BASIC MOTOR QUESTION

[MikeinBaja]

I'm seriously thinking of adding a motor for KU and think I have a good idea of how they work and how I need to install. Searched the threads and could not find an answer to 1 question though.

I note in the motor specs the amount of E/W travel and EL travel they advertise, but what about skew?

How does a motorized set-up adjust the dish/LNB skew across the arc?

 

[Anole]

As those little Ku motors, such as the DG380 from Sadoun, move your dish, they introduce a side-ways tilt to it, which provides the required skew.
And so for all satellites (save one), the tilt of the dish skews the dish+LNB exactly as required.
I'll look for a picture or drawing to help...

edit:
here's the avatar of PSB... see if it shows what I said...
http://www.satelliteguys.us/image.php?u=984&dateline=1134870754

 

[Cband55]

In the subject do you get all sats except amc1 ?
what is the min dish size to get all sats on a motor
thanks

As those little Ku motors, such as the DG380 from Sadoun, move your dish, they introduce a side-ways tilt to it, which provides the required skew.
And so for all satellites (save one), the tilt of the dish skews the dish+LNB exactly as required.
I'll look for a picture or drawing to help...

edit:
here's the avatar of PSB... see if it shows what I said...
http://www.satelliteguys.us/image.php?u=984&dateline=1134870754

 

[Mr Tony]

AMC1 has an oddball skew. Its 25 degrees opposite what it should be

Pentagon and a couple other TP's (the stronger ones) come in on a motorized with "wrong" skew. The NBC news feeds proabbly wont as they are weak to begin with and adding wrong skew will mess it up

what is posted on thelist is what you get even with "wrong" skew
http://www.satelliteguys.us/thelist/index.php?page=103+AMC+1

 

[MikeinBaja]

As those little Ku motors, such as the DG380 from Sadoun, move your dish, they introduce a side-ways tilt to it, which provides the required skew.
And so for all satellites (save one), the tilt of the dish skews the dish+LNB exactly as required.
I'll look for a picture or drawing to help...

edit:
here's the avatar of PSB... see if it shows what I said...
http://www.satelliteguys.us/image.php?u=984&dateline=1134870754

Got it now - the missing piece was the "introduces a side-ways tilt" as the motor moves. Guess I just assumed it rotated E/W on a flat plane. Makes perfect sense to me now.

Guess since I now pretty well understand the theory I need to get off my butt and order one to move into the practical.

 

[turbosat]

While we're talking skew and oddballs and AMC1, I seem to be getting most channels on that satellite from my location, with this .90primestar//DG380 motor. Granted, some are weaker than others. But I've found some sports feeds, and 8-10news feeds channels (I even watched the balloon-boy saga on it!). It does make me wonder if I'm missing anything though on that satellite, even though I'm getting H and V channels.

 

[Anole]

Mike -
As long as you are going to spend the time and money on a motor, I'd put up the biggest dish I could reasonably swing.
Here above the border, 36" is great. Don't fiddle with smaller.
One meter (39") is better by a lot. A molded commercial (Primestar) 1m round would be the gold standard.
I hesitate to suggest 1.2 meters (48"), but that would certainly be the platinum standard if it were one of the commercial molded dishes.
...or probably metal, if it was originally used for two-way sat transmission (highly accurate dish).
But please, don't get sidetracked with the mini-bud urge.

I'd strongly suggest that 1m DirecTV dish MexSunny posted a while back, if you could find one.!. - :up
Show us what ya got.
If you're thinking DirecWay dish like your avatar, that's okay, but you'll have to fab some mount to deal with the weight.


- just my opinion -

 

[brentb636]

"But please, don't get sidetracked with the mini-bud urge. "
I tend to disagree with this. It depends upon your orientation. Using my 1.2M offset dish as a mini-BUD , during baseball season, gets me a lot of HD sports that I can't get otherwise. For the Fall and Winter , though, the 1.2M will be Ku band mostly. It only takes a few minutes to switch from C-band to Ku band, so it's not a BIG BIG problem. Do not bother, though , trying to get a C/Ku combo lnbf working on a small dish. That's not what they're designed for.

 

[MikeinBaja]

Mike -
As long as you are going to spend the time and money on a motor, I'd put up the biggest dish I could reasonably swing.
Here above the border, 36" is great. Don't fiddle with smaller.
One meter (39") is better by a lot. A molded commercial (Primestar) 1m round would be the gold standard.
I hesitate to suggest 1.2 meters (48"), but that would certainly be the platinum standard if it were one of the commercial molded dishes.
...or probably metal, if it was originally used for two-way sat transmission (highly accurate dish).
But please, don't get sidetracked with the mini-bud urge.

I'd strongly suggest that 1m DirecTV dish MexSunny posted a while back, if you could find one.!. - :up
Show us what ya got.
If you're thinking DirecWay dish like your avatar, that's okay, but you'll have to fab some mount to deal with the weight.


- just my opinion -

Anole,

Actually, the dish in the avitar is down and on the "resource" pile (which is nearing a heap) behind the shed - along with 2 others just like it.

The old round metal SKY dishes that I can readily find down here really do outperform it by a wide margin, but I really like the avitar picture of my "back yard" so have not changed it.

I mainly used that dish as a learning platform to tinker with before I did the orphanages.

I MAY have a solid line on an old molded dish that just might be one of the old molded Primestars here in Baja. Need to stop back there again next week with a 6 pack of Tecate (and some home made tamales ) & try to close the deal (third stop). All I can see from the ground is white, molded and probably +/- 4'.

Dish I have my eye on hasn't been used in eons, is drooping on a weak deteriorating pole mount and is covered in dust. Have not gotten close enough for a good ID or for good pix for an ID, but I'm working on it. My gut tells me this might be a solid find, but we will see.

Don't be surprised to see one of the old "ID this dish" threads next week.

As always, thanks for the info & support.

 

[MikeinBaja]

"But please, don't get sidetracked with the mini-bud urge. "
I tend to disagree with this. It depends upon your orientation. Using my 1.2M offset dish as a mini-BUD , during baseball season, gets me a lot of HD sports that I can't get otherwise. For the Fall and Winter , though, the 1.2M will be Ku band mostly. It only takes a few minutes to switch from C-band to Ku band, so it's not a BIG BIG problem. Do not bother, though , trying to get a C/Ku combo lnbf working on a small dish. That's not what they're designed for.

Brent,

Thanks & I agree - however, I'm looking to marry this to a larger dish and if I do score the +/- 4' er I'm looking at I'll definitely try to take that baby KU & C. Very little normal heavy cloud cover here and unobstructed west coast view to the west coast sats shooting over the ocean for my LOS.

The way I figure it - if it won't work here - it won't work anywhere!

 

[Anole]

Mike -
I've actually found a lot of amazing info contained in pictures I took on the fly.
Being able to sit down and examine them in leisure, often exposes many secrets I overlooked by simply looking at the dish!

Have had guys detect little distant dishes in some of my pix, ones I never noticed, and then had a great conversation!
So, any shot, with a decent camera, even from far away, may give us enough to suggest a short list of possibilities.

If this 4' dish is white, and round, the first thing that comes to my mind is a Prodelin.... and that's a real dish! -
We find 'em on tire stores, gas stations, etc.
Yes, that would be killer! :up

Brent -
Disagreement is a good thing!
And I consider Mike a good buddy - so pulling his leg it top priority.
If he wanted to bolt a C2 to a DirecWay dish, I'd be first in line to help him.
Now, I might make jokes too, but I'd certainly provide all the data available.

As for your either/or mode of mounting just one LNBF at the proper focus, I like it.
That's the best possible way to optimize the dish on both bands.

 

[MikeinBaja]

Mike -
I've actually found a lot of amazing info contained in pictures I took on the fly.
Being able to sit down and examine them in leisure, often exposes many secrets I overlooked by simply looking at the dish!

Have had guys detect little distant dishes in some of my pix, ones I never noticed, and then had a great conversation!
So, any shot, with a decent camera, even from far away, may give us enough to suggest a short list of possibilities.

If this 4' dish is white, and round, the first thing that comes to my mind is a Prodelin.... and that's a real dish! -
We find 'em on tire stores, gas stations, etc.
Yes, that would be killer! :up

Brent -
Disagreement is a good thing!
And I consider Mike a good buddy - so pulling his leg it top priority.
If he wanted to bolt a C2 to a DirecWay dish, I'd be first in line to help him.
Now, I might make jokes too, but I'd certainly provide all the data available.

As for your either/or mode of mounting just one LNBF at the proper focus, I like it.
That's the best possible way to optimize the dish on both bands.

Ok, OK, OK - comitted to do brunch on Sunday at the Cantina guys place (remember him Anole?) - will charge the camera & do a special drive-by on the prospect dish (since it's nearby) and post - but don't expect miracles with the pics.

Prospect dish is currently mounted over a "tourista" junk stand/shop. Anybody want a velvet Elvis painting, plastic Jesus or a "lick it - suck it - slam it" tequila T-shirt while I'm there?