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