Mach I

My Feedback: (10)

Hi all,

Here's my delema. I have a Futaba 6XAS on 50 mhz, channel 8. I've had it just over a year, and it has worked well until that last few weeks. My range checks have really sucked and is intermittent.

When I walk about 25-50 paces, and hold the transmitter staight up or a little towards my body, my controls goes nuts. Sometimes when I hold the transmitter 90 degrees to the side, I'll get some glitching as well. Even raising the antenna a few inches, I still have the problem.

So, now I have swapped out everything to eliminate things such as receivers, servos, wiring, swithes, batteries, etc. I've changed planes too. I keep getting glitched. I thought this problem might have been the transmitter being that this was the only thing I did not change. I sent the transmitter into Futaba (Hobby Services), and it checks out great. 150 foot range check per Futaba.

For grins I decided to use my old Conquest transmitter on channel 4. I did a range check at home, and it was solid. Alright then, maybe I do have a problem with my other transmitter. Well when I got to the field, I had the same problem. After describing my problem to Hobby Sevices, they suggested that there might have been something that moved into my area that might be causing this problem and to check it out somewhere else. So I did just that. I drove to a flying site 40 minutes west of my site. Same problem.

So now I've changed radios, receivers, planes, flying sites, etc. Also when I turn the transmitter off, and leave the receiver on, there is no interference with the plane. (Thinking that there might be someone on this frequency)

Could there be some harmonics riding in on 50mhz? Could there be an issue with sun spots? I'm searching here guys. Any ideas or suggestions would be most helpful. Thanx for your time.


-Chuck

transmission_dr

My Feedback: (1)

Chuck,

I did a search and see that you have a channel 2 TV station in your area. Have they made any changes recently? New transmitter, new antenna etc.?

As you know channel 2 is in the 54 to 60 MHZ range, so it is possible there is a bleed over or some sort of beat interference.

HTH

Jerry

Mach I

My Feedback: (10)

Not that I'm aware of. However, if that being the case, then they have a huge bleedover problem, since I'm looking at about a 25 mile minimum range from site to site.

transmission_dr

My Feedback: (1)

Chuck,

Just ran into this on another thread.

http://www.rcuniverse.com/showthread...667&forumid=27

http://www.arrl.org/news/stories/2003/08/08/2/?nc=1

Some power companies are experimenting with power line carrier technology to deliver broad band internet service. It operates in the 2 to 80 MHZ range and is apparently capable of causing major interference.

Jerryy

Mach I

My Feedback: (10)

Thanx for the info. I'll check with our power company to see if this is the case.

Now, if this BPL affects 2-80 mhz, then this will affect all RC bands, 27,72, and 75Mhz. This is huge. They essentially will knock out many RC users, not just the Ham RC'rs.

I really appreciate all your help on this!!

Thanx,

-Chuck

Mach I

My Feedback: (10)

I haven't been able to check with the power companies yet, however I did e-mail a gentleman that does the propagation reports on the ARRL website. He states this:

"There has been a lot of long distance propagation on six meters of late. This could be your problem."

This might be the problem, however not sure. As for the BPL pollution, I'm a little pestimistic about this being the problem at my flying site. My site is in the middle of BuFu. Hills and cows. Although there's a little contruction going on, it's way down the road, and I believe business frequencies are in the 150mhz range. I have this problem at two different flying sites, and at home.

If anyone has other ideas, please let me know. I'll keep searching.

Thanx,

-Chuck

Mach I

My Feedback: (10)

Hi All,

I received my Transmitter from Futaba today. I decided to start over with my testing.

I tested my original plane (Fun world 3d)for the problem again, glitching all over again. I tested my two other planes..(Taurus and kid's trainer)...solid as a rock. Not sure why this is now.

I tested the Fun world 3d again, just to be sure. Still have problems. So I swapped receivers from the Taurus with the Fun world 3d. The glitching went way down. Still have a little, but not near as bad. I put the receiver from my Fun world 3d into the Taurus....solid as a rock.

Now.....this tells me that I might have a problem with the plane....no? I am running pull-pull for the rudder, and wire braces for the tail. I've run this setup before and never had problems, however....

Any suggestions guys?

Thanx,

-Chuck

transmission_dr

My Feedback: (1)

Hi Chuck,

What are you using for the pull pull? Hope it's not wire.

I have heard of metal tail braces causing problems. That's a good place to look. Did you use nylon clevis's? If you used metal I would bet that is your problem.

HTH

Jerry

Mach I

My Feedback: (10)

Thanx Jerry.

Yes, I am using wire for my pull-pull rudder system. As I mentioned before, I've run this setup in the past and never a problem, however I realize that this might not be the case this time.

I have nylon clevises connecting the tail braces, however again, I have run planes with tail braces that made a complete loop with metal connectors (my Nosen Citabria for example) without a problem.

I remember hearing about people wrapping ferret (sp?) coils around thier servo leads to keep strange signals from entering the receiver. Do people still do that?

This is truly difficult to solve being that the configurations and symptoms are not consistant.

Thanx,

-Chuck

transmission_dr

My Feedback: (1)

Chuck,

Something off the top of my head, maybe on this particular airplane the lengths of the wire are just right to resonate at 50 MHZ and cause the problem.

I have also run metal pull pulls with no problem and have used metal pushrods also with no problem.

It just could be that your lengths are ideal and are resonating.

You might try breaking up the lengths with insulators, like the kind that they use on antenna guy wires to break up the lengths. (much smaller of course) LOL

Good Luck

Jerry

Mach I

My Feedback: (10)

Thanx Jerry. I understand what you're talking about, and installing insulators to break up the lenght of wire would be a good place to start.

Thanx again,

-Chuck

Mach I

My Feedback: (10)

Hi all,

I swapped out the receiver from the Fun World 3D and the Taurus and took them flying. I ranged checked the Fun World, and I still had glitching, again however not as bad. So I put 3 flights on it. I didn't see any problems.

I'm not going to be satisfied with that since my range check is still unacceptable. My question is, instead of chopping the pull-pull wires for the rudder and installing insolators, could I use high test fishing line? This would eliminate the wire intirely.

Has anyone done this, and if so, what would be the recommended design to do this properly? I.e., looping the fishing line, connectors, etc.

Thanx,

-Chuck

Lynx

I don't know if it's a good idea or not, but if you do, don't use mono-filimant. Make sure it's multistrand. No matter what the test is mono has a lot more flex in it. Also if you do make sure you pre-tension the strings as after a bit of use they'll stretch even if it's muti-stranded.

transmission_dr

My Feedback: (1)

Hi,

There is a brand of fishing line that is braided and VERY high strength. I have used it in an Extra 300. The only down side is that it is VERY slippery and is hard to tie knots in. I had to CA the knots to keep them from slipping.

Unfortunately I cannot remember the brand name. I bought it at K mart based on a thread on another forum.

I will try to look it up tonight if the memory works.

Jerry

blue62

My Feedback: (3)

its called "spiderwire" get the braid not the fusion! i use this to fish with and believe me it is strong!!! careful not to get any unwanted knots in it because you won't be able to get them out!

john

transmission_dr

My Feedback: (1)

Hi,

Yep, Spiderwire is what I have, the spool says 80 pound test.

The down side is that it was kind of expensive, I think around 12 to 15 dollars for the 300 yard spool. The good side is that if you buy the spool you will likely have a liftimes supply.

Jerry

nav8tor

Jerry,

Is the airplane sitting in a metal hold down when you do the range check?

Mach I

My Feedback: (10)

When I do range checks, the plane has been sitting on the ground, in my driveway, or on a table.

-Chuck

nav8tor

Just wondering because I had a similar problem which turned out to be interference from a metal plane restraint.

Lee