . This will give  significantly reduced Rx performances compared to a waveguide system.

  73
  Dom
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