Upside down Dish!

[PSB]

Anyone tried this with a dish before? I was messing about this afternoon and setup this dish, upside down, the signal is great its just the same as if the dish were the right way up! I don't know how it will work in the winter if/when snow collects on it, but this method can also be used as an under the eaves (of the roof) mount, where the customer does not want any holes in the roof, I have done it one or twice before, and they must still be working as I am sure the customers would have told me : ) I have seen a lot of dish inverted this way on ships and in the middle east, I think the army also use this method to keep the dish as low to the ground as possible.

The elevation for this dish is set at 37 deg. for the DirecTV 101w bird. The signal is screaming in at a 93 on the DirecTV receiver, and when its really hot outside you can fry an egg on it....but that would be crazy.......wouldn't it?

 

[Cascade]

Slow week huh?

Nice paintjob on the plastics, is that Krylon/vinyl dye?

OT: I'm supposed to be driving up to Washington tomorrow to take my father in law out to dinner, think it's worth the risk with the projected path of Charley?

 

[Cascade]

That reminds me..
Pete, remember those mesh Sky dishes from back home? The ones that would rust through 2 days after a bird crapped on them.
I haven't seen any over here.

 

[PSB]

Just seeking to fully understand the workings and angles of an offset satellite dish, in an inverted position and trying to share the knowledge gained.....( yes very slow )

 

[PSB]

I was going to mention the mesh dish in another post, I wonder why they are not used here they really blend into the background, and they let some light through them so they are not such a blight on the skyline, I used a 1 meter mesh dish for years back in the UK! The wind passes right through! And just like your microwave oven door no microwaves pass through!!!!!

 

[Cascade]

You could make a killing importing those suckers over here, I bet there are thousands lying round doing nothing.

 

[PSB]

Black Fishnet satellite dish! They still look great!

 

[Mr Tony]

Very nice Pete!

Now you just need to incorporate that into a motorized unit

 

[sksatellite]

Actually I like those mesh dish. I got a diamond 24" mesh dish four years ago and love it, but sold to a customer who live at an apartment which can't put up bigger dish.
It performed like a 30" round metal dish.

 

[Tom Taylor]

There was a guy that came to the SBCA trade show a few years ago that had a DirecTV dish mounted in a moving cradle on the top of his Pickup truck. Also I have seen dealers use that method to mount a dish under a skylight. Skylights are tricky, some will allow signals to pass and some will block them. Yes it does work.

 

[PSB]

Yet another upside down dish this one I am using on a tripod base, pointing at the KU band satellites at the extreme ends of my viewable arc that my motorized dish cant reach.

 

[Cascade]

One thing puzzles me, why are those Globecast dishes so wide? I thought they only had 1 LNB.

 

[PSB]

I think they are really made for Horizontal polarization only, but work pretty good for FTA, they also came with the Dual LNB Ku/DBS. These white dish are DirecPC dish.

 

[WTguy]

Over at the dbsforums site, some members have posted pictures of their setups and (dont know if it is still there) some guys had inverted an 18" dish in order to bring in a very low horizon satellite. Most of the 18" dishes are about a 24 degree offset so if the satellite is really low on the horizon the mount does not allow you to lower the dish enough to get a signal so these guys inverted it. They were in Canada somewhere.

 

[CharlesO]

Back in '95 when AlphaStar was around, most of the dishes installed in Hawaii were done upside down, the EL for T5(95w) is 13 degrees.

 

[dvbclueless]

the idea of mounting the dish up side down was used years ago. Nothing new at all. It helps when one aims the dish at low elevation angle. It actually disadvatange when the elevation angle is not low. Why?
Let say the elevation angle of a sat is 40 deg. With a dish with 20 offset deg, the face angle is 20. If you mount the dish up-side-down, the face angle becomes : elevation of the sat + offset deg = 60degs. The dish at 60 degs elevation for sure will turn out to be a swiming pool when it rains hard. I don't see why one would need to mount the dish up side down unless he/she aims the dish a very low elevation sat.
DVBCLUELESS

 

[PSB]

I set these satellite dish up in an inverted fashion to promote discussion, this is after all a forum, installing a satellite dish upside down is an option and everyone realises when this application could be used (low elevation angles) We also fully realise that snow would have to be brushed off in winter, and that rain will collect on the reflector ( a small hole drilled in the dish will facilitate water drainage) you miss the point, they look great, weird but great!

 

[MMM]

I have posted thread in another forum. Some guys told me about this thread. Here is what I post previously.

I notice some satellite dishes in Honolulu area are upside down. My friend also told me that it can increase the look angle of the dish. Has anyone tried this before and what does it do.I could not get the stable signal for my dish. I got about 77% strength and 34-37% quality. I put it on the 15 ft. pole with fastened by slings to make it stable. However the look angle is quite vertical. (23.6 degree). The dish azimuth is 93.5 degree. There is some trees that may be in line about 1/2 miles away. I suspect that it may be the trees that can cause the unstable signal. But some say the signal strength from AMC4 (Texas) is not strong enough. Here is my dish info.
Satellite: AMC4
Dish diameter: 72 inches (parabola)
Receiver:Traxis DVS 2500
zipcode:: 96744
Look angle: 23.6 degree

Please help me find the new look angle for upside down dish. Thank you very much in advance

 

[bhenn]

upside down on a truck

I have a vsat dish that I’ll be using while driving from South America to the States. When stopped, we need to connect (not truly mobile). If anyone has ideas about how to do this, I’d love to hear them.

Here’s what I’m planning and I’m working on some assumptions based on what I’ve read (much of it here). Can you please confirm or debunk?

I’m assuming that mounting on the vehicle would be fine. There is some suspension play as passengers enter and exit but I’ve been on building tops and seen greater dish movement in high wind.

Because the bottom of the dish is so much lower than the mounting kit, I’d have to install a pole on the vehicle so it’ll be high enough. I then started to imagine it upside down and found this thread. The only draw back seems to be deposits (water and dirt) but as we’ll be setting up almost daily, this is not a worry for us.

Lastly, to calculate an upside down dish alignment I would double the offset (in this case 15.4ß – ‘ß’ I think is a typo for 8).

So, for this Andrew 960 dish, in Lima Peru, I’d be looking for 52 elevation normally. For upside down, I’d add 31 to get 83.

I’d imagine my polarization angle wouldn’t change (I wouldn’t reverse it, right?)

Any corrections or suggestions or alternative solutions would be welcome.

LØV€, ßRï@Ñ

 

[PSB]

Hello Brian, welcome to the forum : )

Sounds like one heck of a journey you have planned, you seem to have everything worked out and I am sure by the time you get here you will be an expert is finding satellites. I am worried about the passenger weight thing, just a few millimeters will be enough to lose your connection. I would try to come up with some sort of tripod mount or if you decide to mount on the truck be prepared to keep everyone out of the vehicle while on line. I used to install Internet satellite systems and they use much weaker satellites so they have to be aimed bang on!
Thanks for the feed back on the upside down dish, I hope the pictures have given you a few ideas, stay tuned as I am sure the other members will chip in with their suggestions, please keep in touch as we would really enjoy keeping in touch with you as you journey north, if you can find the time!

I would also be interested in what satellite you will be using and what service!