Ground Install Question

[pgcam]

I've had a 1metre dish & patio mount living in the shed for some time & the motorised 80cm dish mounted on the house is showing its age !
I can't put the 1metre dish on the currently installed motor because there wouldn't be enough clearance between the Lower corner of the LNB Support Arm & the roof, so before taking it down & utilising the motor on the 1metre/p mount combo I thought I'd test the 1 metre dish on the p mount as a fixed installation. Result (on a signal meter at the LNB)....zip...no signal...nothing. Everything is correctly lined up on Thor, correct elevation set on the dish & I sighted using a spirit level/inclinometer to ensure the line of site was clear (difficult to tell but looks ok ?).

My guess is that I don't have a clear line of sight despite the check, based on the height (of the house) being roughly equal to the garden length = roughly 45 degrees for clear sight or am I making a stupid assumption ? So are there any maths whizkids out there that want to work out if this is true ? Here are the numbers :

Distance of Dish Face from Back wall of House (Approx'): 22' 2"
Height of Gutter Line of House (Approx'): 15' 8"
Height of Loft Space (Approx'): 5' 3"
And a guess of the thickness of the Roof Beams/Slates of about : 6"

Cheers All
Peter.....

[BGonaSTICK]

OK, by my reckoning, we're going to need two other pieces of information.

1) Height of dish off the ground, and, more importantly...

2) Where you are, i.e. latitude and longitude (to the nearest whole number).

Hey, I'm up for the challenge, but I'm cheating by using the SMW link angle calculator here

Why don't you have a play with it too while I'm making an idiot of myself? :roflmao:

I take it your 80cm motorised dish is currently using a 36V jack if you're planning on stealing the motor for your polar mount on the patio stand?

Oh, and welcome to the forum m8

[pgcam]

Thanks for taking up the challenge

Lat = 52.18 N
Lon = 00.43 W

Patio Mount = 40"

Current 80cm is on a HH120 Mount so if I can get LOS will add about 6" to the height. I've already tried SMWlink with tells me I need about 30degrees but what I'm trying to figure is will this angle clear my house ?

Peter.....

[BGonaSTICK]

OK, so you're going to remove the polar mount from your patio stand when you fit the H-H motor.

Lets have a quick calculation then...

[BGonaSTICK]

Sorry, but I'm going to convert this to metric for ease of calculation.

Total height to the apex of your roof: 15' 8" + 6" + 5' 3" = 21' 5" = 6.53m

Height of dish: 40" + 6" = 3' 10" = 1.17m

Difference in height is therefore: 6.53m - 1.17m = 5.36m

Horizontal distance from dish to rear wall = 22' 2" = 6.76m.

Now, I don't know if you have a pitched roof or which way it's oriented, but let's assume the worst case, and that it's the gable end wall we're talking about. That means the apex of the roof is 6.76m horizontally from the dish.

So, if my schoolboy maths doesn't fail me, the Tan of the angle = opposite over adjacent which is 5.36m/6.76m = 0.793, which gives the angle at 38.41 degrees.

You're stuffed

Would you like me to work out how high you'd have to lift your dish to clear the roof?

If I'm going to do that, it would be easier with a photo, and/or a better description of your roof orientation, as well as the orientation of your house with respect to due south.

Hope this has helped (a little!)

STICK

[pgcam]

Thanks Stick, you've confirmed what I thought ! FYI the dish would be looking at the back of the house (IE. the ridge is running left to right when viewed from the dish), however I'm still stuffed ;-) I prefer not to make the mount any higher as I'm trying to keep the dish out of sight of the local vandals

If I get a chance I'll knock up a diagram on Visio or something...at the moment the Patio mount is in front of the Garden shed, I might be able to add an extra 5/6 foot to the distance from the back wall if I relocate the Mount to the opposite corner.....

Cheers,
Peter.....

[BGonaSTICK]

Bummer isn't it?

Without calculating it, if you could go back 5 feet and up two feet you're going to be close for 1W but by the time you get round to 13E you might be below the roofline again.