A large 40.475 MHz Doppler radar has been constructed near Sunset, Colorado, 16 km west of Boulder, in order to study winds, the troposphere, stratosphere, and mesosphere. Early results from the troposphere are presented here. It is concluded that: (1) With a sensitive VHF radar it is possible to detect echoes from throughout the upper troposphere almost all the time, under both clear and cloudy conditions; (2) Horizontal winds derived from the Doppler shifts of the echoes are consistent at heights more than 2 km above the local terrain with rawinsonde winds measured over 55 km away; (3) The reflectivity of the scatterers in the troposphere is not strongly aspect sensitive, up to an angle of 30° from the zenith