Initial dish aiming questions

[jugghedd]

I seem to always have lots of questions. But, I get answers here and I appreciate it.




To start, I have a 7.5 ft mesh dish, polar mouint, X2 premium HD receiver and a actuator hooked to a VBOX positioner.
Im in upstate NY so.... Latitude: 42.67° Longitude: -74.35°
I would think that 75W BRASILSAT B3 | GOES 13 | STAR ONE C3 is my true south SAT.


I did lots of reading about setting up my dish and how to determine true south, etc.
Everything I read seems to say that true south is not the same as magnetic and that you align your dish mount using true south during the installation phase.


So, I set the actuator for 0 degrees and have the dish pointed straight on with the mount. I set my declination at the proper offset (6.5 if I remember right). Here's where I have some confusion. Dishpointer says my true south elevation is 40.7 at true South and that my true South is at 193 degrees. So, I pointed the dish at 193 and set the elevation for 40.7 My problem is that I cant get any SATs in the top middle of the arc. I tried lowering and raising the dish a VERY LITTLE at a time and rescanning across the top but i get nothing.


Is it possible to have the LNB focal length off and still get some sats at good quality. When I installed the LNB, I sort of guessed on the length and adjusted on a locked in SAT to the highest level I could get. Maybe I shouldnt have dont that. I wonder if I could have been off on my aiming and tuning the LNB to that threw everything else off. Is that even possible? Seems like it could be. Another issue Im having is that the SATs closest to true south for me dont seem to have reliable active transponders that Im sure exist. So, when I brought the TV out to find a signal, I had a hard time deciding which TP to try and lock down. I appreciate any advice.

Some pics of the setup.

 

[Magic Static]

I don't think there is anything hot in that location 75W. I would go for the CW mux on AMC6 at 72W 3937 V 2825 5/6 8PSK

 

[jugghedd]

So, I would still setup my elevation to the same at true south and then just motor over to AMC6 to tune that in? I dont seem to be able to hit anything until I get to Galaxy 17 on 91W.

 

[Magic Static]

You havn't mentioned declination. Check that adjustment. But yea, your elevation for 72W isn't enough different from true south to be a problem for initial setup

 

[FaT Air]

Here's some help:

For the sake of minimizing repetition I've put more detailed instructions here http://theho.web.fc2.com/BUD/9525/
Hope that helps.

 

[jugghedd]

Thanks for the link. Not sure if its the same one, but i read one with that same picture in it. What I dont understand is why you would twist the entire mount if you cant lock a signal. If your true south elevation is different than 5 degrees over from it, I would think that would throw off the entire arc. Everyone seems to say that its not off by enough to effect things. But, one degree off can make a difference for me.

I'm not trying to beat a dead horse here. But how far is off enough from true south to be a problem?

Also, am I wrong in thinking that if I twist my polar mount away from true South, over to AMC6, wouldnt my entire arc be off by the same number of degrees as AMC6 is from south? Sorry if thats the same question worded differently.

I guess the next page of that link did sort of answer that question.

 

[FaT Air]

Set the angles as shown in the picture when your dish is 'square with the mount'.
You're at (approx) 42.665271,-74.54361
So set the latitude angle at ~43 (MOD. declination chart http://theho.web.fc2.com/BUD/8495/)
Make sure the declination+ angle is (43 + ~6) 49

Also, am I wrong in thinking that if I twist my polar mount away from true South, over to AMC6, wouldn't my entire arc be off by the same number of degrees as AMC6 is from south?

Yes, It will be, but only initially. It will be corrected when you tune azimuth.
The height of the arc between your location, and that of AMC6 @ 72W changes very little. Less than a tenth of a degree. So setting elevation(latitude angle) there is alright. You can always go back and 'touch up' later.
As you tune azimuth, further and further away from zenith, the actuator takes over actual 'elevation'. You correct the E-W aim by twisting the mount on the pole. DO NOT ADJUST ELEVATION(latitude angle)anywhere except at Zenith. (Or, your closest to, satellite) Only Actuator and 'twist'(azimuth) either side of zenith.
72w - 3937 V 2825 -DVB-S2 so it may not 'lock on' immediately being a low SR and S2. Take your time.

 

[lamp]

I wrote an article on installing a motor for KU. I think many of the principles apply to C band. Go here for article:

repentnow dot com/FTAMOTORINSTALL.htm Replace the dot with a period and no spaces.

You must compensate for the amount of azimuth angle your nearest south satellite is away from 180 degrees or the arc tracking will be off. Dishpointer dot com uses motor latitude rather than elevation for motorized setups. Perhaps you have used elevation when you should have used motor latitude. For your location motor latitude is 42.7. 193.4 is a magnetic compass heading for south at your location. True south is always 180 anywhere.

 

[madmadworld]

little late here
but if you get a used dish in your area don't mess with it. put it up like you found it. put the Actuator clamp on right where it came off.
should be weathered enough to do this. it should track the arc well enough to figure what adjustments are needed if any. the first would be moving it on the pole.
good luck

 

[jugghedd]

little late here
but if you get a used dish in your area don't mess with it. put it up like you found it. put the Actuator clamp on right where it came off.
should be weathered enough to do this. it should track the arc well enough to figure what adjustments are needed if any. the first would be moving it on the pole.
good luck

Oh if only. I messed with it thinking I could get a better signal. I did mark things but its been a struggle. A good learning experience. But still a struggle. I made a little progress re-reading instructions and following to the T. Helped a bit. But, Im having a hard time with the "take your time" part. This calls for beers and a good day with no plans. Not a bad challenge if you ask me.

 

[FelixN]

Is it posible to receive signals from a satellite working in the c band if i use a 80 cm dish antenna?

 

[madmadworld]

Is it posible to receive signals from a satellite working in the c band if i use a 80 cm dish antenna?

to this place

could happen
but would not try it. but look at all my stuff
a 90 or 1m has got a few here in states
good luck

 

[jugghedd]

Thanks again for the help everyone!

A few observations and updates to my little saga:

1. Initial aiming at my true south SAT never panned out to an actual channel received. I aimed as best as I could for a semi-strong signal and left it at that. MUCH better results on the rest of the arc. Again, patience is the key.

2. Ku band on a dual Ku/C LNB = not so great at all. I had so much trouble with the C side of the BCS621-D2 that I popped an old LNBF into the bracket just to see what I got. Wrong bracket, not aimed, just stuck where it could be tightened up, and I got WAY more signal than the 621. I'm keeping my dishes separate and not trying that again. I guess the LNB cant be a good design for Ku and C without sacrificing something. I may even try a C band only one. Even my old Chaparral (bullseye?) did way better just popped in there with no real aiming. Placing the conical scalar ring just made the C signal worse.

3. Im not moving that thing again. Solid, aimed, scanning, and ready to watch some channels!

By the way, if you decide to try c band, look at someone else's big dish and another small one and you may be surprised. Having tried both, I'm glad I went the big ugly route on that one. The C band challenges and learning curve are enough to deal with without throwing a weak/illusive signal into the mix. That being said, I went from a beginner to having 2 dishes up in around 3-4 weeks. You can do anything you want if you're determined enough. Im still having lots of fun.

I now have 1 Ku 3 footer, 1 C band mesh 8 footer both controlled by 1 receiver. Both motorized with lots of channels. Total $pent....around 300 bucks. not too shabby.

 

[Pi314]

I have a similar experience. I started with a non-motorized Ku only 1.2m dish, and now I am running a motorized 7.5' c-band setup. Just a suggestion, list your equipment in your signature block, it is always interesting to see what others are using when threads are posted.