Upside Down Dish Elevation Offset

[Derwin0]

Okay, I've decided to switch my CBSHD feed to the west coast (for timeshifting since I get East coast OTA).
So, I'm put up a dish for pointing to 148. Problem is, I need an elevation of 6 degrees. Line of sight isn't a problem from my roof, huge field in that direction. Problem is, Dish only goes down to about 13 degrees. So I decided to mount it upside down to get it to point lower.

My question is:
Has anyone done this before, and know what my offset to the elevation should be? aka, if I want 6 degrees, what should I put the elevation to?

 

[SatinKzo]

Would it be easier to mount the dish on a 7 degee slant and put the dish at 13 degrees?

I just had a big lunch and my thinking blood is not in my head, so this might be way off.

 

[Derwin0]

tried that, but it wont really work as the facia I'm mounting it on doesn't face the direction of 148 (270 azimuth). Unless I have the pole plumb, the elevation will change whenever I adjust the azimuth to get 270.

 

[SatinKzo]

here are two links that might help

http://www.satelliteguys.us/showthread.php?t=12719

http://www.satsig.net/22-deg-offset-dish.htm

Looks like in the first one PSB has done it successfully. The second link may help with the math.

Of course with the first link, I could pretend I am chaddux and complain that you didn't search! (Chaddux, when you read this, I am just joking with ya)

 

[Derwin0]

Thanks, I wound up having to do trial and error. It wound up being about a 5 degree offset (set the dish for 11 instead of 6). Managed a signal strength of 48. Will try to get it better later, but got a bit chilly and windy last night

yes, I did a search (both google and on satguys), but couldn't find anything useful. Couldn't get an "and" function to work well, seemed to default to an "or" which cluttered up the search. Made my first post after a couple hours of searching.

fyi, using a dish 500 and removing and reversing the skew plate allowed me to put it upside down with the mast still going upward as normal. Plus kept my elevation in the right direction, bigger numbers go up. Just had a add 5 (or so) to my elevation. Wound up getting 129 first and moved from there. Now to endure CSR-roulette to get my CBSHD-West

btw, just looked at the thread, it didn't give the offset I need, so my pitiful earlier search is Chaddox-proof