Hot spots are the supposed termination regions of jets and may be
sites of extranuclear particle reacceleration in radio sources. There
have recently been reports of systematic side-to-side differences
between jetted and counterjetted hot spots, particularly in 3CR
quasars, including differences in compactness and placement in the
lobes, and, most surprisingly, extended regions of somewhat flatter
high-frequency spectra around the jetted hot spots. These studies
suggest that whatever induces the asymmetry between the brighter and
fainter jets in such sources extends at least as far as the hot spots,
and perhaps beyond them. If the relativistic-jet model is correct,
this implies that some bulk relativistic flow persists into the radio
lobes. This greatly increases interest in detailed imaging and
continuum spectroscopy of jetted and counterjetted hot spots at high
frequencies. The only hot spot structures that have been fully
resolved by the current VLA are in nearby radio galaxies such as
Cygnus A and Pictor A. To resolve the physically-interesting
structures in the hot spots of distant radio galaxies or quasars we
must increase the angular resolution beyond that obtainable now with
the VLA by increasing the u-v baselines, not by going to higher
observing frequencies. Ideally, we need scaled-array capability at
resolutions of order 
from 0.6 to 40 GHz, with enough
sensitivity at the higher frequencies to determine the spectra of the
more emission associated with the hot spots. This requires high
bandwidth at the high frequencies, and the A+ configuration (plus
cross-linking to the VLBA) at the low frequencies.