Thread: AC adapter humm
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Old February 4th 10, 07:30 PM posted to rec.radio.shortwave
matt weber matt weber is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 24
Default AC adapter humm

On Wed, 3 Feb 2010 16:21:54 -0600, "homepc"
wrote:

I'm running a 6v 300ma adapter to run my Sangean ATS800 radio. I was
wondering if applying a couple of ferrite chocks like this to the DC power
cord would eliminate any humming noise created by the adapter.

http://www.piurl.com/p/22mW


The humm is not very loud, but it's noticeable. I know batteries are the
best solution, but in this case it's more convenient to use the adapter.


I doubt it. The ferrite cores act as the core of a choke. If the AC
adapter used a switching supply, perhaps, but most wall warts are very
simple linear supplies (keeps the cost down0, so the hum is at 60Hz.
You are going to need a lot more inductance than a couple of ferrite
cores to keep it out.