  We investigate the beaming of 11 Io-Jupiter decametric (Io-DAM) emissions
observed by Juno/Waves, the Nan\c cay Decameter Array and NenuFAR. Using an
up-to-date magnetic field model and three methods to position the active Io
Flux Tube (IFT), we accurately locate the radiosources and determine their
emission angle $\theta$ from the local magnetic field vector. These methods use
(i) updated models of the IFT equatorial lead angle, (ii) ultraviolet (UV)
images of Jupiter's aurorae and (iii) multi-point radio measurements. The
kinetic energy $E_{e-}$ of source electrons is then inferred from $\theta$ in
the framework of the Cyclotron Maser Instability. The precise position of the
active IFT achieved from methods (ii,iii) can be used to test the effective
torus plasma density. Simultaneous radio/UV observations reveal that multiple
Io-DAM arcs are associated with multiple UV spots and provide the first direct
evidence of an Io-DAM arc associated with a trans-hemispheric beam UV spot.
Multi-point radio observations probe the Io-DAM sources at various altitudes,
times and hemispheres. Overall, $\theta$ varies a function of frequency
(altitude), by decreasing from $75^\circ-80^\circ$ to $70^\circ-75^\circ$ over
$10-40$ MHz with slightly larger values in the northern hemisphere, and
independently varies as a function of time (or longitude of Io). Its
uncertainty of a few degrees is dominated by the error on the longitude of the
active IFT. The inferred values of $E_{e-}$ also vary as a function of altitude
and time. For the 11 investigated cases, they range from 3 to 16 keV, with a
$6.6\pm2.7$ keV average.
