I wonder if those antennas were very efficient? I know that early police radio was usually on a low frequency.
Adequate, at least, in many cases. It does
depend on transmitter power, of course, but
I have no problems pulling in a 1 watt signal
from a short vertical antenna at 7 miles
using a 6” diameter loop on 80.
IIRC police back then were often on the
1750 kHz range, and with a loop antenna were
likely receive-only in the cars. (I have seen
photos of German police on foot in the 1920’s (?)
with a portable receiver for receiving instructions,
but one assumes they would stop at a callbox if
they needed to communicate with HQ.)
But having one-way communications from the
dispatcher to mobile units at least provided a
way to speed up their response to an incident.