• Get involved.
    We want your input!
    Apply for Membership and join the conversations about everything related to broadcasting.

    After we receive your registration, a moderator will review it. After your registration is approved, you will be permitted to post.
    If you use a disposable or false email address, your registration will be rejected.

    After your membership is approved, please take a minute to tell us a little bit about yourself.
    https://www.radiodiscussions.com/forums/introduce-yourself.1088/

    Thanks in advance and have fun!
    RadioDiscussions Administrators

Cellphone chargers

Mark Roberts

Mark Roberts

The hotel I'm staying in while I'm dealing with movers seems to be built like a tank, plus it's in Pleasant Hill, in the Diablo Valley in the East (San Francisco) Bay Area, of which it's said, "The Diablo Valley is where FM signals go to die". But AM has even worse luck in the hotel. Can barely pick up KCBS(AM). If there's a booster for KFRC-FM (//KCBS (AM) on Mt. Diablo, it's not working, because I can't get it. So...that brings us to my Samsung fast cellphone charger. If it's just plugged into the wall, fine. But if it's also plugged into my cellphone, it seems to block even what little signal I can get from KCBS. It doesn't generate noise, though another, similar charger that's not a Samsung does generate noise. The Samsung charger just creates a dead zone.

The lesson to me for this when considering reception is that, if you've got a cellphone charger anywhere near, you might be blocking out (weak) signals, even if it doesn't appear to generate any noise.
 
I've noticed this too, the only charger I ever found that was completely RF silent was the one included with my OnePlus N200. Every other charger I have used generates at least a little noise.

Of course, in a concrete hotel most AM signals get blocked (or at least attenuated) by the rebar used in the structure. And a lot of chain hotels have furniture with built in USB ports, so you often end up surrounded by noisy power supplies. So that works against you too.
 
Listening to AM in a hotel is so difficult nowadays because of the lights, TVs, and other electronics running. Even the fans and heaters can create awful noise. On my last trip to Montana, one of the hotels had very little AM reception at night because of this - and I wasn't willing to go out in the 30F cold weather on an April evening to see what I could find. This was the Hampton Inn, Whitefish.
As I recall, even FM reception sucked in the room. Local translators 8 mi down the road in Kalispell were quite weak even on the 2nd floor, filled with interference.
Luckily, I had excellent AM reception next to the window at the Best Western in Missoula. There were 5-10 channels that had bad interference, the rest of the frequencies were fine and workable. WCKY-1530 Cincinnati (1575 mi) was easily heard behind KFBK.
 
ishelly404 said:
I've noticed this too, the only charger I ever found that was completely RF silent was the one included with my OnePlus N200. Every other charger I have used generates at least a little noise.

Of course, in a concrete hotel most AM signals get blocked (or at least attenuated) by the rebar used in the structure. And a lot of chain hotels have furniture with built in USB ports, so you often end up surrounded by noisy power supplies. So that works against you too.
Click to expand...
That raises an interesting question. Leviton makes wall outlets with built-in USB-A or USB-C ports. I wonder if those would generate noise, too. We're thinking of putting a few of them in our new house.
 
You could tru some clip-on ferrites.

Last time I saw a radio (in the wall) of a hotel room was 15 years ago in San Diego.
Actually worked but could only get a couple of the "X" stations from across the border.
 
I use my PC USB port for charging. Takes a bit longer but much easier on the battery. No noted interference.
 
Mark Roberts said:
That raises an interesting question. Leviton makes wall outlets with built-in USB-A or USB-C ports. I wonder if those would generate noise, too. We're thinking of putting a few of them in our new house.
Click to expand...
They do. I had one (Leviton 2x USB A, probably from 2017ish) by my bedside table that generated a ton of noise on AM when a phone was charging. I ended up removing it and replacing it with a normal outlet eventually.
 
I have a couple of chargers in our room. Noise city. I try to unplug as many as I can shen DXing. Mrs Cyberdad tends to draw the line when I get to her phone, however. LOL.
 
Back
Top Bottom