Two-Way Radio

MultiComm’s Private Carrier Repeaters

For those not familiar with repeater systems we offer this somewhat simplified and brief explanation. A two-way radio has a limit to the distance one radio can be from another and still be able to be heard and understood. There are primarily three things that affect how far the radio will “reach.” First is the frequency at which the radio operates. Second the type of antenna being used and third, the output power of the transmitter.

As a rule of thumb, the higher in frequency the transmitter operates, the more “Line-of-site” the signal will be or “if you can’t see it, you can’t talk to it.” A VHF (very high frequency) signal may travel farther than a UHF (ultra high frequency) and a HF (high frequency) at the same power output may travel farther than either VHF or UHF. At what frequency you operate will be dictated by Federal Communications Commission rules and regulations.

Antennas come in a variety of configurations. Some offer “gain” which makes the radio appear to the receiving station as though it were transmitting much more power than it is. Power may not be as much a factor as transmitter frequency becomes higher.

Many commercial radios operate at UHF frequency therefore their mobile to mobile range is somewhat limited. Two mobiles may be able to talk while only 1 or 2 miles apart but are unheard by other mobiles or even the base station that may be 10 miles away. A UHF repeater placed on a mountain top can help overcome this problem.

Imagine two mobiles talking about a particular job they may be working on and need advice from the boss who is 10 miles away. Most likely the boss will never be able to hear the discussion. If we use a repeater located much higher (remember line-of-site?) than the mobiles involved, which would re-transmit the mobile’s signal on a much larger antenna, with more power and a better view of the receiving mobiles, we can extend the useable range of the mobiles. Now, when using the repeater, one mobile can talk to another many miles away or separated by mountaineous terrain. The scheme works well, and is in fact, a widely accepted way of communicating in today’s business world. Two-way radios can help you realize a savings in cellular telephone bills and missed opportunities because you couldn’t be in touch with your employees. As you’ve already guessed, it’s not cheap to own and maintain your own repeater. That’s why MultiComm has several repeater systems that allow time to be shared on the system with other businesses. Monthly rates are very reasonable, in most cases you can have your entire fleet using the repeater system for the cost of operating a single cellular telephone! Contact MultiComm for more details on repeater systems and two-way radio.

MultiComm’s Digital Repeater Systems

In the same way the private carrier repeaters allow you the expanded coverage for two-way radios; digital repeaters go one step further.

Imagine the repeater to be a sales person waiting on customers at the sales counter of a store, and the two-way users as the customers waiting in line. The sales person, like the repeater, can serve only one person at a time. When the person is finished with their transaction (transmitting their conversation) the next person steps up and carries on their transaction. While one is being served, the others must wait until all is clear. Using a trunking repeater system is almost like adding one salesperson for each customer. All the people in line have the opportunity to move to the next available sales person (repeater) and make their transaction while simultaneously, others are being served. The trunking radios and repeaters automatically select the next available channel. The radio user need only press the push-to-talk button on the radio, wait a moment for a confirmation beep and begin talking. The confirmation beep informs the radio user that they have established connection with a free repeater and are clear to talk. There is virtually no need to wait for a congested system to clear before you can use your radio. MultiComm has several UHF trunking repeater systems in operation. Contact us to have a free demonstration of the trunking repeater system.