Tweaking this dish is defying the odds!

[Blindowl1234]

Over the last few weeks I've mounted my 8 foot dish on a much more secure pole...I've checked and everything is set correctly...elevation, level pole etc...I 'm still having trouble with my highest and lowest sats (55 & 137w). The RTN on 137 is at 72%, 360 North is at 51% and slightly pixelated.
55W I think its VTV4 is at 71% anything else comes and goes on 55W....pixelated. Still if I raise the elevation maybe 1/2 to 3/4 turn on 55W it's much improved. If I lower it 1/2 to 3/4 turn 137W is improved. Yes I've shifted it on the pole east and west. That's where I thought the issue was at to begin with. I've done everything I can think of to get both ends perfect but something still doesn't track right. As far as the ends go 61W and 135 W are fine All measurements are correct as far as I can see. I've tried the dish pointer app and don't see any issues line of sight either. Can anyone think of something really weird that might be causing this? I'm stumped

 

[Cham]

Wonder if you've played with your declination a bit? Maybe it needs a bit more or less (would have to think about it for a bit which way).
I increased mine a bit more than what specs say for my location due to the pole bending more on the ends of travel than in the center. Pole only bends maybe 1/4 of a degree but noticable with the large dish.
How about power lines or telephone lines within the line of sight? Suppose that could cause interference that could make the satellite appear in a different place than it is (at microwave frequencies of course).

 

[coinmaster32]

Besides the elevation setting of the mount itself, some mounts have a setting that adjusts the elevation of the dish itself. This adjustment is called the declination setting.

You can find alot more than you ever need to know about adjust a c-band dish here:
http://www.geo-orbit.org/sizepgs/tuningp4.html#anchor807714

One time I had a dish that I spent over a week trying to track. Come to find out something on the mount was bent.

 

[Blindowl1234]

Thanks Coinmaster, My dish has a bolt closer to where the dish mounts to the mount for declination...serves same purpose. I'm now thinking that with the 8 foot dish that its unable to move to the farthest east and west by design, and get a solid signal. It will pick up NHK 58W at about 60%..anything else on down to 55W is a hit or miss without a very slight upward adjustment of elevation. 137W RTN stuff tonight is at 73% but 360 North is at 50% or so and breaks up unless I adjust elevation down very slightly. Only left to suspect is even though my inclinometer says the pole is level it might be off just enough to cause havoc...guess I'll check it with my bubble level in the morning..Other than that I'm at a loss. 135W and 139W is booming and 61W as well it's just those two birds. 137 and 55W

 

[FaT Air]

Still if I raise the elevation maybe 1/2 to 3/4 turn on 55W it's much improved. If I lower it 1/2 to 3/4 turn 137W is improved.

Being you have to raise the dish at one extreme, and lower it at the other extreme, your azimuth is off. Instead of lowering/raising the dish at the extreme end of the arc, use the actuator to raise or lower as necessary, and re-aligning onto the satellite with the azimuth. (Twist the mount on the pole)
addendum:
To determine if the declination is off:
adjust BUD tracking as normal. When at one end of the arc , with Q peaked, mark the pole/mount relationship. Then adjust azimuth on the other side of the arc. If the pole dish relationship is not at the same place, mark the new relationship.
Move the mount mid way between these marks. See if both sides need the dish raised or lowered.
If the dish requires lowering, increase your declination.
If the dish require raising, decrease your declination.
http://www.geo-orbit.org/sizepgs/tuningp4.html#anchor809560

 

[Blindowl1234]

Fatair, If I move the dish on pole even the width of a pencil lead, either east or west...well I lose several birds. There is no point in between to mark. Thats why I went back to thinking its something different. I may take pics and post tomorrow. I've put up a few more dishes over the years but this is a bud with attitude lol

 

[turbosat]

Blindowl do you think there may be some inaccuracies in the polar mount itself? If the top of the pole is level, and the pole is plumb, and there's no play in the mount's parts, I can't think of anything else other than misadjustment. I've had some that were really tough to align, but haven't tried with that far of a spread in the arc too many times. I'm usually happy with 72-137 and so far my dishes will do that much without too many headaches. Going any further east for me is problematic because of trees and mountains in the way. I can hit the 58easily but anything below 58 is pretty tough to see for me.

 

[FaT Air]

If you adjust the azimuth, you gain on your extreme satellite, but loose others on the arc towards zenith??? That sounds like something is moving that shouldn't be. Think I'd be stringing the dish, leaving the strings taped to the dish face, and watching for changes when the dish is moved from the center to the extremes. Might even do the same with the feed. Strings from the feed to the edge of the dish. See if one or more string is pulled loose.
I'd also check the polar pivot points for wear.

 

[primestar31]

Have you done the STRING TEST on your dish? Are you SURE the feed (and lnb) is centered and squared with the dish properly? Are you SURE your pole is straight, and leveled both ways North-South and East-West? How much slop is there in the polar mount parts including actuator? Are all bolts tightened down? Maybe a cracked weld?

Something is sure wrong! I would start by checking ALL of this, and correct each of them as close to 100% as I could get them. Try for NO compromises, because if you have many, every tiny compromise add's up to a total distortion in the dish that makes it impossible to properly aim.

 

[Blindowl1234]

Strange thing...its 25 degrees out and stupid thing is much better! Most of 58w is 71% weaker tp's are 51% a little pixeled. I wonder if the sun, or heat of the day is the issue. Gonna be 45 & sunny guess I will wait and see. Going to ck other two birds now. Thanks for everyones ideas too!

 

[coinmaster32]

The temperature of the outside can have a major effect on reception. This is called drift. If you notice much weaker signals during the day, then an LNB replacement is in order.

 

[Blindowl1234]

Coinmaster, LNB was changed about a month ago but I've got a spare so I might try it. Just checked a little while ago and 55W is better as is 58. 137w is 72% on RTN but 360 North is 52% and slightly pixelated. I may leave it well enough alone and check this afternoon.

 

[SatelliteAV]

Is the scalar parallel and flat to the reflector? Centered on the reflector? Is the Feedhorn perfectly aimed to the center of the reflector?

I use a level with a 90 degree laser pointer to align the scalar and the Feedhorn. Definitely will have tracking problem with the Feedhorn off- center or the throat not aimed at the center of the reflector.

Dish 101 for us old C-band guys, but the importance of installing and aligning the Feedhorn / scalar is rarely discussed on this forum.

 

[Lak7]

Can you adjust Dish to get a good signal on East and West Sat?

When "exact" measurements do not work, go with what works.
My biggest issue was always Azimuth and Declination - relied too much on Compass and Level. Setting the Elevation with Level, and winging it on Declination and Azimuth is what works for me.

 

[Blindowl1234]

Brian I double checked LNB today looks ok. LAK7 I agree as much as I watch anything on 137 or 55 I not real concerned just picky haha. I did look at how the actuator is mounted the the piece of angle iron today. That's been a problem getting the dish to go exactly to the same bird twice in a row...always had to bump it a little east or west. I took another piece of angle iron and doubled it up. It tends to flex just a bit otherwise with only one piece. Guess since it feels like winter I may have to leave it as is for now.

 

[Blindowl1234]

Turbo, I have the same issues here with trees. 72-137w are not an issue. NHK on 58 is at 60% usually. Some stuff comes in on 55W I think its VTV4 at 70% the weaker stuff is touchy unless I raise the elevation a fraction. 139W is strong also. I wondered if trees were the issue but this morning I had a good signal from 55 to 139w except the three channels on 137...RTN is at 72% or so. Seems like its the weaker tp's that I lose at the ends....could be because it's only an 8 foot dish. 10ft might be better....but I'm not going there haha

 

[Babadem]

Is the scalar parallel and flat to the reflector? Centered on the reflector? Is the Feedhorn perfectly aimed to the center of the reflector?

I use a level with a 90 degree laser pointer to align the scalar and the Feedhorn. Definitely will have tracking problem with the Feedhorn off- center or the throat not aimed at the center of the reflector.

Dish 101 for us old C-band guys, but the importance of installing and aligning the Feedhorn / scalar is rarely discussed on this forum.

Brian, could you post a picture/ brand name of the level 90° with a laser pointer?

 

[Babadem]

Turbo, I have the same issues here with trees. 72-137w are not an issue. NHK on 58 is at 60% usually. Some stuff comes in on 55W I think its VTV4 at 70% the weaker stuff is touchy unless I raise the elevation a fraction. 139W is strong also. I wondered if trees were the issue but this morning I had a good signal from 55 to 139w except the three channels on 137...RTN is at 72% or so. Seems like its the weaker tp's that I lose at the ends....could be because it's only an 8 foot dish. 10ft might be better....but I'm not going there haha

@ the highlighted. I get a 70+% quality on NHK on the MicroHD using the WSI 6ft special.

 

[primestar31]

Brian, could you post a picture/ brand name of the level 90° with a laser pointer?

Here's the one I use. I bought one off of Ebay for $38 after Brian first mentioned them a few months back. Works GREAT!

I mounted mine on a piece of angle-iron with holes in it so it can beam through. That way I can center it on my ortho feed with the lnb's removed since the laser is real close to the end and won't span the feed and be centered by itself.

http://www.boschtools.com/Products/Tools/Pages/BoschProductDetail.aspx?pid=GPL3T

 

[Babadem]

Here's the one I use. I bought one off of Ebay for $38 after Brian first mentioned them a few months back. Works GREAT!

I mounted mine on a piece of angle-iron with holes in it so it can beam through. That way I can center it on my ortho feed with the lnb's removed since the laser is real close to the end and won't span the feed and be centered by itself.

http://www.boschtools.com/Products/Tools/Pages/BoschProductDetail.aspx?pid=GPL3T

View attachment 82574

Thanks for the link and info.