Need Help with multiple LNB formula/configuration

XStreamTV

Thread Starter
Member
Feb 22, 2020
6
1
Castle Rock, WA
Ok - so, I'm new to this and trying to help our Engineers out while they are literally aiming and tuning the multiple LNBs. We only have the boom lift for another few days and our main Engineer hasn't been able to figure it out or get a signal at all. We have two 12 ft dishes with 3 LNBs each and two 10 ft dishes with 2 LNBs each. They are currently working on one of the 12 ft dishes and have gotten signal on one of the LNB's (middle one). I have read LOTS of documents, installation guides as well as formulas to be able to configure and adjust the LNBs, however nothing is working for the equated numbers and I believe we are having to eyeball aiming with the satebeams website. The satelite finder we have is absolutely useless and even a compass can't seem to find north. Any help would be greatly appreciated!!! Thank you
 

Titanium

AI6US
Lifetime Supporter
May 23, 2013
6,770
7,465
Meadow Vista, Northern California
In a different thread you posted what looks like technicians assembling the reflector panels in the air? If so, the dish is likely not forming a perfect parabola. Have you stretched multiple strings from edge to edge crossing in the middle to see if all strings lightly touch? If the strings are not lightly touching, the panels are not properly assembled to focus reflected signals into the LNBF.

Dish brand and models?

Are these dishes fixed or motorized?

Using LNBs on a dedicated single feedhorns for each satellite or multiple LNBFs?

How are the offset feedhorns mounted? Brands, models, C-band, Ku-band? LO frequencies?

Are you aiming for the centered of the multiple satellite first?

How are you measuring the reflector elevation? Using the vertical face of the dish or a different place on the mount?

What satellites and bands are you aiming to receive on each dish? Example: Dish 1 - 97w KU-band, 101w C-band, 105w - C-band.

Does the satellite meter have a spectrum analyzer function? Brand / model?

If you are having difficulties using a compass, try dishpointer.com and identify landmarks that closely align with the target satellite. Use an online solar calculator to plot the sun and shadows to align with target satellite positions. I recall an install many years ago north of your location in Centralia, WA that there was so much iron ore in the ground, that the compass was off by 60 degrees!

Are you setting the correct polarity and skew?

Are the engineers experienced with satellite installs or are they IT computer guys? If not experienced with satellite, probably a great discussion would be to consider bringing in a professional to meet your deadlines.
 

arlo

SatelliteGuys Pro
Dec 4, 2016
191
91
North Eastern
Just an FYI My personal favorite jig is a spray paint can lid that just fits inside of the LNB throat and another one that fits inside it.
Cut them down so they are the length of a .223 laser boresite shell. Use the little dimples in the center of the lids for a drill guide then push the shell in them. Works like a peach. Don't slide it in far enough to hit the probe antennas.
Once your LNB is pointing right at the center of your dish start peaking it for signal with the mount adjustments.
Finalize by tweaking the LNB. Should make adding additional LNB's either side of the primary one easier.
 

Cham

VE4GLS
Pub Member / Supporter
Dec 19, 2008
2,219
786
Boonies
Funny I just read this thread, one of our new local ISP companies appears to be doing the same thing. Couple months ago they had two C-band dishes maybe 8-10' diameter installed with what looked like C-band feed horns (just single not multiple). While later it looked like they changed one of them (dish might be pointing at 82 or 85W) to a fancy Ku feed horn. Drove by a couple days ago and noticed one dish (Ku) had been removed and was sitting face-down in the snow and they had installed a bracket with two 1m Ku dishes on the empty pole and looks like they are pointing at 82 and 91w. The other C-band dish didn't look to be connected, no feedline running to it.
Me is thinking they might be looking to rid themselves of two C-band dishes that are almost brand-new... Wishing I knew someone who works there. Will have to drop by when I see them working on their "ground station" and ask I guess. No luck so far though, maybe they only come out at night.. :)
I did ask about their fibre service, awesome bandwidth, but they quoted me $200,000 for the install! Ouch!
 
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