Antenna location
08-29-2003, 02:45 PM
#1
Antenna location
I attended the Ohio jet meet last week and experienced a couple of engine fail safes on my Rookie. David Reid was kind enough to help me diagnose the first one (thanks again David) and suggested that I relocate the antenna away from some of the components and remove the loop I had created during installation. I did all of this and had still another engine fail safe the next day and even on a different channel. One of David's suggestions was that I run the antenna in the wing if possible as his Bobcat was done and I was wondering if someone can explain or post a pic. for me so that I can see how this is done when installing the wing each time the wing is bolted on the fuselage. This installation makes sense to me I guess because you are moving the antenna completely away from all components in the fuselage.
Thanks in advance for any help. Gary
Thanks in advance for any help. Gary
08-29-2003, 04:37 PM
#2
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Antenna location
Before you go doing all this re-route stuff, you need to determine if you are actually getting any interference on your receiver channel or intermediate frequencies as opposed to just wishful thinking on David's part 
.
This interference could come from the ECU, fuel pump, metal or CF parts rubbing. Certain brands of turbine ECU's may generate more interference on our U.S. frequencies than others.
Other areas include noise feedback from the ECU to the receiver via the servo lead. Remove any servo amplifiers that you may have, amplifiers do just that, the amplify the signal, and the NOISE on the circuit.
Plus, you receiver may be just bad, replace it and test.
Lee Demary could chime in and give you his $0.02 worth on this subject too.
.This interference could come from the ECU, fuel pump, metal or CF parts rubbing. Certain brands of turbine ECU's may generate more interference on our U.S. frequencies than others.
Other areas include noise feedback from the ECU to the receiver via the servo lead. Remove any servo amplifiers that you may have, amplifiers do just that, the amplify the signal, and the NOISE on the circuit.
Plus, you receiver may be just bad, replace it and test.
Lee Demary could chime in and give you his $0.02 worth on this subject too.
08-29-2003, 04:41 PM
#3
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Antenna location
Gary,
Have you performed extensive range tests both running an not to establish whether your getting adequate range?? You need to find why your entering failsafe and this could have nothing to do with antenna location (ie: bad RX, external interference etc...). This would be the first thing to check....
Todd
Have you performed extensive range tests both running an not to establish whether your getting adequate range?? You need to find why your entering failsafe and this could have nothing to do with antenna location (ie: bad RX, external interference etc...). This would be the first thing to check....
Todd
08-29-2003, 05:28 PM
#4
Range check
Todd, moving the location of the antenna did actually help a great deal. I previously had between 70-75 paces engine off and on with the previous antenna location before I moved it. After I moved it I was able to obtain well over 100 paces with the engine running tested on both sides of the plane. I quit counting at 110 paces because I know this is an excellent range check. Moving the antenna to the wing just seems like a very good location and an extra measure of safety by getting it completely away from all components within the fuselage.
Wanting to do this is the result of problems experienced at Heart of Ohio this past weekend, there were a lot of planes going into fail safe (see my other post) and I guess that in my opinion it can't hurt to locate it in the wing where it will be away from all other wiring, metal, etc. It will be very easy to do this on the Rookie. My belief is that the problems were interference related as indicated in my other post and they have only occurred at the Heart of Ohio meet this year out of about 30 flights on my Rookie so far this year. I made no changes to the plane prior to the event to cause these problems and it was flown just a few weeks ago at another event w/o incident...Gary
Wanting to do this is the result of problems experienced at Heart of Ohio this past weekend, there were a lot of planes going into fail safe (see my other post) and I guess that in my opinion it can't hurt to locate it in the wing where it will be away from all other wiring, metal, etc. It will be very easy to do this on the Rookie. My belief is that the problems were interference related as indicated in my other post and they have only occurred at the Heart of Ohio meet this year out of about 30 flights on my Rookie so far this year. I made no changes to the plane prior to the event to cause these problems and it was flown just a few weeks ago at another event w/o incident...Gary
08-29-2003, 05:50 PM
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Same here
Gary
I had similar range with my hot spot. I had the deans attenna in the fuse beside the nose gear. I had around 75 paces for range engine running or off. Once I moved the antenna up into the nose, the same thing, the range went up to over 120 paces and I stopped counting. I now have to decide if I will put the ant. up and out of the fuse or leave it in the nose.
I had similar range with my hot spot. I had the deans attenna in the fuse beside the nose gear. I had around 75 paces for range engine running or off. Once I moved the antenna up into the nose, the same thing, the range went up to over 120 paces and I stopped counting. I now have to decide if I will put the ant. up and out of the fuse or leave it in the nose.
08-29-2003, 06:27 PM
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Gary,
Agreed, placing the antenna in the wing is a good idea. I was just trying to establish whether you had performed a solid range check first, making sure you had a solid signal before assuming a simple re-route of the antenna would solve the failsafe issue. Sounds like you had less than optimal range originally although from your post it is unclear if you had failsafe hits before or after the re-route of the antenna (or both?). I suggest you do go to the extent of your antenna down range to establish a baseline range reading and then check the percentage lost engine on, you may be surprised to find how much noise you are getting with the current placement. I usually do a "out of the box" range check on all new receivers before I install them in a new plane to get a baseline signal check. I then do an engine off installed range check, not accepting anything more than a 5% reduction in range. I then proceed to do a engine on range check, again not accepting anything more than an additional 5%. I also check the range in four quadrants. Knock on wood, this practice has performed flawlessly as I have never had a failsafe hit since I started flying PCM. On a side note, I used a Revolution whip antenna in my Kangaroo so I did not have to run the antenna out the wing, interestingly enough.....This increased my range by approx 10 paces(close to 20 in some quadrants) over my "Out of the box" check!
Regards,
Todd
Agreed, placing the antenna in the wing is a good idea. I was just trying to establish whether you had performed a solid range check first, making sure you had a solid signal before assuming a simple re-route of the antenna would solve the failsafe issue. Sounds like you had less than optimal range originally although from your post it is unclear if you had failsafe hits before or after the re-route of the antenna (or both?). I suggest you do go to the extent of your antenna down range to establish a baseline range reading and then check the percentage lost engine on, you may be surprised to find how much noise you are getting with the current placement. I usually do a "out of the box" range check on all new receivers before I install them in a new plane to get a baseline signal check. I then do an engine off installed range check, not accepting anything more than a 5% reduction in range. I then proceed to do a engine on range check, again not accepting anything more than an additional 5%. I also check the range in four quadrants. Knock on wood, this practice has performed flawlessly as I have never had a failsafe hit since I started flying PCM. On a side note, I used a Revolution whip antenna in my Kangaroo so I did not have to run the antenna out the wing, interestingly enough.....This increased my range by approx 10 paces(close to 20 in some quadrants) over my "Out of the box" check!
Regards,
Todd
08-29-2003, 07:05 PM
#7
Antenna location
Gary,
I have the antenna in my Kangaroo routed in the wing and I plan on doing the same thing in my Panther. What I did on my kangaroo was to run the antenna inside a plastic tube that sticks out the wing root. When I assemble my Kangaroo, I simply slide the plastic tube down the holes in the front of the wing ribs (composite wing) and bolt the wing on. On my Panther, I will run the antenna inside a similar plastic tube and have another, larger tube imbedded in the wing (full ribs in builtup wing) into which the smaller tube slides. When I transport my planes, the flexible tube simply sticks out the side of the fuse, but I have never had any problems with it or the antenna within getting damaged.
Bob
I have the antenna in my Kangaroo routed in the wing and I plan on doing the same thing in my Panther. What I did on my kangaroo was to run the antenna inside a plastic tube that sticks out the wing root. When I assemble my Kangaroo, I simply slide the plastic tube down the holes in the front of the wing ribs (composite wing) and bolt the wing on. On my Panther, I will run the antenna inside a similar plastic tube and have another, larger tube imbedded in the wing (full ribs in builtup wing) into which the smaller tube slides. When I transport my planes, the flexible tube simply sticks out the side of the fuse, but I have never had any problems with it or the antenna within getting damaged.
Bob
08-30-2003, 02:57 PM
#8
Antenna
Thanks to everyone for the help. I have a good idea how to run it in the wing now. Todd, thanks for the detail information. It sounds like you are checking the receiver range prior to installing it in the plane? I do this as well, plus all of my receivers and other radio equipment are test flown in a test plane that I keep just for that purpose, to make sure they are working well prior to installation in the expensive jets. I check at 4 points around the jet with engine off and recheck with engine running at the same 4 points.
I thought that the first time it happened that it might have been related to the antenna placenent, and it probably contributed to the problem, but after moving the antenna & range checking the second time and acheiving over 110 paces range I don't really think that there was a further issue with my installation. There were so many people having fail safe problems at Heart of Ohio that I relly think it was interference related at this point. I was actually able to verify interference problems with my scanner after switching to another channel the second day of the event. The pin for channel 17 which I was using was on the board and not being used and yet my scanner was receiving a maximum signal just as if I was standing there with my transmitter turned on...very scary!! Thanks again for all the help, Gary
I thought that the first time it happened that it might have been related to the antenna placenent, and it probably contributed to the problem, but after moving the antenna & range checking the second time and acheiving over 110 paces range I don't really think that there was a further issue with my installation. There were so many people having fail safe problems at Heart of Ohio that I relly think it was interference related at this point. I was actually able to verify interference problems with my scanner after switching to another channel the second day of the event. The pin for channel 17 which I was using was on the board and not being used and yet my scanner was receiving a maximum signal just as if I was standing there with my transmitter turned on...very scary!! Thanks again for all the help, Gary
