Lowest Feasible KU Elevation

Status
Please reply by conversation.

oblio

SatelliteGuys Family
Original poster
Oct 24, 2011
92
0
the cloud
I'm currently seeing 61.5w to 125w with my 90 cm fortec type dish/sg2100 with my due south 79w and strong inputs at both ends. Some recent 30w threads tweaked my interest in maybe scouting way more easterly on the arc. My question is what is the lowest practical elevation anyone has tried with a Ku dish. Some of the 0 to 15w birds are still above the horizon for me and show tp's pointed this way but to get them I will need as low as a 9 degree tilt. Is this even worth pursuing? Not sure I can even do this as my dish is not perfectly aligned to give me h to h (probably biased a bit west due to my roof alignment) so it may not track far enough east anyway and I may have some ground obstructions in the way but hey, its a hobby.

So worth trying or a waste of time?
 
30W, go for it! I'm at 114°W and can easily get 55.5W, but 30W is out of sight for me. Having a sat near the horizon to lock onto will enable you to make better adjustments on the dish :)
 
Nine degrees is quite high and you should have no problem receiving programming that has a footprint in your region. Personally, I have never been below 7 degrees, but that is just due to physical limitaions on a previous dish mount and now obstructions.

Winter should provide better atmospheric conditions with reduced terrestrial interference for working satellites near the horizon. Have remember reading of old C-band analog installations in Alaska and Northern Canada that were able to receive satellites that are technically below the horizon due to a bending effect as the signals pass through the atmospheric layers.
 
I'm in Michigan and have a fixed dish on 15w Telstar 12, 5 deg elevation for my area.
I've tried for 12.5w Atlantic Bird 1, 3.3 deg elevation for my area, no go. I have the line of sight clearance, but watching on a spectrum analyzer shows that terrestrial noise comes up quickly below 5deg elevation.
 
oblio, I live in Ohio, and my longitude is 81.6 west. I can get Telstar 12 at 15W just fine. For me, it's only 8.8 degrees above the horizon, and that's the farthest east I can get anything. I do have a clear view facing east though. When the dish is pointed at that satellite, it looks like it's pointed toward the ground because it's a 24 degree offset dish.
 
When the dish is pointed at that satellite, it looks like it's pointed toward the ground because it's a 24 degree offset dish.

Try inverting the dish to mount upside down (LNBF arm on top). The face of the dish would then be pointed upward at 33 degrees. This will help minimize undesirable ground noise.
 
One of my old receivers (microyal mrx1000) has a feature on the aiming screen that gives the dish azimuth and elevation settings once you enter in your longitude and latitude,then the sat you want to get.Anything below 18 degrees elevation and it will say below the horizon.Using that as a guide for the east and west I have a span of about plus and minus 50 degrees azimuth from my longitude,which works out since 125w is my west limit and 22w is my east limit.+-50 also matches the skew settings on my primestar lnb scale.
 
One of my old receivers (microyal mrx1000) has a feature on the aiming screen that gives the dish azimuth and elevation settings once you enter in your longitude and latitude,then the sat you want to get.Anything below 18 degrees elevation and it will say below the horizon.

That feature is called USALS (or incorrectly DiSEqC 1.3). USALS normally will provide a calculation to +/- 60 degrees calculated from your installation location's longitude. Calculations for dish angles outside of this window are not calculated and a similar warning is displayed by most STBs. Motors typically have the ability to move lower than this USALS imposed cutoff. Below this elevation, most hobbyist then switch over to the DiSEqC 1.2 motor control mode and manually bump the dish to lower elevations.

In my experience, the closer the satellite is to the horizon, the more likely that a fixed dish that is optimized for dish aiming and LNBF skew will be required.
 
I use diseqc1.2,the sensors on my motor (zero position and limit)are shot so I had to disconnect them.The atmel chip inside the motor is usually in a socket,since northern hemisphere and southern hemisphere chips are programmed differently.It might be possible to tweak the programming for usals,but I never gave it much thought.
For low elevations I use a fixed 1meter dish,which is bigger than my motorized dish.
 
I use to get 30W with a 8 1/2 elevation...but then trees got in the way
(dish on the right)
 

Attachments

  • 000_0136.jpg
    000_0136.jpg
    220 KB · Views: 138
  • 000_0152.jpg
    000_0152.jpg
    60.5 KB · Views: 156
  • 000_0153.jpg
    000_0153.jpg
    41 KB · Views: 152
I have no trouble with 6 deg elevation to get 30W. Had to do some looking before I decided on a place to set the dish though... away from ground clutter etc, and within reach of my feedline! I had to mount the dish and LNBF arm upside down in order to get the elevation low enough on a 33" digiwave. Looks really strange sitting in the middle of the lawn... -C.PICT0008 (Medium).JPGPICT0009 (Medium).JPG
 
Last edited:
Try inverting the dish to mount upside down (LNBF arm on top). The face of the dish would then be pointed upward at 33 degrees. This will help minimize undesirable ground noise.

I have a motorized setup, and right now I can get everything from 30W to 125W. About a month ago, I lowered the dish on the pole so that it wouldn't twist so much in the wind. And since then, I can't get 15W with my motor. The dish points so low that it brushes up with a leg of the tripod, and it can't move any lower. I don't think it's worth the bother to get it back again.

Does anyone know if there's even anything at 12.5W? Lyngsat maps shows a good coverage footprint where I live, but I've never been able to get anything.
 
I have 30W at 6° elevation. CM mounted sideways.
 

Attachments

  • GEDC0641_Crop_small.jpg
    GEDC0641_Crop_small.jpg
    66.1 KB · Views: 125
  • LNB.jpg
    LNB.jpg
    99.4 KB · Views: 168
Does anyone know if there's even anything at 12.5W? Lyngsat maps shows a good coverage footprint where I live, but I've never been able to get anything.
Telstar 12 (15W) is at my 20 degrees elevation. I receive it well. With my 1-metre Ku dish, I can't receive anything east of 15W on Ku, and east is my good direction so I can see almost down to the horizon. The North American footprint of 12.5W would be receivable here on my dish if there was anything being broadcast. Note the lyngsat updates for 12.5 to North America are old dated. I think 15W is as far east as you can go on Ku from this continent.
 
So worth trying or a waste of time?

mmmm... waste of time unless you get a bigger dish. I am at 119 and can receive Amazonas ku, but on a 4' dish. Those linear ku signals are not as strong as the circular signals of 61.5W. My lowest on my horizon is 55W, which comes in great on a 12' BUD.
 
I agree that 15w is probably the lowest satellite with a regular channel lineup for North America but I have on the rare occasion received stuff on 12.5w. I wouldn't spend the time to dedicate a dish just for that sat but It's fun to check once in a while. My SG2100 will go as low as 8 or 9w I think but I have never gotten anything on these sats, I probably wouldn't get anything on them anyway since I replaced my Universal lnb with a standard and of course they are not really beamed at us.
 
The last time I got anything on 12.5w was about a year or so ago, I haven't checked it for a while. What I remember getting was the AFN (Armed Forces Network) for a few hours one evening on my Fortec Mercury 2. I have never watched that channel before (I think it was on 22w for a while) and it was interesting how they played an hour or so of Good Morning America and then swap to something from The Pentagon Channel and then to some other programming, all the while showing the AFN logo in a corner of the screen. None of the stuff listed on Lyngsat looks familiar to me, but I am curious to know where the contributor for the listed North American transponders is located.
 
Nine degrees is quite high and you should have no problem receiving programming that has a footprint in your region. Personally, I have never been below 7 degrees, but that is just due to physical limitaions on a previous dish mount and now obstructions.

Winter should provide better atmospheric conditions with reduced terrestrial interference for working satellites near the horizon. Have remember reading of old C-band analog installations in Alaska and Northern Canada that were able to receive satellites that are technically below the horizon due to a bending effect as the signals pass through the atmospheric layers.
In those days we were able to do some "impossible" things. But analog is allot more robust than digital. I was getting the BBC news from a Russian sat. that was less than 4 ° above the horizon. Hope to be doing some DXing before to long w/ 1 m ku dish.
 
Status
Please reply by conversation.
***

Users Who Are Viewing This Thread (Total: 1, Members: 0, Guests: 1)

Who Read This Thread (Total Members: 1)