Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Submarines => Topic started by: homerlex on June 17, 2008, 03:17:40 pm
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I am getting a Futaba 10C radio for my helicopters. Just curious if FASST systems will work controlling a submarine under water.
Anyone know?
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No it wont :(
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No it wont and as was explaned to me down the pub last night, 40mhz radio sets will only penetrate water to a depth of about 3 - 4 foot.
Jay
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40mhz only three or four foot? Nope, they'll go a lot deeper than that.
Andy
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40mhz will go down to 9 feet according to the submariners web site....out of sight...out of mind...mick
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AS with all radio waves it depends on the water, clean or dirty, salt or fresh etc.
Bob
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Mind you saying that i think i wouldnt trust it if i couldnt see it :'(.
Jay
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40mHz will go deeper than that, in clear fresh water I have had my subs down 5 metres but wouldn't recommend it though. The higher the frequency of radio waves, the less likely they are to penetrate and in fact, the old 27mHz gear had better penetration as the frequency was lower. Salt water will actually block radio waves quite effectively, especially at these high frequencies and thats why real subs have ULF (ultra low frequency) aerials or 'towed arrays' which are streamed out of the aft end or out of pods placed out of reach of the props. These are effectively a very long wire which is held on a spool and trailed behind the boat and they are of this length as they are tuned to transmit the exceedingly low frequencies they operate under and are capable of transmitting right across the globe.
So, high frequncy transmitters have short aerials, ie note the tiny aerials as fitted to 2.4gHz radio gear and the longer ones as fitted to lower frequency 40mHz equipment. This is why our subs won't work with the new 2.4 gHz radio.. even in fresh water.
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From my model aircraft days...if the aircraft was in sight....then it was in radio range....I think 'Sheerline' has the answer...mick
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Hi Mick, it was amazing how far out a model could be and still be in range. I remember retrieving a VERY distant model for a novice fellow flyer who had got into difficulties. This thing was a speck on the horizon when he called for help and it was so far out you couldn't even hear the motor. More by luck than judgement it came slowly home, sniffing fumes from the tank and landed dead stick at our feet. I wonder if modern radio gear has the same range capabilities as the old stuff from the 70s?
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Hello Sheerline , I guess we may be going off topic here, however, I do recall doing flying field ' radio range checks ' with the transmitter aerial retracted, then sending a ' mate ' with the aircraft receiver to the far end of the flying field, until the signal was lost at ground level. Showing our age now....mick.
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Well Mick, at least we lived through the 27mHz age.. it added real spice to flying and probably to sports boats as well as glitching was a curse at times! O0