24 inch actuator & 2,4mtr dish with V box

[satlearner]

Hi all,

I am currently installing a 2,4mtr dish with a 24 inch actuator and V-Box and based in South Africa. I have been reading many posts and have a few questions....any assistance would be welcome.

1) I need to setup an inclination of 36deg and a declination of 4deg.....lat is 26,2Deg.
My question is what do i set first....if I set the inclination to 36deg, then place the angle finder on the declination arm, reduce the angle to 32 deg.... wil this work or do I set the inclination to 40deg and then the declination reduced to 36deg?

2) LNB adjustment....now everything I read mentions not to stand in front of the dish when setting the LNB....okay, this is understandable, but seeing that I am only 1,6mtr tall and the dish diameter is 2,4mtr, how do i get this right.....I am using a C/Ku LNB and have inserted a perspex disc into the throat as well....it would be a nightmare to rotate the LNB, tighten the setscrew, move away and then check the signal status....can anyone help with this one. I have a Satlook Micro Meter available to set the LNB.

3) I envisage tracking from 78,5E to 22W.....which sat should i really be pionting at when making the initial settings to the dish.

Thanking you in advance
satlearner

 

[wium]

Settings to be set with dish true north.Zerorise LNB.Set EL at 36 and tilt adjuster down by 4.With V Box and actuator move dish west to sats at 1 or 5 degrees West.Assuming you have entered the frequencies which you can view in your area(consult Lyngsat).Be patient you will have to fine tune by adjusting your aforementioned settings.

 

[satlearner]

Hi Wium,

Thanks for the info....Will do the settings at True North. I have seen a little arrow on the LNB and would assume that this is the 'zero' position (pic attached). Hopefully if the weather is fine this evening I will be able to try again....still need to modify the upright as the dish is at 36deg elevation now and pointing at 68,5E but the bottom lip of the dish is about 10mm higher than the roof tiles, so I have made a spacer of 100mm which I will need to install first....not looking forward to it as I will have to take the dish off completeley in order to fit the spacer. Will also make another spacer of 50mm today just in case the other is too long as I want the fixture to be as strong as possible.

Another question...how would i know the 'zero' point of the tilt section ? ...I would imagine that i need to level the dish out using the angle gauge then check the tilt angle and zero that as well and only thereafter continue with inclination and tilt settings. Is this correct ?

 

[satlearner]

oops...forgot to attach the pic of the LNB....anyway, here it is including all the data.

Make: Space LNBF C08
C-Band & Ku Band

C- Band
I/P Freq : 3,4 - 4,2 GHz
O/P Freq : 950 - 1750 Mhz
LO Freq : 5,15 GHz
NF : 17K
Gain : 65dB

Ku Band
I/P Freq : 310,70 - 12,75 GHz
O/P Freq : 950 - 2150 Mhz
LO Freq : 9,75 / 10,70 GHz
NF : 0,3 dB (typ)
Gain : 55dB

 

[wium]

The arrow is most likely 0.Polar Mounts differ from one to another and the tilt adjuster could be on a seperate plate.Set that at 36 first and bring it down by 4.That could change when you do the fine tuning.Mate, a matter of caution ,you are working with a 2.4M dish and you must get someone to help you.You mention roof tiles, so you are quite high up.The answer may be to use some scaffolding.
Regarding,your dual LNB, i would mention that i have had no success using it and the ref to .3db (typ) for KU is just not on.Finally,for the Linear Sats E78.5,76.5,68.5 and 17 you can remove the teflon plate ,which will then improve your singal.Remember patience and good luck.

 

[satlearner]

Hi Wium,

Thank you for the info and the note of caution....it is pretty high up....and it's also a double storey houe...so there are risks, but i have installed it in a location that is easy to work on, ie. where the roof pitch comes down from two opposite sides and from a third side as well...it's like working in an inverted cone...lol. So, the weather has not been too great over the past few days...hopefully today will be better and if it is I will get down to setting the dish up....will advise progress as I go along....have a fab weekend.

 

[satlearner]

Well the weekend was quite a busy one...could not do much on Saturday.....'family time'....so was up early on Sunday and got to work. I removed the entire assembly as i noticed that the dish was too close to the roof tiles when the dish is at the extreme east/west. I added an extra 450mm to the upright and also included two baseplates for making adjustments to the upright so that it is 100% level. Managed to assemble everything by 5pm and started to set the angles....pointed the dish at True North and set the inclination at 36Deg with the declination 4Deg less, ie. 32 Deg....Moved the dish from left to right and found that this seemed to be okay....Mounted the actuator and started to move the dish to the west and then all the way back to the east....this is where i got all confused. Had a look at Dishpointer and selected my location and requested info on pointing at True North....according to Dishpointer, the following applies: Motor Latitude = 26,2Deg, Declination - 4,4Deg, Dish Elevation = 36Deg but the footnote mentions that an angle finder should not be used unless one knows the dish offset....how do I find the dish offset, is there a formula that I can use or does this not apply to my dish ? Could not do much more as the weather turned bad once again, so I will have to try again this evening if the weather permits. For now I will try and gather as much info as possible so that when I am up on the roof I can do as much as possible.

 

[wium]

Persevere Mate.Dont worry about Motor latitude and offset.You have got a prime focus dish.Make sure your antenna set up is correct in your receiver ie 5150.Input the 1 and 5 degee West frequencies from Lyngsat into your receiver.Adjust your elevation slightly up and down and move dish from east to west and back a couple of times.

 

[Huevos]

Mate, I don't know where you got this 36º figure from. If you are at 26.2º latitude your motor elevation is 63.2º (i.e. your polar axis is leaning backwards 63.2º away from vertical... or 26.8º up from horizontal). This figure is the same irrespective of whether the dish is PF or offset. To do it properly just offer up a digital level along the polar axis. It is very important to get this figure correct. Declination is 3.8º, but don't worry about that. Get your polar axis correct first and declination will automatically fall into place when you line up on your northernmost satellite.

 

[satlearner]

Thanks Wium / Huevos.

I was up on the roof again last night to check a few things, especially the stability and all looks great. Based on the info from Huevos, I am going to try that this evening if the weather permits. It does make sense as i have seen that if the dish inclination is at 36Deg, the angle looks too low when I move the dish to about 68,5E. I will also take some pics this evening to ensure that I am taking the angle readings on the correct spots....at least if I am not, this will be easily identified.

Will give more feedback tomorrow.

P.S. Another issue that is still not too clear...if I am standing at the back of the dish, Do i mount the actuator on the left or the right. At the moment it is mounted on the right hand side, ie. the rod extends outwards to move the dish from East to West. Can anyone confirm this for me please.

Thanks once again.
Satlearner

 

[wium]

Right hand side Mate.

 

[wium]

A quick check on Johannesburg gave the Lat as 26.24 for that you use 4.4 as the DA.Your polar mount setting will be 26.24 using a digital inclinometer.

 

[satlearner]

Hi Wium,

I am going to try this tonight if the wind calms down a bit...it's almost like we are in August again...lol...I will take some pics to show where I am taking the readings from with the angle finder in place. Hopefully I get this right and then go on to the rest of the setup processes. Will advise further.

 

[Huevos]

A quick check on Johannesburg gave the Lat as 26.24 for that you use 4.4 as the DA.Your polar mount setting will be 26.24 using a digital inclinometer.

This is incorrect information. For latitude 26.2º the polar axis needs to be 26.8º. If you get this wrong you will go off track at either end of the arc. For little dishes it doesn't matter so much but with a 2.4m dish you need to get this right as the beamwidth is so narrow.

About the actuator left or right side it doesn't really matter, but due to geometry whichever side you put the actuator the v-box will do more counts per degree on that side, i.e. you will have finer control over that side of the arc.

 

[satlearner]

Hi Huevos....i am trying to establish which is the correct values. Based on info from Dishpointer and selecting the 'superjack' option under motorised systems, Dishpointer gives the information as Motor Latitude = 26,2Deg, Declination - 4,4Deg, Dish Elevation = 36Deg....so something is definitely not correct. I will make a quick drawing of the mounting structure and then mark the areas where I place the angle finder...I will also give an indication of the angles at the specific points and then we can all decide which is the correct ones....could not take any pics last night due to the weather being on the negative side....one thing that was good was the wind....it gave me a fair idea of how solid the structure is, so all in all, it was not too bad that we had a change of weather. Well, this morning we have rain and it may continue throughout the day with hopes that it clears up by late afternoon...will see what happens.

 

[wium]

Mate ,i suggest you try for yourself.Polarmounts differ from one to another and once you have fine tuned your dish to your satisfaction you most likely will end up with different angles to what is mentioned in this forum.Bear in mind you could be out by .1 of a degree on your vertical pole setting.It is to your advantage to place your actuator on the right hand side and depending on the length of your actuator may it be 24,30 or 36 inches and the attachment thereof, in starting off, with the sateelites 78.2 ,76.2 and 68.5 where most of the channels can be found.Good luck.

 

[mashster]

Satlearner! Were you ever successful here! Would like to know! I have just received my V-Box and Actuator from a German Satshop and would love to try it here ...