Futaba AM vs. Futaba FM w/Hitec Mod
 

Hi All,
Recently, one of my planes crashed from being interfered with by another radio on a different channel. I was on AM channel 24, he was flying a heli on FM channel 35.

I have an older Futaba 5UA transmitter with a 7 channel AM FP-R117H receiver. It is reliable, and I have not been interfered with by another radio since I bought it new.

He had a Futaba 8UAFS with a Hitec synthesized module in it. I do not know if Hitec and Futaba modules are interchangable (obviously they are physically, but are they o.k./approved to use in Futaba transmitters?)

After retreiving the plane, we did some testing and found that at fairly close range (25-50 feet) he was in clean, crisp control of my plane - it was moving the surfaces precisely, not glitching at all. Much further away, and it would no longer do this.

I have never seen this before - can anyone could offer some suggestions? There was one other crash that day where another AM flyer lost radio control as well. He was not on AM channel 24 athough he had a similiar experience.

Any ideas? :confused:

Futaba AM vs. Futaba FM w/Hitec Mod
 

He is operating in violation of FCC regs, because the Hitec module is not approved for use in Futabas. It is also possible that your receiver, getting a little older, was starting to pick up outside signals, especially at close range where it can get 'swamped'. Either way, if the pilot was operating an unapproved radio setup then he needs to accept that responsibility.

Futaba AM vs. Futaba FM w/Hitec Mod
 

Why blame the guy for your receiver being an older, and less efficient model, (obsolete filtering) possibly causing it to be swamped by a more up to date Tx.? That being the case, it`s not his TX that`s at fault (albeit TECHNICALLY illegal). Just out of curiosity, is your system a narrow band?..If it is not, then you would be illegal also!...It`s a very common practice to use the Hitec/Futaba combo ( Although it DOES NOT make it right). As far as FCC Regs..... Did you know that ALL members operating a R/C Tx. who are not registered with the FCC are operating illegally!...If then,.. you are leaning on legal technicalities, it`s probably a draw!...I have the same 5UA radio for about 15 yrs! My point is, that`s the chance we take when we use outdated equipment. It`s just a question of WHEN we will get "hit". Not IF we will get "hit!"! To blame someone else for our misjudgment's in our choice of equipment just isn`t fair. Just another point of view, and food for thought IMHO...Oh!... Just for the record,..YES I do, and will continue to, fly with members that use the same Futaba/Hitec combo.

"Just for today"

Futaba AM vs. Futaba FM w/Hitec Mod
 

I don't think the older equipment was the problem. The mismatched RF deck/transmitter could very well be a problem. Just the fact that he is now suspect is one very good reason for NOT skirting the law . YES the mismatched setup could cause problems . The very setting that makes for "narrow band" transmission is the deviation level. Too much drive to the RF deck could cause off channel harmonics.

Also the RC license is no longer required on the 72 MHz band .
That is an out of date regulation. The type acceptance is gone as soon as the HiTec module is plugged in to the other brand TX and turned on.
May be hard to collect ,if I were him I would pay up just out of embarrassment :eek:
It is nice to be operating within the law when someone has a plane trashed from interference.

Futaba AM vs. Futaba FM w/Hitec Mod
 

Thanks LF,
I stand corrected on the FCC Regs. My apology. As for the Rx vs TX...Unless we were there with a Spec. analyzer, we`ll just never know. We can speculate on decks, RFI, and Rx filters forever! However, if we stick to FCC regs. and use well maintained equipment, lots of planes will be saved. MOST of all the margin of saftey as it pertains to flyers, and specators will increase. And after all, I`m SURE we ALL agree that IS what`s most important. Thanks again to all...

Joe-

Futaba AM vs. Futaba FM w/Hitec Mod
 

Thanks for the replies! I thought this combination of Futaba/Hitec might be suspect. I am not sure if my system is what is referred to as "Dual-conversion" but it is definitely narrow-band. If I understand that whole thing correctly, the transmitter must be gold-stickered and if the receiver is too, then it is dual conversion?

There is also the fact that my old AM set is probably more suceptible to interference - worst part is, I own an 8UAP and had a spare FM receiver that I could have used...I just never had any reason before to worry about flying my trusty old 5UA before now.
Joe, you do have a valid point and I'll probably shelf the set, its not worth wasting another airframe due to folks who won't or don't follow the rules through b/c of ignorance or indifference.

Ladyflyer, I think you and Ryan hit the nail on the head - I also think this guy took someone else down who had a newer model Futaba basic AM 4-channel radio. I don't think the person who took me out knew that this is not o.k. to do. He was very nice and helpful when after the crash we tried to figure out what went wrong. He said he bought the radio with no module in it and bought the synthesized Hitec module for it afterwards. Since I was unsure, I could not fault him on the spot. I now think he should own up and offer to pay. I'm also concerned that he find out that he's indeed operating illegally so he can fix it and nobody else loses any more stuff or worse, gets injured.

Where online or in print, I can find the FCC rules stating that the Futaba/Hitec combo is not approved for use? I want to absolutely sure before taking any action...


Thanks,
Rusty

Futaba AM vs. Futaba FM w/Hitec Mod
 

Rusty,
Try this page for starters. It's a lot easier for me to read this than go searching through government web pages, if you know what I mean.

http://www.futaba-rc.com/faq/faq-9c-q504.html

Futaba AM vs. Futaba FM w/Hitec Mod
 

Thanks, Ryan!! And thanks to all - Happy flying and oh yeah, New Year too!

Rusty

Futaba AM vs. Futaba FM w/Hitec Mod
 

I am disappointed in you guys. I wouldn't pay. Has this old AM radio ever been checked???? I thought this is what was supposed to happen occasionally. A lot of threads have had that suggestion posted, even by LF?? If this was done, it wasn't intentional. Maybe the crash screwed up your receiver. COME ON!
Yes, he's illegal and I wouldn't do it, but I also dumped an old Futaba AM setup given to me(7 channel, top off the line, but old) b4 taking this hobby up because I didn't want to lose or cause someone to lose a plane with old unchecked equipment, that had been working fine.
I believe there are many thousands using that combo of Futaba and Hitec Spectra. I don't condone it but it works. We don't have a clue what that AM is picking up from this info.

Rx Interferance
 

The guy with the AM set has a Receiver that Futaba says is narrowbanded. The FM guy is operating in an illegal manner and therefore is responsible. If he was a gentleman he would accept his responsibility and pay for the damage.
I have personally talked with two equipment manufactures about this practice and there answer is --It works most of the time but not all of the time.
If he was in our club he would pay for the damage or he would be out of our club.

Futaba AM vs. Futaba FM w/Hitec Mod
 

Sorry. :rolleyes: Guess I would be looking for a new field. Your loss.
Look at the caution.
http://www.wdarc.org/Admin/WDAFieldOperations.pdf

Flyfalcons: AGREED

Futaba AM vs. Futaba FM w/Hitec Mod
 

I don't want to start anything, but those rules also state that all radios must be operated in accordance with FCC regs. Can it be proven that the Futaba/Hitec combo caused the crash? No. Can it be proven that the AM receiver is at fault? No. This is a bad deal no matter how you look at it, but even if no blame can be assigned, it should serve as a wake up call for people wanting to operate unapproved combos with their radios and modules.

Edit - this post was in reference to the previous one, which contained a link to a set of club rules mentioning that a specific Futaba receiver be used with caution.

AM interference
 

My isn't it interesting that some of you assume that the guy operating the AM set has not had his radio CHECKED or tuned recently!

But no one here has questioned when the guy operating the newer and ILLEGAL set up last had his radio in for a check up

If I knew I was going to operate my radio in an ILLEGAL manner I would at least have the courtesy to have the ILLEGAL radio configuration checked by a shop to prevent problems.

One fellow even acknowledges using a similar setup himself knowing it is illegal, but points his finger at the other modeler using a LEGAL but older system. Incredible!!!

AM is still 100% LEGAL!! Just as legal as FM!

OK now for the test - Who is responsible if the AM radio is an old Wide Band system and he shoots down the guy with the ILLEGAL Futaba/Hitec system?

Futaba AM vs. Futaba FM w/Hitec Mod
 

Kind of like driving down the road in your legally licensed 1990 Chevy pickup with valid plates and safety inspection . All at once a kid in a hopped up Honda Civic with an Acura engine crosses the center line and you wind up totaled.
Now the Honda driver's lawyer is saying if YOU had a newer truck with anti lock brakes the accident would have been avoided :confused:
This is what we have been saying when we talk about the risks involved with illegal modifications.

Yes it is hard to prove ,but all indications including controlling your plane ,another suspect crash and the illegal operation sure point in that direction. If his transmitter had been a type approved transmitter there would little cause for concern.

I doubt if you can force anything . I do know he would be removed from our club if he didn't pay up and agree to run only legal equipment in the future.

If it were my transmitter you would already have been paid ;)

Futaba AM vs. Futaba FM w/Hitec Mod
 

Where is your evidence?..Just because he was in violation of FCC regs, doesn`t automatically make him the cause!..It was stated that the guy with the TX in question was able to move the surfaces of the downed plane AFTER the crash!..What does that prove? "Pointing in that direction" does NOT constitute proof! Who knows what happened to the RX POST crash?...As for your example of the Honda vs Pickup truck?...Really now!..The question isn`t if the brakes of the pickup were state of the art ABS or not. It`s rather if they were working properly on either vehicle at THE TIME of the incident. Lots of things can happen after vehicles are issued a "valid" inspection sticker. To make a guy pay for something that cant be proved just isn`t fair. All do respect...as far as being asked to leave the club if I didn`t pay for something that can`t be proved?.....You wouldn`t have to. I wouldn`t want to be in it to begin with! As member & President of a club that has had as many a 250 members in it, I have had the dubious job of mediating some "shoot downs" In a case such as this, I would have to insist that the guy NOT violate FCC guidelines, and not fly until he is in FULL compliance. But to make him pay?....I haven`t heard anyone involved in this thread POSITIVELY prove the Tx is at fault yet?..Just what they THINK happened...Not ONE person said they KNOW what happened! Very interesting how everyone became a judge, jury, and Telecom. attorney/Psychic! But, it does serve as a GREAT lesson in why we ALL should follow rules, and regulations, be it the FCC, or at the club level.

Futaba AM vs. Futaba FM w/Hitec Mod
 

This post is a good reminder of why I will not allow anyone to fly at an event that I CD with the Hitec/Futaba Tx combination.

Dan

Futaba AM vs. Futaba FM w/Hitec Mod
 

Hi All,
There's a little more to the story, and I also want to make something clear in reference to my previous post where I referred to "taking action".

First of all, please know that I would not ask another flyer to pay for my loss unless he showed up drunk at the field and then stepped on my plane - I'm just not like that. Crashes happen in this hobby; sometimes they can be prevented, though. I now think this one probably never would have happened if the guy was following the manufacturers guidelines for safe/approved operation. Can I prove it? No, and I'm not going to try to. We tested after the crash and we all saw something that is not supposed to happen. I figured that I'd get some good info on what may have happened here in this forum and thanks to you all, I have. Hopefully it won't happen to me again since my AM days have pretty much come to an end.

What I said in my previous post is I now think he should own up and pay. I would if the roles were reversed. I was flying as a guest with friends at a field in a neighboring county and although we did introduce ourselves, I don't remember the guys name. Will I hunt this guy down and demand payment? Nope. But I will make an effort to contact him and let him know what I found out. He was a decent guy and I honestly don't think he knew (any more than I did) that his radio might be causing troubles for guys flying on AM. If he replaces his module with an approved one it may prevent another crash for the other AM flyers at his field. I would consider that worthwile "action".

Someone on RCU has a signature that says "Perfect landing or total destruction crash - I still love this hobby". That kind of sums it up for me, too.

Later Ya'll and Thanks Again,
Rusty
[email protected]

Futaba AM vs. Futaba FM w/Hitec Mod
 

Hey Rusty,
You, and ALL the flyers that expressed their views on this subject, help make this hobby/sport the great one that it is, and myself most proud to be a part of it. Weather we agreed or not, personally, I would fly with any one of you, anywhere, at anytime.

Thanks,
Joe

Futaba AM vs. Futaba FM w/Hitec Mod
 

Well said Joe ,
I agree !