[Moon-net] 3456MHz EME feed

[SAM JEWELL]

Folks,
  I have been prompted by Peter, G3LTF, to think about 9cm EME using my 2.3m dish (I still haven't sorted a new mounting for the 'big' 3m TVRO dish). When I obtained the 3m dish it came with a dual band C/Ku feed made by ADL. The feed has a small servo motor to rotate the linearly polarised probes (skew) in both the C and Ku parts of the horn. As I have no need for the Ku band part, I carefully removed the concentric Ku band horn from the mouth of the C band horn in order to avoid any aperture blockage.
  My question:
  Has anyone tried using one of these C band feeds, with its  3 ring Chapparal fitting, on 3456MHz? The horn diameter will support 3400 and up and I understand that a wideband version of this feed is available that covers down to 3400MHz. Maybe it's just the probe length that is changed?
  Since I use a polar mount, the probe counter-rotation available with the skew adjustment looks like a good solution to maintaining the required linear polarisation offset as the dish moves across the sky.
  For the record, I plan to both transmit and receive on 3456MHz and receive on 3400MHz for Europe. If we lose 3456MHz (a remote possibility) in the UK then I will move completely to 3400MHz (where my terrestrial system is already).
  I have a WG11A to coax adaptor and hope to check the feed match later this week.
  Any help or advice on the feed would be most welcome.
   
  73 de Sam, G4DDK