All about Birdview and Dish Hunting

[voomvoom]

Well Fred, you've done it again. You're either mighty lucky or you're one heck of a good salesman? Maybe a good salesman with mighty good luck? Either way you've got something good going your way, wish some of it would rub off on me.

Al

 

[linuxman]

Hey Al,

I learned everything I know about "salesmanship" from you!!!

As far as luck is concerned, here is my philosophy about luck.

There is no such thing as luck. "There is either adequate or inadequate preparation!"

 

[linuxman]

I have some guys lined up and am going to pick up the Birdview tomorrow afternoon.

Going down this evening to spray the bolts with PB Penetration Blaster and let them soak overnight to make sure they come loose ok.

Talked to the owner this afternoon and he thinks he may have the owners manual for this dish. If I can get my hands on it and it has some meaningful instructions, I will scan it in and make it available. I don't have a scanner, but have plenty of clients who do.

The owner is a super nice guy, and is trying to help me all he can.

 

[linuxman]

Got everything home.

Have some pics of the inside of the gearbox and the mount. Got a couple of questions that maybe some of you can help me with.

Correct me if I am wrong, but the blue counter in the background looks like this one has not had the reed-sensor conversion kit installed.

Am I correct in my assumption?

The pipe attached is 6" steel pipe, but it is only 1/8" thick wall. The way they got around such a thin wall pipe is explained by the hube bolt in the top of the cap. We couldn't take it apart to move it because I didn't have a big enough wrench to fit the bolt, and not enough clearance for a crescent wrench to take it off. That bolt screws into a block of steel that fits into the pipe from the top and only goes in far enough for the outside bolts to screw into and hold it without crushing the pipe.

I talked it over with my welder, and told him about everyone's idea of filling the pipe with concrete to avoid crushing. His response was that the 1/8" steel wall was not substantial enough to weld the pieces for my mount to attach to.

What I find amazing is that with the right setup etc, a 1/8" thick wall on a 6" pipe has held this dish up for at least 15 years.

We are going to find a piece of at least schedule 40 with a 5.5" - 6" steel OD pipe to weld the brackets to for the mount to hold the dish.

Let me know if you have other suggestions, or the answer to my question above.

Here are the pics:

 

[linuxman]

It looks like the main gear has 50 teeth and the worm gear has 8 full-sized teeth.

Could one of you mathematical smart people tell me what the gear ratio is from that?

Most of the threads on the Birdview dish talk about, which do you think this is? 70:1 or 34:1?

Thanks,

Fred

 

[WyrTwister]

Got everything home.

Have some pics of the inside of the gearbox and the mount. Got a couple of questions that maybe some of you can help me with.

Correct me if I am wrong, but the blue counter in the background looks like this one has not had the reed-sensor conversion kit installed.

Am I correct in my assumption?

The pipe attached is 6" steel pipe, but it is only 1/8" thick wall. The way they got around such a thin wall pipe is explained by the hube bolt in the top of the cap. We couldn't take it apart to move it because I didn't have a big enough wrench to fit the bolt, and not enough clearance for a crescent wrench to take it off. That bolt screws into a block of steel that fits into the pipe from the top and only goes in far enough for the outside bolts to screw into and hold it without crushing the pipe.

I talked it over with my welder, and told him about everyone's idea of filling the pipe with concrete to avoid crushing. His response was that the 1/8" steel wall was not substantial enough to weld the pieces for my mount to attach to.

What I find amazing is that with the right setup etc, a 1/8" thick wall on a 6" pipe has held this dish up for at least 15 years.

We are going to find a piece of at least schedule 40 with a 5.5" - 6" steel OD pipe to weld the brackets to for the mount to hold the dish.

Let me know if you have other suggestions, or the answer to my question above.

Here are the pics:

Go down to Harbor Freight and buy a wrench or socket / ratchet to fit it .

Wyr

 

[linuxman]

Hey Wyr,

I have plans to get a socket to fit tomorrow and take the pole the rest of the way off.

 

[linuxman]

Here is a pic of the back of the wormgear.



Hooked up a 12V trickle charger to it, and the motor works. Doesn't make a sound.

One revolution of the worm-gear moves the main gear about 1/2 of a tooth.

Don't know if that means anything or can give more of a clue as to gear ratio?

Thanks!!

 

[linuxman]

Sorry about all the extra posts, but have another question.

The backing plate that holds the dish onto the mount is steel, and it is almost 48" across.

It is not the same shape as the mesh, but does it reflect any signal back into the feed horn?

Is that part of the reason the dish is supposed to get good Ku signal?

Or is it just that it keeps ground interference from coming back through the dish?

 

[caddata]

There is actually a double reduction involved with the Birdview HH drive. One between the ring and pinion gears and one within the gear motor.

As I recall, the drives were shipped with two different gear motors mine was 17:1 (overall ratio would have been 106:1) I believe the other gearmotor ratio was 20:1 Just make sure your motor and gears are lubed and the motor brushes are working freely.

To answer your new question, the perforated surface is what reflects the satellite signal. It's efficient because the holes are less than the diameter of a No.2 lead pencil and the paraboilc curve was manufactured to a very close tolerance.

Be very careful, during your moving and setup to not drop the dish. While it's made from thick aluminum material and the perimeter is rolled for strength, it's still susceptable to damage from dropping.

 

[caddata]

linuxman

As a side note, with the perforations being less than the diameter of a No.2 wood pencil, the Ku signal thinks the surface is a solid piece of sheetmetal. From an engineering standpoint, the perforated dish is excellent. As long as the perforations are correct for the intended signal, it performs as efficiently as a solid dish and there is much less wind loading. My system survived several close encounters of the "tornado kind". One of the storms picked up a trampoline, that was next to the dish, and flew it two houses down the street. Yet, during all the storms, the dish never lost signal (even during the storms) or required adjustment afterward.

 

[linuxman]

There is actually a double reduction involved with the Birdview HH drive. One between the ring and pinion gears and one within the gear motor.

As I recall, the drives were shipped with two different gear motors mine was 17:1 (overall ratio would have been 106:1) I believe the other gearmotor ratio was 20:1 Just make sure your motor and gears are lubed and the motor brushes are working freely.

Thanks for the explanation!!

I will clean the old grease out, and put new grease on the gears and make sure everything else is well lubed before putting into service.

To answer your new question, the perforated surface is what reflects the satellite signal. It's efficient because the holes are less than the diameter of a No.2 lead pencil and the paraboilc curve was manufactured to a very close tolerance.

Yes, I tried to put a #2 pencil through a hole, and it will not go into it.

I will be very careful about the handling of the dish. The guys who went with me today thought I was nuts because I was so picky about how the dish was handled , placed into the truck, and tied down.

I treat all my dishes like they were my baby's.

 

[linuxman]

As a side note, with the perforations being less than the diameter of a No.2 wood pencil, the Ku signal thinks the surface is a solid piece of sheetmetal. From an engineering standpoint, the perforated dish is excellent. As long as the perforations are correct for the intended signal, it performs as efficiently as a solid dish and there is much less wind loading.

So when we are talking perforated, that isn't the same as a mesh dish? The reason I ask is that so much has been written about how small the holes need to be if talking about a mesh dish.

My system survived several close encounters of the "tornado kind". One of the storms picked up a trampoline, that was next to the dish, and flew it two houses down the street. Yet, during all the storms, the dish never lost signal (even during the storms) or required adjustment afterward.

Wow! I don't even want to think about a tornado getting near my dishes.

Thanks again for the explanations!

Fred

 

[caddata]

Perforated dishes have either round or hexagonal holes punched into the sheetmetal and are then either spun, stamped, or hydroformed into the parabolic curve. While mesh dishes are made with expanded and flattened sheetmetal. The expanded metal process slits the sheetmetal which is then streached to form diamond shaped openings. The sheetmetal is then flattened and cut into pie shaped pieces. Then the pieces are rivited or screwed onto a metal tube frame. If the panels are not carefully formed onto the frame, some of the accuracy of the parabolic surface is lost.

It's impossible to form a perfect parabolic surface because of different manufacturing tolerances and processes. Spinning and hydroforming are the most accurate processes (formed over a machined metal die), but also expensive to produce. Birdview soild dishes were both hydro and spun formed, while the perforated dishes were hydroformed (formed over a metal die but using water pressure).

 

[linuxman]

Thanks caddata,

I appreciate the information, as I am sure that others here do too.

That explains a lot about the way the different dishes perform. A large majority of the posts here and elsewhere are more about how to set up the dish and get it working. I like the posts where the processes are explained in detail.

Once I understand the processes, I understand a little more about why the need to follow the setup instructions so closely.

Thanks again!!

 

[linuxman]

Just put the string test on the Birdview a few minutes ago, and now I have a question.

With one string at the 12/6 position and the other string at the 9/3 position, there is about a 3/8" gap between the stings. With one sting at 10:30/4:30 and the other at 1:30/7:30 position the strings meet fine. Tried it several different ways with changing which strings are over the other and no change.

I would assume this would indicate that the dish is warped slightly.

How badly will this affect the signal?

Edit: Got down on my hands and knees and eye-balled it. The dip is in the 9:00 position. With one end of the sting at 3:00, I can move the string from the 9:00 position to the 7:30 position and the 10:30 position and the strings meet up.

Thanks for your answers!

 

[caddata]

Sounds like the dish may have been dropped sometime in the past. Were the dip at a position nearer the 6:00 position, it could have been ran into by someone while it was mounted on the pole. If you had a concrete patio slab or driveway, you could lay the dish face down for a better idea on how bad it is warped.

It's hard to say how the warped reflector has affected the performance. I know that an undamaged Birdwiew dish 8.5 feet in diameter equals or exceeds other 10 foot dishes.

I'd go ahead and install it and see how it does. I know it'll work whether it's warped or not. After you get it optimized you'll know for sure. You could always swap the reflector out if you were able to find another. Believe me, the HH mount is worth the hard work. You could easily adapt another manufacturer's dish to the Birdview mount.

 

[gabshere]

if you lay it flat , a photo would be nice to see what you got...

 

[linuxman]

Thanks for your replies!

I have it on it's back right now and that may be affecting the way the dish lays somewhat. I picked it up at the 9:00 position and the strings met up, so it isn't too bad and it may straighten out when mounted back on the mount.

Here are some pics with it on the ground. Can't lay it flat on the face as the feedhorn arms are welded in place.

The last picture shows the slight dip better than I thought it would. It looks like it might just be on the surface.





after looking at the picture again, I went out and looked at that side again standing right over it. Hopefully the picture will show what I can see with my eye.

You will see a row of holes that right above them is kind of a sharper curve than the rest. I don't see anything buckled further down the inside of the dish. I think you are correct caddata. It may have been banged on that side, but the damage is limited to right on the edge.

Take a look:



Let me know what you think!

Fred

 

[caddata]

I believe I'd just install it and see what happens. My pole just tall enough that I always bumped my head as I drove under it on the riding mower if I didn't duck.

My Birdview had feed supports that screwed thru the reflector surface and secured with a nut on the back. The legs were "V" shaped like yours but the screwed fitting was moulded around the legs with epoxy.