User`s guide

9-1
9 CONVERSION OF g18-BASED UNITS TO g20 OPERATION
9.1 Description of Problem
The original DCM-200 used a Motorola “g18” GSM cellular radio module. Production of
this device was discontinued in 2005 and was replaced by the “g20”. However, the g20
is not a drop-in replacement for the g18. Metretek has created an adapter assembly that
allows g18s to be replaced with g20 radios with minimal effort and cost.
The original g18 radio supported three frequency bands, only one of which (1900 MHz)
is used in North America. The original analog cellular services which existed on the 850
MHz band are quickly being discontinued and these cellular systems are now being
converted to digital. Another benefit to using a g20 radio is that it supports both the 850
and 1900 MHz bands. This is important if cellular providers are going to change existing
1900 MHz service areas to 850 MHz.
9.2 Required Materials
• Metretek’s MP32 configuration software, Version 3.4.8 or later. This is required
to load new firmware into the DCM-200 to support the change from the g18 to the
g20 radio.
• Programming adapter cable as illustrated in back Figure 2-1. Metretek part
number is 1002-0299C-001.
• #1 and #2 Philips-head screwdriver.
• Metretek 1001-0321-002 adapter assembly as shown in Figure 9-1.
• Metretek 1015-0208-001 quad-band antenna as shown back in Figure 2-18. The
use of this antenna may not be necessary if the cellular service will continue to
be provided on the 1900 MHz band only.
Figure 9-1
g18-to-g20 Conversion Assembly (without antenna)