Fixed dish elevation

[nml]

I should know this but can anyone give me a bit of guidance?

I have bought a second hand 1.5 mtr dish to use in Southern Spain i am not sure if it has the elevation angles marked on the dish mount.
I am going over next week to fit it and i know the elevation required,if the dish mount has no markings how do i set it for the correct elevation?

I do have an inclometer.


Regards nml

[TheBadger]

You need a long straight edge to span the dish with and then you can measure the angle the face makes with the vertical. Subtracting this gives you the apex declination angle for a center focus. Don't forget to allow for offset declination and if the dish is an offset one rather than center focus don't forget to add the offset angle of the dish to the declination offset. Polar axis angle is set using the mount elevation. You can get this directly as long as the mount has a flat surface at right angles to the stub axle the dish goes on.

[nml]

Thanks Badger do dishes have a standard offset angle? if so could you tell me what it is.

nml

[TheBadger]

:confused: Well, I've got a Lenson 1m which has a 22·5° offset angle. I think it depends on the manufacturer but most are between 22° and 23°. Perhaps you can find the manufacturer of your dish and do a Google search.

[echelon]

my triax 1.1m dish has an offset of 26 degrees , but as badger says each manufacturer is different so there is no set standard but I would generally assume its somewhere between 22 and 26 degrees ( if the dish is offset in the first place , ie:- not prime focus )

[nml]

Thanks to you both just what i needed to know.I don't know who the manufacturer is with the dish being second hand but i bought it from Marbella in Spain and i think most dishes supplied in that area are Gibertini that have i believe an offset angle of 21.3.
I have a wolsey lacuna south beam meter so i think i will start off at 21 and work upwards.

Thanks again nml

[TheBadger]

:D Lots of fun ahead m8y - especially as you've got a meter to play with! What longitude will you be setting it up at as this will decide which bird you use for true south to get your initial angles sorted.

[nml]

Hi Badger 4.05 West.I have also just bought a 1.3 to play with i got the 1.5 because i want to use my 4 dreamboxes in Spain ,1.3 is normal for the area that i will be in.

Cheers mate nml

[TheBadger]

:D I'm green with envy! Use the bird at 5W as your true south and then fine tune using 42E and 30W. Let me know if you're not familiar with the procedure.

[nml]

Just got back from Spain everthing went well apart from i had to recalibrate the wolsey for South Beam after that it just took minutes to align the dishes.

nml:D

[nml]

the badger one final question about the lacuna.
I know about the north,south an steerable beams but on the meter i have south beam,High beam and low beam which is which for north and steerable and which one should i use to tweak channel 5?

[TheBadger]

:D Meters are not beam specific but measure signal strength and quality for a given polarisation - horizontal (H) or vertical (V). So to tweak for a particular beam you need to be able to select a transponder specific to a particular beam and then use the meter. However I don't think you can set a particular transponder with the Lacuna but I may be wrong. You can use your receiver though but it's slower and less accurate.

[nml]

Thanks Mate i just wondered why it had 3 different settings for 28 east and not for any others.
High beam vertical or horizontal.
Low beam V or H
and South beam V or H i know why the the South beam is there but why 2 of the others?

nml

[TheBadger]

:D It would seem that the Lacuna is specifically addressing the quirks of the 28E position re. ****. Each setting will be for a specific transponder on each beam.