Using digital techniques has caused a resurgence of interest in VLF — very low frequency — radio. Thanks to software-defined radio, you no longer need huge coils. However, you still need a suitable ...

The single-turn loop antenna is a metallic conductor bent into the shape of a closed curve, such as a circle or a square, with a gap in the conductor to form the terminals. A multiturn loop or coil is ...

While people may know that 24% of DTV stations are reverting back to their original VHF channel assignments, few are prepared for the dramatic power reduction for some of these stations, resulting in ...