Measuring Dish Size

[Kraven]

Are dishes measured by lenght or by diameter?

See attached.

 

[Anole]

B: straight across the open end.

 

[Kraven]

Hmmm... that means the WSI "special" 6 footer isnt really 6ft.

 

[Anole]

...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.

 

[Magic Static]

Hmmm... that means the WSI "special" 6 footer isnt really 6ft.

It should be a 1.8m dish or 5.9'

 

[waylew]

Hmmm... that means the WSI "special" 6 footer isnt really 6ft.

Think of it like computer monitors,they sold you a 17" but you can only actually see 15".

 

[FaT Air]

Think they refer to it as a "6ft" for simplicity. The U.S. cancelled it's 'conversion', or adoption of, the metric system back in the 80's, IIRR, something about it being 'too confusing"?

 

[Lak7]

And if you are explaining to your wife.....
A Dish is measured from the center to the edge.

 

[primestar31]

And if you are explaining to your wife.....
A Dish is measured from the center to the edge.

For some reason after reading this, I have this feeling of "deja vu"

 

[cyberham]

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!

 

[Anole]

Answer: 1 meter

... So what do I call my dish that measures 40" x 44"? Answer: Too small

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.

 

[cyberham]

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.

 

[Anole]

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.

 

[cyberham]

I'll believe you. So why do they make it elliptical? Aesthetics? Wouldn't it be easier to make it round?

 

[SatelliteAV]

Benefits: Vertical elliptical shape attenuates ground noise, Horizontal axis attenuates adjacent satellite interference.

 

[k9mar]

How high can the pole be on a 6 footer WSI dish?

 

[SatelliteAV]

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.

 

[waylew]

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!

Shoulda been more specific,old school bottles (that's a CRT ).

 

[FaT Air]

No, your dish is "round". . . When viewed by the LNBF

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.