Soviet digital clock Elektronika 6 / 4.13 (Электроника 6 / 4.13) was produced in USSR during 1980's.
The wooden cabinet and front panel are identical with Elektronika 6.15 clock,
but the rear panel is different. The schematic is also completely different. Virtually all functions are controlled by
a soviet IC K145IK1901 (К145ИК1901).
Like Elektronika 6 / 6.15 it has s flat 4-digit 7-segment VFD display IVL1-7/5 (ИВЛ1-7/5) with 21mm high digits
It s powered from 220V 50Hz mains and draws about 2.5W. This type doesn't have a backup battery.
It is controlled using 8 buttons at the rear panel and 1 switch at the top.
It has some other functions like stopwatch and kitchen timer.
I had 3 pieces of this clock. All 3 had the same fault. The heater filament of the VFD display was open, despite it looked visually OK.
The vacuum was also OK according to the color of the getter. After VFD replacement, 2 clocks work well, one occasionally resets (probably
damaged IC).
