The cast aluminum "Honeycomb" coil turret developed by National to
improve bandswitching efficiency.
The NC-101X handband receiver, circa 1937. Basically a bandswitched HRO
with the "honeycomb" coil turret [and only one RF stage].
The NC-100 -- similar to the NC-101X but general coverage from 540KC
to 30MC.
1936 -- The National one-ten. Plug-in coils and acorn tubes to cover one
through ten meters.