I guess you would amplify less noise closer to the dish?
You know what the CNR is and you also know what the power levels are.
Once you get past the first stage of amplification, everything kind of ends up being linear, and by this I mean: the noise from the dish is also going to be attenuated through the coax along with the signal. You've seen this on your meter, where the CNR is the same.
When there is no amplification [like an OTA antenna] all the loss before the first amp becomes noise, so this is why a low noise pre-amp is best mounted at the antenna.
If anyone wants to look into this more:http://www.rfcafe.co...oise-figure.htm
Edited by veryoldschool, 07 February 2011 - 11:33 AM.