VHF and UHF Systems
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The work horse of DMAT communications are our VHF and UHF systems. We maintain ten VHF Patriot and fourteen UHF Motorlola JT-1000 handhelds. Each handheld operates up to 5 watts output. We also operate one VHF and two UHF Bendix base radios with outputs up to 45 Watts. We also maintain many different antenna systems for the systems that include mobile and fixed capabilities.
Mitsubishi OmniQuest
At this point in time the satellite link is the most reliable in providing communications back to home base and to government agencies home offices. It provides the easiest way to get phone traffic in and out and it can be set up in minutes or less and used anywhere along the deployment route. It is not as adversely affected by interference in the disaster region, thus it does not suffer many of the pitfalls of other technologies. However, with its low cost, it is expected more and more groups responding to disasters will come to use these units. This could cause an eventual overloading of the satellite systems as well. The biggest problem with satellite systems is its requirement for line of site transmissions. Although some success has been had by bouncing signals from buildings and structures, reliability can not be guaranteed where line of site with the satellite can not be achieved.
Team paging is an important part of our team response. The team uses Arch pagers that allow paging in South-West and Central Ohio and adjacent states. We use them to activate the team leaders and to inform them. Other members may also obtain pagers for a nominal $4.00 per month charge. Pagers are also a useful means to contact members at a disaster site, given systems are in operation. These team pagers allow digital alpha/numeric paging that allow two different paging techniques. The first technique is the standard dial up by touch tone phone. Once contact is made the caller may touch-tone in their phone number and a call will be returned. The second technique uses the alpha/numeric abilities of the pager. This is done by a computer and modem. It is usually preformed by specialized software that allows the message to be entered and sent. Messages are a maximum of 100 characters. Both Windows and DOS software are available to send these messages. However, any general communications software such as PROCOM, QMODEM, etc. may be used to access the paging company directly. Just dial the access telephone number with a modem set for 1200,7,e,1. Once connection has been made and an "ID" requested, send a capital "M" to activate the manual mode of the paging system. Next the system will ask you to enter the pager ID. This is the PIN number of the pager. It will then ask for the message. Next it will ask for any additional PIN numbers and messages. As soon as it sees no data with only a "carriage return", the system signs off and transmits the messages. National pagers will be ordered and obtain during any deploy for key members. This increases the chances of receiving pages in a disaster area. This would allow for member to member paging as well as from the Dayton home base.
The Engenius Wireless Phone System
Years of experience has shown us that doctors and nurses who are busy caring for patients often will ignor and turn down the volume on hand-held radios. This makes them unreachable when the need arises. What was needed was a phone system that would "ring", alerting the occupants that their attention was needed.
OH-5 has developed a "quick in" wireless phone system that allows multiple conversations, digital encryption, connection to phone line, great range and call transfer ability called the Engenius SN-920. We run 6 hand-held phones which allows for 3 simultaneous conversations even without the base turned on. In fact we have used them between mobile units. Each unit has it own intercom phone number that can be dialed by another unit. We have tested the base and a hand-held over a 1.1 mile range and were able to make connection. In addition we have a 900 MHz gain antenna with 60 feet of cable that can be plugged into the base to increase the range and coverage should it be needed. Maximum range is said to be around 8 miles, line-of-sight, with the external antenna. The unit is very similar to a digital cell-phone in power and appearance. It also changes power levels depending upon how strong the incoming signal is to save power.