Tests of 120cm antennas

[Archived-1]

offset angle of CM120 is 22,6

Something ive never thought about, is the offset angle the same on the 1.8 please ?.

 

[RimaNTSS]

Offset angle of Channel Master 1.8m is 22,62* (according to manual), but if you make precise measurements of your dish you could calculate offset angle yourself. .

 

[RimaNTSS]

I have edited my post you have quoted, something happened with PC and it did not respond but then, suddenly lots of unnecessary text appeared. Sorry for that crap.

 

[Archived-1]

Ok thanks again, the 1.8 is easy to get to, these measurements are very precise 1950mm x 1800 x 173, the measurements are the working area.

 

[RimaNTSS]

1950mm x 1400 x 173,

Do not believe that! It can not be 1400mm

 

[Archived-1]

Do not believe that! It can not be 1400mm

I have edited my post you have quoted, something happened with PC and it did not respond but then, suddenly lots of unnecessary text appeared. Sorry for that crap.

 

[Archived-1]

Lol here you go pal 1950mm x 1800 x 173

 

[RimaNTSS]

How and where (on the dish) did you measure depth of the dish Martin?

 

[RimaNTSS]

Measuring of the depth should be done with the precision up to 0,1mm only then we get proper calculations of all dimensions and angles.

 

[Archived-1]

I put two straight edges one top to bottom one side two side and measured the depth in the centre, these measurements are exact ;)

 

[RimaNTSS]

Can measurement of depth be 172,2mm and not 173mm? Will explain later why I am asking that.

 

[Archived-1]

I only have a tape measure, I cant scrutinise it any further sorry, where talking the thickness of a hair/less here

 

[RimaNTSS]

OK, I see, than, please take it as granted that your dish has dimensions 1800 x 1950mm and depth 172,2mm.
There are couple of screenshots, your dish is there. I have translated some terms, others you will understand.
Program is made by one smart person, his nick is Странник, he does not mind to use his program but I should also mention course.

 

[skomedal]

172,2mm and not 173mm

_http://www.answers.com/Q/What_is_the_average_thickness_of_a_human_hair

actually 2.6 x of a male moustache hair

Splitting hairs springs to mind

Regards

 

[Archived-1]

Thank you for your time Rimants ,

Splitting hairs springs to mind

, I have lots of tools, but nothing to measure the size of a nats coc*

 

[RimaNTSS]

Martin! You mentioned before

the best place for the lnb is slightly lower than were the manufacturer puts it 4mm to be precise

so we are speaking about 4mm only. But, if you wish to calculate precise focal point antenna has, you should measure everything with maximum precision possible. For example, for your CM1.8m if you use depth measurement 173mm, than calculated focal point will be about 5mm away from real one. If we have technical possibilities to do precise measurements than we should not use this possibility.

 

[Archived-1]

Martin! You mentioned before
so we are speaking about 4mm only. But, if you wish to calculate precise focal point antenna has, you should measure everything with maximum precision possible. For example, for your CM1.8m if you use depth measurement 173mm, than calculated focal point will be about 5mm away from real one. If we have technical possibilities to do precise measurements than we should use this possibility.

To be honest Rimants all these measurements mean nothing to me, we are calculating something that's been calculated by professors of science etc with the best tools in the world, I am far from a scientist and I don't have precise tools for measurement's and would not dream of trying to prove them wrong.

There is play in CM 1.2 dish arms, when setting it up you could very easy set the dish arms two high, ie 4mm to high, advise, keep everything loose and tilt the side arms down and keep pressure down while tightening and your lnb will be were it should be