fat head Posted October 20, 2008 Share Posted October 20, 2008 Hi i am looking sugestions as to stop possible electronic interference from a Fuji 50cc petrol i have just enstalled in a large litho plate covered aircraft. I am using a good quality JR RX and getting slight glitches while range checking. I am also using a wip ariel and would like some help on this matter. I dont want to miss something and bend the plane on it's maiden with a new engine. Quote Link to comment Share on other sites More sharing options...
Nobby Clarke 2 Posted October 21, 2008 Share Posted October 21, 2008 Hi Fathead Are you getting the interference with the engine running ..?? or is it befire you fire up. Paul Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted October 22, 2008 Share Posted October 22, 2008 Hi FatheadAs Nobby says the first thing is to establish whether the glitches are there even when the engine is not running. Easy enough to check.May be nothing but how much of your aircraft is covered in litho plate and where is it relative to the RX aerial? Large areas of aluminium sheet can block/reflect/distort radio waves quite easily. Simon Quote Link to comment Share on other sites More sharing options...
fat head Posted October 22, 2008 Author Share Posted October 22, 2008 Thanks for the replys,... the model is 80% litho plate and the rest profilm. I had the wip aerial on the nose of the model and the RX over the COG. The slight glitches are when engine is running and areial is down, about 50 paces from the model... fine when aerial is extended! I was going to put some shielding on the plug ?(plug is r rated) and have now moved the areial to the rear of the aircraft. I had previously flown the model with a large 2 stroke S/T and had no problems with glitches with the l/plate. Getting advice from more experenced flyers before i fly it is better than learning the hard way.. Quote Link to comment Share on other sites More sharing options...
Nobby Clarke 2 Posted October 22, 2008 Share Posted October 22, 2008 Fuji electronic ignitions are famous for causing interference, because they are not shielded as well as they should be. Sometimes you get a good one sometimes you don't...!! There is a multitude of things to try to cure the problem, but you need to do it one step at a time. The spark plug needs to be a resistor type ( which you have already checked) make sure the spark plug cap is a good tight fit and move the ignition unit well away from your receiver. Try these things first then take it from there. Let us know how you get on. Paul. Quote Link to comment Share on other sites More sharing options...
Brian Parker Posted October 22, 2008 Share Posted October 22, 2008 I take it that the Fuji has a standard CDI unit. If so, then if all radio equipment including the antenna is correctly installed and is at least 300mm from the Engine/CDI and also if the throttle control is of non-conductive material you should not suffer from breakthrough interference.Why are you using a whip antenna? Whip antennae are base loaded (to make them think they are full size). Generally a whip antenna will have reduced range.How have you fitted the whip to the model? It is possible that the whip could see the litho plate as a ground-plane (no pun) and de-tune the whip thus reducing its effectiveness even further and also promote glitching.On the ground on your range test, when the whip was horizontal, glitching was induced due to the proximity to the ground (earth) (and litho plate?), but in the air the whip may need to be horizontal (H-Polar) to maximise signal reception rather than Vertical (V-Polar). The litho plate will undoubtedly(in my opinion) have an influence. Quote Link to comment Share on other sites More sharing options...
fat head Posted October 23, 2008 Author Share Posted October 23, 2008 I Will move the RX as far away as i can to the rear of the plane. I have had a few flights using the whip without any probs! using a large S/T on this plane but will check this out again. as for the plug lead i will add more shielding to it. Thanks every one again for your input!! Quote Link to comment Share on other sites More sharing options...
Solly Posted November 5, 2008 Share Posted November 5, 2008 What make of servos are you using? I had this trouble and found that switching from Futaba to JR servos completely cured the problem See my post in Radio Gear, Page 4 19-06-08 titled Spark ignition on certain servos. Presumably different makes of servo have different sensitivities to sparks. Quote Link to comment Share on other sites More sharing options...
fat head Posted November 11, 2008 Author Share Posted November 11, 2008 Hi Gordon, i have J.R. servos except on the elevator which is a HI TEC 645. I still have not had the time to give it another run to check things! work does get in the way of having fun!!! win the loto buy a plot of land build a strip and invite a few friends. Work is a 4 letter word! Quote Link to comment Share on other sites More sharing options...
Wonwinglo Posted November 12, 2008 Share Posted November 12, 2008 Just a quick thought you say you are using a good JR RX but not whether it is a PPM or PCM one. If it is not a PCM then swapping the RX for on that is a PCM type may cure the problem. I have a 68" Extra with a Zenoah 26 wiith a metal pushrod for the throttle fitted using a PCM RX and have no problems with glitching at all. Quote Link to comment Share on other sites More sharing options...
fat head Posted November 13, 2008 Author Share Posted November 13, 2008 I might change the RX to a PCM ans see if that helps, again work is hindering me from trying out any advice i have been given so far. Also the weather is putting me off from trying them out. NICE TO SEE A BIT OF RAIN FOR A CHANGE ! . Quote Link to comment Share on other sites More sharing options...
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