Topband: Transformer isolation vs common mode choke was: Re: T Vertical feed

[Pete Smith N4ZR]

Someone recently commented in favor of using transformer isolation in 
lieu of a common mode choke in a receiving application.  I presume this 
would be a 1:1 transformer using a binocular core, or at least 
completely separate primary and secondary windings.  What are the pros 
and cons of this idea?  Does capacitive coupling between primary and 
secondary, or some other factor, limit how much isolation can be 
achieved this way?

73, Pete N4ZR
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On 1/27/2012 1:07 PM, Jim Brown wrote:
> On 1/27/2012 8:40 AM, Charles Moizeau wrote:
>> I am willing to insert a common-mode choke, but don't know what to measure beforehand to learn if one is needed.
> There is NO DOWNSIDE to using a good common mode choke other than cost
> and weight, and as W4TV has noted, there are downsides to NOT using one.
>
> As it turns out, there was a typo in the link I posted to my RFI
> tutorial, which includes Cookbook guidelines for winding effective
> ferrite chokes.  The correct link is
> http://audiosystemsgroup.com/RFI-Ham.pdf
>
> 73, Jim K9YC
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
>