  We present VLA radio continuum observations at 3.6 and 6 cm of a ~0.65
sq.deg. field in the galactic plane at l=+45deg . These observations are meant
to be used in a comparison with ISO observations at 7 and 15 um of the same
region. In this paper we compare the radio results with other radio surveys and
with the IRAS-PSC.
  At 3.6 and/or 6 cm we detect a total of 34 discrete sources, 13 of which are
found in five separate extended complexes. These are all multiple or single
extended thermal ultra-compact HII (UCHII) regions. While for each of these
complexes an IRAS counterpart could be reliably found, no IRAS counterpart
could be reliably identified for any of the remaining 21 sources. Of these 21
compact sources, six are candidate UCHII regions, and the other 15 are most
probably background extragalactic non-thermal sources.
  The five IRAS sources associated with the radio continuum complexes all
satisfy the Wood & Churchwell (1989; WC89) color criteria for UCHII. None of
the other 38 IRAS point sources present in our surveyed field show the same
colors. This fraction of WC89 type to total IRAS sources is consistent with
what is found over the entire galactic plane. The fact that, when observed with
a compact VLA configuration, the IRAS sources with "UCHII colors" are found to
be associated with arcminute-scale extended sources, rather than with compact
or unresolved radio sources, may have important implications on the estimated
lifetime of UCHII regions.

Astrophysics