FM rfi caused by charger

[MikeinDestin]

I have a Tenergy 18650 battery charger. I've noticed it will cause a " hash" type noise while listening to our local station. Even from several feet away. It doesn't seem to bother any AM radios I have, only FM. I've never had anything cause rfi on FM, so it does seem pretty strange. It's a smart charger that works very well, no issues ever. Has anyone else ever had this happen? The model number is 01269-01 Tenergy. The station is on 107.5. The radio is battery powered. The ac charger is powered by an adapter that steps it down to 12v, then the charger converts that to 4.2v.

 

[merlin]

Perhaps a clamp on ferrite near the charger on the power cord. Yes odd it doesn't wipe out AM.
I listen to local AM1240, wall wart and computer noise is S9, 1240 is +20 Db no noise.
FM is noisy, but not excessive.

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[MikeinDestin]

Good idea! I forgot about those. It's quite a distance from the radio, maybe 10ft or more. Soon as I unplug the charger the noise goes away. I had another charger a few years back that would interfere with an AM radio from across the room. Some are very dirty radiators. It figures I left my best quiet phone charger in a hotel last year. Now I understand Samsung doesn't sell them anymore with new phones. The replacement I got for my phone was so noisy I ended up using my old original charger from my Note 4, which is pretty quiet. But not as quiet as the Note 9 original charger.

 

[T680]

My Nitecore Digicharger D2 will cause static on FM even if it's plugged in but not charging. My Radio Solar still pulls in FM but the Xhdata D-109WB either can't or has too much static to listen. I don't think I've tried to listen to AM by it so I can't say what the effect is there.

 

[MikeinDestin]

My Nitecore Digicharger D2 will cause static on FM even if it's plugged in but not charging. My Radio Solar still pulls in FM but the Xhdata D-109WB either can't or has too much static to listen. I don't think I've tried to listen to AM by it so I can't say what the effect is there.

Thanks for your reply. Next time I charge it I'll try moving the charger further away, to see if that helps. I usually try to keep it within eyesight when charging, since it's a Lithium Ion battery. It's for my Tecsun PL-880.

 

[MikeinDestin]

Just tried it with AM. It only affected the radio when close to it, which is bizarre. Tried it on FM across the room, there was still desensitization from several feet away. Had to go into the bedroom before the noise went away, and reception got better. But there are two noise sources, the charger and separate AC adapter.

 

[K9KLC]

I was just recently helping a friend diagnose a problem he was having on the 6 meter ham band. A charger he had plugged up across the room from the radio was causing him a 10db over S9 noise level. The minute we unplugged that charger, POOF he could hear on 6 meters again.