radio interference
09-28-2005, 12:41 AM
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radio interference
I got a million dollar question can flying wire cause radio interferance. I seem to get a lot of glitches at low low throttle settings. I have taken all other precautions keeping all radio equiptment away from the gas engine on ch ignition. Brand new radio and rx but I intalled these 4-40 flying wires made by dubro which forms a diamond shap on the vert and horz stab. I am just wondering is there a chance that it might be resonating a freq that could interupt the pcm mode my radio has.
Can any experts out there answer this mistry
Can any experts out there answer this mistry
09-28-2005, 05:12 AM
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RE: radio interferance
The wire itself, no.
Yes, If you have a metal wire and a metal clevis connected to a metal support strap. Any metal to metal connections that can vibrate has the potential to produce/cause RF.
This applies on gas and glow.
I have even seen a tail wheel assembly that was worn out cause RF.
Yes, If you have a metal wire and a metal clevis connected to a metal support strap. Any metal to metal connections that can vibrate has the potential to produce/cause RF.
This applies on gas and glow.
I have even seen a tail wheel assembly that was worn out cause RF.
09-28-2005, 05:34 AM
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RE: radio interferance
Any metal to metal make/break contact may cause interference. Never join metal to metal unless it's tight. Use nylon clevises, etc.
Dr.1
Dr.1
10-09-2005, 09:07 AM
#8
RE: radio interferance
ORIGINAL: airbr
Hi, How can I get my hands on a 4-40 die does home depot sell them.
Hi, How can I get my hands on a 4-40 die does home depot sell them.
http://www2.towerhobbies.com/cgi-bin...&I=LXR767&P=ML
10-09-2005, 12:13 PM
#9
RE: radio interferance
I sure won't say that metal brace wires won't cause radio interference but I have never had a problem with them. I always keep them tight.
One thing that you might try is to take them off and and do a ground range test with the engine off and running. The distance should be about the same.
Ken
One thing that you might try is to take them off and and do a ground range test with the engine off and running. The distance should be about the same.
Ken
10-09-2005, 01:23 PM
#10
RE: radio interferance
If it's not the clevis'--then it could be the C&H ignition.
I had a problem with a C&H synchrospark on my G-62. I had all my RX stuff about 12" away from the ignition and battery. But, my switch for the ign. was only about 9" away from my RX.
I moved my RX, RX battery, and RX switch 18" away from all the ignition stuff and the problem went away.
Also re-routed my RX antenna out the opposide of the plane from where the ign. switch is. Ignition switch is on the right----so I routed the RX antenna out the left side. The RX antenna is NEVER any closer than 18" from the C&H ign. unit, switch or battery.
Nobody is gonna like this idea---but if you run your antenna back and then put a 90 degree bend in the last 1/4 of the wire---you can sometimes get better recepetion--or eliminate an RF problem. Not 1/4"---I'm saying the last 1/4 of the total length of the antenna lead. About 10--12"
I always run my RX antenna outside the plane. So, I run it out the side of the plane and down the side of the fuse. untill it reaches the LE of the horizontal stab. Then I bend it 90 degrees and run it right along the LE of the stab. Get some monokote or other covering to match your stab and cut little 1" wide strips. Iron 3 or 4 of the strips down along the LE of the stab to secure the antenna wire. Works great and looks decent.
I'm not sure exactly how to explain WHY this works to improve reception. We had a problem with reception at a field I used to fly at. It was discovered that putting a bend in the RX antenna would help. Something to do with how the RX antenna would recieve the waves from the TX. Your presenting a larger profile of the antenna to the TX when you have a bend in it--as opposed to having it all run parrellel to the fuse sides. When the antenna is parrellel to the fuse sides--your only presenting a cross section of the antenna thats as big as it is in diameter. So, the antenna is only exposed to the TX waves by the size of it's diameter---which--on an antenna wire is about 1/16".
By placing the bend in the wire in the last 1/3 or 1/4 of the length---your exposing a larger profile of the antenna to the TX waves. Your getting at least 10--12" of the wire exposed to the TX waves---as oppossed to only the size of the diameter ---1/16"
Hope this makes sense.
If you've got your throttle servo mounted in the front of the plane---only a few inches away from the C&H unit---then that could be a problem too. I know a lot of guys do it successfully--but if your having problems--then don't rule this out.
I had a problem with a C&H synchrospark on my G-62. I had all my RX stuff about 12" away from the ignition and battery. But, my switch for the ign. was only about 9" away from my RX.
I moved my RX, RX battery, and RX switch 18" away from all the ignition stuff and the problem went away.
Also re-routed my RX antenna out the opposide of the plane from where the ign. switch is. Ignition switch is on the right----so I routed the RX antenna out the left side. The RX antenna is NEVER any closer than 18" from the C&H ign. unit, switch or battery.
Nobody is gonna like this idea---but if you run your antenna back and then put a 90 degree bend in the last 1/4 of the wire---you can sometimes get better recepetion--or eliminate an RF problem. Not 1/4"---I'm saying the last 1/4 of the total length of the antenna lead. About 10--12"
I always run my RX antenna outside the plane. So, I run it out the side of the plane and down the side of the fuse. untill it reaches the LE of the horizontal stab. Then I bend it 90 degrees and run it right along the LE of the stab. Get some monokote or other covering to match your stab and cut little 1" wide strips. Iron 3 or 4 of the strips down along the LE of the stab to secure the antenna wire. Works great and looks decent.
I'm not sure exactly how to explain WHY this works to improve reception. We had a problem with reception at a field I used to fly at. It was discovered that putting a bend in the RX antenna would help. Something to do with how the RX antenna would recieve the waves from the TX. Your presenting a larger profile of the antenna to the TX when you have a bend in it--as opposed to having it all run parrellel to the fuse sides. When the antenna is parrellel to the fuse sides--your only presenting a cross section of the antenna thats as big as it is in diameter. So, the antenna is only exposed to the TX waves by the size of it's diameter---which--on an antenna wire is about 1/16".
By placing the bend in the wire in the last 1/3 or 1/4 of the length---your exposing a larger profile of the antenna to the TX waves. Your getting at least 10--12" of the wire exposed to the TX waves---as oppossed to only the size of the diameter ---1/16"
Hope this makes sense.
If you've got your throttle servo mounted in the front of the plane---only a few inches away from the C&H unit---then that could be a problem too. I know a lot of guys do it successfully--but if your having problems--then don't rule this out.
10-09-2005, 03:08 PM
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RE: radio interferance
Thanks guys for all the of your replies. I have had this problem a year ago in this same type aircraft it is like bad luck or somthing. I ended up loosing that aircraft and have remade it since.
I have replace my tx and rx with brand new futaba's as well. The only thing that is the same in relation to the old one is the flying wires and the extensions going to the ailerons. Brand new radio brand new cd ignition different engine. All my components are at the safe required distance from each other 12 to 24 inches. My antenna goes straight from the rx up through the turtle deck and back to the vert stab. The antenna is rather close to these wires which is what makes them suspect on both old and new model. They are soildered tight as far as I can tell. But when I check the area of the wires when the connect through the stab it adds up to be well over 4 feet. So I am taking a while guess off the top of my head that they are becoming an antenna as well with the rx antenna running on top of it may be closer in flight when it dangles, I could be wrong because this is not my area of expert.
I don't know guys I am at a lost with this can't have any fun flying this aircraft that flies like a dream. I have just replaced the bearings as well in the engine thinking that they could cause the problem but have not had the chance to fly it. I am going to replace those flying rods with the pull pull type and see what happens. Have not had the chance to find the 4-40 dyes yet.
I have replace my tx and rx with brand new futaba's as well. The only thing that is the same in relation to the old one is the flying wires and the extensions going to the ailerons. Brand new radio brand new cd ignition different engine. All my components are at the safe required distance from each other 12 to 24 inches. My antenna goes straight from the rx up through the turtle deck and back to the vert stab. The antenna is rather close to these wires which is what makes them suspect on both old and new model. They are soildered tight as far as I can tell. But when I check the area of the wires when the connect through the stab it adds up to be well over 4 feet. So I am taking a while guess off the top of my head that they are becoming an antenna as well with the rx antenna running on top of it may be closer in flight when it dangles, I could be wrong because this is not my area of expert.
I don't know guys I am at a lost with this can't have any fun flying this aircraft that flies like a dream. I have just replaced the bearings as well in the engine thinking that they could cause the problem but have not had the chance to fly it. I am going to replace those flying rods with the pull pull type and see what happens. Have not had the chance to find the 4-40 dyes yet.
10-09-2005, 07:58 PM
#12
RE: radio interferance
ORIGINAL: Big_Bird
One thing that you might try is to take them off and and do a ground range test with the engine off and running. The distance should be about the same.
Ken
One thing that you might try is to take them off and and do a ground range test with the engine off and running. The distance should be about the same.
Ken
10-10-2005, 08:38 AM
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RE: radio interferance
The Problem only exist in flight coming down from a vertical manuever or on the glide slopjust as the motor is going to idle. I have done 360 degrees radio check on the ground with and without motor running and could not duplicate. The braces are functional so I cannot fly without them.
10-10-2005, 09:35 AM
#14
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RE: radio interferance
Do any of the braces (flying wires) rub together? If so, there could be an airspeed that causes them to resonate (vibrate) and that could cause interferance. If so, insulate with a piece of electrical tape and see if the problem dissappears.
10-10-2005, 11:14 AM
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RE: radio interferance
ORIGINAL: airbr
The Problem only exist in flight coming down from a vertical manuever or on the glide slopjust as the motor is going to idle. I have done 360 degrees radio check on the ground with and without motor running and could not duplicate. The braces are functional so I cannot fly without them.
The Problem only exist in flight coming down from a vertical manuever or on the glide slopjust as the motor is going to idle. I have done 360 degrees radio check on the ground with and without motor running and could not duplicate. The braces are functional so I cannot fly without them.
Multipath can cause a lot of problems that will change from day to day sometimes. Our hand held antennas that rely on ground reflections for a counterpoise almost guarentee that.
10-10-2005, 01:37 PM
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RE: radio interferance
Could it be reflecting from the braces or flying wires just like you said. I have another model with a homie 25 on CDI using the pull pull cable set up flying at the same field with a much better flying experience.
10-10-2005, 06:39 PM
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RE: radio interferance
My flying wires made a continuous steel box shape from the stab to the fin top & bottom. I changed the metal strap joining them on the bottom to a plastic strap, moved the antenna outside the fuse, separated all ignition & Rx stuff. All made no difference. Your demon sounds like metal to metal somewhere.
10-10-2005, 07:53 PM
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RE: radio interferance
Absolutely! In fact a friend of mine had exactly the same problem. The wires (plastic jacketed) abrade through the plastic and abrade (metal to metal) against the metal brackets that Sullivan supply with this "kit" and cause RF interference.
Funny you should mention this since he used this crappy tail wire kit nearly three years ago and I see that they're still marketed and packaged the same way....
The ignorance of some of these supposed Manufacture's is just astounding sometimes......
Funny you should mention this since he used this crappy tail wire kit nearly three years ago and I see that they're still marketed and packaged the same way....
The ignorance of some of these supposed Manufacture's is just astounding sometimes......
ORIGINAL: airbr
I got a million dollar question can flying wire cause radio interferance. I seem to get alot of glitches at low low throttle settings. I have taken all other precautionskeeping all radio equiptment away from the gas engine on ch ignition. Brand new radio and rx but I intalled these 4-40 flying wires made by dubro which forms a diamond shap on the vert and horz stab. I am just wondering is there a chance that it might be resonating a freq that could interupt the pcm mode my radio has.
Can any experts out there answer this mistry.
I got a million dollar question can flying wire cause radio interferance. I seem to get alot of glitches at low low throttle settings. I have taken all other precautionskeeping all radio equiptment away from the gas engine on ch ignition. Brand new radio and rx but I intalled these 4-40 flying wires made by dubro which forms a diamond shap on the vert and horz stab. I am just wondering is there a chance that it might be resonating a freq that could interupt the pcm mode my radio has.
Can any experts out there answer this mistry.
10-10-2005, 08:42 PM
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RE: radio interferance
You are so right about that. The straps seems to be made of soft steel which would be reacted more to radio, static and electromagnetic currents. I bet if I change the straps to aluminum or plastic the problem would go away. Can anyone elaberate on this subject in greater detail.
10-10-2005, 11:42 PM
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RE: radio interferance
What you have with that setup is a continuous loop. if you use nylon bolts to attach the brackets, it will brake the loop and reduce the chance of causing glitches. Plastic clevises will brake the circuit as well.
10-11-2005, 08:51 PM
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RE: radio interferance
ORIGINAL: mstroh3961
What you have with that setup is a continuous loop. if you use nylon bolts to attach the brackets, it will brake the loop and reduce the chance of causing glitches. Plastic clevises will brake the circuit as well.
What you have with that setup is a continuous loop. if you use nylon bolts to attach the brackets, it will brake the loop and reduce the chance of causing glitches. Plastic clevises will brake the circuit as well.
This is a common misconception, or one of the many wives tales that seem to carry on... It has absolutely nothing to do with "a continuous loop"..
The same thing would happen regardless of the geometry of the routing of the wire.
It's the metal to meatal abrasion that causes the interference. NOT the routing of the wire itself....
