[RFI] telephone system RFI

Jeff Otterson/N1KDO Jeff Otterson/N1KDO <otterson@mindspring.com>
Thu, 29 Jan 1998 19:32:22 -0500

  I have an old Northern Telecom key system in my house.  It is the source
of lots of RFI.  I isolated the RFI to the phone system by switching off
breakers, then pulling plugs on the troublesome circuit until I found the

Here's what I have done so far to try to rid myself of the RFI...

  1) Disconnected telephone CO and set lines from the central control box.
no change in the RFI levels.

  2) Grounded cabinet of control box, and put a pair of the snap-together
type regtangular ferrites on the CO & set lines, and the AC power line.  No

  3) made sure the cover was screwed on tight, and that there were good
clean connection points between the front and back covers.

  Any ideas are appreciated...


Jeff Otterson
Maker and user of tools.
PGP key available at http://www.mindspring.com/~otterson/pgp.html

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