I'm running out of ideas on this problem and so far nothing seems to work. Here's whats happening;
I get quick glitches at each end of the runway at the same places. This also happens up to 150 to 200 ft straight up from the runway ends, and if you were to stand center runway straight out to each end i get hit when passing through these zones. I sometimes get them in other areas while flying but its infrequent and random. The hits are very quick 1 second or less

The planes pitch violently up or roll or yaw. This is troublesome on landings as the planes always balloon at these spots. Some members claim it to be the wind swirling up the hill. But no way is the wind causing my throttle servo to move! My planes are getting larger and more expensive and I don't enjoy nor can I relax when flying.

All FOUR of my planes do this( 3 glow 1 gas), I have moved things around inside each and no change. The gasser is more affected. My first radio was a tx6as on #43. I had this problem then but didn't notice too much because I was green. Second radio was a 8u # 53 with the same problems. I now have the new 9c on #53 still getting hits. I chose these channels because they're not used by anyone else in the club. Our club is small and there's several channels empty.

In the early spring and fall I fly at the in-laws place (large bean field) and I get absolutely no hits whatsoever. Flying here is much more enjoyable until the tractors show up and I'm forced back to the clubs field. I have come to the conclusion that my places are fine and it's something at the field. No one else there seems to have this problem or at least haven't spoken up. There are no other clubs around with a reasonable driving distance.

When asking around about this I get nothing, no ones heard of this happening. Should I try a different channel say, high 60's or seventy's? I could try one of the more popular ones but was trying to avoid the accidental turn on. I don't know, the beans will be out in a month so I'll be good till spring. But flying alone gets old and probably not too safe. I posted this in the radio forum also for more visibility.

If anyone has ideas, thoughts or anything please post. Sorry for the length but thought a good explanation would help.

Thanks,
Dave

Try borrowning someone's crystal and TX on a different channel. Fly and see if it happens again. It it hits your plane and not their, it is not a RADIO interference problem, but something in the way you set up your planes that is causing the hits.

I had a similar problem I sent my radio in and futaba put me on a low band. That fixed the problem

Have you tried standing at different spots on the flight line? Move to the upwind end so you can see the runway as you're on approach and see if you still get the glitch.

Do you happen to have a barbed wire fence at the ends of your field? We had one at one end of our field, and had to remove it to clear up the numerous glitches flyers were having.

Call AMA they have a freg scanner they will send your club.

I always stand in the same spot or pretty close to it. Never thought about moving.

We have a fence, it's plastic but held with steel post. Everyone stands next to the fence along runway while flying.

I was told the field was scanned when considered for a club and all checked out well.

Would any of you know if I can go to low band by changing the module and rx crystal. Currently on high band.
I don't have this problem at the other place I fly at.

Dave

This is kind of a wild shot, but you are not pointing your antenna at the plane when you get these glitches are you? It can cause glitches if you do.
fossil

Ok fossil put down the crack pipe I've never heard that one before.

I was always told to never point your antenna at the plane, that there is whats called a cone of silence from the tip of the antenna. It might be an old wives tale, but if it is theres a lot of people that believe it. CAP232CM You wouldn't happen to be a fellow Chiefs fan would you.
fossil

OK,

I think I will just get a module and one crystal on high band and try in one plane. After reading on other forums It seems I should probably stay on high band.

Now one for the crack pipe, I've heard/read that the middle of the band hi/low is more stable then the edges. Sounds strange to me.

Question is should I shoot for a channel far from 43 or what? As you can see this is not a area of vast knowledge for me.

Thanks Dave

fossil,

Hey just kidding about the pipe I couldn't resist. I like the pic in your signature. I like the Chiefs hope they do something this year.

davham,

I quess it might be true about the attenna being directly pointed at the plane but I usually point mine about level with or below ground level. I just went through a glitching problem with my Somethin Extra boy what a mess. I found out from a lic ham radio guy that a metal fence will reflect the signal. Sure enough that was the problem. Also finding that if a reciever is not tuned right it will cause intermintant problems as well. My solution was installing a different reciever and my problem was solved. Good Luck!

Well I do tend to rotate my whole body following the plane across the sky. So I guess you could say my radio is pointed at it to a certain degree. I can guarantee you there is a steel fence post on each side of me and when rotating my body I'm sure my antenna is sweeping over top of them. I am going to the field Saturday so I'll try and get there early long before anyone else. That way I can stand in the parking lot and fly. Nothing out there for sure.
Thanks for the ideas.

Dave

It is a fact and not fiction that you will get reduced range if the tip of the TX antenna is pointed directly at the aircraft when the model is at certain angles in relation to the TX antenna. The weakest signal is when the tip of the TX antenna is pointed directly at the model while the model is either flying at you or away from you. (Provided the RX antenna is running down the length of the fuselage) The TX antenna is giving you max range when the entire length of it is facing the model. I have gone to the base loaded RX whip antennas (Revolution brand) on all of my models, both turbine and prop jobs, and have seen a drastic increase in range verified by a range check.

It just kills me to see modelers doing this and other range reducing no-no's, including pointing the TX antenna at the ground. If your transmitter has a swivel so that you can adjust your TX antenna---adjust it so that the antenna is pointing straight up. With the whip RX antennas the TX antenna is never pointing directly at the model unless the model is in a knife edge and the TX antenna is pointing directly at the model. Even then range is not reduced that much because the speed of the model will make the whip antenna bend rearward a little so you never really have that "Point to Point" antenna problem!!!

Just a little food for thought---------Kevin

I too had a phantom glitching problem with an Edge 540 that I flew for 2 years. I loved the plane, and the way it flew, but every so often, it would jump around, without any warning. I switched Rx's, and even got a new wing, without a cure. Then a club member bought the plane from me, (with a warning) and had the same problem, but very severe. After landing, and upon inspection, it turned out to be a stripped elevator servo gear. On the ground, it worked fine. In the air with some torque on it, it didn't. Problem solved, and no further glitching incedent all summer long....

CAP232CM I didn't take offense to the crack pipe joke, I actually thought it was funny. Glad to know I'm not off my rocker on the antenna thing, I thought it was true. My avatar is from a cigar company, ain't nothing better than a good stogie. davham if its not the body english causing you to point the antenna I would have my receiver and servos checked out.
fossil

When changing/trying frequencies go lower than 45-46. We have a field with interference and the higher frequncies seem to have more problems. When researching the problem I read that industrial R/C and also some pager towers get near the 50+ frequencies. Near enough to bleed over.

Good luck...

Could be the cut ends of the re-bar used in the concrete of the runway creating an electrical distrurbance in the area over the threshold (the stripes at the end of real runways).

If it is an asphalt runway, there still may be re-bar used in the bed of the form.
In full sized airplanes, doing a yearly compass correction (kinda like noting the devience in compass headings) it is always impossible to get accurate readings at the end of the active, or in some corner of the apron where you are outta the way. The compass needle will even swing.



Just a thought............take a simple cracker jack compass, and walk the active, see if you have electrical disturbances.....


Steve-o

Hallo!
What radio do you have ....Hitech??

Regards!
Jan K
Sweden

Are you running PCM or PPM receivers? Also there is some evidence that the re-bar in the runway will cause radio problems, had that happen at a field in Co. I beleive.
John Diniz

davham, I answered this question in depth last night but the post disappeared.

I cannot believe it is a field problem if others aren't having it, too.

I believe you said it happened on ch 43 and 53. Is there some way you can get one of the planes on the lower half of the 72MHz band? Can you swap with someone?

It is possible that channels 43 and 53 are the only ones affected my intermod, but doubtful.

I am an antenna engineer, so I take these things seriously, as do you, I'm sure, but I am not convinced by what I've read that there is a field problem.

Dig into this will you, and keep us posted.

How far can you range check on the ground? You should be ok at 150' on PPM and 200' on PCM.

Do you have anything that is metal to metal contacting in the plane like a metal rod to your engine's metal horn?

We have a similar problem at our field. There are 2 spots on the field where you get hit. The kicker is it's only on high band and only with Futaba receivers. I assume because all of your xmitters are Futaba you are using the Futaba recievers that came with them.

I fly nine different planes on my Futaba T6xa and T6xas on channel 54 and the two that get hits are the ones with the Futaba receivers. All the others have Hitec Supremes and never get hit. We have other members in the high range and they are guaranteed a hit in these two spots if they have high band Futaba receivers. It doesn't matter what xmitters.

Like yours the hits are quick. You get full throttle and down elevator. Bad combo. We've gotten used to them and laugh about them. They haven't claimed a plane YET.

Another thing about ours is that you have to be headed in one certain direction. We have carried a plane to the "spot" and it will go nuts but if you turn it 20 degress in any direction it stops.

This field has been in use for almost 30 years and this just started this year.

I also have a similiar problem, when I'm flying and coming in for a landing it's always 50 feet up 200 feet away or so when im just ready to line up. The plane does the same thing everytime, it snaps almost.

Strangly enough would a fence have a big influence on this? or wind?

Well, I flew one this morning and stood at different places on the field. I noticed the hits would move around a little. Some places it got a little worse and some the same. One guy showed up later on and we decided he would follow me around in the air. Places where I got hit he flew through fine. He is on channel 27 I believe. His stuff was JR so we couldn't swap. I will just get a module and crystal and see what happens.

Dave