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PPL Hobbyist
21st Apr 2014, 12:54
I have a question that I dying to ask, and suggest a solution which may be, and I think should be discussed. Yes, my question stems from the disappearance of Malaysian MH370 which has still not been found after a month, but there is already a thread on that, so I don't want to encroach on that. What I would like to do in this thread concentrate on ULBs installed on all planes. Please feel free to disagree with me if you don't agree with me.


We should all know that lower frequencies travel much further than higher frequencies through air and water. In fact, further in water than in air, so I can't understand why a ULB transmits a 10 mS ping every second at a frequency as high as 37.5 KHz where it can only be picked up 2 to 4 km away when a lower frequency in the water can be picked up thousands of miles away. Isn't that already looking for the haystack in the field in our vast oceans? A 10 ms ping is certainly a very short ping for my liking.


It may be argued by other electronics engineers that it would consume much more power than the current battery used on a ULB is capable of supplying to transmit sound at a lower frequency with a longer ping for 30 days. My solution is this: Install a bigger battery.


I was intrigued by a post from Ian W where he said:


With all this doubt on whether the ULB pings were from the MH370 ULB. would it be an idea to modulate the ping with an aircraft/equipment ID? This would be extremely simple circuitry which would take little power but would stop these guessing games. The ping would then be indisputably from a particular aircraft and definitely not a 'natural' source.
Why not develop a ULB that will transmit a 500 Hz Morse code, containing a ULB, FDR or CVR serial number that could could be heard by any sonar system over thousands of nautical miles and immediately pinpointed and by tracing the serial number be linked to the plane/wreck?


Please don't come here and tell me that it has to be compliant with EUROCAE ED55, ED56 Fiken A and ED112. I know all that! I am not going to suggest going to Radio Shack and buy an NE555 oscillator chip and 2 cent speaker.


Why not find haystack first, then look for the needle later?


Happy Easter to you all.

Edit: Please Mr. Moderator, don't delete this thread.

kcockayne
21st Apr 2014, 15:51
PPL Hobbyist

On the face of it - a very good idea. You may have something there.