Specifications

86 MDS 4790/9790 Series I/O Guide MDS 05-3438A01, Rev. E
MDS 4790—400 MHz Notch-Type Duplexers
The radio’s transmit frequency can be changed up to 100 KHz without
re-tuning the duplexer. The duplexers shown in Figure 41 can be aligned
in the field by experienced technicians using high-quality test equip-
ment. For assistance, please consult MDS Technical Support for addi-
tional details about tuning.
Figure 41. 400 MHz Notch Duplexer
(No adjustment needed for transmit changes up to 100 kHz)
Duplexer alignment is a sophisticated procedure and a
duplexer can be easily damaged if not handled carefully. It is
highly-recommended duplexers needing re-alignment be
returned to the Microwave Data Systems, or the original
duplexer manufacturer, for alignment. In some cases, it may be
more economical to replace the unit than to have it re-aligned.
MDS 9790—Bandpass-Type Duplexers
These duplexers (Figure 42) typically allow the transmitter frequency to
change up to 500 kHz without undesired results. Since this type of
duplexer cannot be re-aligned in the field, we recommend contacting the
MDS Technical Support Department if you suspect a duplexer problem
or need one for a different frequency.
Figure 42. 900 MHz Bandpass Duplexer
(No adjustment needed for transmit changes up to 500 kHz)
CAUTION
POSSIBLE
EQUIPMENT
DAMAGE