Anyone tried to make BIG dish at home?

[BombedOne]

People and especially military, are doing this for a long long time, but for much much lower frequencies, where less mechanical precision is needed. And it's called "phased antenna array".

_ttp://i2.guns.ru/forums/icons/forum_pictures/000449/449759.jpg

Such unit, decomissioned, now is being used for aerial TV reception. Allows absolute stunning TV reception results. (like getting stable signals from opposite coast of black sea)

[weedsy]

Could a pseudo dish be created by using a square mirror bent to a 2D parabola (using the sun to get the 'bend' right) and held in place. This could be focussed onto a second 2D parabola perpendicular to the first. In other words we focus the signal in two stages, first horizontally, then vertically. I can certainly focus the sun onto a very small spot using this technique and use it to heat water, so why shouldn't it work for satellite signals. There's probably a good reason why this won't work, so please let me know.

[weedsy]

Could a pseudo dish be created by using a square mirror bent to a 2D parabola (using the sun to get the 'bend' right) and held in place. This could be focussed onto a second 2D parabola perpendicular to the first. In other words we focus the signal in two stages, first horizontally, then vertically. I can certainly focus the sun onto a very small spot using this technique and use it to heat water, so why shouldn't it work for satellite signals. There's probably a good reason why this won't work, so please let me know.

[BombedOne]

think about polarisation.

[deepbluesky]

Allows absolute stunning TV reception results. (like getting stable signals from opposite coast of black sea)

Pardon me ? You mean regular (no Tropo or Es) reception of Odessa, Constanta, Varna, Burgas from the heart of Georgia ? We do speak of VHF and not of UHF don't we ?

[BombedOne]

Not exactly.

This is an old story, from 60's of past century. There was an decomissioned military radist, living in city of Zugdidi (Relatively close to black sea, 42°30'34.82"N, 41°51'45.57"E). TV was not so common in these times, but he was really enthusiastic. He erected 20 meter high tower (tower components still remain now, just antennas are broken off), and fitted antenna aray on it. There's not much information available exactly what was he receiving, but as still alive neighbours say, they were watching bulgarian and poland tv at evenings. Only one "legal" information I've tracked down about him was a small notice in soviet amateur radio journal - regarding his death. Article was like "the enthusiast tv dxer, who managed to receive tv signals from opposite coast of black sea, died at age of 67".

Also to be noted, when living in Sukhumi, during late 80s, I was able to receive Istambul local tv broadcasts almost regularily. But soviet propaganda was sending false signal on that frequency. I quickly learned, that during daytime, they have 1 hour break, and turn transmitter off, so I can watch that channel. I have recorded it to VHS, so I can check my archives and try to digitalize that video (This was NOT sporadic reception, signal was always stable).

[deepbluesky]

Very interesting post BombedOne

[Low Profile]

One other factor to take into consideration is the frequency range. If you're contemplating phasing IF (950MHz to 2150MHz) then it soon becomes apparent that you cant use the same techniques as narrow band transformation.
On the plus side is technology. With the advent of DSP it should be easier to phase signals than through 'traditional' methods.

[Pawel Pietrolay]

Hello

I live in Right corner of the map, It's my nice Poland country.
I woud like to view transmissions from ASTRA 2D (freesat UK), there is a vide range of English language programs (160canals) ,

I need theoritically A dish with diameter 200cm, a price of a such sat dish in Poland is aprox. 800 dollar

_http://img32.imageshack.us/i/mapaastra2dodnowiona2.jpg

So I should do it myself. I have to gain a knowleage of the shapes and dimensions of the parabola,I'll learn from U my friends.

I'm soo sorry for my english' I have been still learning English, so I need English television. My Age is 22years old. The biggest mystery is a shape of parabola and proper materials. Whats is the best material for wave exposed surface.

Greetings from Poland

Pawel

[Pawel Pietrolay]

I heard that current signal receivers "converters" can't gain signal from entire surface of dish so the signal level for 200cm dish is the same for 90-120cm dish. So what i have to use instead standard receivers. Useful surface for huge disher during using standard converter is 30-40%

[Satcom1]

Hello

I live in Right corner of the map, It's my nice Poland country.
I woud like to view transmissions from ASTRA 2D (freesat UK), there is a vide range of English language programs (160canals) ,

I need theoritically A dish with diameter 200cm, a price of a such sat dish in Poland is aprox. 800 dollar

_http://img32.imageshack.us/i/mapaastra2dodnowiona2.jpg

So I should do it myself. I have to gain a knowleage of the shapes and dimensions of the parabola,I'll learn from U my friends.

I'm soo sorry for my english' I have been still learning English, so I need English television. My Age is 22years old. The biggest mystery is a shape of parabola and proper materials. Whats is the best material for wave exposed surface.

Greetings from Poland

Pawel

Parabola 1.1 is a nice program to use to design your dish. Please Google and download.

Your English is good

Your comments about only achieving effective use of part of a dish is not usually the case. If properly "Illuminated" by the lnbf more then 90% of the dish is usable. If the dish surface is not a good parabola shape then you are correct.

I do suggest you go hunting for an unused dish before you attempt to build your own. A 2 meter dish is not easy to build. A Ku 2 meter dish will be unlikely. A 2 Meter C band is something you can do at home.

[Pawel Pietrolay]

There is a map of needed dish for polarisation H and V

I need a dish with diameter 200cm

_http://obrazki.elektroda.net/8_1258182322.jpg

_http://obrazki.elektroda.net/5_1258182322.jpg

I have found a big parabola dish 200cm but There is a problem. My friend dug it into gound in garden and he is using it as a smal pond with water. It is hard to persuade him to sell it.

Next question is which LNB is proper for parabolic dish.

Cheap First option

_http://ecx.images- amazon.com/images/I/41cBBe520cL._SL500_AA280_.jpg


or:


second option
_http://www.hollex.pl/zdjecia/925.jpg

+

_http://www.hollex.pl/zdjecia/3232.jpg

the second option is 5 times more expensive


I wil try to borow a dish from my friend and to make a resin cast. I heard that I'll should put one or more aluminium foil layer, between glass fiber layers.

So my questions are.

Which precision is needed in mm ? (in order to 200cm dish)
Is payable to buy second LNB option and why,(or NOT)
Which kind of Resin and glass fiber i have to use
Where I have to put Aluminium Layers?
Which kind of paint is proper or unproper for dish reflective surface


So you mean that I can use simple LNB?
What's is the best focal lenght for 200cm dish and for 10.77325 GHz

or 11.95350 GHz

I am planning to do glass fiber connectable elements like pieces of birthday cake. I mean to part a whole parabola to separate triangles, and connect it finally with bolts.

i explored all scrap heaps, and i heard that a utilisation of parabola 1,8-2,0m occurs one time for 4-5 years. So it nearly impossible to find a such old wide and big dish.

[Pawel Pietrolay]

Is feedhorn for self made parabola 200cm needed? for example for freq H 11836.00 MHz . Why feedhorn is needef for parabola?

[driver]

Hello

I live in Right corner of the map, It's my nice Poland country.
I woud like to view transmissions from ASTRA 2D (freesat UK), there is a vide range of English language programs (160canals) ,

I need theoritically A dish with diameter 200cm, a price of a such sat dish in Poland is aprox. 800 dollar

_http://img32.imageshack.us/i/mapaastra2dodnowiona2.jpg

So I should do it myself. I have to gain a knowleage of the shapes and dimensions of the parabola,I'll learn from U my friends.

I'm soo sorry for my english' I have been still learning English, so I need English television. My Age is 22years old. The biggest mystery is a shape of parabola and proper materials. Whats is the best material for wave exposed surface.

Greetings from Poland

Pawel

hi m8,try internet streaming,bbc,possibly itv,for free!

[Pawel Pietrolay]

Good idea but not acceptable.

First-1 have got 1Mb/s internet (low quality of video)
Second-Computer power comsumption is three times bigger than TV
Third- I can use dish to wathing transmissions from numerous Satellites

I am a student of Building Civil Engeenery so I have a soul of constructor.
My father has some equipment for cutting drilling and polishing.

I though over the technnology and steps of home producing, and I'll try to prepare such dish. I don;t know which material is proper to make a such dish. I afraid that I'll make a dish from material which wont be wave's reflective. So how about aluminium foil, is it needed?My idea is to prepare a such disch from glas fiber.

[Turok]

Hello!
here i have very good signal with the gregory 1,25m around 6,5 db also on the orbit package, badr 6,sometimes not always i got also nearly all transponder,some are stronger in the night,or via versa,signal variation!
when 25,5 east will be replaced!
some showtime channels still on 25,5 but no ppv i dont know,when the rest follow.?

[Pawel Pietrolay]

People from forum use aluminium foil to make wave reflective surface, what's other way to gain the same result and similar efficency.Meaby any paint, zinc paint with graphite, or paint mixed with aluminium powder. I have no idea to find somethinq instead of aluminium foil. There is surely alternative for Aluminium foil, but nowbody knows what paint flexible material could be proper solution.Using foil we get not ideal surface like in parabolic mirrors. So i am waiting for solution. I am not sufficent inteligent to say which materials are wave reflective and which not.

[lloowen]

Hello all,

What a fascinating thread. I have not waded through all of it. But reading the earlier posts regarding how to build a dish, I thought I'd draw your attention to these people on how the make large circular molds.
These people are pros at creating large molds. This is the way to create a large satellite dish.

_http://www.flastatuary.com/mold/MM016.JPG

_http://www.flastatuary.com/molds.html

[Satcom1]

People from forum use aluminium foil to make wave reflective surface, what's other way to gain the same result and similar efficency.Meaby any paint, zinc paint with graphite, or paint mixed with aluminium powder. I have no idea to find somethinq instead of aluminium foil. There is surely alternative for Aluminium foil, but nowbody knows what paint flexible material could be proper solution.Using foil we get not ideal surface like in parabolic mirrors. So i am waiting for solution. I am not sufficent inteligent to say which materials are wave reflective and which not.

Paint is not a good choice. Aluminum window screen is good. Cheap and conforms to parabola.
If you are making a Ku band Prime Focus dish then you must use a Flat Scalar ring for C120 LNBF. Chek out Invacom.

[zanjansat]

waht technology selfsat antenna?
merci.....

[JanH]

Hi,

I am quite impressed of the tema. We built up dishes about 1,8m big from composite in 80's to receive ECS1 in Czechoslovakia.
Results was not so good but worked.

Another idea from this time - wooden construction on plain roof as parabolic sector. I should have some photo somewhere.

There is much more influences on dish construction, for example type of paint and color of the paint or thicknes of dielectric before aluminium from signal side. Etc.

JH

[Channel Hopper]

People from forum use aluminium foil to make wave reflective surface, what's other way to gain the same result and similar efficency.Meaby any paint, zinc paint with graphite, or paint mixed with aluminium powder. I have no idea to find somethinq instead of aluminium foil. There is surely alternative for Aluminium foil, but nowbody knows what paint flexible material could be proper solution.Using foil we get not ideal surface like in parabolic mirrors. So i am waiting for solution. I am not sufficent inteligent to say which materials are wave reflective and which not.

Almost all metal is opaque to microwaves, but for a good reflector, you need a thick layer to fully concentrate the waves. A thin layer of metallic powder, or foil allows much of the wanted signal to pass through.

[Satcom1]

Example of Ku Prime Focus LNBF.

[bonou2]

Next question is which LNB is proper for parabolic dish.

Hi @Pawel Pietrolay take a look here _http://astra2d.proboards.com/index.cgi?board=Eastern i use this lnb inverto+feedhorn C120 for astra2d reception _http://i56.photobucket.com/albums/g171/bonou12/DSCF5248.jpg

[tomharrison]

Thanks you all guys