Hal Communications CWR6850, Инструкция по эксплуатации

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CHAPTER 5 PAGE 45
Experience has shown that the TV monitor itself may be a source or conductor of RF interference.
Various circuits of the TV monitor (particularly the sweep circuits) can and do generate RF interfer-
ence which may be heard in the receiver. Also, the video output to the monitor is a wide band-
width digital signal with rich harmonic content as is required to produce the crisp character display.
If the TV set is poorly shielded (not at all in some plastic-cabinet models) or lacks proper power
line by-passing, the RF from the monitors circuits or from the video output may escape to cause
receiver interference. Also, RF from the transmitter may enter the monitor and. disrupt the monitor
or CWR6850 operation. This may be quickly tested by simply disconnecting the video cable from
the CWR6850. There is no substitute for good shielding and by-passing; metal cabinet monitors
are highly recommended!
When the CWR6850 is used in a mobile or portable installation, trouble may be experienced from
transients caused by the battery-charging system. These transients may be minimized by connect-
ing the CWR6850 power cord directly to the storage battery terminals, avoiding connections to the
vehicles DC terminal block. Any voltage drop between the battery and terminal block may also in-
clude the transient spikes. It may be necessary to install additional filtering on the DC leads to the
CWR6850 and some on automotive accessories (such as blower and wiper motors) to eliminate
such problems. Consult the ARRL Radio Amateur's Handbook for more information.
The CWB6850 has been tested and is verified by HAL Communications Corp. to be in compliance
with Part 15, Subpart J of the FCC Rules And Regulations, Class B computing device. The following
text is a requirement of that regulation:
"This equipment generates and uses radio frequency energy and if not installed and used
properly, that is, in strict accordance with the manufacturer's instructions, may cause inter-
ference to radio and television reception. It has been type tested and found to comply with
the limits for a Class B computing device in accordance with the specifications in Subpart J
of Part 15 of FCC Rules, which are designed to provide reasonable protection against such
interference in a residential installation. However, there is no guarantee that interference
will not occur in a particular installation. If this equipment does cause interference to radio
or television reception, which can be determined by turning the equipment off and on, the
user is encouraged to try to correct the interference by one or more of the following meas-
ures:
reorient the receiving antenna
relocate the computer with respect to the receiver
move the computer away from the receiver
plug the computer into a different outlet so that computer and receiver are on different
branch circuits.
If necessary, the user should consult the dealer or an experienced radio/television techni-
cian for additional suggestions. The user may find the following booklet prepared by the
Federal Communications Commission helpful:
"How to Identify and Resolve Radio-TV Interference Problems." This booklet is available
from the US Government Printing Office, Washington, DC 20402, Stock No. 004-000-00345-
4."
In addition, the following rear-panel label is located on the CWR6850 rear panel:
"This equipment has been tested and found to comply with the technical specifications in
Part 15 of FCC Rules for a Class B computing device."