Radio Links Provide Phones Far From Telephone Lines Jim Longnecker Home Power readers have in common more than just the need to generate their electricity. Many are also miles away from the public telephone service, and are denied hardline communication with the outside world. Recent advances in electronics, and new laws freeing more of the radio spectrum for personal and business communication, are rapidly changing the way people can use radio equipment to provide rural telephone service. In the past, as an alternative to bringing in expensive overhead or buried wires, those areas without telephone service were forced to either use crowded mobile telephone channels, or crude "phone patches" on business radio systems. How Radio Links Work Radio links provide connection of the telephone line to conventional telephone equipment at a remote site. All links use a full-duplex radio (talk and listen at the same time- just like downtown!) at each end. Directional radio antennas link the remote site with the phone line. The radios used are low powered (under 25 Watts) UHF transceivers, usually licensed on the "split" frequencies between the UHF business channels. The remote site has a conventional telephone, and normally the user cannot detect a radio link in use. Also, computer modems can be used on most links. Where to Install a Link In order to get phone service to a remote site with a radio link, there are a few physical requirements. First, there must be a telephone service available within a few miles of the site, in most cases less than 20 miles. Second, and equally important, there must be a "path" for the radio waves between the remote site and the telephone lines. By a path, we mean nearly line-of-sight, although trees and even some terrain variations can be overcome. Jim Carlson of Carlson Electronics has installed links even in situations where a path did not seem to exist. Careful examination of topographical maps, prior to rejecting a site is important. The link end at the remote site can be installed as far as 1,000 feet from where the telephone is to be used, allowing even more flexibility in many cases. Each end of the link must be supplied with either 12 VDC or 117 volt ac power. A single PV module, of 40 watts output, together with a battery, will supply adequate power in most applications. Money Matters Initial cost of a radio link may seem high, compared to the cost of simply buying a telephone for your home or business, as most run about $3,500. When compared to the costs, and esthetic considerations of placing telephone poles for miles or burying miles of cable, the figure is much easier to justify. Also the user owns the link and is billed by the phone co. as a regular land line telephone at normal downtown rates. Compare this with radiotelephone services using the phone company's equipment (like IMTS radiotelephone, see Home Power #4, pages 29 to 32), where air time charges are made of about $1.00 per minute. And this is addition to all regular telephone charges like long distance charges. At a buck a minute, it doesn't take long to run up an enormous phone bill. Maintenance of a link should be much less than wireline, especially over rough terrain. Low powered radio equipment is very reliable, and should last 10 years or more, with minimum maintenance. Jim Carlson says his customers rarely call for service, and then most calls do not involve equipment failure, but environmental damage like wind damaged antennas, etc. Telephone Company Tariffs, The FCC & More Your telephone company can be either cooperative or not, depending on their individual policies, when you ask for a telephone connection that they know is destined for transmission by a radio link. Jim Carlson spent many hours with the California Public Utilities Commission, and representatives of Continental Telephone, when first starting to install these links, and can usually answer, to the utilities satisfaction, any legal questions. These links also are licensed by the FCC, usually in the Business Radio Service. There are a few requirements for the licenses, and Carlson's firm can help potential link users with any questions. A new radio service, the BETRS or Basic Exchange Radio Telephone Service has just been announced by the FCC. This service, announced in FCC Docket 86-495, makes 50 pairs of frequencies available to private users. Licensing for this service is in its infancy, however Jim Carlson is following through in researching this, and will report back to Home Power readers as the procedures are established. Multiple Lines & Microwave Stuff In cases where multiple lines (6 or more) are required to areas, such as remote subdivisions or industrial plants, Carlson installs short hop microwave systems. New equipment is available on the market that makes microwave cost effective at this level. Sources Jim Carlson, Jim Longnecker and Carlson Electronics can be contacted at 707-923-2911 or at 774 Redwood Drive, Garberville, CA 95440. Carlson Electronics sells equipment from TELEMOBILE, RITRON, and others. Microwave equipment from SR TELECOM of Canada and DIGITAL MICROWAVE of San Jose, CA is also available that meets the needs of multiple line users. Editor's Note: We are currently trying out the Telemobile UHF radiotelephone system. We'll let Home Power readers know how it works to our remote office site in Home Power #8. Early indications are that it is a real winner. RP. CQ HOME POWER HAMS Windy Dankoff KE5HV & Brian Green N6HWY We are proposing a new schedule for hams: Regional Home Power Nets 7.230 MHz on Sundays at 1330 Pacific, Central, & Eastern time. 3.900 MHz on Wednesday at 2000 Pacific and Eastern time. 14.290 MHz Sunday at 1900 UTC. Novices 7.110 MHz on Wednesday and Saturdays at 0500 UTC. Regional nets will keep the same times when we resume normal Standard time this fall.