  BATSE/OSSE observations of the high redshift quasar 4C 71.07 indicate that
this is the brightest and furthest AGN so far detected above 20 keV. BATSE
Earth occultation data have been used to search for emission from 4C 71.07 from
nearly 3 years of observation. The mean source flux over the whole period in
the BATSE energy range 20-100 keV is (13.2 +/- 1.06) x 10^(-11) erg cm^(-2)
s^(-1) corresponding to a luminosity of 2 x 10^(48) erg s^(-1). The BATSE light
curve over the 3 years of observations shows several flare-like events, one of
which (in January 1996) is associated with an optical flare (R=16.1) but with a
delay of 55 days. The OSSE/BATSE spectral analysis indicates that the source is
characterized by a flat power spectrum (Gamma about 1.1 - 1.3) when in a low
state; this spectral form is consistent within errors with the ASCA and ROSAT
spectra. This means that the power law observed from 0.1 to 10 keV extends up
to at least 1 MeV but steepens soon after to meet EGRET high energy data. BATSE
data taken around the January 1996 flare suggests that the spectrum could be
steeper when the source is in a bright state. The nuF-nu representation of the
source is typical of a low frequency peaked/gamma-ray dominated blazar, with
the synchrotron peak in the mm-FIR band and the Compton peak in the MeV band.
The BATSE and OSSE spectral data seem to favour a model in which the high
energy flux is due to the sum of the synchrotron self-Compton and the external
Compton contributions; this is also supported by the variability behaviour of
the source.
