Also the receiver is somewhat broad. I think they built the receiver with a broad IF because frequency tolerances and control was not that good back in the old days and maybe they felt wide IF was better to account for everyone not being right on channel but that’s just pure speculation on my part.
I was fortunate enough in my younger days to know some of the OTs who were AAF radio ops; mostly aircraft ops. In addition to the noted reasons, which somewhat agree with their comments, they said that it was not always easy to tune a receiver exactly if you had to change freqs for some reason due to such things as turbulence, cold and the clothing required to combat it, and flak. Xtal control of the transmitters apparently was more common than the receivers, but I fail to understand why.
