SuperDisc Alternative

[JonUrban]

Why can't I just take my 61.5 dish and aim it at 105? (leaving my Dish 500 where it is?)

 

[fv3]

You can. It will not work.

You need a different LNBF (a Ku band LNBF instead of a DBS LNBF.)

Also, due to the lower transponder power, the existing 61.5 dish will probably be too small. Even if it works, it will likely be too susceptible to rain fade.

 

[Stargazer]

The signals that we are receiving right now are high power. The reason that we will need a different lnbf and a bigger dish for receiving 105 is that it is lower power. The lower the power the bigger the dish has to be to receive the same quality signal.

We have to start using lower power satellites because there is limited space for high power satellites. You have to keep them spaced apart enough to where they will not cause interference if they are using the same frequencies.

Different power satellites use different frequencies so the only solution to getting satellites closer together to allow one dish solutions such as the SuperDish is to use different frequencies.

 

[fv3]

The signals that we are receiving right now are high power. The reason that we will need a different lnbf and a bigger dish for receiving 105 is that it is lower power. The lower the power the bigger the dish has to be to receive the same quality signal.

We have to start using lower power satellites because there is limited space for high power satellites. You have to keep them spaced apart enough to where they will not cause interference if they are using the same frequencies.

Different power satellites use different frequencies so the only solution to getting satellites closer together to allow one dish solutions such as the SuperDish is to use different frequencies.

The reason we need a different LNBF has nothing to do with power. The different LNBF is needed because the frequencies are different and the polarization of the signal is different.

The newest generation of Ku band FSS satellites (such as AMC-9) have transponder power levels almost as high as Echostar's DBS satellites do.

The reason Dish is using a lower powered satellite at 105 is because they had to lease one from another company, and the one they got was built at a time when Ku band satellites were not being equipped with 110-120 watt transponders. The replacement (AMC-15) will be higher powered. The 5 degree offset from 110 is not that significant. (Note E*9 and E*7 are only 2 degrees apart.)

I am not convinced the SuperDuperDish is actually "bigger" in the sense that it delivers increased signal (over the Dish 500) to each LNBF. Physically bigger, yes, absolutely.

Interesting tidbit from recent SES-Americom press release:

AMC-15 will succeed AMC-2 and offer both circular polarization and high-power on the FSS Ku-band platform composed of 24 transponders of 36 MHz each, as well as 12 Ka-band spotbeams of 125 MHz each.

http://www.ses-americom.com/media/2003/09_08_03.html
Hummm... Circular polarization.... AMC-2 is linear polarization.... What does this mean for Dish's future plans? Will they have to swap out all the HD SuperDishes for Phase II SuperDishes?

 

[Stargazer]

Interesting indeed. So I was wrong about the lnbf, correct on needing the larger dish because of the lower power though. If they are going to have 125 MHz of power on each transponder then that should mean that you could get by with a smaller dish for those transponders if you was pointing only at 105, am I right, or would this be no different than Dish having double power mode on some of their transponders in which I have read in the past?

I notice that DirecTv has a ParaTodos dish in which is only 20 inches wide (for Phase III) and 24 inches wide for picking up 101, 110, 119 in which has 18 degrees apart but Dish Network's SuperDish is going to be 26 inches wide picking up 105, 110, 119 which is 14 degress, 4 degress apart less than the ParaTodos dish, yet it is bigger. Once this new satellite goes up would this allow Dish Network to go to a smaller SuperDish to a similar size or smaller than the ParaTodos dish?

How was DirecTv able to reduce the size of their dish from 24 inches wide to 20 inches wide?

 

[fv3]

Without knowing any of the details about DirecTV's satellites, etc., my first guess would be that all their birds have high power transponders, and therefore require a smaller reflector to receive adequate signal. I also think Echostar may be doing some planning for the future, so the new SuperDish is sized to allow for other LNBFs to be added later.....

FYI - Mhz (megaHertz) is a measure of frequency. Transponder output power is usually stated in Watts.

The 125 Mhz transponders you refer to are Ka, not Ku, and will probably be used for Internet and broadband services instead of Dish Network DBS services.

 

[davhol]

Stargazer, you need a bigger dish to see a bigger portion of the sky. Dish 500 is just big enough to see the 9 degree spread between 110 and 119. The precision with which the dish needs to be aligned is also more crucial with the FSS frequencies, also requiring a larger dish. Power IS part of the equation, but only a minor one. The LNBFs will do most of the job of making up for the power differences at the transponders.

 

[fv3]

.... The precision with which the dish needs to be aligned is also more crucial with the FSS frequencies, also requiring a larger dish.....

I have heard this stated several times. I do not believe it.

Traditionally, FSS satellites have been lower powered than DBS satellites, so antenna installaters have needed to do a better job of optimizing the dish pointing to get a usable signal. In other words, DBS has allowed the installers to get away with being a little sloppy if they choose to....

The reflector size is really not much impacted by whether the signal is Ku-FSS or Ku-DBS.

 

[Stargazer]

I was thinking that they were going to use those higher frequency transponders for future internet services but thought they were going to be put at 121 instead of 105.

I know that you need a bigger dish to see more orbital slot locations in the sky seeing how the dishes get bigger the more slots that need to be picked up.

If one were needing to use a larger span of the dish for one type of signal then should the lnbf be focused more towards the center of the dish than the other lnbf's in which do not require as much of the reflector making the lnbf picking up the 105 slot more towards the center than the lnbf's for 110 and 119 in which only need to use part of the refector on one side to receive the signal?

 

[fv3]

I was thinking that they were going to use those higher frequency transponders for future internet services but thought they were going to be put at 121 instead of 105.

I know that you need a bigger dish to see more orbital slot locations in the sky seeing how the dishes get bigger the more slots that need to be picked up.

If one were needing to use a larger span of the dish for one type of signal then should the lnbf be focused more towards the center of the dish than the other lnbf's in which do not require as much of the reflector making the lnbf picking up the 105 slot more towards the center than the lnbf's for 110 and 119 in which only need to use part of the refector on one side to receive the signal?

Remember that the satellite (and usage rights) at 105 are owned by SES-Americom. I am not sure Echostar has any arrangements to make use of the Ka band transponders on AMC-15 at 105 after launch. I think you are correct that Dish intends to use 121 for the internet products.

How many satellites one intends to pick up with a dish has more impact on the shape of the reflector than the size. For a traditional round (prime-focus) reflector, all the signal reflected by the dish are focused on the LNB Feedhorn. As the size increases, the signal gathered increases. (The gain of an antenna is proportional to the square of the diameter.)

As you change from a prime-focus feed to an offset feed, you change the shape of the reflector to optimize it for that configuration. So it becomes taller than it is wide. It appears the additional width on the SuperDish is to increase the gain of the reflector.

The real question, which nobody yet has the answer to, is "does the SuperDish have gain numbers higher than or less than the numbers for the Dish 500?"

The LNB placement on the antenna is a function of the position of the satellites in the sky. Remember the thing we commonly call the "dish" is just a reflector, to focus additional microwave energy on the feedhorn than would be gathered by the feedhorn itself (if it were pointed directly at the satellite instead of towards the reflector....)

 

[Mike500]

An old DirecPC dish, including the lnb would work fine for 105. You would have ti replace it with a dual lnb, if you have more than one HD set. Whatever switch SuperDish uses, it will probably connect to it. This would be SuperDish on the cheap. Primestar dishes would also work, but you need the one that is voltage switched instead of the one with dedicated horizontal and vertical lnb feeds. Also would work, and even more resistant to rain fade would be a 30" or a 36" FTA dish.

 

[Stargazer]

Most of the Primestar dishes did not come with the voltage switched lnbf but had two outputs, one for horizontal and one for vertical, although I have seen only few with the one output. I wish I would have had some of those now.

Couldn't a switch be connected to those H/V lnbf's to allow it to switch on its own or would there be an issue for those that want to connect switch(es) to receive 110 and 119 as well on the same receiver? Seeing that the lnbf is not DishPro that would create a problem since the switches that are coming out are going to be DishPro, unless there will be some aftermarket switches that are not DishPro that will allow this setup.

 

[Mike500]

I have not heard what kind of H/V lnb Echostar plans to use for the 105/121 position. If it is stacked, it would be a NEW DishPro dedicated single lnb. If Dish plans only to use transponders dedicated to either the horizontal or vertical polarization component for all of it's offerings on SuperDish, which is the most likely and least expense alternative, then a DirecPC, any Primestar, or fta lnb will work.

 

[Stargazer]

I thankfully got a Bob Jones University dish last year from someone that did not need it and the lnbf has the one output on it instead of two for horizontal and vertical.

I know that the dish works because I hooked it up to an old Uniden C/Ku band receiver last year and picked up channels from different satellites with it. I have had it connected to the Primestar dishes as well as a small 6 ft. C-Band dish that I have (could only receive channels using horizonal on the Primestar dishes because I did not buy the switch).

I was hoping that I could at least use this dish if I needed a spare but will still take Dish's upgrade offer on the SuperDish.

 

[fv3]

I have not heard what kind of H/V lnb Echostar plans to use for the 105/121 position. If it is stacked, it would be a NEW DishPro dedicated single lnb. If Dish plans only to use transponders dedicated to either the horizontal or vertical polarization component for all of it's offerings on SuperDish, which is the most likely and least expense alternative, then a DirecPC, any Primestar, or fta lnb will work.

Dish is already using both even and odd transponders (thus both H and V) on AMC-2....

 

[north]

Will the Sat-C LNB from Directv work? My understanding is that it's a KU LNB.

north

 

[fv3]

I don't know a whole lot about D*, but if the Sat-C LNB is the one that points at 110, then it is KU-BSS (a.k.a. DBS), not Ku-FSS (a.k.a. Ku).

 

[mike123abc]

Ok lets clear up a few items:

1. A larger Dish is needed for 105 and 121 because the spacing of the satellites is only 2 degrees apart on the KU-FSS band. The DBS band has 9 degree spacing. The larger the dish the smaller point in the sky it can focus. Most of the Ku-FSS dishes run about 1 meter. Dish has managed to shrink the SuperDish some by specially shaping it to focus it better.

2. Both the FSS and DBS bands are both parts of the Ku range of frequencies. The FSS satellites are 2 degrees apart, the DBS ones are 9 degrees apart. The 9 degrees was selected to allow smaller dishes (see #1).

3. The DBS LNBs will not work with the FSS band satellites since they are completely different frequencies (and polarizations).

4. The "Sat C" LNB from DirecTV is a completely different animal. It actually makes the 110 satellite transponders look like they are on 119. Since DirecTV owns the higher number transponders on 119, the Sat-C LNB maps the 3 transponders from 110 to the lower numbered frequencies on 119. So, the receiver just sees 2 satellites 101 and 119. With Sat-C installed, 119 has 3 more transponders active (from the reciever's perspective).

 

[Guest]

Just for clarification of possible substitute of Superdish:
using latest version SW 7.80 and 6000/8PSK model with regular 18' aimed to 148W and combined by SW21 with signal from other 1m dish with regular Ku LNBF (11.7-12.2 GHz, H/V switching by 13/18V from SW21) you will get all that test channels regardless type of modulation - QPSK,8PSK and turbo coding. Please, be aware - the channels could not be decoded if you have regular subscription.

 

[Scott Greczkowski]

Please, be aware - the channels could not be decoded if you have regular subscription.

So what your saying is this setup wont work if you have a legal subscription? Or have they not made the mirroed channels at 105 available to anyone with a dish pointed at 105 yet?