Traditionally, most broadcasters had their own tower. It was widely accepted that the top spot on a tower was by far the best location, reaching far more viewers than an antenna mounted 40 or 50 feet lower. Besides, it was simply the manly thing to do. Stations sharing their towers was as unforgivable and unthinkable as engineers sharing their underwear. Fortunately, that school of thought (the tower one) has vanished along with the intention to sue as a matter of principle when the cost of such principle is realized.
The cost of high steel is simply too much, in many cases, for an individual station to insist on their own tower. When considering the added problems of zoning, the cost and availability of useable sites, and the additional expenses involved in building several small buildings instead of one big one, the practicality of a community tower grows at a rapid rate.
A single tower can often be built to handle all of the television stations in a given market. This may be in the form of a standard tower with stacked antennas on the top and side-mounted antennas below the top, a "T-Bar" type of tower with four or more antennas on or near the top, or a full-blown "candelabra" with multiple TV and FM antennas above and below the top and side-mounted antennas on the basic structure. Transmitting antennas can be either mounted on top of such structures or suspended from the arms or platform, effectively doubling the available space. Careful coordination and selection of the antenna types and locations can minimize interference and pattern distortion, leading to a successful operation for all involved.
Building community towers There are three conventional ways to approach such a project, all of which have problems. First, one of the stations can simply build the tower and provide space to all others. The problem here is obvious. The station building the tower will get the choice real estate on the tower. It is the golden rule - the one with the gold rules. This doesn't have to be a source of problems but often becomes one as personnel change, etc. In this type of operation, the station owning the tower does not usually provide building space for other stations, although that isn't a rule. Owning such a structure can create something of a cash cow. Providing the building space simply increases the cash flow if the owner is willing to put up that much money.
The second approach to a community tower finds all of the stations in the market joining together to form a new corporation whose only function is to own and operate the tower. The stations each hold stock in the corporation and jointly select a project manager who is employed by the tower corporation. This often results in one big building being constructed to hold all of the transmitters in separate rooms. That is probably the most economical way to provide equal facilities for all stations and is a very good approach to the problem. The stations mutually agree on the type of tower and building, on the architect to design the building, the contractor for the tower and a single contractor for the building construction. If the individual stations underwrite loans, the cost of the structure can often be covered by a single large loan to be repaid by rental fees from the stations, resulting in a much smaller initial cash outlay. The economies of scale are obvious in such a situation.
The third approach is for all the stations to contract with a third party to build the tower and lease space to everyone. Several corporations are now in the business and can put such a project together quickly and fairly. The advantage of this approach is the stations don't have to put up the cash for the tower immediately. They pay for their tower space every year, and it is an operating expense rather than a cost to be amortized. The biggest disadvantage is the stations lose a degree of control. That is, they are dependent upon someone else for maintenance of the tower and building. They also run the danger of losing the whole structure if the underlying corporation owning the tower goes down the drain. In reality, this is not a bad method of putting together a community tower project, given a careful selection of the company to be the tower owner and well-written contracts to fairly protect everyone's interests.
Advantages of shared towers The first advantage of a community tower is usually in the site itself. The fact that such a project may be necessary demonstrates that at least one of the stations in a market has a tower that is unsuitable for additional antennas or is nearing the end of its reasonable life expectancy. The existing tower site may well be suitable for the new tower, avoiding the problem of finding a new location. The fact that a tower currently exists on the site will greatly improve the prospects for zoning. The existing tower has already broken the skyline and is familiar to the neighbors. The existing zoning for the present structure may mean that no new zoning is necessary. That is an enormous boon in today's atmosphere of "NIMBY" (not in my back yard). In some areas of the country, that atmosphere has now changed to "BANANA" (build absolutely nothing anywhere near anything).
In any case, zoning boards are usually in favor of having one structure to accommodate all users, rather than multiple towers. In approaching the zoning authorities, the point should be made that the tower will be built to hold all foreseeable antennas. Besides being appealing to zoning authorities, such construction only makes good sense. Provide for plenty of future antenna space. Additional rentals only increase the cash flow to the owners. The construction of a tower acts as a magnet, drawing unanticipated users with little antennas and checkbook in hand. It would not be unusual to find the tower not only pays for itself but also provides a good source of income.
The economies of scale extend to ancillary items such as electric power. First, it may not be necessary for each station to have its own transformer. Depending on the local and state regulations for utilities, it may be possible for the tower corporation to buy power at the distribution voltage. This involves purchasing your own step-down transformer and protection equipment, but the cost savings over the years should more than pay back the original investment. The corporation would receive only one power bill. Individual metering would be performed for each station as well as for the tower and building use and each station would then be billed appropriately. Current regulations allow the large user to purchase power from any desired provider. Such an approach is much more feasible if only one customer is involved with an accordingly larger power demand.
Standby power in such a situation could be provided by a single, large standby power plant. Again, one large plant is a far more reasonable solution to the problem than a number of individual plants. After all, if the main power source fails, everyone will need an alternate source, not just one station.
The insurance and maintenance costs of the community tower will also be far less than for individual towers for all stations. There is no question that the most economical solution to multiple users' needs is a single structure. It also offers the advantage that all antennas in the area can be pointed to a single source for optimum reception.
Again, the use of an outside party to construct and own the community tower can still be a viable option and it avoids the initial large expense. But think of one major point before calling in someone else to build your tower. There is only one reason why these outside companies are interested in building your tower: these structures make money - lots of money. Renting space is just like renting housing - it goes on and on without end and, certainly, without reduction in the annual rate. If the stations build their own tower, the rental rate for those stations that participate in the ownership can be reduced as other renters come on the tower and assist in repaying the original debt. With a little luck, this will eventually result in very low annual cost to the original stations. The tower cost will have been repaid and a positive cash flow will result. The final result - money is saved, service improved and the suits in the front office are happy. As the chief engineer bringing them this great idea, you will be a hero - at least until the ENG truck breaks down again. Then, all will be forgotten and you will revert to the status quo.