Measuring Dish Size
- Thread starter Kraven
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...and if there is a rolled edge, it's more honest to measure inside the lip, before the roll.
After all, a rolled edge isn't exactly reflecting signal to your LNB.
After all, a rolled edge isn't exactly reflecting signal to your LNB.
Think of it like computer monitors,they sold you a 17" but you can only actually see 15".
My 17" LCD monitor measures 17" diagonally, 14.5" horizontally. So what do I call my dish that measures 40" x 44"? Answer: Too small!Think of it like computer monitors,they sold you a 17" but you can only actually see 15".
Answer: 1 meter
And to the offset LNBF, it looks to be the same height as width. (perfectly round)
Elliptical offset dishes need to have their (larger) width as well as their (smaller) height listed.
As long as they use a matching feedhorn that fully illuminates the dish, their beamwidth will be similar to a round dish of equal width.
For those who aren't just laughing, a "round" offset dish is measured by its width.
And to the offset LNBF, it looks to be the same height as width. (perfectly round)
Elliptical offset dishes need to have their (larger) width as well as their (smaller) height listed.
As long as they use a matching feedhorn that fully illuminates the dish, their beamwidth will be similar to a round dish of equal width.
Mine is eliptical, but the height is the larger dimension. Does that make it equivalent to a round dish equal to my height dimension? Although the LNB is a conventional universal type obtained separately and not designed specifically for use with this dish.
No, your dish is "round". . . When viewed by the LNBF.
Take out the LNBF and sight through the hole at the dish: Round!
And so a common round feedhorn matches the dish perfectly. :up
Yes the dish is physically taller, but when you view it from an angle, it looks round.
Take out the LNBF and sight through the hole at the dish: Round!
And so a common round feedhorn matches the dish perfectly. :up
Yes the dish is physically taller, but when you view it from an angle, it looks round.
I'll believe you. So why do they make it elliptical? Aesthetics? Wouldn't it be easier to make it round?
Benefits: Vertical elliptical shape attenuates ground noise, Horizontal axis attenuates adjacent satellite interference.
How high does your dish need to be?
Typical install where you do not need to clear obstructions... take the height of your dish, divide by 1/2 and add two or three feet (or average height of snow) to get the dish off of the ground.
Typical install where you do not need to clear obstructions... take the height of your dish, divide by 1/2 and add two or three feet (or average height of snow) to get the dish off of the ground.
AND, from the satellite. To 'understand this' take a 20 ft length of pipe. Cut one end off at a 20° angle. Look down the the pipe from the flush cut side. What do you 'see'?
Yep, it's only a circle.
BITD, we'd install 10ft BUDs on a 4ft pole. OK, that's on top of a 6 inch slab. So 4.5ft to the top of the pole. Still had about a foot between the BUD's lip and ground. I added a foot 'cause I know I get 'normally' 2ft where my BUD is.
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