DELL 211S User Manual
support.dell.com
Maintaining Your Storage System
B-5
!" # $
Electromagnetic interference (EMI) and radio frequency interference (RFI) from a
computer can adversely affect devices such as radio and TV receivers operating near
the computer. Radio frequencies emanating from a computer system can also inter-
fere with cordless and low-power telephones. Conversely, RFI from high-power
telephones can cause spurious characters to appear on the system's monitor screen.
computer can adversely affect devices such as radio and TV receivers operating near
the computer. Radio frequencies emanating from a computer system can also inter-
fere with cordless and low-power telephones. Conversely, RFI from high-power
telephones can cause spurious characters to appear on the system's monitor screen.
RFI is defined as any EMI with a frequency above 10 kilohertz (kHz). This type of inter-
ference can travel from the storage system to other devices through the AC power
cable and power source or through the air like transmitted radio waves. The Federal
Communications Commission (FCC) publishes specific regulations to limit the
amount of EMI and RFI emitted by computing equipment. Each Dell storage system
meets these FCC regulations.
ference can travel from the storage system to other devices through the AC power
cable and power source or through the air like transmitted radio waves. The Federal
Communications Commission (FCC) publishes specific regulations to limit the
amount of EMI and RFI emitted by computing equipment. Each Dell storage system
meets these FCC regulations.
To reduce the possibility of EMI and RFI, always use shielded small computer system
interface (SCSI) cables to connect the storage system to the host computer.
interface (SCSI) cables to connect the storage system to the host computer.
To prevent the possibility of RFI from a storage system affecting TV reception, follow
these guidelines:
these guidelines:
Keep any TV set at least 6 ft away from the storage system.
Use cable TV when possible.
Use a directional outdoor TV antenna.
Attach line filters to the TV set.
Use 75-ohm coaxial cable for the TV set rather than twin-lead antenna wire.
If interference occurs, rotate the storage system or the TV set 90 degrees.
%
Because they store data magnetically, hard-disk drives are extremely susceptible to
the effects of magnetism from sources such as the following:
the effects of magnetism from sources such as the following:
Monitors
TV sets
Printers
Telephones with real bells
Fluorescent lights