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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.

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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.

Actually the 9 degree spacing for DBS was to allow a smaller dish. A smaller dish does not focus on a small a segment of the sky as a larger dish would. Echostar 9 has more power than Echostar 3. Echostar 9 is FSS, Echostar 3 is DBS. You can easily get a good signal on E3 with a small dish BECAUSE of the the 9 degree spacing, there is not adjacent satellite interference. E9 requires a larger dish to focus in on the 121 slot and ignore 119 and 123.

So if the satellite spacing was 18 degrees instead of 9 then a smaller dish than 18" could be used or would it at that point anything past 9 degree seperation would not make much difference?

Originally Voom had said they could use a 13" Dish. But, when you start to get really tiny dishes you run into rain fade quickly. Larger dishes give you much more cushion. One of the debates now at the FCC is if they can move from 9 degrees down to 4.5 or even 3 degree spacing on DBS satellites. This would open up more slots over the CONUS, but would the existing dishes still work ok?

I also saw someone post that they chose to use the 18" dish instead of the 13" one because they wanted to be able to broadcast more channels on their satellite and the 18" dish would be required to do so.

If making the spacing of the satellites to 3 or 4.5 degree spacing from the 9 degree spacing it has now would cause the dishes to be larger then why not just use satellites with different frequencies in between those dbs slots? Would it be due to the fact that the dbs slots may not end up with dishes as large as those like the SuperDish at those frequencies? I am sure there would be some cost issues along with issues in losing customers if they had to swap out all customers.