We're talking about Soviet aircraft having just receivers but not transmitters?
It was mentioned in a variety of sources. I definitely recall Mark Solonin mentioning it regarding certain Yak-3 series in 1944.
As well Gennadiy Serov + Mikhail Timin's documentary series of shows "How Soviet Fighters fought in (Year)" mentioned something similar IIRC. I would have to go through about 30+ videos a couple of hours each, to find exactly where. I definitely do recall them mentioning how in a lot of orders "the squadron commander must have a working radio transmitter while pilots must have working receivers" implying that pilots may not have transmitters.
EDIT: Found it. 29:00 minute here:
"From Oct 1, 1942, all Soviet aircraft must have receivers RSI-4, and every third aircraft must have a transmitter as per the Government Committee of Defense order"
Afterwards when Soviet aircraft officially went from 3-plane formations to 2-plane formations, "Every second fighter must have a transmitter"
Also you see it here regarding the Yak-3 fighter AFTER WW2 ENDED:
А.С. Москалев: По-прежнему не удавалось наладить производство достаточного количества радиостанций так, чтобы каж¬дый самолет оснащался приемником и передатчиком. Все самолеты оборудовались приемниками, а передатчики имелись лишь на каждой второй машине."
A.S. Moskalev: It was still not possible to set up production of a sufficient number of radio stations so that each aircraft would be equipped with a receiver and transmitter. All aircraft were equipped with receivers, but transmitters were only available on every second fighter." Later "