[Electrothaumaturgist]

Move the Zenith where the Philco is, and move the Philco to where the Zenith was, to determine if it simply is a matter of antenna misalignment. I know on the 42-400, a slight turn of the antenna (or perhaps any linear movement of the radio itself) can cause noise, or clarify the signal, especially in the evening. Or if not, maybe the Z brand is just more sensitive to rogue noises than the Philco. That is one thing I noticed when I powered up the 42-400 (my phirst philco), there was dead silence between stations. Philco may have more filtering power than the Z's, as I've heard that "scratching" sound you speak of (under similar situations) on other Z sets.