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ochbchuck 10-05-2014 2:09 PM

Scanner and phone car chargers.
I have a question. My uniden 396xt does not receive anything when I am charging my i phone using the 12 car charger.
As soon as I unplug the charger from the phone the scanner comes alive. I am using batteries in the scanner. The same thing happens in two different cars. It feels like the rf shielding has failed. It thats even possible Any ideas?
Thank you.

kayn1n32008 10-05-2014 2:13 PM

Scanner and phone car chargers.
Double post

kayn1n32008 10-05-2014 2:14 PM

Scanner and phone car chargers.
Both my BB and Ipad do the same thing with my V71a and my NX-700 in my truck

krokus 10-05-2014 2:24 PM

Many smartphones seem to generate a significant amount of RFI while charging. My AM/FM radio starts to get static on any station that is not very close. (A 50 kW FM station that is about 30 miles away gets noisy, for example.)

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ochbchuck 11-02-2014 1:55 PM

Sorry for the late reply. Work got in the way.
Thank you for the replies. How does one charge an Iphone and monitor while in the car. I was searching the web, i can across about having a good ground within the radio. I may try to re-solder the ground wire in the radio.

popnokick 11-02-2014 2:29 PM

It's the USB phone charger that you are plugging into the 12V cigarette lighter socket. They are cheaply built switching power supplies that generate huge amounts of RFI. I have found the more discharged my iPhone is when I connect it to the USB charger, the worse the scanner interference. Some USB car chargers are worse than others, but if you find a "quiet" one let us all know.

ochbchuck 11-02-2014 2:42 PM

Copy that. I am on the hunt.
It sucks that when i am driving and need to use a map app. That I can not charge my phone and monitor at the same time. I will let you know what I find.

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EDCScanner 11-05-2014 7:21 AM

Just so I understood correctly. If you are charging your iPhone your 396XT won't scan? Is the scanner plugged up charging as well along side with the phone? I have never experienced this before. What kind of case is on your iPhone?

jaspence 11-05-2014 8:17 AM

iphone interference
You shouldn't have to have a metal case around the phone to prevent interference, and it may come from the cable or charger as readily as the phone. I can charge my Moto X in the car and my radios still work like they should.

jackj 11-05-2014 9:15 AM


Originally Posted by ochbchuck (Post 2278975)
I was searching the web, i can across about having a good ground within the radio. I may try to re-solder the ground wire in the radio.

I wouldn't do that ochbchuck. Your problem isn't inside the radio, it is caused by the DC/DC converter in your iPhone's charger. Those things have a high frequency oscillator that drives a RF transformer with square waves (really high harmonic content) and they generate a lot of interference all across the spectrum.

Two things you can try that might help. Get a ferrite choke for the lead between the charger and the iPhone and move it around on the wire to find where it cuts down on the interference the most. Also try wrapping aluminum foil around the portion of the charger that sticks out of your car's power outlet. Also make sure you are using the 12v charger that Apple sells, not some cheap, after-market knock-off.

Good luck.

robertmac 11-05-2014 1:58 PM

I haven't had any problems with my portable Uniden scanner when charging my BB. However, my on board camera does produce some RFI on frequencies around the 160 mHz.

KZ9G 11-26-2014 5:24 PM

I had a charger that did the same thing. Most of the hard wired ones you can add will not have this issue. I think powerwerx has a 3amp usb port that is pretty clean.

n9mxq 11-26-2014 6:40 PM

I have one USB double charger that completely blanks VHF and broadcast stereo when I use it.. Which I don't do unless I'm desperate now..

It was a cheapy, purchased at the local gas station.

jaspence 11-26-2014 7:02 PM

Radio vs phone charger
My Moto X charger doesn't cause my scanner or dual bander to have any problems. I also have a couple of hts that I carry with me and they haven't been bothered, but they are not plugged into the car electrical circuit. There was a discussion on a local repeater about this problem, and most of the ones who complained were using iphones.

scottyhetzel 12-06-2014 10:17 AM

On a side note, buy 2.1 amp USB chargers, they charge quickly. The 1.2 stock amps are slow, which is where you find everywhere for the car. I run Leviton duplex wall units at home that are 3.6 amp. They do a stellar job super fast. I like the ferrite core idea..I thought it has to be a certain type ferrite?

popnokick 12-29-2014 7:29 AM

Mobile scanner USB interference-SOLVED!
Eureka! The 3rd try was the charm in solving my mobile scanner interference. I knew the problem was coming from the 12V USB cigarette lighter phone charger.... and had tried two other chargers up until now. Most recently a Kensington single USB port with a power indicator LED. But I was given a dual-port 3.6 amp smartphone / tablet charger made by iFlash and tried it yesterday. Took out the Kensington, put the iFlash in the lighter socket. Connected my iPhone to the charger, turned on the scanner, and headed out with the car on an errand. Interference was gone!
Before the iFlash, the Kensington unit used to cause the scanner to stop on a channel (mostly VHF low band, but some milair as well) and sound as though the squelch was open. All you would hear is hissing of an open squelch. However, no amount of squelch adjustment would remove the noise. You could turn up the squelch as high as you liked and scanning would not resume. Not only did that not happen anymore with the iFlash, but I discovered that the Kensington unit when it was charging my iPhone was also desensing my scanner even when it didn't stop scanning. I noticed much greater sensitivity on all bands when hearing the usual "locals" I listen to, and was regularly hearing both sides of the regional ARTCC air conversations... including the ground station / ARTCC remote base.
I'm not saying an iFlash dual-port USB 12V car adapter is the only one that doesn't apparently emit RFI garbage, and YMMV... but it's working for me.

jackj 12-29-2014 9:58 AM

There are several types of ferrite chokes out there, Scotty. The type you need will depend on the frequency you want to suppress. But they aren't really a fix, more like a band aid. The real fix is finding one that doesn't generate the interference to start with and it sounds like popnokick has done that.

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