What really happens when you get shot down?
01-09-2003 | 12:09 AM
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From: Jackson,
TN
What really happens when you get shot down?
Excuse me guy's I have posted a similar question in different area's of the forum, but I have never gotton a answer to my satisfaction from the forum or my local club member's. What actually happens when two transmitters are turned on on the same frequency:
1 - Will the stronger tranmitter control the plane?
2 - Will it be mix of signals?
3 - In everybody's past experience (not what Futaba or any other manufacturer says) what is the safe distance for two transmitter's to operate?
I would like to hear from "experience" rather than theory's.
Thanks,
Jimmy
1 - Will the stronger tranmitter control the plane?
2 - Will it be mix of signals?
3 - In everybody's past experience (not what Futaba or any other manufacturer says) what is the safe distance for two transmitter's to operate?
I would like to hear from "experience" rather than theory's.
Thanks,
Jimmy
01-09-2003 | 12:49 AM
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What really happens when you get shot down?
To answer your questions:
1) If your airplane is far away from you, and someone turns on a transmiter closer to the airplane than you, the stronger signal wins.
2) If two transmiters have full range over the same airplane, it will react totally erratic, according to control inputs on each transmiter.
3) About 2 miles.
In real life, things vary, I remember I was flying a twin airplane on a fun fly event, when someone (outside of the flying field) wanted to have fun in his own way, and turned on a powerful transmiter signal, my airplane went full throttle in a vertical dive from about 200 feet, my inputs were totally nulled. (12 other aircraft were destroyed by this genious on that Sunday).
On a Sunday morning I was flying my 1/4 scale Decathlon, when someone turned the same frequency to check his radio, I was flying at about 100 feet high, the airplane went on a dive of about 30 deg., I had no control whatsoever.
I've had other hits, were my airplane went completely crazy, totally without control and doing loops and rolls and snaps and you name it, and then all of a sudden, full control again.
Today's radios are much better and less problems occurr .
1) If your airplane is far away from you, and someone turns on a transmiter closer to the airplane than you, the stronger signal wins.
2) If two transmiters have full range over the same airplane, it will react totally erratic, according to control inputs on each transmiter.
3) About 2 miles.
In real life, things vary, I remember I was flying a twin airplane on a fun fly event, when someone (outside of the flying field) wanted to have fun in his own way, and turned on a powerful transmiter signal, my airplane went full throttle in a vertical dive from about 200 feet, my inputs were totally nulled. (12 other aircraft were destroyed by this genious on that Sunday).
On a Sunday morning I was flying my 1/4 scale Decathlon, when someone turned the same frequency to check his radio, I was flying at about 100 feet high, the airplane went on a dive of about 30 deg., I had no control whatsoever.
I've had other hits, were my airplane went completely crazy, totally without control and doing loops and rolls and snaps and you name it, and then all of a sudden, full control again.
Today's radios are much better and less problems occurr .
01-09-2003 | 01:05 AM
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From: Jackson,
TN
What really happens when you get shot down?
Walter D, thanks for your input.
I wish I could remember where I saw this on the web, but it goes somewhat like the following:
1 - **% of all crashes occur because of poor setup on the plane.
2 - **% of all crashes occur because of poor maintenance of the plane.
3 - *% of all crashes occur because of "dumb thumbs".
4 - .00*% of all crashes occur because of frequency "hits".
I have one plane to crash because of "suspected reasons" but, because this plane had come out of a radical rebuild I suspect reason no. 1 was the culprit.
I wish I could remember where I saw this on the web, but it goes somewhat like the following:
1 - **% of all crashes occur because of poor setup on the plane.
2 - **% of all crashes occur because of poor maintenance of the plane.
3 - *% of all crashes occur because of "dumb thumbs".
4 - .00*% of all crashes occur because of frequency "hits".
I have one plane to crash because of "suspected reasons" but, because this plane had come out of a radical rebuild I suspect reason no. 1 was the culprit.
01-09-2003 | 01:07 AM
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What really happens when you get shot down?
Originally posted by Walter D
In real life, things vary, I remember I was flying a twin airplane on a fun fly event, when someone (outside of the flying field) wanted to have fun in his own way, and turned on a powerful transmiter signal, my airplane went full throttle in a vertical dive from about 200 feet, my inputs were totally nulled. (12 other aircraft were destroyed by this genious on that Sunday).
In real life, things vary, I remember I was flying a twin airplane on a fun fly event, when someone (outside of the flying field) wanted to have fun in his own way, and turned on a powerful transmiter signal, my airplane went full throttle in a vertical dive from about 200 feet, my inputs were totally nulled. (12 other aircraft were destroyed by this genious on that Sunday).
01-10-2003 | 01:59 AM
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From: Brockton, MA,
What really happens when you get shot down?
Hi Hooter,
I can't speak from experience, but I seem to remember reading years ago in RCM that someone was 'stealing' R/C planes (or at least, took over control of one of them). The memory is foggy but here goes...
The planes used to fly near the edge of a tree line. Apparently someone was hiding in the tree line and had a tx on the same freq as someone flying. When the plane got over the tree line (and downrange from the original pilot) the guy hiding in the trees switched on his tx and 'stole' the plane.
As I said, this was a story in a magazine years ago, and the details are a bit foggy. But, it does make for some amusing reading...
Bob
I can't speak from experience, but I seem to remember reading years ago in RCM that someone was 'stealing' R/C planes (or at least, took over control of one of them). The memory is foggy but here goes...
The planes used to fly near the edge of a tree line. Apparently someone was hiding in the tree line and had a tx on the same freq as someone flying. When the plane got over the tree line (and downrange from the original pilot) the guy hiding in the trees switched on his tx and 'stole' the plane.
As I said, this was a story in a magazine years ago, and the details are a bit foggy. But, it does make for some amusing reading...
Bob
01-10-2003 | 10:12 PM
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What really happens when you get shot down?
I've only been shot down once. On the trim flight no less!!!! (talk about making you really mad). Plane was about 75' up and about 500' out. somebody standing about 50' BEHIND me (a.k.a. farther away from the plane than I was) turned on. The plane went into a roll straight into the ground. I couldn't even pull the throttle back. I had no control at all.
When two transmitters are on that close to each other, their signals seem to mix and the receiver just gets garbage signals in.
Just my 2 cents worth
When two transmitters are on that close to each other, their signals seem to mix and the receiver just gets garbage signals in.
Just my 2 cents worth
01-10-2003 | 11:28 PM
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From: Haltom City,
TX
What really happens when you get shot down?
If you think about what the RX would be seeing.
First the RX receives a signal that is FM modulated (most radios). This signal is slightly being shifted in frequency based on the controls your inputing with your thumbs. Now a second signal pops up that is also slightly shifting but based on totally different thumb inputs. This will obvious confuse the RX since it cannot pick out one signal from the other and would not respond to either control but the combination of the two thus erractic behaviour. I don't see how one TX could override the other one in the case of the stolen plane. Seems to me it would take significant distance (maybe 3 miles) to attenuate the signal so as not to cause interference and erractic behaviour of the plane but this is all just my $0.02.
Also, what about intermodulation. Two signals offset from your channel that cause a 3rd order product to show up in your band. I guess the quality of the RX is all that would help prevent that. Does anyone have any information on this?
First the RX receives a signal that is FM modulated (most radios). This signal is slightly being shifted in frequency based on the controls your inputing with your thumbs. Now a second signal pops up that is also slightly shifting but based on totally different thumb inputs. This will obvious confuse the RX since it cannot pick out one signal from the other and would not respond to either control but the combination of the two thus erractic behaviour. I don't see how one TX could override the other one in the case of the stolen plane. Seems to me it would take significant distance (maybe 3 miles) to attenuate the signal so as not to cause interference and erractic behaviour of the plane but this is all just my $0.02.
Also, what about intermodulation. Two signals offset from your channel that cause a 3rd order product to show up in your band. I guess the quality of the RX is all that would help prevent that. Does anyone have any information on this?
