Will an 18x24 Dish (or Phase 1) hit 121?

[alebowgm]

Hey,

I have seen some diagrams saying that this setup will work, however I have yet to try it. Supposivly, if you have an 18x24 aka a DTV Phase 1 dish, you can add a Stacked FSS LNB (such as a Dish Network Canada LNB, the ones that are reappearing again) and tape it on to the 119 BSS LNB and you will be able to recieve the 121 signal. I know this is possible by taping on a BSS LNB to the 101 location so that NIMIQ 1/3 can be recieved however that location is of no use for me.

My concern, before I go and try this, has to do with me not having a strong understanding of FSS equipment and more than anything the 'BORE EYE'. My understanding, or lack there of, is that FSS LNBs for the 105/121 (and in the future DTV 95), requries that the FSS LNB be in the middle of the satellite where as the BSS LNBs can be anywhere on the satellite to get a signal. This is why on the DishNetwork Superdishes, the 105 and 121 are in the middle and the other LNBs are able to be on angles on either side.

If this is this case, then how would the 121 work on an 18x24 properly? Wouldn't it need to be in the middle of the dish.

Here is the diagram I am refering to (from 18inch.com)

BTW: I am installing a 18x24 this weekend for my neighboor, it is not my dish so I am unaware of how much playing around I will actually be able to do, which is why I am wondering if anyone has any knowledge of this setup. I already have the Stacked Dish Network Canada (now called Bell Expressvu) LNB that I got off of eBay.

Thanx

 

[Mr Tony]

nope. You need at LEAST a 30" dish to make it work. Any size smaller dish wouldn't work. I tried it on a straight 24" dish and got nada.

The 18X24 is actually the same area as a regular 20" dish

 

[Mr Tony]

My concern, before I go and try this, has to do with me not having a strong understanding of FSS equipment and more than anything the 'BORE EYE'. My understanding, or lack there of, is that FSS LNBs for the 105/121 (and in the future DTV 95), requries that the FSS LNB be in the middle of the satellite where as the BSS LNBs can be anywhere on the satellite to get a signal. This is why on the DishNetwork Superdishes, the 105 and 121 are in the middle and the other LNBs are able to be on angles on either side.

Actually, the Superdishes have the FSS aimed at the center and the other 2 at angles. The 105 SD has 119 way off angled to the dish. The 121 SD is a little better

 

[alebowgm]

Also, the image shows that what is combining the 119 and 121 is a DP21 and the 119 is a DISHPRO LNB. I dont see why this has to be the case. Why cant a Legacy LNB be used for the 119 and a SW21 to combine the 119/121 signals?

 

[alebowgm]

Well that is what I am saying. The 105/121, arent they in the bore eye (and if anyone can define bore eye in grade 2 english, that would be great because the explinationsI have read havent helped).

Obviously, it will also depend on where you are in North America. I have read success storys where people have used smaller than 30 dishes in the deep south to get a low signal on the 121 but it was locked...

 

[Mr Tony]

Also, the image shows that what is combining the 119 and 121 is a DP21 and the 119 is a DISHPRO LNB. I dont see why this has to be the case. Why cant a Legacy LNB be used for the 119 and a SW21 to combine the 119/121 signals?

UNless its a SD, the DLNB at 119 would have to be Legacy. FSS LNB's arent DishPro (except for the one that comes with the SD)

The issue is the dish isn't big enough for it to work, since 121 is a lower powered satellite, you need a 30" dish

 

[Mr Tony]

Well that is what I am saying. The 105/121, arent they in the bore eye (and if anyone can define bore eye in grade 2 english, that would be great because the explinationsI have read havent helped).

the bore eye is the point where it bounces off the dish and hits the LNB. It has to be straight on or it won't work well.
Since DBS is higher powered, you have a lot more flexibility from the focal point (bore eye)

Obviously, it will also depend on where you are in North America. I have read success storys where people have used smaller than 30 dishes in the deep south to get a low signal on the 121 but it was locked...

a 18x24 won't work...it is no bigger than a 20" dish. You need at least a 30" for FSS/KU band.

 

[larrystotler]

You may actually get a signal if the FSS was at the center of the dish, but I doubt it. Also, you can't have the FSS at 121 right beside the 119 since there isn't enough spacing. The SD 121 uses a curved horn to get signal since the locations are so close. I have seen a similar setup used the get Bell's 92 on the plus dish, but it will not work for the 121.

 

[hondalover]

I have tried this particular setup with a dtv oval dish and I was able to get 110 and 119 together but not the 121.If I lost the 110 then I would pick up 119 and 121,so I think if I pointed the dish to 110 and 119 and some how spaced the 121 fss lnb more south from the 119 lnb I would get all 3 on thee dish.haven't tried it yet since weather here was alittle snowy when I did it.

 

[SimpleSimon]

While all this stuff is neato cool fun (I've done some of it), if all you're after is TV, fuggedaboudit. Just mount the "correct" dishes.

The primary problem - as Iceberg is trying to pound into heads out there - is the surface area of the dish. Even a SuperDish is barely big enough to collect enough of the right FSS microwaves to run a perfectly engineered dish/LNBF arrangement.

The larger dish has TWO purposes. Concentrate enough signal from the desired location, AND reject signal from adjacent ones - remember, FSS spacing is only TWO degrees. This simple physics can NOT be overcome.

 

[Mr Tony]

While all this stuff is neato cool fun (I've done some of it), if all you're after is TV, fuggedaboudit. Just mount the "correct" dishes.

very true. The exception is a Legacy Dish500 and 30" dish for 105/121. This works on one or two receivers

The primary problem - as Iceberg is trying to pound into heads out there - is the surface area of the dish. Even a SuperDish is barely big enough to collect enough of the right FSS microwaves to run a perfectly engineered dish/LNBF arrangement.

thanks Simon. People just don't get it...a 18" wont work, a 20" wont work and a 24" wont work, but people keep asking. I can get a 90 on 121 with a 30" dish aimed at it...and use a Dish500 for 110/119

I dont have a Superdish

 

[SimpleSimon]

... The exception is a Legacy Dish500 and 30" dish for 105/121. This works on one or two receivers ...

Or add a SW64 and run up to four tuners.