User`s guide

2-14
2.10 Internal Antennas
There are several types of internal antennas including the rigid radio-mounted one
shown in Figure 2-17. This antenna is specifically designed for 1900 MHz operation,
which was the primary operating frequency in North America when the GSM system first
began operation.
Figure 2-17
1008-0012B-001Single-band Antenna
The earlier analog cellular services started on the 850 MHz band. Analog services are
now being phased out and the original 850 MHz band is being converted to digital
operation by most carriers. The original DCM-200 (built prior to 2006) used a Motorola
“g18” GSM cellular radio module. Production of this device was discontinued in 2005
and was replaced by the “g20”. The original g18 radio supported three frequency bands,
including 1900 MHz but not
including the 850 band. The g20 radio supports two bands.
One model supports 850 / 1900 MHz operation while another supports 900 / 1800 MHz.
Metretek now offers a quad-band antenna to cover all cellular frequencies. This is
shown in Figure 2-18. If the cellular service being used operates on the 1900 MHz band
only then either internal antenna can be used.
Figure 2-18
1015-0208-001 Quad-band Antenna
An adhesive strip on the back of the antenna allows the antenna to be mounted to the
top inside wall of the enclosure as seen in Figure 2-19. A short coaxial cable attaches to
the radio’s antenna connector.