10.14.2002 12:00 PM
High-power, high frequencies and high towers equal high costs
The 500 plus DTV stations that have come on with full assigned power and coverage have pumped a lot of money into the economy, as these facilities are not built cheap. High-power transmitters start at more than $300K and can push $1 million for a high-power upper UHF rig. In fact, the higher the frequency, the more everything RF related costs. Antennas at the high end of the band are generally larger and more expensive than ones in the VHF band or even the low UHF band. VHF typically requires less RF power than UHF, thus allowing the use of smaller antennas, which reduces installation costs.
Prices for transmission antennas at the two extremes of the RF bands can be twenty times apart in price. High-power upper end UHF antennas can reach $500K. Installation costs are based on mounted height and antenna weight. These costs can range from a few thousand dollars and quickly reach $100K. Transmission lines feeding the antennas aren't inexpensive either. Feedline can easily cost $100K on a 1500 to 2000 foot tower. While a relatively less expensive 3 1/8-inch transmission line can be used for VHF antennas, that line has to be 8-inch or larger waveguide for high power upper UHF band applications. This can push the cost of the waveguide to $400K.
The tower is one component that doesn’t change a lot, at least percentage wise, with frequency. While tower loading requirements will change depending on antenna/feedline weight, the overall effect on the tower price is small in comparison.
The cost of materials to build a tower can hit $1 million dollars quickly. If you need one that’s 2000-ft tall, be prepared to spend $2 million before it’s even erected. Stacking steel 1500-ft in the air creates a lot of weight on the concrete foundation. Plan on another $200,000 just for the foundation. Now, you’re ready to have the tower erected. Cost: $300K.
The cost of building the RF portion of a DTV system ranges widely. An RF system providing modest power in the VHF range, requiring no new tower, can be done for less than $500K. If you need a new 2000 foot tower add $2.5 million. If you need a high power, high UHF channel operation and a new tower you’re over $4 million.
Many stations are looking to save money by working with tower management services. These companies can do everything from just managing the tower project to even building the entire RF facility and operate it for you. You end up just paying a lease fee for the operation. This type of solution is welcome news to stations in locations where building new towers is out of the question and station owners are willing to get over the idea that every station still must own their “vertical real estate.”
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