[Amps] RF in the Audio

[Rob Atkinson]

You don't wind your balanced feed on a torroid for crying out loud, a
method I find preposterous, and probably subject to heating and loss;
you employ a link coupled balanced tuner and float the balanced feeds
so their connection to the unbalanced line is via capacitive and
inductive coupling and not a direct electrical connection.  The link
(think of it as both a variable balun and isolation transformer) stops
common mode RF.


73

Rob
K5UJ


On 9/23/2011 3:08 PM, Robert Kirkland wrote:
> I think your quite right in "seriously choking off your feeders". But
> please tell me how to use toroids on a 600 ohm open wire line.

>Wind a bifilar choke using 12-14 bifilar turns of #12 THHN on a #31
>2.4-in o.d. toroid. It introduces a small mismatch (Zo approx 100 ohms),
>but only about two feet of line. Photos and details in the latest
>version of my RFI tutorial. http://audiosystemsgroup.com/RFI-Ham.pdf

>73, Jim K9YC