With that piece of tubing I do think you will have any problems with what ever size slots you need to put in it.
Best Way to Receive Whole Ku Arc With Fixed Dishes?
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My big question is:
Considering the much thicker walled tubing, do I need to have 1 inch of solid between the slots?
We are talking the difference between 5 inch slots, or 5-1/2 inch slots except in the middle.
I know 1 inch of solid between the slots will be plenty stable, just wondering if I can get by with 1/2 inch of solid?
Take a look and let me know what you think please.
I still am of the opinion that you should do a handheld test for the various satellites and mark their rough position and then drill slots. I got to thinking about you not wanting to mount it and then drill. I would suggest using the template that you made (cardboard is it?) and make a wooden template, mount it and then do the handheld test and mark the location. Smaller slots, more solid area, would equal a stronger bracket. As well, without determining where each LNB will go, there is bound to be at least one satellite that the sweet spot is in the 1/2" or 1" solid area!
Thanks Keith and Gremlin!
I appreciate your conservative input, and I agree that no matter where the slots are, there will be at least one where there is no slot pre-drilled.
Let me think it over.
Time for a little theoretical discussion as to why we do what we do to use multiple lnbs on one dish and how to receive the reflected signal.
It is also for those just thinking about doing something like this on a smaller dish.
For one thing it is too cold to go outside here and do anything else and I am waiting on my tube to be bent. I can't even get the dog to go out and pee. She knows when she does, she is going to pee an instant icicle.
So I have made a couple of drawings. Didn't have sense enough to snap the exact pictures I needed for this demonstration with the support arm still on, so I improvised.
The most important thing to remember is that the dish is a concave shaped mirror for microwave signals. What you think might should be for getting western satellites would be to put the lnb on the left side of the dish. It just doesn't work that way. It is just the opposite. Western satellites are received on the right side of the dish, and eastern satellites are received on the left side of the dish.
Same thing with higher and lower signals.
In the pictures below I have tried to demonstrate this principle. I have used 91W which is my TS Satellite and 44.9 degrees elevation in the sky for me, and 79W which is 12 degrees off to the East for me and 43.3 degrees in elevation.
As you will see, the highest signal source is where your lowest lnb sets.
Don't ask me why. It just does. Anole and I have a huge "discussion" about this a while back, and he proved me wrong. Just remember with a concave mirror, when you pull the source down, the reflection comes up to match it. :yikes:
Those of you who have done this and have a better explanation, or can come up with better drawings, feel free to chime in. If you have theoretical or technical questions, someone will surely answer.
Here are the illustrations:
It is also for those just thinking about doing something like this on a smaller dish.
For one thing it is too cold to go outside here and do anything else and I am waiting on my tube to be bent. I can't even get the dog to go out and pee. She knows when she does, she is going to pee an instant icicle.
So I have made a couple of drawings. Didn't have sense enough to snap the exact pictures I needed for this demonstration with the support arm still on, so I improvised.
The most important thing to remember is that the dish is a concave shaped mirror for microwave signals. What you think might should be for getting western satellites would be to put the lnb on the left side of the dish. It just doesn't work that way. It is just the opposite. Western satellites are received on the right side of the dish, and eastern satellites are received on the left side of the dish.
Same thing with higher and lower signals.
In the pictures below I have tried to demonstrate this principle. I have used 91W which is my TS Satellite and 44.9 degrees elevation in the sky for me, and 79W which is 12 degrees off to the East for me and 43.3 degrees in elevation.
As you will see, the highest signal source is where your lowest lnb sets.
Don't ask me why. It just does. Anole and I have a huge "discussion" about this a while back, and he proved me wrong.
Just remember with a concave mirror, when you pull the source down, the reflection comes up to match it. :yikes:Those of you who have done this and have a better explanation, or can come up with better drawings, feel free to chime in. If you have theoretical or technical questions, someone will surely answer.
Here are the illustrations:
Just found out from the guy who was supposed to be able to bend the tube.
It seems that square tubing can't be bent without a square tube bending machine. It just crushes the tube without the proper side support. I was told by some of my contacts in the steel industry that it couldn't be done without the proper machine and no one has one. They all have pipe benders, and flat steel benders, but no square tube benders.
Their suggestion is to notch it on three sides, move it to the desired bend, and weld it back.
The original guy has a plasma cutter and a mig welder, and he agreed to let me use them to notch and weld, so I will do that Monday when it is back to 40 degrees outside.
It seems that square tubing can't be bent without a square tube bending machine. It just crushes the tube without the proper side support. I was told by some of my contacts in the steel industry that it couldn't be done without the proper machine and no one has one. They all have pipe benders, and flat steel benders, but no square tube benders.
Their suggestion is to notch it on three sides, move it to the desired bend, and weld it back.
The original guy has a plasma cutter and a mig welder, and he agreed to let me use them to notch and weld, so I will do that Monday when it is back to 40 degrees outside.
most here have to notch square tube also
you could probably achive your mount with a round 1 inch conduit ( at least they can bend that) and find your placement points.
i would suspect that your lnb mount with have a high end and low end and will almost give you a diagonal impression.
you could probably achive your mount with a round 1 inch conduit ( at least they can bend that) and find your placement points.
i would suspect that your lnb mount with have a high end and low end and will almost give you a diagonal impression.
I could do that, but what the heck. that piece of tubing only cost me $10.00 so if I ruin it, I can get another.
I believe Keith described it like the LNBFs will be a "big smile" with 91W in the lowest part of the smile.
I think it might, but you would need to weld a plate on one end, fill with sand, then weld another plate on the filling end, and even then it might be enough to hold back the pressure.
It is probably just as easy to notch and weld it back.
support arm woes
okay, i follow linuxman actively, as you all know. i have the same dish, but i have different plans. i want a c at 107.3, and several ku lnbs added. the support arm is the area of gripe. with a three way bar support like the prodelin 89 i should have the support now that the c band horn and lnb doesn't weigh thirty five pounds.
inspired by linuxman's effort in making the notched bar, what about creating a mod that is a support and lnb bar all in one. something that is lightweight yet strong, with a lightweight cband lnb like a BSC621 and a bunch of GEOSATpro SL2 Bullet LNBF. Think along the lines of the avatar of gremlin411.
Board members seem to not like the BSC621, but it is lightweight, which would be nice.
the tripod support idea seems promising, and works for my testing ku on the 89, but sadly the orbital slots adjacent to the focal point are obstructed by you guessed it...the support bar! AAAHHHH! any ideas on creating an invisible bar that is supportive but not obstructive? all ideas as always are greatly appreciated!
okay, i follow linuxman actively, as you all know. i have the same dish, but i have different plans. i want a c at 107.3, and several ku lnbs added. the support arm is the area of gripe. with a three way bar support like the prodelin 89 i should have the support now that the c band horn and lnb doesn't weigh thirty five pounds.
inspired by linuxman's effort in making the notched bar, what about creating a mod that is a support and lnb bar all in one. something that is lightweight yet strong, with a lightweight cband lnb like a BSC621 and a bunch of GEOSATpro SL2 Bullet LNBF. Think along the lines of the avatar of gremlin411.
Board members seem to not like the BSC621, but it is lightweight, which would be nice.
the tripod support idea seems promising, and works for my testing ku on the 89, but sadly the orbital slots adjacent to the focal point are obstructed by you guessed it...the support bar! AAAHHHH! any ideas on creating an invisible bar that is supportive but not obstructive? all ideas as always are greatly appreciated!
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In answer to your last question, I wish I could help you with some ideas. The dishes are just designed differently.
That's part of the reason I waited so long for "this" dish is because of the single heavy duty support arm.
I am surprised that others haven't responded with some ideas, but as I say, I just don't have any to offer.
Perhaps if you started a new thread with what you are trying to do, you might get more help with your project.
different goals
English -
Start a new thread.
Post a picture of the dish.
And we'll get off to the races.
I have some ideas for you, but since your goal is very different, would not post them in this thread.
English -
Start a new thread.
Post a picture of the dish.
And we'll get off to the races.
I have some ideas for you, but since your goal is very different, would not post them in this thread.
English thanks for that ? I have the same problem. The 1.2 meter prodelin in my avatar I would like to see a mod it also. I had no forsight when I got it and the 1.8 meter prodelin just like it on the ground at my house. Both are recieve only. Make a new post and I will follow it close. if you like I have some pic's of my 1.8 meter I post in that thread unless you have some already.
Sorry for the hijack of this thread.
Sorry for the hijack of this thread.
Well I got a couple of things accomplished today.
I now have the new heavier bar drilled and supported with 5/16" bolts which are 5" long.
By doing that, hopefully there will be a little more support in the center, and the 5" bolts allowed me to bring the LNBF down to the rod by about an inch. Since the center LNBF is the lowest in this project, no since in having it higher than necessary.
According to Anole's math, I have a 2.9" center distance between the 91W LNBF and the 89W, and also the 93W. The big problem I can foresee is the support bolt closest to the 91W LNBF will be right in the middle of the main support bolt.
That is going to require me to get a little more creative in how I hang those next 2 LNBFs.
I want to place them for signal before I go to all that trouble which has led me to re-think the bends.
I am now thinking I won't make any bends until later and only if needed. I will proceed with cutting some slots tomorrow. The thing is like a tank and since any bends made will not be made with a machine, but by notching and welding back, slots in it won't hurt a thing as long as placed properly and a good amount of solid metal in between.
Here's a pic of the progress.
I now have the new heavier bar drilled and supported with 5/16" bolts which are 5" long.
By doing that, hopefully there will be a little more support in the center, and the 5" bolts allowed me to bring the LNBF down to the rod by about an inch. Since the center LNBF is the lowest in this project, no since in having it higher than necessary.
According to Anole's math, I have a 2.9" center distance between the 91W LNBF and the 89W, and also the 93W. The big problem I can foresee is the support bolt closest to the 91W LNBF will be right in the middle of the main support bolt.
That is going to require me to get a little more creative in how I hang those next 2 LNBFs.
I want to place them for signal before I go to all that trouble which has led me to re-think the bends.
I am now thinking I won't make any bends until later and only if needed. I will proceed with cutting some slots tomorrow. The thing is like a tank and since any bends made will not be made with a machine, but by notching and welding back, slots in it won't hurt a thing as long as placed properly and a good amount of solid metal in between.
Here's a pic of the progress.
The LNBF rail constructed of square tube and slots may prevent optimized LNBF placement. Have you considered using a pipe instead? Fabricate a clamped sleeve to slide on the LNBF rail with treaded riser to support the LNBF clamp. The sleeve could be clamped into position with a single bolt tensioning the oversized sleeve against the LNBF Rail.
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Hi Brian,
I haven't considered thick wall pipe simply because I have tried conduit on small dishes before, and I found conduit to be unsatisfactory. Others may have used it with great success.
I already have the square tube and if I don't get the optimal signals I want using it, I might consider giving thick wall pipe a try.
One thing that would definitely be in favor of the pipe is that you can get it bent most anywhere.
Thanks for the idea, it is one I hadn't thought of.
This sure sounds like a good project this coming spring. Perhaps I can finally get those 15 to 20 dishes out of the garage.
This sure sounds like a good project this coming spring. Perhaps I can finally get those 15 to 20 dishes out of the garage.
It is a great project Popcorn. I hope you enjoy yours as much as I am enjoying this one.
Long story, but finally got the tube back this morning. I only had the slots cut, and partial bends performed. It's not perfect, but is a good beginning. You can see the heat bowed it some.
I worked a while this morning cleaning up the slots with a grinder to make sure the bolts would pass through and slide back and forth easily.
Got the support arm and tube put back on the dish with 3 lnbfs. I put everything back just like it was when I took it off, and now the focal length is 50 inches when before I measured on the monster LNBF 52 inches. The book said 48, and I measured 52 before, so I don't know which is correct.
I got outstanding signal on 91W with 12060V at a solid 99% SQ and nothing else lower than 90% SQ.
Flipped to the 89W LNBF and never got a signal. I have never used this particular LNBF, so I don't even know if it is working or not. Look at the picture of the three setting side by side and see if you notice anything. Someone may have gotten the can put on the horn incorrectly and have polarity out which might account for no signal. I'll swap it with the 93W position tomorrow and see if it does anything.
Jumped to the 93W LNBF, and got it without any problems. The signal was lower than I had anticipated it being so close to center. 75% SQ on Macy's. I will need to adjust a little.
If the focal length truly is 52 inches, that might account for signal degradation on 93W. Fifty inches of length would put the LNBFs too far apart whereas 52 inches focal length would put them in the right place where they are now.
If the best signal on 91W turns out to be 48 Inches, I won't be able to use the Pstar LNBFs at all. Will be too big I think.
Lots of playing and adjusting to do. I feel it is imperative that I get these 3 lnbfs with maximum signal if I hope to get anything worthwhile 12 degrees off-center.
This was my first attempt, I might not even have 91W bored in correctly.
Here are the pics so far:
Let me know what you think, and what I should adjust first?
few observations
The 89° LNB looks like it's off by maybe 45° or so.
It's certainly not out by 180°, which would be fine.
Are they all from the same era?
Do the outputs on each have the H and V marks?
Cant tell how close the LNB -horns- are, since there's no picture from directly in front of them.
Think you might have room in that 48/52" to squeeze the camera in?
That's sure a request that couldn't be met on many little Ku dishes! - :up
Don't give up on the Primestar LNBs.
I finally have one, so guess I can measure the horn width.
Assuming the horns on other LNBs like the JSC322 (or certainly the MINI dual) are smaller, you could use one of THOSE as the 91° LNB.
Then put a Primestar to each side at 89° and 93°
Next, two more small LNBs, and perhaps then another pair of Primestars.
edit: nail down that focal length question.
Then, we can recalculate spacing and height, if necessary.
Sure, getting the three central LNBs fired up is great, but then maybe a couple more out across the arm would be good to test to see about signal drop off.
Once a range is confirmed, we can fill in the intermediate LNBs.
The 89° LNB looks like it's off by maybe 45° or so.
It's certainly not out by 180°, which would be fine.
Are they all from the same era?
Do the outputs on each have the H and V marks?
Cant tell how close the LNB -horns- are, since there's no picture from directly in front of them.
Think you might have room in that 48/52" to squeeze the camera in?
That's sure a request that couldn't be met on many little Ku dishes! - :up
Don't give up on the Primestar LNBs.
I finally have one, so guess I can measure the horn width.
Assuming the horns on other LNBs like the JSC322 (or certainly the MINI dual) are smaller, you could use one of THOSE as the 91° LNB.
Then put a Primestar to each side at 89° and 93°
Next, two more small LNBs, and perhaps then another pair of Primestars.
edit: nail down that focal length question.
Then, we can recalculate spacing and height, if necessary.
Sure, getting the three central LNBs fired up is great, but then maybe a couple more out across the arm would be good to test to see about signal drop off.
Once a range is confirmed, we can fill in the intermediate LNBs.
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