[Milsurplus] "ART-13" Variants

[Ray Fantini]

While on the subject of the ART-13, what's the relationship between the
ART-13 and the ATD transmitter? would assume the ATD came before the ART
but both are about the same size and function. did the ART replace the
ATD or were both being deployed at the same time due to different
procurement contracts?  was the ATD screen modulated or plate modulated?
think the ATD had a 813 output with 811 modulators but don't remember.
also would assume that anywhere a ATD was installed it would be replaced
with the ART to allow additional preset channels, and if that's not
enough questions what was the companion receiver for the ATD? was it a
BC-348 or some RU type set.
Ray Fantini KA3EKH