Elevation query

fogoflyer · #1 (**permalink**) 01-05-2007, 10:00 AM

Just set up my 31" FC80P Fortec Star 80cm Offset Dish with HH90 motor and a Sadoun Standard Linear Single Ku 0.4 dB LNBF. My location is 29N 81W. Most southerly Sat is Nimiq 2. The dish elevation angle from the tool at Sadoun is 41 but the sat elevation is 56. Is there a difference? I have set up several dishes over time using the old hunt & seek method and never had a problem but for some reason I just can't get a signal. Tried from elevations 35 to 56. And the pole is vertical

. Probably I have the LNB attached incorrectly. It is attached in a maner when looking at the dish diretly the cable is verticaly attached and the writing on the LNB is perfectly horizontal. I am replacing my old 18" dish. If I remove the LNB (old DirectTv)from that dish, will it work on this dish? Just to verify that I don't have a dead LNB. Any suggestions are welcomed.

wejones · #2 (**permalink**) 01-05-2007, 11:36 AM

Quote:

Originally Posted by fogoflyer

Just set up my 31" FC80P Fortec Star 80cm Offset Dish with HH90 motor and a Sadoun Standard Linear Single Ku 0.4 dB LNBF. My location is 29N 81W. Most southerly Sat is Nimiq 2. The dish elevation angle from the tool at Sadoun is 41 but the sat elevation is 56. Is there a difference? I have set up several dishes over time using the old hunt & seek method and never had a problem but for some reason I just can't get a signal. Tried from elevations 35 to 56. And the pole is vertical

. Probably I have the LNB attached incorrectly. It is attached in a maner when looking at the dish diretly the cable is verticaly attached and the writing on the LNB is perfectly horizontal. I am replacing my old 18" dish. If I remove the LNB (old DirectTv)from that dish, will it work on this dish? Just to verify that I don't have a dead LNB. Any suggestions are welcomed.

The elevation of the satellite is in fact 56. However with a motorized system you don't use the elevation of a satellite for anything.
The dish elevation is basically a way to obtain your declination. It is basically the offset angle of your motor shaft (45 deg in your case) minus your declination (either 4.2 or 4.8 in your case). So basically the 41 thing you are reading is 45-4 approximately.

You didn't mention motor elevation above. Actually what you have is a motor elevation, which should be approximately 60 degrees (ie 90 minus your latitude), and to see the satellite you have to look down from that by your 4 degree declination, ie 60-4 = 56, ie the actual elevation of the satellite.

Hope that explains it. And for once I didn't get off track into "modified declination".

rainman · #3 (**permalink**) 01-05-2007, 01:40 PM

also your true south sat is circular polarization and you have a linear lnbf may want to use another sat near by that does linear polarization like amc 5 at 79 degrees.

fogoflyer · #4 (**permalink**) 01-05-2007, 06:32 PM

Quote:

Originally Posted by rainman

also your true south sat is circular polarization and you have a linear lnbf may want to use another sat near by that does linear polarization like amc 5 at 79 degrees.

Oh oh. The Sats that I want are Circular. I guess my LNB is useless. Can I attach my old Directv LNB? The next Q is how would I go about placing it on the arm? Mechanically I can do it with my trusty hacksaw and a few bolts but will this alter the focal point in any way by increasing/decreasing the arm lenth?

wejones · #5 (**permalink**) 01-05-2007, 06:40 PM

Quote:

Originally Posted by fogoflyer

Oh oh. The Sats that I want are Circular. I guess my LNB is useless. Can I attach my old Directv LNB? The next Q is how would I go about placing it on the arm? Mechanically I can do it with my trusty hacksaw and a few bolts but will this alter the focal point in any way by increasing/decreasing the arm lenth?

When you say "the sats I want are Circular", are you talking about just for alignment or is that where you are expecting to view programming? If you're just worried about using Nimiq as your true south for alignment, you will be able to lock the 12224 transponder for alignment purposes. If you're talking about viewing the programming then ..................................

be236 · #6 (**permalink**) 01-05-2007, 07:11 PM

Heh... when I was new new to this FTA stuff, I wanted to see if my DTV LNB (circular) would work with my 80cm dish for fun and people said it would work (just to get a signal)...

Anyways, physically as you know the neck of the DTV LNB is too small and wont fit snug into the LNB holder of the 80cm dish. So, I didnt know how precise I needed to be, but I just put some "foam" material (use a rag or small cloth, something like that), so that I could put it into the neck and pad it with the foam to make it somewhat "snug." It turns out it didnt have to be precise, but "close" enough to aim the head of the LNB directly at the dish center and it worked. heheh.

Now, the reverse may be more difficult (to take the Fortec LNB) and attach it to a DTV dish and arm, since there's no "neck brace" to hold the LNB.. I guess you would have to tape it up somehow.heeheh.. I havent tried this yet....

rainman · #7 (**permalink**) 01-05-2007, 08:05 PM

Quote:

Originally Posted by fogoflyer

Oh oh. The Sats that I want are Circular. I guess my LNB is useless. Can I attach my old Directv LNB? The next Q is how would I go about placing it on the arm? Mechanically I can do it with my trusty hacksaw and a few bolts but will this alter the focal point in any way by increasing/decreasing the arm lenth?

what channels are you trying to get from these sats?

fogoflyer · #8 (**permalink**) 01-05-2007, 08:09 PM

Quote:

Originally Posted by be236

Heh... when I was new new to this FTA stuff, I wanted to see if my DTV LNB (circular) would work with my 80cm dish for fun and people said it would work (just to get a signal)...

Anyways, physically as you know the neck of the DTV LNB is too small and wont fit snug into the LNB holder of the 80cm dish. So, I didnt know how precise I needed to be, but I just put some "foam" material (use a rag or small cloth, something like that), so that I could put it into the neck and pad it with the foam to make it somewhat "snug." It turns out it didnt have to be precise, but "close" enough to aim the head of the LNB directly at the dish center and it worked. heheh.

Now, the reverse may be more difficult (to take the Fortec LNB) and attach it to a DTV dish and arm, since there's no "neck brace" to hold the LNB.. I guess you would have to tape it up somehow.heeheh.. I havent tried this yet....

Thanks for all the help guys. Going to give it a go and build up the DTV LNB neck. I got a few ideas on what to use. I just love a challenge. The last resort of course is to buy a circular LNB but us FTA guys don't do that do we

.

N4ST · #9 (**permalink**) 01-06-2007, 09:20 AM

I use a DSS LNB (actually the Invacom quad) with my 90cm FTA dish for superior rain fade reception of DTV. It's fixed on 101° for FTA reception of AMC4, so the DTV reception is a bonus.

rainman · #10 (**permalink**) 01-06-2007, 09:29 AM

Quote:

Originally Posted by N4ST

I use a DSS LNB (actually the Invacom quad) with my 90cm FTA dish for superior rain fade reception of DTV. It's fixed on 101° for FTA reception of AMC4, so the DTV reception is a bonus.

yeah the invacom is a nice LNBF got one on my 36" also and it does a real nice job.