Notices
Insert BS here A place to discuss anything you want

RF noise elimination

Thread Tools
 
Search this Thread
 
Old Jul 1, 2022 | 01:11 PM
  #1  
Slayer's Avatar
Thread Starter
Junior Member
iTrader: (6)
 
Joined: Mar 2009
Posts: 205
Total Cats: 19
From: Fighting blue-haired female warriors in CA
Default RF noise elimination

I put a chest freezer in my TV room near my computer.

When the freezer kicks on, the PC speakers make a loud pop. When it cycles off, the speakers pop even louder. Naturally, if the speakers are off, there isn't a pop.

I switched the freezer power source to another outlet using an extension chord (on another breaker). It helped a little, but not much.

I read that the pop could be from RF interference created by arcing in the freezer's compressor motor, and it can be mitigated with a suppressor or snubber circuit, which I understand is a combined capacitor and resistor. Like this: https://www.digikey.com/en/product-h...nubber-network

That's where I stopped understanding. I have no idea what to get and where to install it. Taking apart the freezer and soldering in a couple components is not a problem, but I don't know what to get.

Help appreciated.
Old Jul 1, 2022 | 01:52 PM
  #2  
maplewood's Avatar
Junior Member
iTrader: (2)
 
Joined: Oct 2014
Posts: 82
Total Cats: 14
From: Chandler, AZ
Default

The easiest solution is making sure that the audio cable is as short as possible and moving it around some to try and stop the noise. I'm lazy so that's as far as I've ever gone. A discussion I happened to be reading yesterday mentioned that these little ferrite core clips were magic, they seem cheap enough and you can get them easy enough. https://www.cablechick.com.au/cables...ml#productTab3 is the one they were discussing in particular.
Old Jul 6, 2022 | 01:33 PM
  #3  
mazpr's Avatar
Senior Member
iTrader: (1)
 
Joined: Oct 2008
Posts: 531
Total Cats: -19
From: Trailer County
Default

May or may not work, I use to fix similar noise on my cheap car stereo system by twisting the cables.

The cable itself just twist it. The goal is to do a similar loop, the more, the more efficient it will be.

You can also use ferrite core noise suppressors:



Old Jul 6, 2022 | 02:10 PM
  #4  
Slayer's Avatar
Thread Starter
Junior Member
iTrader: (6)
 
Joined: Mar 2009
Posts: 205
Total Cats: 19
From: Fighting blue-haired female warriors in CA
Default

Thanks a lot you guys.
I'm pretty sure the pop is caused by the opening of the contacts in the thermostat since it's loudest when the freezer clicks off.
Since I moved the freezer to another room, the noise is not as loud, but it's still annoying as ****.
I have an old cable with a ferrite clip molded onto it; I could swap that in just to try.
I'm really want to try a snubber circuit, but I just don't know which one to get...
Old Jul 7, 2022 | 01:07 PM
  #5  
Spaceman Spiff's Avatar
Junior Member
 
Joined: Apr 2018
Posts: 356
Total Cats: 93
From: Central Texas
Default

You might also want to try powering your speaker amp through a common mode choke, see if you can't isolate the issue to speaker leads vs. the common AC supply (all your breakers are connected to the same bus, there is no isolation as standard for high freq noise).
Amazon Amazon

That said if the freezer is riiiiight next to the speakers, then yeah EMI from the compressor motor clicking on (i.e. coils energizing or the B field collapsing when the motor turns off) can for sure be the culprit. A shielded lead form amp to speaker would be your next bet there IMO.
Old Jul 8, 2022 | 09:38 PM
  #6  
JasonC SBB's Avatar
Elite Member
 
Joined: Jul 2005
Posts: 6,420
Total Cats: 84
Default

You connect the snubber electrically across the contacts that open.
Old Dec 30, 2022 | 04:20 PM
  #7  
Slayer's Avatar
Thread Starter
Junior Member
iTrader: (6)
 
Joined: Mar 2009
Posts: 205
Total Cats: 19
From: Fighting blue-haired female warriors in CA
Default

Wanted to come back and close this out. I got a snubber circuit from ebay for $1.59 and wired it as Jason suggested. It has worked perfectly now for a few months. Nothing else seemed to work. Thanks for the help.
Old Jan 15, 2024 | 12:46 AM
  #8  
YvetteSpencer's Avatar
Newb
 
Joined: Dec 2023
Posts: 1
Total Cats: 0
Default

Originally Posted by maplewood
The easiest solution is making sure that the audio cable is as short as possible and moving it around some to try and stop the noise. I'm lazy so that's as far as I've ever gone. A discussion I happened to be reading yesterday mentioned that these little ferrite core clips were magic, they seem cheap enough and you can get them easy enough. https://www.cablechick.com.au/cables...ml#productTab3 is the one they were discussing in particular.
Thanks for the link, you made my day. If I want to know more, I will ask by starting my own thread.

Last edited by YvetteSpencer; Mar 28, 2024 at 06:37 AM.
Old Apr 9, 2024 | 03:58 AM
  #9  
LoganOwens's Avatar
Newb
 
Joined: Mar 2024
Posts: 1
Total Cats: 0
Default

Thank you so much for the information, I am going to buy it.
Spoiler
 


Last edited by LoganOwens; Apr 20, 2024 at 02:02 AM.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Joe Perez
Insert BS here
15
Apr 3, 2018 07:34 PM
rmcelwee
Insert BS here
7
Jan 15, 2012 09:54 PM
jeff_man
Insert BS here
12
Dec 11, 2011 11:52 AM
rider384
Insert BS here
97
Mar 31, 2011 08:02 PM
levnubhin
Insert BS here
8
Mar 19, 2008 07:52 AM




All times are GMT -4. The time now is 02:18 AM.