Radiotelephone by Richard Perez When you move out beyond the power lines, you leave the telephone lines behind also. Next to making electricity, communications is one of the biggest problems facing those of us living in the outback. One solution to this problem is commercial radiotelephones. So why a phone anyway? When most of us moved to the country the telephone was one modern convenience that we gladly did without. As time passed and we lost the tensions generated by rat race living, we found that we indeed still had a need for communications. In some cases, we have family & friends to keep in touch with, in others our livelihood depended on communication with boss, business, and/or customers. Radiotelephone is one solution to communication beyond the lines. Its major advantage is that it links us with the entire telephone network spanning all of this planet. Types of Radiotelephones There are two basic types of commercial radiotelephone services suitable for back country use. They vary widely as to type of service, range, cost, advantages and disadvantages. Let's go through each in turn and hopefully we can find something to ease your communications problems. It is important to remember that all radiotelephone services are oriented toward mobile operation. Most of the users of these services are in motion in a vehicle. We country folks sneak into the system because we have the 12 VDC necessary to run the phone, and because the radiotelephone network doesn't care if our signal originates from a fixed antenna or a vehicle antenna in motion. Radio Common Carrier (RCC) This is the cheapest and least "telephone-like" of the mobile (portable or remote) telephone services. Type of Service RCC systems are independent communication services. When you use one of these systems you are dealing with an independent business that is licensed by the FCC to run a radiotelephone service. You are not dealing with the telephone companies directly. The quality and range that an RCC service delivers is directly tied to its equipment and drive of the RCC company. Some services spend the money necessary to install good equipment and see that it is maintained properly, while others don't. So investigate the performance of an RCC system with those already using it before you sign on. The RCC service is simplex. Simplex operation is like a CB radio. You push the microphone button to talk and must release the button in order to hear. Only one person in the conversation can talk at once, and when you are talking you CANNOT listen. Another common name for Simplex operation is "push to talk". The opposite of Simplex is Duplex. Duplex means that the equipment (and thereby both parties in communication) is capable of both talking and listening at the same time. Regular telephone communication is duplex; the person you are talking with may interrupt you and, even though you are talking at the time, you'll hear him. In order to place a call into the regular telephone network, the RCC system requires that you go through an operator. All calls, either incoming or outgoing must be routed through an operator. There is no direct dialing out, or direct ringing in, with an RCC system. Think of an RCC system as a telephone switchboard where you can communicate with the operator via a simplex radio link. When you communicate through an RCC system you are not actually talking directly to the office where the phone lines are connected. In most cases you are talking with a repeater located on a mountain or high tower. The repeater electronically relays your radiotelephone's signal to the RCC office. So what really matters is where the repeater is located, not where the office is. Most RCC systems operate in the mid VHF range, with frequency outputs around 150 to 170 MHz. Every RCC telephone serviced by a particular RCC company has exactly the same telephone number. You are distinguished by the RCC company by a Unit Number. While this is OK with family and friends, it is often cumbersome in business usage. Range & Antennas The RCC system is capable of spanning over 35 miles with radio signals. In any radio communication installation, the nature of the antenna is critical. Usage of a good fixed antenna, on a mast high in the air, can quadruple the range of an RCC radiotelephone designed to operate on a much smaller (and lower) mobile antenna. Terrain also plays a big role in the distance that an RCC unit can work. In flat lands, operation is fairly predictable. In the mountains, however, range will vary radically with location. Cost The cost of the RCC radiotelephone itself is moderate, between $600 and $1,200. The company running the RCC service will charge you between $25 and $50 per month for their service. In addition to this there is a charge for all long distance calls at the regular long distance rates. In some cases, RCC companies will charge for the amount of time you spend on the air. This varies widely from 20˘ to over $1 per minute of actual repeater usage and depends on the RCC company you are dealing with. Most RCC companies don't charge for air time. Advantages The prime advantage of an RCC system is low cost. The cost of the radiotelephone itself is the lowest of any type of radiotelephone service. In many cases the RCC company will sell, lease, or rent you the required equipment. The charges of the RCC company you are dealing with is substantially less than other types of radiotelephone services. Disadvantages First of all, the RCC system is simplex. While you may understand that only one party on the line may talk at once, the person you are talking to probably won't. Consider the perspective of the person you are talking to. He's got a telephone in this hand and doesn't understand that he can't use it like he always has. He has a lifetime of telephone experience telling him that he is talking on a duplex service. He may try to interrupt you while you are talking, but YOU WON'T HEAR HIM because you have the transmit button down and are talking at the time. In our experience, it is virtually impossible to get the person you are talking with to realize this simplex situation. The net result is that communication is difficult. While this limitation may be OK with family and friends, it's death in business. RCC systems make communication complicated by using simplex mode on a telephone system that is standardized in duplex operation. Another disadvantage of RCC systems is that they are essentially party lines. All the customers of any particular RCC service company (and there will be many, otherwise the company wouldn't be in business) use the same frequency and equipment. This means that anyone in the system is free to listen to your phone calls, just as you can listen in on everyone else's calls. The RCC system is not for the shy or self-conscious communicator. So don't say anything on an RCC system that you don't want the entire neighborhood to know. A byproduct of everyone using the same channel for communication is that the channel gets crowded. Some RCC companies are forced to limit air time to 5 to 10 minutes per call. Improved Mobile Telephone Service (IMTS) The IMTS system is the regular telephone companies' effort to improve on the RCC system. In this case, you are dealing directly with Ma Bell or your local telephone company. In some areas IMTS is VHF, while in others it operates in the higher frequency UHF band. In general, the VHF units work better in the mountains. Don't confuse IMTS service with the newer "cellular" type of mobile telephone service. The cellular type is only working in urban areas, and the cells are usually less than 10 miles in diameter. Cellular mobile phone is for short range urban mobile communication. It is not suitable for back woods communication. The application of repeaters is much the same as with the RCC service. You don't talk with the phone network direct, but through a radio repeater located in a wide coverage radio location. However, in this case the repeaters are being purchased and maintained by the telephone network rather than a small business. This means that the repeaters are of much higher quality, with better audio quality and longer range. Type of Service The IMTS system is full duplex. The transmitter and the receiver in the unit are both operating at the same time, and through the same antenna! This is a radio tech marvel. IMTS operation is indistinguishable from regular, land line, telephone operation. I ran an IMTS radiotelephone as a business line for Electron Connection for over two years. None of the people I talked to knew that they were using a radio link unless I told them. The system is so good and transparent that it is virtually identical to having a regular, hard wired, land line in operation. Each IMTS radiotelephone has its own individual telephone number, just like downtown. This number must be programmed by an FCC licensed technician into the radio (cost about $25). The IMTS service uses direct dialing output and reception. There are no operators to deal with in this service. Everything is automatic just like any regular telephone. Making a call on an IMTS system only requires that you lift the telephone handset and dial the number, operation is identical to a regular telephone. Your IMTS unit can be reached by any telephone anywhere in the World, without the assistance of an operator. The IMTS system is very highly developed. For example, in California there are 73 VHF IMTS repeaters working. In many areas of the United States, folks living in the country may have a choice of which repeater they wish to access. In the IMTS system I used, I was able to access three repeaters, one in California and two in Oregon. The IMTS radiotelephones are designed to run from a 12 VDC battery system. The basic IMTS transmitter is limited in power output to 30 Watts by the FCC. This means that the transmitter, which is about 50% efficient, consumes about 5 amperes of DC current from a 12 VDC battery. The transmitter is only activated when you are actually talking on the phone. My IMTS receiver consumes about 10 Watts, 0.8 amperes of 12 VDC. In order to receive incoming calls the receiver must be on. In a 24 hour period the radiotelephone's receiver will consume 240 Watt-hours, 20 ampere-hours of 12 VDC. Transmitter power is regulated by the FCC and most every IMTS unit will consume the same amount of power on transmit. Receiver design, however, varies greatly from manufacturer to manufacturer. So check the receiver's consumption before you buy it. If you leave the telephone active 24 hours a day, then even small differences in receiver consumption will add up. Range & Antennas The range of an IMTS system is between 35 and 70 miles . The IMTS system is designed for communication with moving vehicles. The antenna situation on a vehicle is marginal, so the IMTS system has to be very sensitive. The vehicle antenna must be small and low enough to clear overhead objects. The antenna situation for home use is much better. Stationary IMTS use allows us to employ a gain antenna, mounted on a high mast, to greatly increase communication range. The telephone company running an IMTS system is usually very conservative when quoting range predictions for their system. So when you talk to them about a system, remember that they are used to dealing with mobile situations. Fixed use, with a proper antenna setup, can almost always more than double their predicted system range. The IMTS system operates in the mid VHF range, from 155 to 165 MHz. The gain antennas suitable for this service are of two types: omni directional (works in all directions), and directional (works in one direction only). We have used the omni directional "IsopoleŞ" made by Advanced Electronic Applications, Inc., POB C2160, Lynnwood, WA 98036, call: 206-775-7373. This antenna costs about $60. and is available at just about any VHF radio store. Range with this antenna, mounted on a 36 foot, or higher, mast, is well over 50 miles depending on terrain. The directional antennas for IMTS service are called "Beams" because they focus the radio energy output of the antenna in one direction. This focused beam output is pointed at the repeater that you desire to access. Operation is much like a TV antenna which must be pointed at the station to be received. Once the antenna is positioned facing the IMTS desired repeater, further rotation of the antenna in not necessary and it may be secured in that position. The use of a beam type directional antenna can more than double the range over an omnidirectional antenna, and quadruple the range over a mobile antenna. If you are living more than 50 miles from the IMTS repeater, or if you live in a difficult radio spot like the bottom of a canyon, then use the beam. Beams, like every other antenna, work best when they are high in the air. Consider 36 feet the minimum mast height. Hand in hand with a gain antenna comes a good grade of coaxial cable. This coax cable must get the signals to and from the antenna efficiently. Use RG-8U (for feedline lengths over 50 feet) or RG-8X (for runs less than 50 feet). This cable will cost you between 25˘ and 50˘ per foot. The higher operating frequencies of the IMTS system make good coaxial cable essential. Cost Those of you interested in an IMTS system, please sit down if you are not already doing so. Fasten your seat belt and hold on to your wallet. When you get into IMTS you get into expense. The phone companies consider the IMTS a business service for on the go, affluent, executives and price it accordingly. The cost is high and this is the biggest drawback to IMTS. The actual radiotelephone unit will cost between $1,000 and $3,500. depending on the type and manufacturer. Since these radios are designed for mobile service, they are very ruggedly built. The imported models costing around a grand seem to work well, but they lack the heavy hardware and longevity of the mid priced domestic units. Check on service and installation help from the company before you buy from them. During the two years I operated the Motorola Pulsar IMTS unit it gave me not a lick of trouble. Antenna, mast and coaxial cable will cost about $150 to $300. Considering the cost of the basic IMTS transceiver, scrimping on the antenna system is a very false economy. Why pay thousands of dollars for high tech electronics and then have it work poorly (or not at all) because you saved a hundred bucks on the antenna system. If you think that the above is expensive, hold on because we getting to the phone company's piece of the pie. There is usually a $200 to $300 deposit required to start the IMTS service. The basic rate for service is low about $25 to $60 per month. The phone company does, however, charge for air time and long distance. In my experience, it is this air time charge that is the most expensive single component in the entire system. The cost figures I'm supplying here are what I was being charged in northern California from 1985 to 1987. Yours may be lower or higher, so check with your local phone company. In my situation, air time was charged by the minute or fraction thereof. There is a sliding rate based on the duration of the call and the time of day (locally at the IMTS repeater) that the call is made. For example, for the hours of 8AM to 8PM on weekdays, the first minute on the machine cost 50˘, minutes 2 through 5 cost 70˘ each, and minutes 6 and over cost $1.05 per minute. During 8PM to 8AM (overnight) and on weekends the rates were 40˘ for the first minute, 45˘ for 2 thru 5, and 55˘ for minute 6 or more. The IMTS pricing structure makes it evident that they want you to keep your calls short. Air time is charged for BOTH incoming and outgoing calls. This is difficult to explain to a person calling you. He's called you and his entire telephone experience tells him that he is picking up the bill. However, you will receive a bill for the air time on the incoming call. During business hours, the air time on the call is much greater than the next expense-- the long distance charges. If the telephone you place an outgoing call to is not within the local telephone area where the REPEATER is located, then regular long distance rates apply and this cost is added to the air time of the call. Let's total all the costs up. There is about $2,000. in hardware-- the IMTS radiotelephone, antenna, mast, and cable. Air time will cost an unknown amount depending on how much you use. In our case we were running a business over the IMTS system. Most of our calls were during business hours. Almost all of them were also long distance. Our air time combined with long distance was running us about $10 per call and over $300 monthly. In a years time we had pumped over $3,000 into the phone system. This is a lot of money for communication. But having a telephone, especially one that was full duplex, greatly boosted our business which more than paid for the system. So I think the lesson to be learned here is that IMTS is suitable for business use. Personal use of the system is cost effective only if you keep the calls short in duration and make them after 8PM or on weekends. When you use your IMTS unit during business hours, think a dollar a minute and you'll be in the right neighborhood. Advantages The prime advantage of an IMTS radiotelephone is that it works just like a regular telephone. It is full duplex and has its own individual telephone number. The IMTS service has, in most cases, longer range and better audio quality than RCC services. Disadvantages The major disadvantage to IMTS service is cost. It's expensive. Unless you have a business to pay the bills, it's not really affordable for the average country homestead. In Conclusion Radiotelephone services offer communications to remote sites. The RCC service is really not very expensive, while the IMTS system certainly is. For those who can afford and need radio access to the regular telephone system, a radiotelephone is the answer. For those who communications needs are less rigorous, there is still CB and Amateur radio. Both these radio services are adequate for emergency use. It is legal to use CBs for business purposes, while it is not for Ham radios. A good alternative to radiotelephone is to communicate via CB with a neighbor who has a regular land-line telephone. Next month we are going to talk about Ham radio. Topics for the future communications columns include more antenna projects, cordless telephones, TVs, satellite TV, and FM stereos. Just because we live in the middle of nowhere doesn't mean we can't listen and have our say. We just have to do it the hard way. So, what else is new?