Hi !!!
According to Squadron/Signal publications nr.78 and polish publications TBU nr.25 and 92 ,night fighter YAK7B/PVO (anti-aircraft defence) was equiped with RPK-10 radio-compass,electrical illuminated gunsight, a light for night landing and electrically powered undercarriage position indicator lights.Besides,RSI-4 radio-set and a kind of radio-localizator were installed on it. The rest of its equipment was like Yak 7B standard. The Yak 7B/PVO night fighters were used during the defence of Moscow.Although, I haven't found any picture of the Yak 7B/PVO yet,it seems that the camouflage of Yak7B was like the russian daily scheme.