Many times during the past few years I’ve talked with police and fire executives who are considering replacing their radio systems with new digital equipment because they believe it is mandated by the FCC’s requirement to convert to narrowband operation prior to January 2013. This is a common, but highly inaccurate myth.

There is no mandate to convert to digital and there are many compelling reasons to stay with analog. Narrowband analog operation works fine and meets the FCC requirement for 2013. There are thousands of narrowband analog radio systems in use by government agencies and businesses all over the United States. In most cases, the radio system users can’t tell the difference between wide and narrow operation.

The FCC required all two-way mobile and portable radios manufactured after February 14, 1997 that operate below 512 MHz be capable of operation on wide and narrow channels. Furthermore, the FCC has mandated all two-way radios that operate below 512 MHz must use narrowband mode prior to January 1, 2013. FCC rules allow for analog or digital modulation, so long as the narrowband requirement is met. There are more disadvantages to digital operation than benefits. It is not necessary to replace analog equipment with digital in order to meet the January 2013 requirement.

SSFPD Radio System Characteristics

South San Francisco Police Department operates three UHF T-band radio systems. All three systems were converted to narrowband operation in August 2007. There has been no perceptible reduction in coverage or audio quality since the change was made. The total cost of reprogramming all SSFPD’s radio equipment was less than $5,000.

SSFPD demands and gets nearly 100% coverage on handheld radios from the interior of most buildings on its primary dispatch channel. This has not changed with the conversion to narrowband. The primary dispatch channel uses three voting receivers and a single transmitter. The secondary channels use standalone Motorola Quantar repeaters with wireline control. All three systems sound just as good as they did prior to the narrowband conversion. The equipment includes:

• Motorola Quantar repeaters and AstroTac voting receivers
• Kenwood TK-890 mobile radios
• Motorola HT-1250 portable radios
• Kenwood TK-350 and TK-390 portable radios

The City of South San Francisco

South San Francisco covers about 9 square miles and has a resident population of about 60,500 with a daytime business population that exceeds 100,000. The City participates fully in the San Mateo County coordinated law enforcement radio system which allows seamless radio communication among all 19 police departments and the Sheriff’s Office.

Conclusion

Our experience has consistently shown that the difference in coverage between wideband and narrowband systems is imperceptible to the radio user. This is especially true for multisite voted radio systems that cover a relatively small geographic area. We have yet to see a compelling set of circumstances to justify a digital police or fire radio system.

Please read my comments on “The real difference between digital and analog…” by clicking on the link.

March 21, 2008 — Related Information

The Burlingame Police Department, also located in San Mateo County, successfully converted its two UHF T-band radio systems to 12.5 KHz narrowband operation this week. The system used for primary dispatch operations is comprised of two Ericsson Mastr III duplex base stations in a main/standby configuration, four Mastr III voting receivers, one Motorola AstroTac voting receiver, and a Motorola Digitac comparator. A secondary channel uses a standalone Ericsson Mastr III repeater.

The radio system users report no apparent reduction in coverage or reduction in audio quality. A quantity of Kenwood TK-390 portable radios was deployed at the same time as the narrowband conversion, and we have noticed that there is a noticeable squelch tail on the AstroTac receiver because the Kenwood portables are not configured to transmit “reverse burst” CTCSS. This annoying noise is not related to the narrowband conversion and will be addressed by reprogramming of the Kenwood portables or by replacing the AstroTac receiver with a different product.

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