... 9- volt alkalines, which cost around $2.50 each. The most common cause of... be checked with a digital volt meter. Inexpensive digital meterscan be purchased at Radio... on professional motion picture sets. The yagi type of antenna resembles a two ... of household rooftop TV antennas. The yagi works like a shotgun mic. It...range, try utilizing a dipole or yagi antenna system. You canrequest them when ...