Please help with azimuth arc angle?

[kevink]

Hi,

Could you please help me on how to get the arc angle set (azimuth?) to track from ThaiCom 2/5 (78.5E) to JCSAT5A/ Vinasat 1 at (132E).

I currently have a 2.1 mesh with motorised arm set to pick up Thaicom 2/5, Asiasats 2/3, palapa C2, intelsate 8 etc on a C band but would like to work out the arc angle to just to pick up Thaicom and JCSAT5a/Vinasat 1 only. Am I correct in assuming that since I use thaicom as a base (point A) and to go from Thaicom to JCSAT 5A (point B), all I need to do in this case adjust the azimuth angle to that of JSAT 5A/Vinasat 1 and track from there?

here are the details:

I am in Melbourne:
Latitude : 37.45 degrees
Longtitude: 144.58 degrees

I use this site here to calculate:

Thaicom 2/5 is on :
78.5 E ==> satellite elevation 9.9 degrees a==>Azimuth 284.90 degrees

JCSAT 5A / Vinasat 1 is on :
132 E ==> satellite elevation 44.2 degrees a==>Azimuth 339.37 degrees

Thanks in advance
kevin

[beer4life]

Hi,

Could you please help me on how to get the arc angle set (azimuth?) to track from ThaiCom 2/5 (78.5E) to JCSAT5A/ Vinasat 1 at (132E).

I currently have a 2.1 mesh with motorised arm set to pick up Thaicom 2/5, Asiasats 2/3, palapa C2, intelsate 8 etc on a C band but would like to work out the arc angle to just to pick up Thaicom and JCSAT5a/Vinasat 1 only. Am I correct in assuming that since I use thaicom as a base (point A) and to go from Thaicom to JCSAT 5A (point B), all I need to do in this case adjust the azimuth angle to that of JSAT 5A/Vinasat 1 and track from there?

here are the details:

I am in Melbourne:
Latitude : 37.45 degrees.(This should be -37.45 for Southern Latitude.)
Longtitude: 144.58 degrees

I use this site here to calculate:

Thaicom 2/5 is on :
78.5 E ==> satellite elevation 9.9 degrees a==>Azimuth 284.90 degrees

JCSAT 5A / Vinasat 1 is on :
132 E ==> satellite elevation 44.2 degrees a==>Azimuth 339.37 degrees

Thanks in advance
kevin

G'Day Kevin,

I think you will have better luck with this dish pointing program:



There is more to it than changing Azimuth. Elevation and LNB Skew also change with Azimuth.
Thaicom2/5.......Elevation 9.8 Deg......Skew -49.8 Deg.
JCSAT 3.......................42.7...................-20.6 (Near enough for this illustration).

As you can see there is a considerable difference in elevation as well as Skew.
The reason for this is that the Clarke Belt describes a parabolic arc from H to H from the observer's location.

I trust that this will help you.
Kindest Regards, " The Druid ".

[cableguy49]

Kevink
Get hold of a copy of sat facts dated aug 15 1998 it has a great article on tracking the Clarke belt, and when its done properly you will get a lot more than 2 satellites.
regards
CG49

[rawill]

Cableguy49 is so right. I have never done C band, but assume the principle is the same as ku band with a moteck. Make sure your mount is "perfectly" plumb. Most issues concerning getting some sats and not others start here. Get everything else right and this wrong and not much works. My story is in the AS4 thread about 2-3 years ago. Read plenty, think about it lots, and fine tune. Oops, that is the As 4 thread on another site!

[kevink]

Hi all, thanks for the quick replies. Sorry I should clarify this a bit further. The 2.1 mesh is currently pointing to to Thaicom 2/5 with the arc already set to pick up asiasat 2/3, palapa c2, pas 8 and pas 2. This dish is actually setup for my mother who apparently watch just the Cambodian/Thai/and Vietnamese channels only and not interested in the other sats.

Just put put a selectv dish for myself the other day and through browsing have found out that on Vinasat 1 there are other vietnamese channels which the 2.1 dish can pick up (c band).

I would like to just pick up, in this instant, the Thaicom2/5 and Vinasat 1 only but unsure how to go about doing it. Since the old lady is not really watching any other channels on other sats, is there a way to perhaps adjust the arc so it will track Thaicom and Vinsat1 using the existing motor? The dish is pointing to Thaicom 2/5 atm, if I am to change the degree of arc so that it will gradually move from thaicom to vinasat, will that be the way to go? How do you work out the arc angle to the dish so that it will elevate at 44.2 degree when it reaches Vinasat 1 (132 E).

Thanks,
Kevin

[kevink]

Hi again,

Just been reading some more. The Vinasat 1 sat is quite new but the c band footprint is can be picked up using a 2.1 dish from melbourne.

Am i correct in assuming that since the existing arc is set up pick up thaicom 2/5, asiasat 2/3, palapa C2, PAS 8 and PAS 2 along the Clarke belt, that the new Vinasat 1 (which is between the palapa C2 and PAS 8) would therefore be on the same arc and it is just a matter of me entering the sat info/frequencies (vinasat 1) and track for the signal?

Thanks,
Kevin

[Godzilla]

Hi again,

Just been reading some more. The Vinasat 1 sat is quite new but the c band footprint is can be picked up using a 2.1 dish from melbourne.

Am i correct in assuming that since the existing arc is set up pick up thaicom 2/5, asiasat 2/3, palapa C2, PAS 8 and PAS 2 along the Clarke belt, that the new Vinasat 1 (which is between the palapa C2 and PAS 8) would therefore be on the same arc and it is just a matter of me entering the sat info/frequencies (vinasat 1) and track for the signal?

Thanks,
Kevin

Yes.
Your system is catching all the sats on the clark belt, vinsat should also be on the belt.

[kevink]

Hi Godzilla,

Thank you for the clarification. I will give it a try this weekend.

Thanks to all the others as well.

Cheers,
Kevin