"A couple of watts on 109MHz could take down a light aircraft."
is without doubt the sort of unnecessary hyperbolic statement that leads directly to the modern security-theatre over reaction. Sure, it might lead to navigation problems which combined with enough other co-incidental bad luck might lead to a crash, but the reductio ad absurdum statement "$30 worth of widely available electronics could crash a Cessna" would surely lead to an entirely justified call from Cessna's legal department if published prominently enough.
Yeah, fucking around with poorly controlled transmitters in the FM broadcast band isn't a great idea. but telling people "you'll crash planes!" is a sure-fire way to have the rest of your message's reliability questioned.
(And, for the record, I'm going to try this out with my RaspberryPi and see if I can get some sort of handle on unexpected emissions using my FunCube software radio to listen above and below the tx frequency...)
While it may be true that jamming a VOR signal is unlikely to cause a crash without other co-incidental bad luck, consider this: The localizer portion of ILS operates on those frequencies, too.
I don't think it's all that far-fetched to imagine that an unfiltered transmitter like the one described could generate signals which 'trick' the localizer receiver and guide a low-flying airplane into an obstruction which is technically outside, yet near, the approach path. (The wikipedia page on ILS describes how it works, so I won't repeat it here.) AMing the right carrier with 150 and 90 Hz tones (which really means generating carrier + and - 150 Hz and carrier + and - 90 Hz) would cause the localizer to show the plane centered on the glide path, even if it isn't.
I agree that if you intentionally try to jam it using something like this you may be able to, however to unintentionally as a side effect of mucking around with FM transmissions seems unlikely.
Also I suspect the actual ILS transmitters are a lot more powerful, so unless you have this on the plane it probably wouldn't do anything.
"A couple of watts on 109MHz could take down a light aircraft."
is without doubt the sort of unnecessary hyperbolic statement that leads directly to the modern security-theatre over reaction. Sure, it might lead to navigation problems which combined with enough other co-incidental bad luck might lead to a crash, but the reductio ad absurdum statement "$30 worth of widely available electronics could crash a Cessna" would surely lead to an entirely justified call from Cessna's legal department if published prominently enough.
Yeah, fucking around with poorly controlled transmitters in the FM broadcast band isn't a great idea. but telling people "you'll crash planes!" is a sure-fire way to have the rest of your message's reliability questioned.
(And, for the record, I'm going to try this out with my RaspberryPi and see if I can get some sort of handle on unexpected emissions using my FunCube software radio to listen above and below the tx frequency...)