kc Posted October 14, 2010 Share Posted October 14, 2010 A fellow club member cut the tip off his Futaba 2.4Ghz aerial by catching it in the prop. He thinks it will be OK to fly. Maybe 20mm is missing ( its cut down far enough to reveal it is hollow ) Is it safe to fly? Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted October 14, 2010 Share Posted October 14, 2010 NO Quote Link to comment Share on other sites More sharing options...
kc Posted October 14, 2010 Author Share Posted October 14, 2010 That's what I thought but I could not convince him! He thought he would try it....... What technical reason can I give him to convince him? Quote Link to comment Share on other sites More sharing options...
Steve W-O Posted October 14, 2010 Share Posted October 14, 2010 The active part of the antenna is only just over an inch, so he effectivbly has no antenna!!! Quote Link to comment Share on other sites More sharing options...
John Privett Posted October 14, 2010 Share Posted October 14, 2010 Steve is absolutely right. Most of the "aerial" is not actually an aerial, but just a coaxial cable leading to the aerial. The exposed wire bit at the end is the aerial - and it sounds like your friend has chopped most of that off! Think of it as being like your TV aerial. The aerial sits on the roof and has a long coax cable running down to the TV. Remove the aerial and you'll find the coax cable picks up virtually no signal at all. Actually - just to clarify... We've all been talking about Rx aerials. But could you be talking about the Tx aerial? If it's the tx aerial then you might get away with it if it's just the plastic cover that's damaged - but I certainly wouldn't want to risk it! Quote Link to comment Share on other sites More sharing options...
Erfolg Posted October 14, 2010 Share Posted October 14, 2010 can you stick a longer piece of wire back on, say with PVA or Tape on with PVC tape? Quote Link to comment Share on other sites More sharing options...
David perry 1 Posted October 14, 2010 Share Posted October 14, 2010 I love it. Ask him if he'd cut two feet off his 35MHz aerial and still fly?? Tell him he is also uninsured if he flies it, and probably breaking the law (ANO) D Quote Link to comment Share on other sites More sharing options...
kc Posted October 14, 2010 Author Share Posted October 14, 2010 Sorry I did not make it really clear that it was the Transmitter aerial! I thought he had caught his finger in the 120 four stroke by the noise but he was lucky it was just the Tx aerial. The tip went far away......if it was fingertip I would have searched! So the question remains is it safe to use a 2.4Ghz Tx with the tip of the Tx aerial missing? Edited By kc on 14/10/2010 11:38:19 Quote Link to comment Share on other sites More sharing options...
Erfolg Posted October 14, 2010 Share Posted October 14, 2010 I do luv a good argument, particularly when pointless. But how can he be breaking the LAW, it is at worst a free flight model Is there an issue with a short 35 aerial. I find the best solution with a overlong 35 aerial is to just coil it up, neatly, and tape inside the fus. It is April isn't it? Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted October 14, 2010 Share Posted October 14, 2010 If is is the Rx aerial, and its one of those with a co-ax then an end, then he could strip off a length of the outer, revealing some nore inner, and make it back into an aerial. Importantly, he should match the exposed length that it used to be. If it's a Tx aerial, more likely if it went in the prop, then that is probably a similar cable (coax then some exposed) pushed up inside a tube. However, it could be more technical than that and have a feature that matches it to the transmitter circuit, so it should be replaced with a manufacturers spare. Quote Link to comment Share on other sites More sharing options...
kc Posted October 14, 2010 Author Share Posted October 14, 2010 We are getting away from the real facts. Its a Futaba 6EX 2.4ghz Tx.Also can one change the Tx aerial oneself? Or is it a specialist job? Quote Link to comment Share on other sites More sharing options...
David perry 1 Posted October 14, 2010 Share Posted October 14, 2010 Erfolg, I was rather hoping someone would argue! I reckon that deliberately flying a model designed to be pilot controlled (it is NOT a freeflight model) when the pilot knows the controlling system to be possibly impaired because of a previous, unrepaired accident, is to permit or cause an aeroplane to operated in a dangerous fashion. Its not like an aerial is a bit of a wing tip or a wheel! I know there is no MEL or CDL for models, but if there WAS, the aerial system would surely be in it! Can you imagine it ? So, er, Mr Twit, can you tell the court the state of your model on the day of the crash? Well, your dishonour, it was perfect, well, all apart from me aerial which was chopped off earlier that day. Order! Order! The court will stop laughing!!! D Quote Link to comment Share on other sites More sharing options...
Steve W-O Posted October 14, 2010 Share Posted October 14, 2010 Posted by David perry 1 on 14/10/2010 11:56:04:.....................................................................ion. Its not like an aerial is a bit of a wing tip or a wheel!..................... No, it was bit off by a prop............................. To get back on subject, Yes the antenna can be changed by "oneself" but I would suggest that someone who doesn't know he can't use it as is, would not have the needed knowledge to change it, So I would suggest it is done by a competent person, who need not be a specialist. Quote Link to comment Share on other sites More sharing options...
kc Posted October 14, 2010 Author Share Posted October 14, 2010 I think David Perry is right it would be wrong to use equipment that one knows is faulty. But is it faulty or just cosmetic? Is the very tip of a 2.4 Ghz Tx an essential part. Thats the question. Quote Link to comment Share on other sites More sharing options...
Steve W-O Posted October 14, 2010 Share Posted October 14, 2010 Posted by kc on 14/10/2010 12:21:33:I think David Perry is right it would be wrong to use equipment that one knows is faulty. But is it faulty or just cosmetic? Is the very tip of a 2.4 Ghz Tx an essential part. Thats the question. Inside the plastic antenna case is a wire antenna, if the wire is not damaged, then the bnit of missing plastic will make no difference, but if the wire is damaged, it will not work correctly. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted October 14, 2010 Share Posted October 14, 2010 My original and rather brief answer stands m'lord. Quote Link to comment Share on other sites More sharing options...
BrianB Posted October 14, 2010 Share Posted October 14, 2010 How stupid can you get?Would this person drive a car with no brakes?Surely the minimum requirement is to buy/fit anew ariel or send it to the maker to get it checked. Quote Link to comment Share on other sites More sharing options...
Steve W-O Posted October 14, 2010 Share Posted October 14, 2010 Posted by Tim Mackey - Administrator on 14/10/2010 13:34:19:My original and rather brief answer stands m'lord. I would agree, (as I did) but then the question changed Now it's rather like buying a Bristol, if you have to ask the price, you can't afford it. Quote Link to comment Share on other sites More sharing options...
John Privett Posted October 14, 2010 Share Posted October 14, 2010 I would replace the aerial. The only reason not to would be if you KNEW exactly what the inside of the plastic-encased tx aerial should contain and could thus be CERTAIN that the aerial (rather than just the case) had not been damaged. I'm fairly sure the person this has happened to is not in this position! The insurance issue is - I believe - a red herring here. Flying a defective plane would help prove that there was in fact a liability and thus a reason for the insurance to pay out. However it could also leave you wide open to prosecution under the ANO and no insurance is going to help you defend that or pay any fine! So, swings and roundabouts! Quote Link to comment Share on other sites More sharing options...
Geoff N Posted October 14, 2010 Share Posted October 14, 2010 Do a Range Range check? Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted October 14, 2010 Share Posted October 14, 2010 I agree with John. As there is no way he can be sure the aerial is OK he would be taking an unwarranted risk and leaving himself open to a possible prosecution under the ANO. Get it back to Ripmax and let them fix it. Then he is in the clear because he can say he had the repair done by a "competant" person and had every reason to believe "in good faith" that all was well with his aerial - subject to him diligently carrying out the standard range check as you would with any installation of course. BEB Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted October 14, 2010 Share Posted October 14, 2010 With a different and now unmatched aerial, some transmitter power could be being reflected back towards the transmitter circuitry. This has the potential of damaging the transmitter further. Get it repaired. Quote Link to comment Share on other sites More sharing options...
BB Posted October 14, 2010 Share Posted October 14, 2010 Sounds like your mate needs one of these: Futaba replacement aerial £15.75p from Ripmax (ssp) Part No: Y-9M99Z02203 Available through your LMS. BTW - The aerial is glued into the housing at the tip. Hence no simlpe seperate housing or wire replacement. Overall aerial length aprx is 20cm. Your friends TX is effectively now a 'modified' set. It no longer conforms to its 'CE' declaration. In the event of an accident. He will not be covered by BMFA insurance or any other insurance scheme covering the use of that TX. Any guarantee associated with the set will be void. If he continues to use it. Q: Will it still work as is ? Yes it will. But, its range can't be guaranteed. Therefore it is not safe to use. Quote Link to comment Share on other sites More sharing options...
kc Posted October 15, 2010 Author Share Posted October 15, 2010 At the field this was the only 2.4Ghz transmitter so no chance to compare with an undamaged one. Having inspected a brand new one I must say my estimate of the missing bit was probably wrong. Only a mm or two was probably cut off.I was under the impression that the black plastic bit was actually the aerial ( metalised in some way ) but this correspondence and inspection of a good aerial suggest there is a wire inside the plastic. BB says the aerial is 20cm ( 200mm ) but the (original ) plastic bit is only 77mm long ( to the pivot ) so how does this agree? Surely £15.75 is a ridiculous price for a plastic aerial and a bit of wire? Quote Link to comment Share on other sites More sharing options...
Kelly Posted October 15, 2010 Share Posted October 15, 2010 It costs a lot less than the loss of a model . Replace it Quote Link to comment Share on other sites More sharing options...
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