Few tools are as essential to firefighters as their portable radios. And, few devices can lead to as disastrous results when they malfunction.
There are many reasons why portable radios fail firefighters. Malfunctions could be due to the radios themselves or they could be caused by networks that connect the radios. Other times, operator error is to blame.
It is impossible to prevent every possible radio malfunction. But, with understanding and proper usage by firefighters, radio failures can be reduced and reliability can be improved.
Portable radios are not perfect. Even the best portable is a compromise between the conflicting factors of cost, size and functionality, according to John Facella, the director of public safety markets with Harris Public Safety and Professional Communications. “Seventy-two percent of firefighters today are volunteers, and so, in general, require cost-effective radios,” he said. “But, even in the career fire service, budget reductions are forcing fire departments to think carefully about value.”
Radio sizes have been going down for some time, he said, and that can cause problems. “There is a limit to how small a radio can be before it is too small to be used with gloved hands and so small that it is easily lost,” he said.
Regarding functionality, he noted firefighters have some unique requirements, including water-resistant or water-immersion capabilities and the need for intrinsic safety in explosive atmospheres. Also, he said firefighters must be able to transmit in high-noise environments and still be intelligible.
Functional compromises may be made because of the cost of portable radios. “The limitations often seem to be limitations in operational capabilities, such as single-band operation in areas where agencies may be scattered among several frequency bands, or a limited number of channels, forcing the communications officer to decide what channels to delete from the communications plan,” said Steve Makky Sr. He is a staff engineer with the Association of Public-Safety Communications Officials (APCO International) and a portable radio expert with decades of practical radio experience in both fire and EMS positions.
“Other issues,” he said, “may be attributable to system infrastructure incompatibilities, such as an analog-only radio not being compatible with a digital radio system or perhaps a proprietary digital radio being used in a standards-based digital system, like Project 25.”
Some portable radio limits are physical, and they apply to all radios no matter how much you pay for them. For instance, Facella said some firefighters believe the radios can withstand any high heat situation.
“NIST did some testing of radios in a simulated fire environment in August 2006,” he said. “The result was the recognition that if the radio is worn under the turnout coat or in the turnout pocket, it would survive high temperatures (500 degrees Fahrenheit for five minutes). If the radios are worn on a sling outside the turnout coat, they will fail.”
Heat is not the only environmental limit that can make a radio malfunction. “Water may intrude into antenna mounts or wick into the cable,” Makky said. “Antenna connections may corrode. The connector which hooks up to the radio may vibrate off. Power or ground connections may corrode, especially near battery connections or in places where water may intrude. These wires may heat up under high current draw seen in transmit.”
Malfunctions of radios often happen because the radio is mistreated or the radio and its associated system are not used properly, Facella said. “Sometimes a firefighter will get on the wrong channel and become confused,” he said. “Many fire departments prevent this by having the main channel or talk group on the first and last position of the rotary switch on the radio. This makes it easy to go to the right channel even if one hand is trapped.”
Sometimes, he said, users play with the radios, twirling them on their speaker microphone cord or holding them by the “rubber ducky” antenna. “Both can shorten the radio’s life span,” he said.
But even without mistreatment and in optimal conditions, portable radios can and do malfunction. “One of the most impairing malfunctions may be a stuck microphone,” said Makky. “This may happen from a number of issues, from poor microphone placement to interfacing issues to peripheral equipment, such as a short somewhere in the connection of headsets in the apparatus.”
Whatever the cause, the consequences are the same. Effective communication is blocked for however long the unit is locked in transmit mode. “This could block a call for water, a Mayday call or an order to evacuate,” he said. “Alert messages from dispatch signaling an open mic on the channel aren’t heard; the radio is not receiving, it’s transmitting. The unit remains unaware of the stuck mic. And this whole scenario may be easily prevented.”
Solutions, he said, include setting a time out timer (TOT) on the radio that automatically shuts off transmission after a pre-set time period, ensuring that mic buttons are not being accidentally triggered by hitting clips and other objects, and doing regular maintenance to spot any wiring/short-circuit issues.
Some radio malfunctions are due the networks that support them. Such is the case in Charleston County, S.C. A $17.5 million Motorola digital radio system was installed in 2007 to serve 5,500 first responders county-wide. But tower coverage was inadequate to support the new system, according to Isle of Palms Fire Department Chief Ann Graham. “In a nutshell,” she said, “there were not enough antenna sites to go from analog to 800-MHz digital.”
According to reports in the Charleston Post and Courier Web site, Charleston County’s inadequate first responder network has frequently put fire and police officers in danger. To remedy the problem, Charleston County is considering spending $12 million more on a network upgrade and more tower sites.
“In a properly designed system there are levels of backup to provide redundancy and survivability,” said Facella. “But no system can guarantee 100 percent coverage. We recommend that fire departments test their system throughout their response area and in buildings where there are significant dangers or life safety threats.”
Based on that testing, he said they can determine if there are coverage problems and then develop plans to surmount them. Some methods of overcoming coverage gaps include installing in-building amplifiers, using passive antenna systems, vehicular repeaters, portable suitcase repeaters and relaying information radio-to-radio or in person.
When it comes to minimizing equipment limitations, the remedy begins long before any equipment has been purchased. The people in charge of communications must first find out exactly what firefighters need from their portable radios and then decide what to purchase.
“The buyer should perform his or her due diligence, look at what the department needs and has budgeted and then compare that against what the marketplace bears,” Makky said. “Make an informed decision by consulting with your radio system manager, vendor and especially the firefighters who will ultimately use the equipment.”
The next step, he said, is to look inside the equipment: “Look for things like gasketing that can prevent water or chemical intrusion, connectors that might come loose or break or other things that can be problematic down the road.”
Once radios have been purchased, follow the manufacturer’s maintenance instructions to the letter – and then some. At the Isle of Palms Fire Department, Chief Graham said, “We do preventative maintenance on our digital radios at least once a year, and at the slightest sign of a radio going out of alignment, we take it out of service and send it to the shop.”
Day-to-day maintenance enhances radio reliability and reduces the chances of failure. Some maintenance is so basic, it’s mundane. For instance, “The radio should be kept clean by wiping it with a moist cloth,” Facella said. “If the radio is water immersion-rated, it may be washed in a laundry tub.”
As for batteries, they have a finite life span and need to be replaced when they are at their end-of-service expiration date. And if a portable radio’s case is cracked or has a hole in it, the case needs to be replaced so water and contaminants do not get to the radio’s electronics.
Finally, he said, “The radio itself should be checked annually to ensure that it is on frequency and within all required tolerances and FCC license parameters. If you’re paying for a maintenance agreement with some scheduled preventative maintenance, make sure someone actually comes in and does it.”
More Fire Apparatus Current Issue Articles
More Fire Apparatus Archives Issue Articles
