Big dishes

[hb505]

I currently have 90cm technomate motorised dish with DM800SE. Im just curious to find out the pros and cons of larger dishes. Why do people opt for larger dishes? If some one could explain in a laymans terms id ever so be grateful


Sent from my iPhone using Tapatalk - now Free

 

[trevortron]

Quite simple: bigger dish = more gain = more likelihood of picking up weak transponders on satellites intended for other locations.
For instance- to receive all Sky's offerings on Astra 2 here in Portugal, we need a minimum 133cm, because Astra 2 is not meant to be received here. Hispasat on the other hand can be received on a 45cm dish here, as the signal is strong and there is no need for all the extra gain. Seemples

 

[hb505]

Makes sense. Thanks for that. Any one know what satelite stations here in the UK we will benefit from having large dish?


Sent from my iPhone using Tapatalk - now Free

 

[mdt]

i just need that lottery win lol,regards mdt

 

[wiz569]

Makes sense. Thanks for that. Any one know what satelite stations here in the UK we will benefit from having large dish?


Sent from my iPhone using Tapatalk - now Free

None m8 60cm will get you all you need, would also get you 19.2E and maybe 13E

 

[hb505]

I thought for 42 east and 7 eutelsat you need minimum 80cm?

 

[wiz569]

I thought for 42 east and 7 eutelsat you need minimum 80cm?

Nobody mentioned 42E or 7E??

 

[gibby999]

Further north here in Glasgow i have 110cm bit overkill but works well in all weathers

 

[simon123456]

I sugest u get a 1.2 m dish there plenty avable in the uk

 

[simon123456]

there of 2 sort of big dishs offset dishs or prime focus dish its up to u realy what u go for I like the prime focus my self onse u go for 1.2 u are beter off using the 36 volt motors

 

[digi247]

there of 2 sort of big dishs offset dishs or prime focus dish its up to u realy what u go for I like the prime focus my self onse u go for 1.2 u are beter off using the 36 volt motors

An Offset Dish performs better than a prime focus Dish of the same size, This should be taken into consideration when deciding between the two

 

[simon123456]

u don't no that ewar do u get that from then tell us all abaut it then lol

 

[Rumpelstiltskin.]

Post in English or get an adult to check your posts please.

 

[dantis]

Simple Simon says........

 

[cappuccino99]

u don't no that ewar do u get that from then tell us all abaut it then lol

google translated =

You don't know that, where do you get that from then? tell us all about it then, laugh out loud

A prime focus dish suffers from the lnb, feedhorn and feed support arms all being in the way of the signal reducing the signal area received, an offset dish puts them out of the beam usually below it but the offset dish does need to be a little taller so that in offset it sees & reflects a round beam equal to it's width.

Offset dishes below about 1.2m-1.3m surface reflector used for ku band beat prime focus dishes on size v signal & obviously much more so for the bigger C band lnbs & feedhorns, but above that the shadow from the feed & feed arms reduce as a percentage of the area of the dish & so the pfs match & then overtake as you go up in size. There's a noise versus elevation, ground noise difference too which the more sheltered pf's feeds gain a little over the more exposed offset's feed.

We've just got an old plastic 1.2m pf in - it'll be interesting to see if it can match or beat a Channel Master 1.2 right next to it, the feed arms are shot though on the old 1.2 pf so will need some spare time to remake them.

 

[simon123456]

let me no the results please

 

[Rumpelstiltskin.]

Nurse, he's out of bed again lol

 

[trevortron]

google translated =



A prime focus dish suffers from the lnb, feedhorn and feed support arms all being in the way of the signal reducing the signal area received, an offset dish puts them out of the beam usually below it but the offset dish does need to be a little taller so that in offset it sees & reflects a round beam equal to it's width.

Offset dishes below about 1.2m-1.3m surface reflector used for ku band beat prime focus dishes on size v signal & obviously much more so for the bigger C band lnbs & feedhorns, but above that the shadow from the feed & feed arms reduce as a percentage of the area of the dish & so the pfs match & then overtake as you go up in size. There's a noise versus elevation, ground noise difference too which the more sheltered pf's feeds gain a little over the more exposed offset's feed.

We've just got an old plastic 1.2m pf in - it'll be interesting to see if it can match or beat a Channel Master 1.2 right next to it, the feed arms are shot though on the old 1.2 pf so will need some spare time to remake them.

Very well put @cappuccino99-, but can Google translate it back into 'Simon-ese'?

That Channel Master will take some beating, is it the fibo one? Re. the feed arms for the p/f, I wonder if it would make any difference making them out of plastic? Apart from slight refraction, the radio waves might pass through, reducing signal block?

 

[cappuccino99]

That Channel Master will take some beating, is it the fibo one? Re. the feed arms for the p/f, I wonder if it would make any difference making them out of plastic? Apart from slight refraction, the radio waves might pass through, reducing signal block?

wish I had the time, if I get it done it'll just be boring old aluminium or steel & getting the focal length and f/d ratio right.

Don't know what make it is, could be 30 years old.

 

[trevortron]

:worthlessthread:

I'll post some pic's of an old motorised Gregorian 95cm I was given the other day. When I get a chance.... Any idea on the advantage of Gregorian?