Penberthy Crystal Set - Penberthy Injector Co.
Detroit, Michigan - circa 1925
Tabs on other condenser plate eliminate wires to phone terminals.
One turn spirals make contact to coil winding.
Phone condenser plate is thick enough to hold coil in place.
Leaf springs maintain contact on coil.
Bakelite panel with tuning scales hot stamped around knobs.
“Penberthy” die stamped on shell of enclosed detector.
