Yah, these types of things would be hard to detect (just point an LNB at the southbound sky... no dish... cheap electronics...)
What it's not is turnkey or filled with a good feed of information that people would want at baseline. There's no adoption model besides being a dissident, and people tend to start planning for that too late.
It is receive only-- not an uplink.
(I'm sure a tiny bit of RF leaks out of the LNB, but that could be mitigated as it is not designed for stealth).
definitely not solving the same ‘problem’ at all though.
Any receiver using the heterodyne principle (this includes most current digital radio modems) is trivially detected by its local oscillator, often to some considerable range (potentially hundreds of metres).
In the UK, the BBC used to exploit this, with radio detection vans patrolling the streets for unauthorized receivers, to fine people for watching TV without a license. So did the USSR with shortwave receivers, where the penalty was potentially more than a fine. A satellite receiver is the same, in principle.
I'm sorry. This is not intrinsic; this is a design choice. Yes, most LOs just care about getting under legal emission masks, but there's nothing to prevent one from bringing it much lower.
Further, as I explained: the LO frequency of the LNB for the first conversion is often the exact same frequency as you'd use to downconvert digital TV broadcast.
> In the UK, the BBC used to exploit this, with radio detection vans patrolling the streets for unauthorized receivers, to fine people for watching TV without a license.
They never found anyone in a way that could be used for prosecution. "A freedom of information act has revealed that TV Detector vans have never to date provided evidence to be used in court against the TV Licence Non-payer, and have therefore never succeeded in enforcing the TV licence."
Better testing to compliance standards has pushed LOs down way lower than they were in the 40s-60s. We have relatively cheap high quality spectrum analyzers and big integrated measurements. So-- kinda everyone pushes things down pretty low now.
> My point was merely that with an average radio, which was designed to just not be harmfully interfering, such as typical satellite TV receiver?
Yah-- this LNB looks just like a satellite TV receiver, with the exact same LO frequency. So your rogue downlink looks exactly like something that there's hundreds of innocent versions around.
Then a SDR inside your house chooses a different signal from the transponder and gets the data.
[https://gulfnews.com/world/asia/pakistan/government-bans-imp...]
Of course, so are most drugs in the US.
Point taken though!
I mean, I guess it's possible. But probably not your top priority during a time of potential unrest. And it probably won't work that well as a way to find people with the links.
Such a device would likely look peculiar enough to be easily recognizable, though, so you'll need to hide it, possibly inside some innocuous-looking other device or enclosure.
The whole setup becomes somehow more involved, but still cheap enough.
Yes-- and every piece you mention is "quality radio design 101".
> Such a device would likely look peculiar enough to be easily recognizable
I'm not sure about that.
The biggest most suspicious thing is, if they're resourced to investigate everyone with a piece of coax going outside-- where does yours plug into?
Of course, if you're really dedicated-- get a satellite TV receiver, empty out the nice metal box, put the receiver inside ;).