That's an excellent reference document, thanks for finding the real duty cycle!The duty cycle is limited to 11% to comply w/ RF limits, but a more realistic duty cycle is probably around 1%.
That's an excellent reference document, thanks for finding the real duty cycle!
Just curious, why do you think a more realistic duty cycle would be 1 percent?
Cheers,
Dave
RF safety is not my specialty and authoritative safe distance numbers should come from SpaceX. But as an engineering exercise I did some resarch and ran some numbers.
SpaceX says in their FCC filing that the effective transmit power (transmitter power plus antenna gain) at 14 GHz is 33.2 dBW, or around 2 kilowatts, at when the beam is pointing directly away from the antenna face. It’s a little less when the beam is pointing off-broadside.
In the absence of any distance numbers from SpaceX, plugging the above numbers into an RF exposure calculator says that the minimum safe distance in the beam is around 5 to 11 feet assuming an always-on transmit duty cycle. Because this is a phased array antenna there’s likely to be a lot less RF outside of the transmit beam but to know exactly how much, you’d need information that SpaceX didn’t provide.
Perhaps a Mini owner on this thread can look in the user manual and see if it lists anything about RF safety.
HTH
Dave
Starlink review was by Walter White from New Mexico
That's another consideration as well. If it's generating a WiFi hotspot, it's probably intending that to work over a range sufficient to cover an area a lot larger than the cockpit of an RV, and not with a focused beam.The only limit in consumer facing Starlink materials that i could find was an 11" limit between radiator and body, but that's actually for the wifi signal, not the uplink.
Well, actually, there have been... This is older information, but the lesson is still true today; what you're seeing may be older than you think, and using Wx radar to try to dodge trouble can be a bad idea.
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Nexrad Weather Radar Linked to Small Plane Crash Deaths
Federal transportation experts are warning that a weather radar system used in many small planes may have caused the deaths of at least two pilots whowww.aboutlawsuits.com
Even with noahhl's better analysis, I have to admit that I'm reluctant to put either the satellite RF or wifi RF that close to my head in the RV-7 cockpit. It's not necessarily rational, it just is.Of course I say that typing on my laptop with my cell phone sitting next to me on the table. Both are >12" away from my body, so who knows.
Same here. I'm axiously awaitingMusk's cell phone (satellite-based) service for all the same reasons.I have a mini on the roam plan, it's great, we use it at the airport and plan to throw it in the back of the plane for trips, but no plans to try to use it in flight. It's going to let me/us take longer trips from work into more remote areas and fly-ins and still be able to have an effective internet connection for work. It's frankly just what we've been waiting for.
Looks like 13.4 inches is needed.How much power does this thing transmit with? Is it safe that close to your head?
I remember him in that video mentioning that he does not run it while he is in the plane due to concerns with being directly under/near it during operation as a potential health concern. He basically said he powers it on after landing to get service while in a remote location. I’m not educated enough on the topic to give an opinion on whether it being in your immediate vicinity while operating is harmful to your health, but I’m sure someone here may have some input.I thought the mini was designed to stop working when it detects motion to keep users from using it mobile. Trent Palmer installed Starlink in his Kitfox with the antenna mounted in the skylight.
Part of the snip you nicely attached states "Users must not operate the Starlink Kit within the safety zone of an airport."Looks like 13.4 inches is needed.
My educated guess is that the perceived issue is with 2.4 GHz/5 GHz wifi signal interference with GPS, TCAS, ATC radar, ADS-B, and most importantly, aircraft radar altimeters that operate around those frequencies. For example, existing radar altimeters have such poor RF filtering that they're vulnerable to RF interference several hundred megahertz away from their operating frequencies; that's the reason for all those 5G RADALT NOTAMs you see in your preflight briefings.In any event, can anyone indicate what the actual specific issue is/might be for such a "must not operate" statement?
OK now we are finally talking about something in my wheel house.RF safety is not my specialty and authoritative safe distance numbers should come from SpaceX. But as an engineering exercise I did some resarch and ran some numbers.
SpaceX says in their FCC filing that the effective transmit power (transmitter power plus antenna gain) at 14 GHz is 33.2 dBW, or around 2 kilowatts, at when the beam is pointing directly away from the antenna face. It’s a little less when the beam is pointing off-broadside.
In the absence of any distance numbers from SpaceX, plugging the above numbers into an RF exposure calculator says that the minimum safe distance in the beam is around 5 to 11 feet assuming an always-on transmit duty cycle. Because this is a phased array antenna there’s likely to be a lot less RF outside of the transmit beam but to know exactly how much, you’d need information that SpaceX didn’t provide.
Perhaps a Mini owner on this thread can look in the user manual and see if it lists anything about RF safety.
HTH
Dave
Do you want to quantify this assessment based on the published numbers? Starlink does have radiation warnings on their larger more powerful antennas, though not on the smaller consumer oriented terminals.OK now we are finally talking about something in my wheel house.
Given the small size of the antenna, there will probably be considerable side lobes. This means that there will be considerable radiaition directed to your head. I would put a small metal shield between the antenna and your head. (Tin foil hat, seriously)
It one gets head aches, or prone to cancer or starts seeing red areas of the skin on the back of thier neck, then this is too much exposure. Unfortunately, the worst problem will be cancer from the exposure, and this is not detectable until its too late. I would heed the Starlink warning and put it in a wing tip. Gosh, cant believe there are people putting this in the baggage compartment.