flight1 Posted January 18, 2015 Share Posted January 18, 2015 no one is trying to dig or insult any ability ,just trying to analise the situation. And to get at likely probable causes you need to be able to stand back and be quite abstract with all information. sometimes we just don't like it ,but it ain't personnel. Edited By flight1 on 18/01/2015 13:06:17 Quote Link to comment Share on other sites More sharing options...
ben goodfellow 1 Posted January 18, 2015 Author Share Posted January 18, 2015 i know that your not being personal... perhaps for the new poll we could have .out of spektrum users how many have had problems.... Quote Link to comment Share on other sites More sharing options...
flight1 Posted January 18, 2015 Share Posted January 18, 2015 If we could get every one to do the pole it would be quite informaive, but we know that won't happen and we would have to do one for all the different makes to be able to compare. There is also the factor that the majority who are happy will not post anything as there is no need. Talking about rcexl optical throttle safe Ihave had two fail on me, out of only 4 I have had, proberly just unlucky. Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted January 18, 2015 Share Posted January 18, 2015 I'm not doing any pole dancing, but would consider a poll Quote Link to comment Share on other sites More sharing options...
Dave Hopkin Posted January 18, 2015 Share Posted January 18, 2015 A question, the optical throttle safe device - what happens to it if there is no power to the device? If it were a servo going short circuit and sucking all the power out of the system, the RX would have dropped below minimum level and browned out (and of course recover fully when power was restored) but what would the throttle safe switch do? Quote Link to comment Share on other sites More sharing options...
flight1 Posted January 18, 2015 Share Posted January 18, 2015 It would turn back on with the return of the Rx's signal , but in the meatime the engine would have cut and their is no auto start for that. Was the ignition bat checked? Edited By flight1 on 18/01/2015 13:37:57 Quote Link to comment Share on other sites More sharing options...
ben goodfellow 1 Posted January 18, 2015 Author Share Posted January 18, 2015 yes ...its fine Quote Link to comment Share on other sites More sharing options...
flight1 Posted January 18, 2015 Share Posted January 18, 2015 Posted by Frank Skilbeck on 18/01/2015 13:24:24: I'm not doing any pole dancing, but would consider a poll That remids me I went to Ansterdam once and ondered why there were all these pole in the bars I do say these pole are usefull, I sopose thats were it all started Quote Link to comment Share on other sites More sharing options...
ben goodfellow 1 Posted January 18, 2015 Author Share Posted January 18, 2015 cannit half tell its rubbish weather ........ Quote Link to comment Share on other sites More sharing options...
Piers Bowlan Posted January 18, 2015 Share Posted January 18, 2015 Just a thought Ben... Did you have any of the satellite receivers mounted in the wing or on top of the tail fin perhaps? If not, then perhaps with a big sparky petrol up front (plus ignition unit and batteries) they may have obscured the antennas in the fuz from the RF signal when the model was flying straight towards you to land? Still does not explain the pitch down when the signal was lost however (if it was). Quote Link to comment Share on other sites More sharing options...
ben goodfellow 1 Posted January 18, 2015 Author Share Posted January 18, 2015 tail fin...no not there, but spread in differing orientations around the inside of the fuz ,well spread apart. nearest one to ign was approx 12-15" Edited By ben goodfellow 1 on 18/01/2015 15:25:07 Quote Link to comment Share on other sites More sharing options...
gangster Posted January 18, 2015 Share Posted January 18, 2015 I have watched this thread with interest, and lots of sympathy for Ben, but until now have had nothing to add, there are so many unknowns. There is however something that concerns me about the pitch down. Ignoring all the other possibilitys and focussing on Ben's believe that there was indeed a radio issue. The title of the thread is signal loss . Surely if there was a signal loss the rx would hold and failsafe regardless if it was brownout blackout or any other thing that involved the signal path. For the servos to move, and we are talking elevator and throttle would involve either an erronious signal from the TX or an issue with the RX. Servos decking the suppy has been suggested and that could be significant Manufacturers have tried to tell us ,origionally PCM and then 2.4 was the great panacea and we would live happily ever after. I have always been very sceptical that with a minor burst of interference or signal loss it could, in certain circumstances get us into worse problems than the old pretend digital that we have had for decades I recall someone in our club once suggesting that we should all be made to use PCM because it glitched less, I think my reply was keeping your eyes closed was more effective in not seeing the interference. I have been fortunate over the last 35 years of flying radio never to have crashed due to TX or RX or interference issues, (have many many crashes due to every other reason, mainly pilot (me) induced. I have used most makes of radio over that time including Micron and RCME and have never felt any better than any other, choice has been on the feel and features of the TX. Once problem does however spring to mind, I had a fault develop on a Sanwa Black Custom RX (very expensive in its day) a tantalum capacitor went faulty and intermittently decked the supply this manifested itself in a large glitch and the flair voltage monitor latching a supply fault and flashing. As I said it gave large glitches in flight. Now if this happened in a modern PCM or 2.4 RX I am convinced it would rtesult in the RX getting its knickers in a hell of a twist and resulting in a black bag. Someone mentioned a servo decking the supply intermittently, remember failsafe cannot work correctly if its own supply is compromised. So to conclude it may be radio issues but probably not signal loss. Its always easy to tell others what they should do my instinct would be to accept the new TX and quaranteen the RX and servos for a while maybe test later in something of little value. Good luck mate hope it goes well for you. Quote Link to comment Share on other sites More sharing options...
ben goodfellow 1 Posted January 18, 2015 Author Share Posted January 18, 2015 i am sitting now putting my slick together... everything is new, my rx from my dx18 qq, and all the servos , the only thing that would be common would be the tx . that is ofcoarse if i dont take the offer of a v2. i dont know why but the pich down seems to be fairly common when people are saying they have had problems. Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted January 18, 2015 Share Posted January 18, 2015 Just a thought, you say the satellites were all in the fuselage and you were on landing approach, would that have put all the aerials behind the engine, ignition, batteries etc so they are all shielded by these components. Normally you got away with it because you've been a bit higher, there's less damp in the air etc etc but in this situation it's been marginal, and on the last flight it just tipped over the edge. Have you looked at any flight logs from earlier flights to see if you have been getting drop outs in this location before, can you do a full power range check in that area with the plane in the same orientation to see if you get a failsafe condition. My radio has LQI (Level Quality Indicator) which reports the signal quality (not signal strength) and I have a GPS logger which records this information, and while I've never had a lock out, I've noticed when looking back at the GPS logs that the lowest LQI is usually when the plane is near to the ground or has landed out a bit (gliders). Unfortunately the GPS logger I'm using doesn't work with DSMx/DSM2 as it would be a good way of checking where the weak spots are on your field etc. The pitch down might be no more than when it failsafed you were holding in some up and the failsafe returned the elevator to neutral, I can't see why just the elevator servo would move in one direction, you would think if it was that type of fault in would be on all channels. Quote Link to comment Share on other sites More sharing options...
ben goodfellow 1 Posted January 18, 2015 Author Share Posted January 18, 2015 i was approx 45- 90 degrees off a front view Edited By ben goodfellow 1 on 18/01/2015 17:38:48 Quote Link to comment Share on other sites More sharing options...
ben goodfellow 1 Posted January 18, 2015 Author Share Posted January 18, 2015 didnt have a logger in Quote Link to comment Share on other sites More sharing options...
bert baker Posted January 18, 2015 Share Posted January 18, 2015 I have thought about a Spektrum logger, I have never seen one used, is there any benefits to be had by using one. I have not even looked it up on the net before. Quote Link to comment Share on other sites More sharing options...
bert baker Posted January 18, 2015 Share Posted January 18, 2015 Did find an interesting installation video from HH Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted January 18, 2015 Share Posted January 18, 2015 A benefit of a logger or telemetry, is that you can check after every flight to see if you've had any individual antenna fades, frame losses or failsafes (holds). Checking this for the first few flights of a new model can certainly help identify any installation issues, particularly with aerial positioning. Quote Link to comment Share on other sites More sharing options...
Phil Green Posted January 18, 2015 Share Posted January 18, 2015 Posted by gangster on 18/01/2015 15:56:54: Surely if there was a signal loss the rx would hold and failsafe regardless if it was brownout blackout... I'm baffled as to why these terms cause so much confusion. Both are power conditions, nothing whatever to do with signal strength. Without power there is no failsafe - but a throttle-spring might overcome the throttle servo, closing the throttle if theres no battery power. Quote Link to comment Share on other sites More sharing options...
gangster Posted January 18, 2015 Share Posted January 18, 2015 Yes Phil I made a total pigs ear of that sentence didnt I ! Few words missing and power and signal loss ran into each other. Hopefully I clarified it later on and separated the two situations . Thanks for re-emphasising my point that failsafe cannot necessarily overcome power related issues Good point about the spring Quote Link to comment Share on other sites More sharing options...
Phil Green Posted January 18, 2015 Share Posted January 18, 2015 Quote Link to comment Share on other sites More sharing options...
ben goodfellow 1 Posted January 18, 2015 Author Share Posted January 18, 2015 throttle spring is irrelvent. if servo breaks tx can cut engine , if signal is lost ign is killed .if power is lost ign is killed . the dive is a signal related problem, and as my failsafe was correctly set the dive is unacounted for . but as in so many of the other cases this was also the case ive heard of turbines , aerobatic , edfs .sport models .in the first 2 pages of this thread there are 5 examples of this.. Quote Link to comment Share on other sites More sharing options...
bert baker Posted January 18, 2015 Share Posted January 18, 2015 Lost one on landing finals with enough height to get myself out of trouble, but radio said no . lost another at full throttle on a large banked turn. and another kept loosing aileron. I have been flying since 1980 and do know how to tip stall Throttle spring, never tried and never will, plus in my view it will probably cause excessive current draw Edited By bert baker on 18/01/2015 21:05:43 Quote Link to comment Share on other sites More sharing options...
cymaz Posted January 18, 2015 Share Posted January 18, 2015 You have my full support Ben. When you have something like this happen, ( the similarities of our crashes are plane manoeuvre into the ground and Both using 2.4 you don't know what to think and it knocks confidence. Edited By cymaz on 18/01/2015 21:14:19 Edited By cymaz on 18/01/2015 21:14:55 Edited By cymaz on 18/01/2015 21:16:09 Quote Link to comment Share on other sites More sharing options...
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