Elevation Angle - UpsideDown - Offset 1.2m Dish

[phlatwound]

Another option, and this has already been said in this thread in a roundabout way but...

If you are attempting to fix this dish on one satellite, and you don't have enough adjustment range in your mount to get to the required elevation (in a non-inverted orientation) you can lean your pole (or shim your mount) in whatever direction is required to get the elevation needed.

A plumb pole is only required for a motorized setup, so the dish will track the arc. A fixed (single satellite) installation has no such rules, just figure out how to point that dish at an object 22,000+ miles away however you can.

Lots of ways to skin this cat.

 

[Y-Naught]

Hi , Y-Naught . what ever you do , don't loose heart . Once you get thru all the "trial & error" , hit those 99w signals again and tune everything on your dish , to max those signal levels , then the fun should began . Until the conical scalar ring is position just right and the lnb skew is close , these small dish c-bands can give you fits . I use a small tv outside with a coolsat 5000 , using a cheap signal meter to figure out where 99w should be , go to manual scan or tp scan , set it to "tp 3845 H 15030" for the Puerto Rico mux & slowly move the dish until the green signal bars fly . For me , that scalar ring works best at the end of the lnb , about like your picture shows it , but the postion (up & down , back & forth) it's tighten to, on the lnb , often makes a big difference . Hope I didn't make it more confusing , (I live confused) , but I love playing with small dish c band , You're upside down 4 ft'r , looks like alot of fun .

Thanks, and ya - if it wasn't for that random-miraculous-luck that got that one set of channels from the ABC Puerto Rico transponder, I would've thought the LNB was defective. I really am doing this just as much out of necessity as hobby, and once done I will most certainly have it "set and forget" so to speak, and only adjust when the wind nocks it. Glad you think it's a fun one! LOL I think the most difficult part is the elevation angle upside down... Being a complete noobie at it and trying my first one upside down was probably a mistake though lol. I wish there was an alternative.

A c band, or a c/ku lnbf, is larger in diameter than 40mm so it will sit higher in the 'saddle' meant for a 40mm ku lnbf throat. This will make the elevation scale on the dish inaccurate. (I've never heard of a small offset dish designed for a C band feed horn. Only hobbyist 'improvised' ones ) A conical scalar does not correct this. It only focuses the feed horn on the dish. There's no need to invert the dish to aim at an elevation of 29°. Trying to set the elevation scale to 4.38 for a satellite at elevation of 29 is the wrong way. You don't tip it forward. You'd Tip it back from vertical. The elevation scale on the mount should be set to 29. And with the elevation scale now inaccurate because of the feed placement, think you'll have to raise it an additional 3 or 4 degrees. Maybe more. Can't 'see' the what, or 'picture it, that's hitting the other thing. Some pictures would probably explain more than a 1000 words can.

I have a newer version of THIS: http://www.digiwavetechnologies.com/images/pagemaster/DWD120T.jpg ... do you see the base support bars? Mine is slightly different but same concept. As for the angle thing, this is what I'm basing it on: http://www.satsig.net/22-deg-offset-dish.htm ... There it literally shows 22°... and in the example, it states that perfectly vertical means it's still a 22° angle because of the offset...Therefore in my case, 24.62° instead. So when my dish is vertical it has a 24.62° angle to it because of the offset... Therefor, to get 29° would I not take the offset and the difference of 4.38 to get to the 29°??? Oh and I know the actual scaler part doesn't accommodate for the difference in size, but the black bracket it came with (in a set together) I believed would... Maybe I assumed wrong lol.

Another option, and this has already been said in this thread in a roundabout way but... If you are attempting to fix this dish on one satellite, and you don't have enough adjustment range in your mount to get to the required elevation (in a non-inverted orientation) you can lean your pole (or shim your mount) in whatever direction is required to get the elevation needed. A plumb pole is only required for a motorized setup, so the dish will track the arc. A fixed (single satellite) installation has no such rules, just figure out how to point that dish at an object 22,000+ miles away however you can. Lots of ways to skin this cat.

I had thought about mounting the entire thing on a slightly angled block of wood at one point, but the upside down idea had me fascinated lol. Plus upside down keeps the snow/rain away from the lnb...

 

[FaT Air]

Therefor, to get 29° would I not take the offset and the difference of 4.38 to get to the 29°???

With the dish mounted 'normal' and the face perfectly vertical the dish is looking offset degrees above the horizon. So the top of the dish would have to tip back (dish face aimed higher in the sky) making it 'look' 4.38° higher.

the actual scaler part doesn't accommodate for the difference in size, but the black bracket it came with (in a set together) I believed would

I doubt it. Too many dishes with different characteristics to make it 'universal' and accommodate all the different offsets without introducing (elevation and focal point) errors.
2 cents-
K.I.S.S. Break it down and simplify - Get to 'know' the dish one step at a time. "Baby steps" if you will.
Being every small offset dish is intended for Ku. I'd put a Ku LNBF on it. Then find the satellite. Then experiment with the C/Ku LNBF, as there, you have taken one variable out of the equation. The azimuth. The only adjustment left is the new (modified) elevation. OK- there's one more, your focal distance. (moving the lnbf in/out from the dish) As that's going to be upset also. Then - place it inverted. Nothing left but adjusting the elevation.
I guess I say this, now, is everything is an unknown.

 

[Y-Naught]

With the dish mounted 'normal' and the face perfectly vertical the dish is looking offset degrees above the horizon. So the top of the dish would have to tip back (dish face aimed higher in the sky) making it 'look' 4.38° higher. I doubt it. Too many dishes with different characteristics to make it 'universal' and accommodate all the different offsets without introducing (elevation and focal point) errors.

Again... The only problem with that, is that I can't actually get it DOWN to 4.38° facing it the normal way, because of that support bar. At this point I'm almost thinking of just doing away with that dumb bar...Though my elevation angle and it's sturdyness in the wind would suffer.

2 cents- K.I.S.S. Break it down and simplify - Get to 'know' the dish one step at a time. "Baby steps" if you will. Being every small offset dish is intended for Ku. I'd put a Ku LNBF on it. Then find the satellite. Then experiment with the C/Ku LNBF, as there, you have taken one variable out of the equation. The azimuth. The only adjustment left is the new (modified) elevation. OK- there's one more, your focal distance. (moving the lnbf in/out from the dish) As that's going to be upset also. Then - place it inverted. Nothing left but adjusting the elevation. I guess I say this, now, is everything is an unknown.

Yes... I would love to do it right side up, and use a "proper" Ku-LNB... but it's not like I just have an extra one lying around lol .... I'd have to special order one to here just like the C/Ku LNB. And I have tested it both with solely Ku and solely C ... My LNB doesn't bring both in one connection... I've forgone the diseqc switch altogether to, as you say, "break it down and simplify"...So only Ku connected or only C band connected at any one time... (usually it requires 2 short cables to go to each of the coaxial connectors for each individual band)

 

[catamount]

I'll make it simple for you. Are you telling us that you can't mount the dish properly, and set the elevation scale on the side to 29 degrees. If so, someone must have cut the pole short.

Catamount

 

[Y-Naught]

It was supposed to be new, and looked it... I had no indication to believe otherwise... I can set it to 29 degrees on the side... but as far as I've been told, that bracket doesn't accommodate the offset...Therefor, offset plus the difference between it and the 29 degrees I need should give me the right angle...Maybe it was too short...but there's no way for me to get it higher.... Either way, whatever be, I keep changing the elevation and rotating it back and forth and get nothing...Haven't hit anything in many hours playing with it now....

 

[FaT Air]

Think you're trying to 'over think' it.

I can set it to 29 degrees on the side.

That's what you set it for, to aim at a satellite at that (29°) elevation.
The scale on the mount reads directly, the elevation it's aimed at, with the dish orientation as in the picture attached earlier. Upright, NOT inverted.
Although, with that LNBF on it, it will be somewhat inaccurate, so you may have to try acquire the satellite higher or lower. Maybe as much as 10°. Make adjustments in 1° steps and pan dish
(Forget about that 4.38 whatever)

 

[polgyver]

Is it possible to rotate the triangle base of your dish stand so the dish, when lowered to needed 29 degree, will "nest" in between supporting legs, instead of hitting one of them? Cheers, polgyver

 

[polgyver]

I had thought about mounting the entire thing on a slightly angled block of wood at one point, but the upside down idea had me fascinated lol. Plus upside down keeps the snow/rain away from the lnb...[/QUOTE]

Yes, keeps the snow away from LNB, but... enables the snow to accumulate on almost horizontal dish face

 

[FaT Air]

Hope the OP hasn't 'trashed' the project. Thought I'd post a couple of pictures. Think they explain the situation.

Also, when panning the dish looking for a signal, make very small adjustments, and wait. It may take some time for the receiver to lock onto the signal and display Quality. 5 - 10 seconds isn't unreasonable.

 

[catamount]

Awesome job, Fat Air. Those pics truly explain everything.

 

[phlatwound]

Awesome job, Fat Air. Those pics truly explain everything.

Ditto.

Very well done.