Radio noise

Went out to fly today. When I turned the radio on, there was a constant noise like a stuck mic. I took off and the noise persisted on both radios. When it continued after switching freqs, I Started troubleshooting. I tried everything I could think of. I then asked myself, "what did you do differently today?"

i then realized that I had plugged a USB charge adapter from Amazon into my power port. It was charging my IPad and phone. When I unplugged the charger, the radios went quiet. Guess some of these put out a lot of RF interference.

Eddie

It's surprising how much noise some of these items put out. If I recharge my phone in my truck, it puts noise on all AM stations and some FM stations. In my case I think it's the phone itself as the frequency and volume change if I hold it up or stretch the cord out. But my Ipod makes no noise at all. More 'FM' theory! Something we all need to be more aware of as we use more of these items. Makes me wonder about their effect on other nav and com items.

Web

You sometimes see a "complies with part 15 unintentional radiators" or similar tag on consumer equipment which basically means the manufacturer tested his product to be below the part 15 radiation requirements for unintentional radiators. One of the problems is sometimes different equipment can put out different signals at different voltages, temperatures, configurations and so on. On some of receivers with a 455 kc intermediate frequency you can select a receive frequency 455kc higher or lower on a second receiver than the what you are listening to the first one and the first one will get a full quieting signal from the second receiver local oscillator. Nothing you can do to eliminate it except don't run in that configuration.

http://www.law.cornell.edu/cfr/text/47/part-15/subpart-B

What he said. Whatever it was.

Electronics At least with hydraulics, you can see the leak most of the time.:-?

My charger in a F150 is so noisey it pretty much totally blanks out my FM radio to useless, so when its pluged in ghe radio is off!

Once upon a time in Kansas, I worked on a municipal wastewater project for a smal town that had a note on the plans to "Relocate EMS Box." I finally just had to ask...and the engineer's answer was "you know EMS, Electricial Magical ****!"

skywagon8a said:

Electrons At least with hydraulics, you can see the leak most of the time.:-?

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Yea, but don't put your finger on it

Glenn

Lefoy84 said:

What he said. Whatever it was.

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That means that some equipment can produce noise and there aint much we can do about it. Try it. If it makes noise, don't try it anymore.

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