pete_l
Member
- Joined
- May 30, 2006
- Messages
- 8
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- Age
- 67
- My Satellite Setup
- dm800hd se
- My Location
- S.E. England
I'm using a C120 LNB with an Invacom ADF-120 adjustable feedhorn.
The datasheet. for the feedhorn states it has an adjustable beam width
F/D of 0.32 to 0.43. Now, the calculator here tells me that my 2.4m dish
has a F/D of 0.38, OK so far. There are 2 graphs on the datasheet.
From the first one, I can see that for a F/D of 0.38, I need to screw the
feedhorn in for a 4mm protrusion. (I guess this means the thread is
protruding 4mm proud of the corrugations).
The problem I have is with the second graph. The "Y" axis has no units.
The 4mm protrusion from graph 1 seems to correspond to "120" on the
second graph - but I don't know what it's 120 of. Can anyone shed any
light on what this graph signifies?
Thanks,
Pete
The datasheet. for the feedhorn states it has an adjustable beam width
F/D of 0.32 to 0.43. Now, the calculator here tells me that my 2.4m dish
has a F/D of 0.38, OK so far. There are 2 graphs on the datasheet.
From the first one, I can see that for a F/D of 0.38, I need to screw the
feedhorn in for a 4mm protrusion. (I guess this means the thread is
protruding 4mm proud of the corrugations).
The problem I have is with the second graph. The "Y" axis has no units.
The 4mm protrusion from graph 1 seems to correspond to "120" on the
second graph - but I don't know what it's 120 of. Can anyone shed any
light on what this graph signifies?
Thanks,
Pete