mike123abc said:
Actually it does not quite work this way. Most of the DBS transponders are over 200W now and the new FSS are over 100 (E9 is around 120 I believe).
The size and shape of the beam also controls the EIRP. You can look at the satellite footprint maps to see the power levels based on the beam size and shape (for example see http://www.ses-americom.com/satellites/fleet.html). Spot beams may only have a 40watt transmitter, but appear more powerful than a 200W+ national beam.
The thread was discussing a satellite meter not being able to read 105 and subsequently low signal levels on 105 as compared to 110. The subject inferred CONUS coverage beams. I addressed these two issues. Granted the contour power lines in the foot print are not identifical. That is why I caveatted the statement with "Ignoring a number of other variables..." Nothing in the previous postings alluded to a spot beam scenario.
The source of information of the power levels stated in my thread may be wrong. I am now questioning the source. However, the relative comparison between FSS and DBS is correct. DBS is allowed far more power than FSS birds as evidenced by the fact DBS birds require 9 degree spacing to prevent adjacent satellite interference as comparied to 2 degree FSS spacing. The power differences was the point.
Regarding the comment, "Spot beams may only have a 40watt transmitter, but appear more powerful than a 200W+ national beam" cannot be accepted at face value. Certainly the majority of receivers outside the spot beam not receiving any measureable signal would not agree. Also spot beams are not locked to only 40 watts. The comment "The size and shape of the beam also controls the EIRP" also bares questioning. Effective Isotropic Radiated Power is merely a gain figure comparing transmitted power toward the receiver(s) to an isotropic radiator. Nothing more.
Any posting can be nit picked. I normally refrain if it does not bring value to the discussion.