Does skewing an LNB improve reception?

Discussions about low-noise blocks, waveguides, horns and other components used at the prime focus of your reflector dish.
Post Reply
belter-one
TVRO Guru
TVRO Guru
Articles: 0
Posts: 331
Joined: Wed Apr 11, 2018 11:23 am
Has thanked: 141 times
Been thanked: 15 times

Does skewing an LNB improve reception?

Post by belter-one » Wed Sep 02, 2020 11:46 am

Hello,

We recently bought a titanium positioner which is capable of skewing an LNB using, I think a servo. We have a 10 foot dish with a stationary LNB. Does skewing the LNB help reception in any way? Is skewing tilting or rotating the LNB? Any information on this would be very much appreciated.

Cheers,

belter-one

DRIVN78415
TVRO Member
TVRO Member
Articles: 0
Posts: 46
Joined: Fri Feb 14, 2020 12:35 am
Has thanked: 2 times
Been thanked: 9 times

Re: Does skewing an LNB improve reception?

Post by DRIVN78415 » Wed Sep 02, 2020 2:40 pm

depending on your dish if is level to the ground, is really up to the user had it first setup, like mine...some of my yard is not level due to drought cause it to form a trench between house and fence line or it rains too much cause some part of the ground to form humps that is higher than other location...but my point is, if your dish level flat to your scaller and is aligned correctly to the center then only rotate at center position by moving inward and outward while turning for fine tuining, careful 58w is only sat can recieve signals in backwards polarity if not skew accuratlly from the chart on this site, kind it wierd that half transponders from H become V ...but in my case ..i had it backwards without knowing if the site is wrong or i had it wrong entire time, but in my 8th foot dish is awkwardly not center from scaler due to my issue what i mention about my ground on dish is not level to begin with but still work but not perfected accurate that lnb has follow what dish face set from the ground..my lnb on 8 foot is like more tilted toward to right than the center to the dish face....i probably need to redjust to different location of my yard since my its not pole version...mine came with cheap stationary kit included that design to be bolted down to pallet or concrete pad..problem with those, they are very hard to work with on moving and tracking ...but they are more mobile if i had on pallet with bricks over it than having easier model with tracking on pipe but pipe and ground will cause other issues will be permanent like i having now with my 10 foot dish recent now...but its workable to correct it over period of time ground sets by weather patterns in my area...i don't get snow often , cause its very rare in south texas as we get rain and more wind often...

belter-one
TVRO Guru
TVRO Guru
Articles: 0
Posts: 331
Joined: Wed Apr 11, 2018 11:23 am
Has thanked: 141 times
Been thanked: 15 times

Re: Does skewing an LNB improve reception?

Post by belter-one » Wed Sep 02, 2020 5:06 pm

Thank you DRIVN78415,

For you for the reply and the useful information. Our dish is on a concrete pad mounted with concrete anchor bolts. I hope to never have to move it. :-)
Interesting.

Cheers,

belter-one

zack
TVRO Member
TVRO Member
Articles: 0
Posts: 24
Joined: Thu Sep 28, 2017 7:10 pm
Been thanked: 1 time

Re: Does skewing an LNB improve reception?

Post by zack » Thu Sep 03, 2020 12:40 am

Yes, Belter, it can!

Even better, you can change the skew from the comfort of your Lazyboy!

No need to go outside and climb up on a ladder and loosen those screws around that old LNBF to turn it manually!.

Go back inside to that Lazyboy and WHOOPS! You turned it the wrong way! Go back outside and repeat?

I know that a LNB set up with a skew motor means more wiring and more work overall but any time a sat signal goes a little wonky ,I can move the skew all the way from from +90 to -90! from my living room!

Also, a perfect setting of 45 on most sats will not work on all all of them if you are trying to watch weaker signals, ( if your lnb is oriented at the correct position related to North and the skew motor is also in right, 45 is it!)

On a recent mux on SES 101 I was certain I had a radar problem from my nearby airport! I even tried the metal window screen around the schaler! On the first try the screen was too long, lost almost all, the second time shortened the screen to 4" doubled over on itself on each edge to help retain its round shape, no help for Folk channel, but, did not seem to affect others!

Next day I I noticed that Newsy was very low on signal! Which is saying something with a Linkbox 9000! So i played withed the skew and got it up to 98 Q and 98 sig!

I had already been at Folk and it was unwatchable, now it was better! Kept playing at the skew and after moving the dish 2 clicks to the east-
98Q 98 sig!

The next day I had to change the skew back to 45 from 62 and then go 2 clicks west to get Folk! Very weak signal back then!

That was back when they were playing the very old John Wayne westerns at 12 noon central time! ( Lone Star)

belter-one
TVRO Guru
TVRO Guru
Articles: 0
Posts: 331
Joined: Wed Apr 11, 2018 11:23 am
Has thanked: 141 times
Been thanked: 15 times

Re: Does skewing an LNB improve reception?

Post by belter-one » Thu Sep 03, 2020 1:25 am

Thank you Zack,

For a very useful reply. I will eventually be getting the equipment to do this, if it is still sold. Sounds like fun!

Cheers,

belter-one

User avatar
tvroadmin
TVRO Administrator
TVRO Administrator
Articles: 1
Posts: 902
Joined: Sat Mar 01, 2014 1:00 am
Has thanked: 13 times
Been thanked: 56 times

Re: Does skewing an LNB improve reception?

Post by tvroadmin » Thu Sep 03, 2020 5:17 am

belter-one wrote:
Wed Sep 02, 2020 11:46 am
Hello,

We recently bought a titanium positioner which is capable of skewing an LNB using, I think a servo. We have a 10 foot dish with a stationary LNB. Does skewing the LNB help reception in any way? Is skewing tilting or rotating the LNB? Any information on this would be very much appreciated.

Cheers,

belter-one

Skew adjustment means rotating the probe inside the feed horn. Tilting the LNB won't help you, it will change the illumination pattern on the reflector, which is NOT good for a prime focus dish. Your LNBF / scalar ring should be perfectly centered. The company that made the rotating probe with servo motor feed horn closed down last year. You may be able to find a used one.

The satellite operators detect the Earth's magnetic field and use it to align the vertical and horizontal fields. When locking your zenith satellite (highest in the sky), the probe in your feed horn needs to point straight down. The other polarity will be perpendicular. As your dish tracks the arc, your feed horn will for the most part track the polarities of the satellites. The advantage of using a single rotating probe is for fine tuning the polarization. Also, a single probe will not mess up the field distributions in the wave guide as much as two fixed probes would, so slightly better gain. But perhaps the biggest advantage of an adjustable skew is the suppression of terrestrial interference, if any.
Administrator
([email protected])

Post Reply

Return to “Feed Systems”