We present new radio observations of the ''prototypical'' ultraluminou
s far-infrared galaxy NGC 6240, obtained using the VLA at lambda = 20
cm in B-configuration and at lambda = 3.6 cm in A-configuration. These
data, along with those from four previous VLA observations, are used
to perform a comprehensive study of the radio emission from NGC 6240.
Approximately 70% (similar to 3 X 10(23) W Hz(-1)) of the total radio
power at 20 cm originates from the nuclear region (less than or simila
r to 1.5 kpc), of which half is emitted by two unresolved (R less than
or similar to 36 pc) cores and half by a diffuse component. The radio
spectrum of the nuclear emission is relatively flat (alpha approximat
e to 0.6; S-nu) proportional to nu(-alpha). The supernova rate require
d to power the diffuse component is consistent with that predicted by
the stellar evolution models of Rieke et al. (1985). If the radio emis
sion from the two compact cores is powered by supernova remnants, then
either the remnants overlap and form hot bubbles in the cores, or the
y are very young (less than or similar to 100 yr). Nearly all of the r
emaining 30% of the total radio power comes from an ''armlike'' region
extending westward from the nuclear region. The western arm emission
has a steep spectrum (alpha approximate to 1.0), suggestive of aging e
ffects from synchrotron or inverse-Compton losses, and is not correlat
ed with starlight; we suggest that it is synchrotron emission from a s
hell of material driven by a galactic superwind. Inverse Compton scatt
ering of far-infrared photons in the radio sources is expected to prod
uce an X-ray flux of similar to 2- 6 x 10(-14) ergs s(-1) cm(-2) in th
e 2-10 keV band. No significant radio emission is detected from or nea
r the possible ultramassive ''dark core'' hypothesized by Bland-Hawtho
rn, Wilson, & Tully (1991).