ilikeplanes

I just about lost my brand new Extra twice yesterday. First time I figured it was high winds, second time I was positive I had a radio problem. The radio is a brand new 6XAS, Its's in a DP Extra. 5 cell Rx pack all HS645MG servos. Pull-pull rudder and elevator (six cable runs to tail). One clue I had was the antenna down range test. It was good to only 75 feet or so (seems like I get better with my other radios). I've been flying for 20 years and have set-up dozens of airplanes with no problems. The only deficiency in this particular installation was the antenna was within 1/4 inch of a servo and passed by a bundle of servo wires. I have changed the Rx mounting for ideal straight out antenna routing. The antenna is at least an inch from any servo but very close to a rudder control cable.

How do I check this out and regain confidence in the system?

amcross

My Feedback: (2)

Ilike,
Consider installing the radio in a less complex, less expensive, less stress aircraft. fly the beegeebers out of it to regain your confidence.

As far as finding the phantom if there is one in the airplane, is this a gasoline installation or nitro?

Sincerely,
AnnMarie Cross
President
Crosswinds Equine Rescue, Inc
http://www.crosswindseqresq.org/

ilikeplanes

It's a glow engine. I don't have a problem with my personal confidence, just confidence in the equipment. I am considering swapping to a different airplane. I also have a tried a true radio that I could use. That doesn't solve my problem though. I still need a fool proof way to range check this radio/airplane.

amcross

My Feedback: (2)

Ilike, Unfortunately, there is no foolproof way to range check anything. A range chck is just a comparison test to the radio's normal behavior to see if it appears to be operating the same today as it normally does. It is not an end all or be all test for anything.

Sorry, didnt mean your personal confidence, just a model you would be less concerned about if the radio performs poorly. I would put a 'tried and true' on board and see how it performs on the bench and go from there.

rik756

My Feedback: (12)

I bought an XF631 brand new. We ranged checked it antenna down etc and no problems. Flew the plane (a trainer) and crashed about 250 feet out. I thought it was my fault since I was low and fast. Repaired the plane and flew a few more times with no problems. A long time pilot flew the plane and crashed at almost the same range area I did but again we were showboating it so we thought it was our fault. I put the radio gear in another plane and flew at another location. Again, all range checks were fine. This time I *lost it* for a moment (no control) but got it back so I was going to land it quickly. Just as I came around to make the final approach it crashed at the same range and just like the other crashes, a hard right into the dirt.

This time we left the radio on the bench and walked out to the plane. When we got there the servos were going nuts. We had a couple guys walk around with the radio (antenna up) and it stopped as the got close AND a little further away.

I sent the radio and two stripped servos back to Horizon. They said there was a faulty power output something or other and fixed it all for free. Sad thing is it tore up one plane pretty bad and totaled another before we figured it out. I would either do the full 360 with engine on/off and or send all the gear back to have it checked. If you tell them you have had a similar problem I'm sure they would check it for free.

ramcfarland

My Feedback: (44)

Are you running the Rx. Ant. inside the fuesalage? Running a reciever antenna in close proximity to steel "pull pull cables "can (possibly) cause range problems.

ilikeplanes

I am running the antenna inside through a ny-rod. If I moved it out, I would only gain 1/4 inch more separation. It gets closest at the very end. This set-up is an improvement over the set-up I had initially (read first post).

I'm going to do one more range test at the field. If I don't get warm fuzzies, I'm sending it back to Futaba.

What a pain.

rik756

My Feedback: (12)

Is it at all possible you have some metal to metal contact somewhere? Metal virbating can also cause freq problems. One of the guys I fly with can turn his radio off, leave the plane on and control his ailerons by switching his electric fuel pump on and off from 10 feet.... Maybe a clevis or pushrod is rubbing something ? Perhaps a bad connection on the antenna at the receiver? Just some thoughts..

DGrant

My Feedback: (4)

I used coated kevlar on my pull-pull set-ups on my giant Extra. Don's hobby(Salina,KS) has the stuff in bulk and you can make your own rigging very easily using aluminum tubing for crimps. You'll also need the eye-bolts, and links to fix to the servo arms.
Matter of fact...he sells the kits. Get one of those kits, and just install like directions call for. No Rf interference there....and that might settle one issue. Plus...it's stronger then steel, and NO stretch. Good luck.. ..it does sound like it might be Rf from cabling if your using steel..my 2cents.

ilikeplanes

The closest metal to metal is the Sullivan clevis in a Sullivan horn. There is a nylon separator molded onto the horn. I'll double check. All other joints are either plastic to metal or screwed tight with lock nuts.

Another thing - When I originally set-up the airplane, I noticed that if I rattled a screwdriver on my servo clevises, the servos went wild. With my new set-up, I get a slight twitch when I touch the screwdriver to a clevis.

Do I really have to remove my steel cables and replace with Kevlar. I've never had problems with steel cables before.

airbatic

It's a Futaba! Well then, you're the problem.

Kraus

dirtybird

My Feedback: (5)

When you turn on the receiver (with the transmitter off) the AGC circuit increases receiver the gain to its maximum level. It will pick up any stray RF that happens to be around.
When you touch the metal screwdriver to the clevis the static electricity in your body passes to the metal you are touching. The result is a small spark. You will not see it unless you are in the dark. Even then it might be hard to see but it is there. This spark creates the RF that causes the servo to jump. This is not a problem unless you plan to fly around yourself with the transmitter off and jab the airplane with a screwdriver