LNB aiming with multi bracket

[cruzin]

Hello, I have a old muzak dish 42widex54tall, I have it pointed at 97, works great. I bought a multi lnb bracket the type that is a round tube you bolt on to your lnb arm and it extends right and left of the center, It will hold 3 lnbs. I bought 2 more linear lnbs and am trying to get AMC 9 at 83 degrees. My question is can someone give me some pointers on how far left of the center (97) lnb (looking at it from the front) I should mount the lnb I am trying to get 83 on. And should I point the lnb at center of the dish like the one for 97 is or would it be to one side or the other. I hope I explained this so it can be understood. I have a channel list for RTN with the beep on signal set but I am getting 0 quality. I have the satellite set up as 11750 LO. standard and in my case I run a zinwell 6x8 I use the 22khz. One thing I do not understand about the zinwell markings above the 2 22khz connecters there is also a 13 and 18 v marking. I have to other lines on the
connections marked 13 and 18 volt. Do I have to also choose a 13 or 18 v setting along with 22hz on or off? thanks for any help.

 

[voomvoom]

If you have 97 as the center for the dish, I don't think you will get 83 with that dish. If you move the center to 90 degrees, you will then have better chance to get both 83 & 97 on that dish, but it will still be hard, although it should be do-able? You would be better off to use a separate dish (my opinion). As far as the Zinwell 6x8 switch, you would do better if you had a dual/twin lnbf and use one output for 13 (vertical) and the other for 18 (horizontal), or be sure and use the polarity that RTN is on, if your lnbf is one output. 13 = vertical and 18 = horizontal.
Do the same with 22KHz on or off and set your receiver up correctly. Good Luck!

 

[Keith Brannen]

If you have 97 as the center for the dish, I don't think you will get 83 with that dish. If you move the center to 90 degrees, you will then have better chance to get both 83 & 97 on that dish, but it will still be hard, although it should be do-able? You would be better off to use a separate dish (my opinion).

Agree totally, especially since the OP is trying to get RTN on 83, which is a very weak signal, even for dishes pointed directly at it.

A good rule of thumb for multiple LNBs on a single dish, try to keep the outside LNB within eight degrees of centre. There are a few satellites where you can get away with it farther away, and there are some where even six degrees off-centre is too much. Main thing is to experiment and see whether what signals/quality you can get is acceptable to you.

 

[cruzin]

thanks everyone for the reply, I was in hopes of using the multi bracket. I have been using the zinwell for about 3 years without thinking I could set the 22khz with a 13 or 18 also. I was just using power on and it was working for 97 so I tried 13 v with 22 khz on for 97 and it still worked but not with 18v 22khz on. I did try by hand trying to find 83 by pointing the lnb around and never got above 7 on quality. I will either set up another muzak dish or get one with a motor. thanks again.

 

[Anole]

calculate LNB spacing:

Hi again, I am going to set up a second dish (muzak 1.2meter) at 90* and try for both 97 and 83 birds. Can someone suggest the placement of linear lnbs in inches right and left of center lnb holder? and would this dish have to be plumb vertical to make it work? as I do not have a pole to mount this on only a non penatrateing angle iron and pipe one from a flat roof and my lawn is less than flat. If I can tune them in on the dish I will then swing my other muzak dish to 90 and tune it in. But I do not really want to mess up my 97 aiming on my pole dish before I make the perminate change. thanks

Sure, the thread below shows how to calculate the offset.
Just assume the dish is aimed down the middle as suggested above, and then place your two LNBS to the left and right of that location.
(also above and below, as required)
No opinion whether you'll get your birds that far off the boresight of the dish.

MJflash and his math to put two LNBs on a single dish:
http://www.satelliteguys.us/free-air-fta-discussion/89049-offset-lnbs-theory-practice.html