Main difference in setting up a C band and KU band satellites dishes?

F

ftanut

Legit VIP
Not new to FTA but still learning. Did some reading on setting up a C band satellite dish and there was a statement about raising or lowering just slightly by hand the front of the dish to determine as to whether to rotate the dish on the pole East or West to obtain a higher quality satellite signal...Does this rule also applies to the offset Ku band satellite dish as well?

Thanks.
 
An offset dish does not have the lnb centered, hence the name offset dish.
The lnb should illuminate the offset dish in a perfect circle, the same as a prime focus dish.
An offset dish is diamond shaped or it has a bit of extra material on the top and the bottom of the dish. This is done in order to keep the lnb from seeing the ground that is behind the dish because the lnb is not centered on the dish.

You set up an offset dish the same as you would a prime focus dish. The main difference between these two dish antenna designs is where the lnb is placed. EB
 
Thanks for responding...One of the main reason for the above question is that I have just rescanned my Ku dish, did a multiple satellite scan, now I am receiving most of the satellites one satellite off, in other words I am receiving a higher number satellite than the one I am suppose to scan. For example I am receiving the entire 97W Galaxy 19, when scanning for 95W...

Started at 72W with good results, and as the higher satellites were scanned, then after 87W this change was noticed when some of 87W TPs were scanned alone with the next upper satellite...Obviously I am missing quite a few TPs, but whatever Tps are comming in the TPs are of fairly high quality value.

Any suggestions as how to go about correcting this problem, is appreciated...my home satellite is between 89W and 91W, I am located at 89.75W...Which one would be the best for me to shoot for in this case. Something deffinitely moved since my last satellites scanned.

Thanks.
 
89W would probably be the best one to use for a center satellite.

Post a list of the satellites that you can get. Post what the actual degrees are and then post the degrees you are actually receiving the satellite. Include satellites on both sides of your center satellite, and include as many satellites as possible. Doing this should show us some sort of pattern.

What lnb and dish are you using?

Are you using USALS? Are you using the correct coordinates for your area?

Is the motor pole plumb?
 
Ok, here are some answers to the questions: The motor pole is plumb, The LNBF is a Titanium PLL-1KS, The dish is believed to be from what I have researched, a 1M Winegard, using USALS, the receiver is a X2 Premium.

The satellites received are as follows:
72W AMC6 - all the NBC muxes 12052V6890
83W AMC9 - Luken 11734H4439
87W SES2 - 4 TPs 11720H4856, 11964H29267, 11717H4858, 11740V8333
89W G28 - 1 TP 12131V1037
91W G17 - 12011V11574, 12127V2219
95W G3C - 11780H20760 freeze. This is were everything start going crazy, at this satellite all of 97W G19 is picked up.
99W G16 - picks up 1 Tp from 101W 11820H2000
101W SES1 - picks up 103W AMC1 11760H30000, 11840H30000, 12083H4231, 12089H4231, (12095H4231 freeze), 11942V20000
113W SM6 - picks up 118.8 11807H20000
123W G18 - picks up 125W AMC1 12174H4443 at 0%.

All the other satellies TPs vary from 72W at 75% to 123W (125W) 0%

That is the satellites as I went thru them starting from 72W to 123W.

Thanks.
 
I just started using Usals again so I will try to help as best as I can. Are your usals coordinates correct in your receiver. I would like you to test something for me, move your dish to 95w and leave it on a 97w channel that scanned in. Go into the motor menu and change your west setting to 1 degree more then what you have it set at. Go back and check the channel to see if there is any signal quality, if there isn't then rescan and see if the 11780 tp scans in and with stong quality. If this doesn't work then try reducing to 1 degree less. I do this all the time because I am having motor issues on my end. If your scanning in the NBC tp on Amc 1 at 103w then your dish is probably arcing well since those tp are inclined and sometimes hard scan in.
 
Costactc said:
I just started using Usals again so I will try to help as best as I can. Are your usals coordinates correct in your receiver. I would like you to test something for me, move your dish to 95w and leave it on a 97w channel that scanned in. Go into the motor menu and change your west setting to 1 degree more then what you have it set at. Go back and check the channel to see if there is any signal quality, if there isn't then rescan and see if the 11780 tp scans in and with stong quality. If this doesn't work then try reducing to 1 degree less. I do this all the time because I am having motor issues on my end. If your scanning in the NBC tp on Amc 1 at 103w then your dish is probably arcing well since those tp are inclined and sometimes hard scan in.
Click to expand...

I know this would only be a band aid fix but just curious as to your results. In my opinion your point of reference on your motor( 0 ) is slightly off.
 
See if you can get the 12172V 30000 transponder at 61.0W. This will give you more of a spread in degrees each side of center (89w) and may give more clues as to what you need to do.

The dish is supposed to be at its highest point when it is aimed at the center satellite. There is a plateau of a few degrees each side of center where the dish drops a little bit, but not enough to give much of a clue of what adjustment(s) need to be made. The dish drops faster as it moves farther away from center.

Your dish seems to be going past the target by a couple of degrees. The dish could be set too high or it could just be out of alignment. I assume your dish motor is set for the correct elevation for your area, so it is possible that loosening the motor and moving the entire motor/dish assembly two degrees East would fix it. It is hard to tell without having more information from the Eastern satellites such as 61w.

Try Aligning the dish at 89W using tp 11798v 26660.This is a full time tp and should be strong. If the dish is correctly aligned to this tp, then you will notice the signal drop when you slightly push or pull at the top, bottom, or either side of the dish.
You may use a damp rag pr a piece of tin foil to cover part of the lnb if you need to make the tp signal weaker. if the dish is properly adjusted, the signal will drop when the dish is sightly moved in any direction.

The tp at 118.8 should be ignored until you have the dish aligned correctly. Unless something has recently changed, all ku signals from that bird are circular polarized. Your lnb is designed for horizontal and vertical transponders.
 
..or try to move/rotate/ the whole LNB and the holder together to the left while you are standing up front of the dish ..
Maybe the LNB is not pointed correct to the dish ..
 
Last edited:
Costactc, I did what you asked me to do...When the USALS value was upped by approximate half of degree, 95W and scanning of 97W, the quality value readings got worse, when the USALS value was downed, the quality readings flactuated a little, not as steady as when the original USALS parameters were used, but did gain a couple of TPs on the higher satellites.

It seems that I will have to chech and rework the dish alignment and the whole setup. Will try to do it tomorrow. Will report my findings after the rework. As I said earlier, something must have moved and made things go out of wack.

Thanks.
 
If possible, take a few clear pictures of the dish at different angles and post them.
Sometimes it helps to put paint marks at all adjusting points of the dish motor and pole. Doing this may give you some idea as to what has moved. Find another satellite below 72W. You do not have enough spread in degrees yet to make it clear what needs to be adjusted.
Some dishes and motors have a bolt that runs through the center of the motor shaft so the dish is aligned correctly to the motor. If you do not have this bolt then the dish may have shifted West on the motor stem.
 
The dish and motor bracket do not have the bolt that runs through the center of the motor shaft, which means that the dish did actually rotated in the bracket. Now I have to see how much movement did accured, and snug the bracket's bolts.

Before anything is loosen, I will take a reading with my GPS to get a better coordinace bearing...Work is still in progress.
 
High winds knocked my ku band dish out of whack several times and to the point where the motor arm is loose and that's why I fluctuate my coordinates accordingly. I have already invested in a new sg6100 motor but up here in the North Pole we must wait for Spring. I still think your motor is just slightly off.
 
Yesterday I worked/played with the dish for a while, rotated the dish a bit to the East, and also up and down to see if the quality signal would improved , well the quality did improved but lost some satellites on both ends. No 72W nor 78W..No 116.8W, and beyond that. Yesterday was also a rainy day which did not help matters at all. Things are good from 83W to 113W. This morning the backyard is too soaked and mushy to do anything. Maybe tomorrow.

Thanks.
 
It has rained on and off for a few days, and have not had time to do some more adjusting of the dish setup. After observing the dish movement/travel it is noticeabled that the dish motor is not up to par, and this could be part of the problem for not getting some of the satellites to come in.

Might have buy a new dish motor replace the GEOSATpro GS120 motor. I have a 1.2M dish, so I need something with enough power to drive, any recommendations for a new dish motor is welcomed.
Thanks.
 
Why do you think the motor is not any good? Ku dish motors usually slow down as they get older and this usually does not have any effect on the tracking.

Which brand of 1.2 meter dish do you have? What size is the motor tube? Pay attention to what you get because some motors such as the SG6100 have a small diameter shaft on them that will make it difficult to use on most 1.2 meter dishes.

I used a Stab HH120 for years. The only problem is it is a slow motor. I am currently using a DG380 to turn my 1.2 meter Geosat dish. This motor has been in service for a few years without giving any problems.
 
Sorry for not being more informative, and much clear on my statement. When I mentioned the dish motor I was talking about the GEASATpro GS120 motor being installed on the 1M Winegard dish not on a 1.2M dish. The dish does jerk some when traveling the arc, and noticed that it at times struggles to move off of the center of the arc.

I do have a 1.2M "Commercial" dish which I was lucky to have scored it from an old gas station. This dish is made out of fiberglass and it is very heavy for it's size (approximate 35#). I would also like to have this motorized. Did some reseach on the dish and it suppose to be an "Andrews" dish, which in reality has changed names three times. Anyhow the dish right now is installed on a NPRM at ground level, and pointed to 97W Galaxy 19. To me it is a waste of a dish by not being motorized.

Back to my original question, what would be a recommended good motor for the 1M Winegard dish, and if anyone knows of a good working horse of a dish motor for the 1.2 "Commercial" dish please point me to the right way. LOL!!.

As always Thanks.
 
Back
Top