Superdish Rain Fade?

[Fred]

When I was using a DISH500 I experienced frequent rain fade, so I upgraded to 2 separate 24" dishes. Now I hardly ever get rain fade.

Anyone have any theories about what to expect when I go to SUPERDISH? Will rain fade be better? Worse?

 

[fv3]

When I was using a DISH500 I experienced frequent rain fade, so I upgraded to 2 separate 24" dishes. Now I hardly ever get rain fade.

Anyone have any theories about what to expect when I go to SUPERDISH? Will rain fade be better? Worse?

There is no question a larger dish (in terms of the amount of signal reflected back to the LNBF) will improve resistance to rain fade.

However, one would not normally expect the difference between a 24" dish and the Dish 500 dish to be so great. It is possible your Dish 500 installation was not optimally aligned, making it more susceptable to rain fade than it should have been.

When discussing multiple-LNBF non-paraboloid dishes, one must remember that just because a dish physically has more surface area does not mean it is actually concentrating more signal on each LNBF than a physically smaller standard round paraboloid dish does.

Bottom line: we don't know yet.

 

[Mike500]

Compared with the Dish500 rain fade will probably be less for the circularly polarized lnb's at 110 and 119. However, the bigest problem with rian fade will be with the 105 or 121 linearly polarized ku digital lnb. Because this is why Superdish is necessary due to the lower power of these satellites rain fade will most likely affect these satellite positions first.

 

[Stargazer]

Actually I do not know if that would be the case. I have known lower powered satellites to have less rain fade in the past, such as Primestar and C-Band where people have said that they had less problems with rain fade with those satellites than with Dish or Direct. The signal beam is wider therefore it would take more to block out the entire signal, but I could be wrong.

Seeing that the SuperDish is smaller than what Primestar or other services have used then that may cause a lower signal strength causing more rain fade. You would have to get a bigger dish than the 26 inch SuperDish that is coming out.

I would think that they would have a bigger SuperDish available for those that live in fringe areas or need the larger span of the dish for a better signal.

 

[fv3]

C band frequencies are much less susceptible to rain fade than are Ku bands. (Not immune, just much less susceptible....) Generally speaking, attenuation due to rain increases as the signal frequency increases.

Your comments about the beam being "wider" are incorrect. But the wavelength does increase as frequency decreases, and there is a relationship between wavelength and raindrop size that contributes to rain attenuation....

I do not think Dish worries too much about those in "fringe areas", as they can not provide service to Canada, Mexico or the Caribbean (except Puerto Rico).

[Should also mention that, for the same size antenna, Ku band antennas will have higher gain than C band antennas.]

 

[Fred]

Interesting comments. This might be a question worth asking on the next Tech Forum.