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This booklet is available from the U.S. Government Printing Office, Washington, D.C., 20402 by
ordering Stock No. 004-00000345-4.
RFI SUPPRESSION
In moving to the world of digital communications via computers, a new dimension of RFI may
be encountered. In spite of the equipment manufacturers' diligence, each new piece of electronic
equipment will react differently in each separate environment. Every amateur station will have its
own unique layout, equipment variation and antenna installations. Experience has shown that
these differences are related to the total RF environments and may causative factors in RFI in-
duced problems. The suggestions given here may assist in resolving RFI problems you may en-
counter in your "unique" station.
1. Use shielded cable for all interconnections between equipment.
2. Make all interconnecting cables as short as practical. A balance should be maintained between
cable length and equipment proximity. At times simply moving the video monitor one foot fur-
ther from an interface or other device will solve the "screen hash" problem.
3. Antenna runs should be kept away from equipment control lines and/or interconnecting cables.
4. Ground leads should be as short as possible and go to a GOOD EARTH GROUND.
5. Interconnecting cables appearing to act as radiators or antennas should be looped through a
toroid. Be certain toroids, if used, are designed for the frequency in use.
