Topband: Reducing Noise in the Shack

[John Harden, D.M.D.]

Dear Topbanders,

I use an ICE Model 475-3 AC Line filter in the shack. It provides 
inductive isolation, overvoltage control, capacitive decoupling and 
interference control of both common mode and differential mode signals. 
It will handle 25 amp at 110 VAC.

Usually across the line capacitors are used to suppress differential 
mode noise (usually termed X-capacitors).

And, too, common mode choke coils are used to suppress common mode noise 
(in series); line bypass capacitors (Y-capacitors) supress common mode 
noise.

This unit really works.

73,

John, W4NU

On 6/21/2012 3:07 PM, Guy Olinger K2AV wrote:
> On Thu, Jun 21, 2012 at 2:59 PM, DAVID CUTHBERT <telegrapher9 at gmail.com>wrote:
>
>> The W7NQN line filter is a differential-mode filter. You need a filter that
>> is designed for common-mode filtering.
>>
>> Dave WX7G
>
> This is from the web page advertisement:
> ---------
> Compare this with a Brand "C" filter which only handles common-mode
> interference problems.  The NQN AC power-line filters are optimized for
> common-mode and differential-mode filtering and have about 3 times the
> components of brand "C".
> ---------
>
> Seems to specifically include common mode.
>
> See  http://arraysolutions.com/Products/nqnaclinefilter.htm
>
> 73, Guy.
> _______________________________________________
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