  In this letter, we propose an improved cosmological model independent method
of determining the value of the Hubble constant $H_0$. The method uses
unanchored luminosity distances $H_0d_L(z)$ from SN Ia Pantheon data combined
with angular diameter distances $d_A(z)$ from a sample of intermediate
luminosity radio quasars calibrated as standard rulers. The distance duality
relation between $d_L(z)$ and $d_A(z)$, which is robust and independent of any
cosmological model, allows to disentangle $H_0$ from such combination. However,
the number of redshift matched quasars and SN Ia pairs is small (37
data-points). Hence, we take an advantage from the Artificial Neural Network
(ANN) method to recover the $d_A(z)$ relation from a network trained on full
120 radio quasar sample. In this case, the result is unambiguously consistent
with values of $H_0$ obtained from local probes by SH0ES and H0LiCOW
collaborations. Three statistical summary measures: weighted mean
$\widetilde{H}_0=73.51(\pm0.67) {~km~s^{-1}~Mpc^{-1}}$, median
$Med(H_0)=74.71(\pm4.08) {~km~s^{-1}~Mpc^{-1}}$ and MCMC simulated posterior
distribution $H_0=73.52^{+0.66}_{-0.68} {~km~s^{-1}~Mpc^{-1}}$ are fully
consistent with each other and the precision reached $1\%$ level. This is
encouraging for the future applications of our method. Because individual
measurements of $H_0$ are related to different redshifts spanning the range
$z=0.5 - 2.0$, we take advantage of this fact to check if there is any
noticeable trend in $H_0$ measurements with redshift of objects used for this
purpose. However, our result is that the data we used strongly support the lack
of such systematic effects.
