Using AM Radio Towers

One existing resource that is often overlooked in designing wireless networks is AM radio towers. For the most part, companies deploying fixed wireless and microwave antenna have avoided these towers. The conventional wisdom has been to avoid the AM towers as being too hot in power and frequency to use for other purposes. But the AM towers don’t have to be a wasted asset. There are two methods that can be used to install other radios on AM towers that often get overlooked by cellular companies and wireless broadband providers. The first technique is known as a folded unipole. This consists of a vertical metal rod, called a mast, that is connected at the base of the AM tower to a conductive surface called a ground plane. This is a common technique used to connect an FM transmitter to an existing AM tower, but it can also allow for cellular or fixed wireless radios. The other method for isolation is to install electronics on the transmission line that carries the radio content signal to the antenna. The most common device is called an iso coupler, which allows RF signals within a certain frequency range to pass through while continuing to isolate the AM signal from the ground. Both of these methods are referred to as detuning, meaning that a new radio can be isolated from the tuned AM signal that permeates the whole tower. Anybody looking for tower space shouldn’t shy away from this option because the folks who own AM towers are likely to be open to negotiating an affordable connection since they don’t often get the opportunity.