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Is there a simple way to make a NO dish antenna that can receive C-band or Ku-band satellite TV?

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abs

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For strange reasons. Receiving foreign satellite TV programs is illegal(Forbidden) in China.
So I can't use a common dish antenna. It's too easy to be find out and :sick:.
Is there any other form of antenna that can provide good camouflage effect?
 

betwixt

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It is primarily the capture area of the dish that gives the gain and there is no substitute for it. However, the dish does not have to be solid, you can use a mesh as the reflector as long as the holes in it are small. It isn't perfect camouflage but being partially 'see through' and painted in the background color it would be far less visible.

Brian.
 

    tony_lth

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c_mitra

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Is there any other form of antenna that can provide good camouflage effect?

First you need to find out whether any visible satellite is broadcasting channels you want to see.

You can tilt the dish at an angle and move the focus to the side accordingly.

These days almost all channels are encrypted. But that is a different story.

You should not directly point the dish towards the satellite- shift it by 20-30 degrees and compensate by moving the focus (LNA).
 

    tony_lth

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betwixt

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c_mitra, I think the issue here is that some governments prohibit viewing news and entertainment sources they cannot themselves control. ANY attempt to view outside information is banned so it isn't what the dish is pointing at that matters, its that any dish could be viewing foreign material so they are all banned.

True, an offset-fed dish wouldn't be pointing directly at the offending satellite, at least in one axis, but the presence of any dish would indicate someone was receiving and possibly transmitting programs or data. I have a relatively innocent small dish here for example that at first glance looks like a domestic receiving dish but is actually a 30GHz data UPlink. Not something a more restrictive government would allow.

Brian.
 

    tony_lth

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c_mitra

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c_mitra, I think the issue here is that some governments prohibit viewing news and entertainment sources they cannot themselves control. ANY attempt to view outside information is banned so it isn't what the dish is pointing at that matters, its that any dish could be viewing foreign material so they are all banned.

When I was young (and that was a very long time ago), we were not supposed to listen to any radio broadcast other than the domestic ones. But we all wanted to listen to BBC for news and other channels for entertainment. When we first got our TV (that was in 1984) we had to to pay tax and the license did mention that we are not allowed to watch foreign channels.

I stays in a fancy five star hotel in China and when I asked for internet access, I was shown one desktop that says everything in Chinese. Because it was not running linux or windows, I could not even change the display language. Next time I carried my desktop and I discovered that the great firewall of china is not really that great.

In south asia, the concept of democracy is rather fuzzy and banning things (??) are rather common. We ban books, internet access, mobile service, news, and what not. We usually take it very sportingly- it is a cat and mouse game. Catch me if you can.

But a dish can look and function like a local TV dish and can actually receive signal from other satellites.

The dish service provider (for me) has not bothered to customise the software - so with a wrench and a screw driver (and a signal meter) I can select one of the 30 satellites that are visible in the chart. But the signals are encrypted and my box cannot decrypt.

The box looks simple but is quite sophisticated; I have not probed much though.
 

    abs

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tony_lth

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Almost 30 years ago, I tried to receive another satellite without tilt the dish. The core idea is that a 2nd satellite can have a 2nd focus on some position in the dish. If you do some basic calculation, you can find its position easily.
I even designed the LNA module and RF amp amplifier with a very poor transistor, and finally received the 2nd TV channel with very poor picture.
I think that may work with an integrated 70K LNA module .
 

betwixt

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Just a thought - it may be feasible to receive from satellite using a flay array of phased dipoles. Something like this was done in the UK around the end of the 1980s and early 1990s with DMAC broadcasts using a 'squarial'. A square flat plate about 30cm each side. It was very effective but maybe not scalable if @abs signals are below 'K' band.

Brian.
 

vfone

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c_mitra

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Just a thought - it may be feasible to receive from satellite using a flay array of phased dipoles.

This is the same technique used in side looking radars and in very long baseline radio telescopes. But anything that does not look like a regular dish is going to attract the attention and the philosophy is simple: anything that cannot be controlled must be banned.

My personal advise: avoid risks and your neighbors may be the first ones to report.
 

abs

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Because the situation is deteriorating, I need an backup channel of information.
Although the Internet is still the best way.
But maybe one morning you wake up and the Internet won't be able to connect.This is not without precedent.
Maybe I can cut the dish and make it square or triangular.
Of course, this will lose the gain of the corresponding area.
Maybe I can also paint it grey or black. This is my plan so far.
One or two free news channels will be enough for me.

Another alternative is a shortwave receiver. But it's too easy to jam. In fact, they do jam a lot of radio channels.
 
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c_mitra

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But maybe one morning you wake up and the Internet won't be able to connect.This is not without precedent.

In the last one hour my internet connection dropped 4-5 times (I do not keep a count) - I feel happy that some people are working hard...
One or two free news channels will be enough for me.
Most news channels know far more than they are willing to say; they are in the business of making money and not to distribute free news.

Another alternative is a shortwave receiver. But it's too easy to jam. In fact, they do jam a lot of radio channels.

To jam a radio transmission, you need to set up another station with the same frequency. Or, if they know the location of the receiver, they can add noise (in a similar fashion to block mobile phones). But how do you uplink? Decent SW reception needs a long external antenna (internal antennas can work in some cases depending on your location).
 

G4BCH

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Some other antenna types that you could consider are a horn or a fresnell lens. Both will need to be disguised in some way of course, and that will depend on your local circumstances. A horn could may be disguised as a method of collecting rain water, particulary if you can put up a number of them that are used for rain water. A fresnell lens could look like an artistic sunshade perhaps.
I'm not sure if it would have enough gain , but a dielectric rod antenna for Ku band may be something that could be relatively easily hidden.

In all cases it will take some ingenuity to avoid suspicion.
 

BradtheRad

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Possibilities:

* Can you place the dish indoors and point it through an open window at a transmitting satellite?

* At reflected signal from a building or wall?

* At the ground where a smooth surface reflects signal upward to your window?

* Can you fabricate a smooth reflector which is a portion of a parabola, off-center so that it focusses to your receiver? The reflector might be made to resemble a birdbath, or sculpture, or splash-block, or sundial base, etc.

Anticipate the position of every object where your reflector concentrates sun's rays to a point, since this can generate heat that ignites flammable materials. The sun shines from various angles over the course of a year. You need to make it impossible for any human or animal to move into the concentrated sun's rays.
 

dick_freebird

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There are flat panel antenna options (like, how
airliners get Internet service - no dish sticking out
on those, just a nondescript low profile "bump").
Probably not cheap, and how you'd do antenna
"beam steering" I do not know, other than buying
a full RX solution with all that built in.

What about "it's just a pigeon coop" sitting on
the roof, made of low-attenuation materials
(like fiberglass panels for roof)? Maybe even
make room for some pigeons, around a solid
center section that houses the dish?
 

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