  We present 6-GHz Very Large Array radio images of 70 gravitational lens
systems at 300-mas resolution, in which the source is an optically-selected
quasar, and nearly all of which have two lensed images. We find that about in
half of the systems (40/70, with 33/70 secure), one or more lensed images are
detected down to our detection limit of 20microJy/beam, similar to previous
investigations and reinforcing the conclusion that typical optically-selected
quasars have intrinsic GHz radio flux densities of a few microJy
($\sim10^{23}$WHz$^{-1}$ at redshifts of 1--2). In addition, for ten cases it
is likely that the lensing galaxies are detected in the radio. Available
detections of, and limits on the far-infrared luminosities from the literature,
suggest that nearly all of the sample lie on the radio-FIR correlation typical
of star-forming galaxies, and that their radio luminosities are at least
compatible with the radio emission being produced by star formation processes.
One object, WISE2329$-$1258, has an extra radio component that is not present
in optical images, and is difficult to explain using simple lens models.
In-band spectral indices, where these can be determined, are generally
moderately steep and consistent with synchrotron processes either from
star-formation/supernovae or AGN. Comparison of the A/B image flux ratios at
radio and optical wavelengths suggests a 10 per cent level contribution from
finite source effects or optical extinction to the optical flux ratios,
together with sporadic larger discrepancies that are likely to be due to
optical microlensing.
