Hi

Ive read somewhere that cellphones can't interfer with transmitter/receiver of rc planes, bc the frequencys are far from each other. But one time, i was testing my radio, and i had some glitches when someone called me! Do you fly with your cellphone near you? I did, but now i dont

I don't! i leave my phone in the car.
Not worth the risk. U can't answer it when ur flying so there really is no point having it with you.[8D]

I do! I listen to MP3 on it, with earbud and set to auto answer. Never had so much as a peep of trouble out of it.

Gentlemen, I am from Australia , and our governing body, MAAA, recommends that mobile phones should be kept well away from radio transmitters. It is interesting that a major radio manufacturer recommends that mobile phones should not be taken near transmitters as the signal from them, ie, the telephone, exceeds the design specification of their equipment.If your radio has been close to a mobile phone that was switched on, check very carefully that it functions correctly before takeoff. There are reliable reports of information in the memory of your radio being changed. This happened just last weekend to one of our fellow members, who on take off found all his controls were changed to 15degrees of down elevator and ailerons 10 degrees of right aileron. The result was a cartwheel down the runway.

If you worry about cell phones, please don't come to my club field. Three quarters of the fliers, including myself, have cell phones on their belts or in pockets. We have yet to see a problem.

I think a lot of the warnings are to protect the manufacturer and national organization from product liability law suits.

As for having a phone close to a radio, I don't run my battery lead near servo leads, if possible and I run the receiver antenna out of the fuselage and away from battery and servo leads. If's just good practice. I would imagine putting a cell antenna very close to any other type of antenna could cause some swamping or interference, but I don't thing you would get any after a couple of feet.

This controversy has been around for at least a couple of years. No one in our club has seen any effects frm cell phones, however, as a due dilligence initiative we have banned cell phones from the flightline.

Oh boy, here we go again. This subject pops up about twice a year here, and everytime it does there's always a huge arguement from both sides. There will be those that say it's completely safe and they will offer all kinds of scientific research, frequency charts, and examples of how safe it is and how it's impossible for cell phones to interfere with our radios. And then there will be the group that will swear up and down that a cell phone will interfere with our radios and they will offer all kinds of first hand accounts about planes that crashed as soon as a cell phone rang at the field, or how they got shot down because somebody at the field was making a call and how their field has banned cell phones within a 10 mile radius of their clubhouse because of the problems.

No matter where you weigh in on this discussion I will ask that everybody stay friendly and respect others here in this forum during this discussion. If not I'll close it down.

Enjoy the discussion

Ken

The question of cell phones interfering with our R/C equipment is a tough one that presently has no definite answer.
I have never experienced any trouble with cell phone interference even though I always carry a mobile phone in a belt clip when flying. On occasions I received calls during flight (using a hands free head set), without any problems whatsoever. I have tried really hard to induce some kind of disturbance in my trusty old JR X-388 Tx by deliberately operating my cell phone as close as possible to the transmitter. So far the Tx has withstood my abuse with no signs of problems.

Having said that, there is a possibility of cell phones interfering with electronic equipment:

- Multiplex recommends that cell phones should not be operated in the immediate vicinity of their Royal Evo transmitter. Apparently there have been some incidents where the "computer" part of the transmitter has malfunctioned due to soft error interference.

- It appears that the latest version of the Apple iPod has a problem with cell phones, see this link: [link=http://www.theinquirer.net/?article=27709]http://www.theinquirer.net/?article=27709[/link].

IMHO cell phones have no effect on the radio link between the Tx and Rx in the traditional "radio interference" sense. Instead it appears that the radiation emitted from cell phones might induce soft errors in the digital circuits used in modern "computer radios".

It may be a good idea to test your own Tx by operating your cell phone, i.e. making a call with the cell phone in different positions as close to the Tx as possible. This should ideally be done in a location where cell phone reception is poor in order to make it operate at the highest power. If your transmitter stands up to that you are probably safe. Remember that this is a worst case scenario. The power intensity of the radio waves emitted from the cell phones decreases with distance squared, e.g., at 3 feet the intensity is only 1/9 of the intensity at 1 feet.

/Red B.

I would guess the elevator and aileron problem stemmed more from the lack of changing over to the correct model before takeoff--rather than some cell phone "re-programming."

Personally, I don't like phones--period. I hate them. I especially hate cell phones. I have one, and it stays in the truck always. Every now and then I'll check to see how many calls I've missed over the past week or so , but other than that, I don't get it out and use it. My brother uses his all the time, and there has been no problems whatsoever with it!

2slow2matter, i acknowledge your comment about wrong model selected before takeoff, and i agree that is a problem often occuring. But in the case i mentioned above , the flyer only has one model, and had already flown 2 flights successfully. To clarify the situation, he had his phone sitting on his lunchbox, and the transmitter resting against it. After refueling he reached behind himself, turned on the transmitter, and then the aircraft, proceded to start the motor , picked up the transmitter and carried the model to the center of the strip. Upon throttling up the problem occured. So the only criteria that could have caused the drastic change in his controls was the close proximity of the transmitter to the phone.

MINE NEITHER .............

I wish most of you would read up on FREQUENCY before dispelling this myth. Cell Phones, Beepers, radios, cordless phones, Ipods, etc all work off of FREQUENCIES. How in the world can somebody sit back and worry about interference from a long list of electronic devices that use FREQ'S ?

I agree with 2slow... I don't have a cell phone and don't want one. Not because I'm worried about interference, but because when I'm at the field I leave the real world behind and relax with my friends and my planes.

In all seriousness though, there are a lot of them at my field and I have never heard of a problem. Nice to be able to call for help whenever you might need it. Or order a pizza![8D]

It never occurred to me to bring my phone to the flight line. However I have seen many people use their phones at the field. I wasn't aware this was a controversy. For me, its just my personal choice.

There is no telephone at either field I fly at, or at any slope site, so I keep my cell phone with me when I fly in case of an emergency. I've never had an incident of any kind with interference from the cell phone, but then again, I don't use it while I'm flying. It's just there in case it's needed. If someone calls while I've got a plane up, that's what voice mail is for.

papermache

Got an RF interference question? Ask a ham!

On the surface, one wouldn't think a cell phone could cause problems with RC gear. After all, the RC gear is operating in the low VHF region (or high HF, for 27 MHz) and cell phones range from 800+ MHz on up. You'd also expect that a cell phone, IF it were going to interfere with anything at all, would interfere with your receiver, NOT your transmitter. Think about it... your transmitter doesn't have any receiver circuits, so why would it care about other transmitters?

Now let's talk about reality. Cell phones do put out a little bit of RF enegy. If one is close enough to your gear when the phone's transmitter fires up, there is a chance that some of the RF energy can affect poorly designed or poorly shielded electronics. This includes receivers, digital electronics like computers, or pretty much anything else. When I have my cell phone sitting on the desk next to my POS land-line phone, I can hear a little blip from the wired phone just before the cell phone rings. Of course, that land line phone also goes nuts when I transmit on HF even al low power levels, so it's an extreme case. However, it's not at all unusual for some electronic devices to be affected by very close cell phones. You'll find all kinds of TVs, phones, rdios, etc. that will give a little tick, beep or whatever when a cell phone placed a few inches away rings.

Note that I said a few inches away. On the practical side, there's no way your cell phone is going to affect your plane's receiver or servos if it's more than a couple of feet away. If your transmitter is bothered by your cell phone (assuming you're not carrying an old 3 Watt Motorola brick), you really probably should think about getting a new transmitter or getting yours fixed. If it can't deal with a cell phone clipped to your belt it's either poorly designed, poorly shielded or has a problem. In any case, leaving the cell phone with your flight box while flying will give you more than enough distance to be safe. It will certainly make your flying more enjoyable!

Regards,
Dale
NØXAS

Dale, it's good to see another Ham post to a thread like this one. KCØDJH here. I agree with what you say. We could go into the technicalities of Cell phone/ RC transmitter-receiver interference all day long.

The easist way that I have found to show people that cell phones do put out a strong initial pulse is to place a phone near a speaker. Paticularly a computer speaker which is supposed to be shielded. Usually, the speaker will hum when a phone receives or sends a call. However, the phone has to be within 12 inches or less in proximity to the speaker. It is possible that a phone could cause some level of interference, but it's highly unlikely. I still don't buy the "my cell phone reprogrammed my transmitter" line.

Rule of thumb, keep your phone away from your computer radio if you are concerned.

I'LL put an end to this topic once and for all !!!!!!!! CELL PHONES and flying is the same as..........ummmmm...........hhhhhhmmmmm.......... ...duuuuuuhhhhhhhh........WOMEN DRIVING WITH A CELL PHONE. It cant be done!!!! Totally impossible. Ever see a woman driving 10mph in a 35mph and you finally pass her and WHAM a cell phone in the ear ! It cant be done, they can drive with one, and we cant fly with one.
I need two hands to fly. NOW I was at TOP GUN in Florida a few years ago and I seen a gentelman fly with one arm. He used his arm that was amputated at the elbow to use the throttle and rudder. AWESOME FLYER. I'LL bet he could use a cell phone and fly.
Bottom line is, why chance it. Unless your a bad flyer and need an excuse for a crash.

Alan

dbotkin wrote: I agree fully with you!

I agree with you. However, in the manual for the Multiplex Royal Evo it is stated that:

"Minimum distance to mobile phones: 2 m !
When operating the transmitter maintain a minimum
distance to mobile phones of 2 meters."

(see page 5, [link=http://www.multiplex-rc.de/cms/vorschau/upload/d_anleitungen/t_re_9_12_2_gb.pdf]Royal Evo Manual[/link])

I don't think that Multiplex is worse than other manufacturers in this respect, but as far as I know they are the first to actually acknowledge that there may be a problem. Cudos to Multiplex to be brave enough to acknowledge this. Now I'm waiting for the manufacturers to actually manufacture equipment that can operated safely in the close vicinity of mobile phones.

/Red B.

In my Opinion, cell phones and computer transmitters do not mix. I have had problems and will not have them that close again. For anyone who says that there is not a chance, then why is it not advisable to have a pacemaker near a cell phone?

I was at the field one day when there was just one other flyer and me. He's a good flyer and I've seen him fly many different planes. He was flying a Twist and during his flight, he answered his cell phone. And instead of saying "I'll call you back" and hanging up, he kept on talking and flying.

But that's not all. Awhile later, while he was flying, he pulls out his cell phone and makes a call!! He talked for a long time while flying. I think he even landed and took off while talking.

I couldn't believe that someone would actually do that!!

So it's all true, a cell will and can bring down a weak receiver as "a HAM" said it's a common problem with skip,side band ,side lode, harmonic etc... Is it a problem to stop using them NO not enough to argue over, can it be proven good question and in my view it will never be proven. Cell phones transmit RF and a damaged one could to anything. We also allow cell phones I myself leave it on in the field box. Saved my a.. when Iam late and boss wants me [:@]. But a club solution could be to keep them at the pin area away from the other planes to keep peace in family.
Rich

I know it happened to my twice.
Do I need to prove it, NO.
Will I allow a cell phone near my TX while it is on, NO

We had two guys at the field test out this very thing. They called each other while both were flying on the flight line and you know what happened? They mid aired! So that proves it, cell phones will cause interferance!

RADIATION.

True -- electromagnetic radiation.

In the same vein (nyuck, nyuck ), if there is no problem, why are cells banned from hospitals? --- 'cause there have been instances of interference with electronic medical equipment.