17' BUD Ideas?

[phlatwound]

I may have the opportunity to be paid to take down and haul off the 17' behemoth in the pics below.

It is fiberglass, appears to have good parabolic shape and to be in fairly good condition. The tower/mount is az/el adjustable. No feed mounting arms, and no obvious places to attach any on the dish face, I'm wondering if it may have had some sort of buttonhook arrangement originally.

Was wondering how many degrees of arc this beast might "see" if deployed as a multi-feed fixed unit, and if standard-sized scalars could be placed for 2 degree spacings without cutting them up for clearance?

Any thoughts and/or ideas are most welcome (besides telling me that I am nuts for even considering putting this thing up in my yard....I will stipulate to that fact).

 

[coinmaster32]

I would say forget it, and here is why.

1. No polar mount, so your stuck one one sat at a time.
2. With that large of a reflector your going to have interference from adjacent sats.
3. Figuring out the F/D ratio is gonna be a pita.

 

[phlatwound]

I would say forget it, and here is why.

1. No polar mount, so your stuck one one sat at a time.
2. With that large of a reflector your going to have interference from adjacent sats.
3. Figuring out the F/D ratio is gonna be a pita.

1.) That is why I am inquiring about multi-feeds...i.e. multiple sats.
2.) Bigger reflector=less adjacent sat interference, not more.
3.) Simple math, just need diameter and depth.

 

[Beano_face]

sweet dish...
you should be able to hit a few sats at once with that thing... with multiple feeds...

too bad you couldnt find a polar mount... or make one...

 

[USDownlink]

Any thoughts and/or ideas are most welcome (besides telling me that I am nuts for even considering putting this thing up in my yard....I will stipulate to that fact).

Actually, I was going to tell you you are nuts for considering trying to dismantle and take it down. Putting it back up in your yard, well, I'm just jealous about that part.

17 feet?! Are you kidding? Any idea what it was originally used for? I can tell it is located in a very affluent and vibrant neighborhood.

I don't know how my understanding of a larger dish having a narrower look angle will affect adjacent offset reception. Looking forward to to hearing this conversation.

 

[phlatwound]

sweet dish...
you should be able to hit a few sats at once with that thing... with multiple feeds...

too bad you couldnt find a polar mount... or make one...

I don't think I have enough electrical service run to my house to run the motor for a polar mount of that magnitude.

 

[cracklincrotch]

I would say forget it, and here is why.

1. No polar mount, so your stuck one one sat at a time.
2. With that large of a reflector your going to have interference from adjacent sats.
3. Figuring out the F/D ratio is gonna be a pita.

I might agree with your first point. But a large dish will eliminate interference from adjacent satellites.

As for F/D ratio. A 17' dish is 204". The depth is probably 36" or so. Based on that, the F/d can be calculated. F = 204 x 204 / 16 * 36 = 72-1/4" to the focal point. F/d = 72.25" / 204 = .354. Easy.

From there, subtract the depth of the dish from the focal point to get a right triangle to calculate the length of the feed struts. One side of your right triangle is now 36.25" at the center of the dish. The bottom of your right triangle is the radius of the dish, 102". Then to get your approximate strut length, take the square root of 102 x 102 + 36.25 x 36.25 = 10404 + 1314.0625 = 11718.0625. The square root of that is 108.25". There's your approximate strut length. Probably need to take off a couple of inches from that to connect to the scalar ring.

My wife said no way to 17'. You have no competition from me.

 

[phlatwound]

Actually, I was going to tell you you are nuts for considering trying to dismantle and take it down. Putting it back up in your yard, well, I'm just jealous about that part.

17 feet?! Are you kidding? Any idea what it was originally used for? I can tell it is located in a very affluent and vibrant neighborhood.

I don't know how my understanding of a larger dish having a narrower look angle will affect adjacent offset reception. Looking forward to to hearing this conversation.

I was told that this is the last remaining dish from this small town's (original and long gone) cable company, the rest have been gone for over 10 years. It's actually in a thriving downtown of a very small town in the Ozarks, right on Main Street.

And that is a good point, my knowledge of offsetting feeds is nil, don't have a clue about adjacent rejection in that situation. But that center feed is going to reject about anything.

 

[turbosat]

You're going to need a very nice stepladder, LOL
Go for it, that thing would look awesome in the yard , with a little cleaning and maybe some new paint.

 

[Pixl]

How about moving it around with TWO actuators and two G-boxes. For set up you move one actuator manually for East/West then the other for elevation. With your G-boxes looped one behind the other on the same coax, one command from the receiver would save each position in the respective G-box.

 

[Anole]

you're nuts!

I'd find a radio or TV station stupid enough to give you $500 or $1000 to install it for them! - :up

As for a ladder, I'd think: bucket truck.
Adjusting the feed on that thing would be a nightmare.

Now, if you are serious about multiple feeds, go look up the thread Linuxman made for his 6' Prodelin.
He put a bunch of Ku LNBs on it, so all the math you'll need to know feed spacing is referenced there.

How many C-feeds can you get before signal fall off?
Dunno, but I'd guess quite a few.
Pick a place in the sky where there are a lot C-band birds you want! - :up
... and go nuts.!. -

edit:
Hey.!. - this looks like a dish over near Linuxman's place.
Are you guys conspiring? -

 

[Tron]

That thing probably weighs close to 1000 pounds, maybe more. Don't let it fall on you! You're not going to get it anywhere in one piece. It looks like it comes apart in sections, but the bolts are likely rusted. If you're willing to be patient and drill them out carefully, you might be able to take it apart piece by piece. Some things to consider:

- If married, make sure your prenuptial agreements are in order. Book a hotel for the week in advance in case there's violence. Be ready to leave town if things really get ugly.

- If you need more shade in the yard, this can be a good selling point to your spouse (if you can get close enough to argue your case without getting hurt).

- Get ready for the SETI/NASA/space alien jokes from the neighbors.

Heck, I'd go for it!

 

[Lak7]

I don't think I have enough electrical service run to my house to run the motor for a polar mount of that magnitude.

That's what tractors are for.

Are the cows sitting?

 

[Bill_KY]

To dismantle.
A heavy duty flat trailer, crane , cut off saw (s) for the bolts, drill, various power tools, gallon of WD40, rope and at least five people. No crane? Cut the pipe and let the dish fall backwards, it should not damage the dish. We did it that way when we moved a dish from Ohio to here in Kentucky and it did not damage anything.


Re-assemble
Consider getting quotes from your local Construction Rental Place for crane, earth mover, backhoe..etc. Quote for Cement truck will cost for a 1/2 load of cement. Crew of five to six people (if not more). LNB, arm, coax, new bolts, mount, heavy duty pipe. I suggest obtaining the original owners manual and assembly guide. Maybe try to contact someone who used to work for that cable company. They might be able to give some more information on the dish.


.

 

[whatchel1]

May be warped

I blew up the photos of the reflector. And it looks like it may be warped. First thing you need to do is see if it is or not. Put 4 strings across the the dish and see if the touch each other or are several inches apart. If the later than it is warped. If it is warped it may not be worth the effort of trying to re-use it.

 

[phlatwound]

You're going to need a very nice stepladder, LOL
Go for it, that thing would look awesome in the yard , with a little cleaning and maybe some new paint.

Lotssssssss of paint.

How about moving it around with TWO actuators and two G-boxes. For set up you move one actuator manually for East/West then the other for elevation. With your G-boxes looped one behind the other on the same coax, one command from the receiver would save each position in the respective G-box.

I guess with the proper gearing anything is possible, but I don't think a G-Box could produce enough current to move that much weight. The base of the tower is a circular ring, I think they just clamped it down to the concrete with brackets, it would need some rollers and a track to make it "easily" az-adjustable.

I'd find a radio or TV station stupid enough to give you $500 or $1000 to install it for them! -

As for a ladder, I'd think: bucket truck.
Adjusting the feed on that thing would be a nightmare.

Now, if you are serious about multiple feeds, go look up the thread Linuxman made for his 6' Prodelin.
He put a bunch of Ku LNBs on it, so all the math you'll need to know feed spacing is referenced there.

How many C-feeds can you get before signal fall off?
Dunno, but I'd guess quite a few.
Pick a place in the sky where there are a lot C-band birds you want! -

... and go nuts.!. -

edit:
Hey.!. - this looks like a dish over near Linuxman's place.
Are you guys conspiring? -

The Owner actually has a bucket truck that they said I could use to take that monster down. I will check out that multi-feed 6' Prodelin thread and see if I can make sense of it. I am thinking the way to do this is to fix the dish and have the feed support structure built independent of the dish.

No conspiracies here.....that you know of.

That thing probably weighs close to 1000 pounds, maybe more. Don't let it fall on you! You're not going to get it anywhere in one piece. It looks like it comes apart in sections, but the bolts are likely rusted. If you're willing to be patient and drill them out carefully, you might be able to take it apart piece by piece. Some things to consider:

- If married, make sure your prenuptial agreements are in order. Book a hotel for the week in advance in case there's violence. Be ready to leave town if things really get ugly.

- If you need more shade in the yard, this can be a good selling point to your spouse (if you can get close enough to argue your case without getting hurt).

- Get ready for the SETI/NASA/space alien jokes from the neighbors.

Heck, I'd go for it!

You are correct, the dish breaks into 8 sections, and I have electric and air impacts to twist the bolts loose.

All good points concerning the WAF but that is really not an issue in my case. You know the old saying..."Opposites attract"? Well that's a load of heifer hockey in our case.....she's CRAZY too!

Also, what's a "neighbor"?

That's what tractors are for.

Are the cows sitting?

That 75 horse New Holland of ours would probably gin up enough KWh to move that rascal, if not I will yoke up the oxen.

To dismantle.
A heavy duty flat trailer, crane , cut off saw (s) for the bolts, drill, various power tools, gallon of WD40, rope and at least five people. No crane? Cut the pipe and let the dish fall backwards, it should not damage the dish. We did it that way when we moved a dish from Ohio to here in Kentucky and it did not damage anything.


Re-assemble
Consider getting quotes from your local Construction Rental Place for crane, earth mover, backhoe..etc. Quote for Cement truck will cost for a 1/2 load of cement. Crew of five to six people (if not more). LNB, arm, coax, new bolts, mount, heavy duty pipe. I suggest obtaining the original owners manual and assembly guide. Maybe try to contact someone who used to work for that cable company. They might be able to give some more information on the dish.

It's not apparent from my pics but that dish is supported by a 4-sided pipe lattice tower, definitely don't want to cut and drop that one, it would destroy the dish. There is a support arm coming off the tower for each of the 8 dish sections.

Good idea about finding someone that may have worked for the old cableco, I know several indigenous characters from that area, probably get a good lead on that.

I blew up the photos of the reflector. And it looks like it may be warped. First thing you need to do is see if it is or not. Put 4 strings across the the dish and see if the touch each other or are several inches apart. If the later than it is warped. If it is warped it may not be worth the effort of trying to re-use it.

I have sighted across the dish from both sides and if it is warped it's not obvious, but I would definitely string test it before considering reusing it. The plan is to give them a price for removal that would make it worth my while, and if the dish can be reused that will just be gravy.

 

[Comptech]

You are correct, the dish breaks into 8 sections, and I have electric and air impacts to twist the bolts loose.

And don't forget, tightening them and breaking them of and replacing with new is alot easier.

 

[whatchel1]

Mark the sections

You are correct, the dish breaks into 8 sections, and I have electric and air impacts to twist the bolts loose.

And don't forget, tightening them and breaking them of and replacing with new is alot easier.

Before you take it down you need to mark each section. That way it can go back together the same way as it was taken apart. Some these type of dishes had the holes for combining the sections drilled at the site. So each section has to be match the sections that it mated before. I vaguely remember Comtech made(or had made for them) a dish that looked a lot like this about 15 or 20 yrs ago. If by chance it is one of those then it is really considered a 16ft dish. The measurement is from the inside edge of the aperture to inside edge.

 

[Lak7]

Are the cows sitting?

As in: Is it going to Rain?

That's what I learned this summer during a 12 car ride

 

[1captain]

if you can weld and work with steel, and have the tools and no how, you may want to think about making a polar mount for it Phlatwound. you just need to think about over building it when selecting you're steel, like in a heavy gauge 3/8" to 3/4" material.

as far as a actuator to move it, wile you're in the fab process just move you're actuator bolt locations out farther and that will give you a greater push factor with less resistance. I have built several polar mounts threw out my years from scratch, and it is not take a rocket scientist to do it, but you need to understand how it will track the ark, as far as a elevation and declination adjustments, and their locations. you can even limit the dishes travel from a low elevation positions, this will lessen the amp draw on you're mover source, like having it start at 25 to 30-degrees and work up from their.

if you go this route you should give me a call, and can give you a lot of pointers on how and the different ways that I have done it. last winter I built a polar mount for a 15-ft Andrews 16-panel aluminum dish, that came from a cable company, and I had several hours in it some where around 90 hours of total time, and its pivot points rode on 1 1/4" grade-8 bolts on bake-lite bushings threw double backed 3/4" steel, along with a 8" I.D. pole cap.