1955 RCA 7BT-10K
Portable radio, leather cabinet with aluminum face
10 x 6 5/8 x 4 inches / 254 x 168 x 102 mm
Seven transistors (Texas Instruments, RCA: 2x 234, 235, 4x 2N109), superheterodyne circuit
One 9-volt "battery pack"
RCA's second (possibly first) transistor radio, released in late 1955 at about the same time as the 7BT-9J coat pocket radio, maybe within weeks or even at the same time. It used nearly the same transistor complement as the 7BT-9J — three silver oval TI transistors (234, 235) and four black epoxy 2N109 RCA transistors (the 7BT-9J used only three 2N109s). Like several other early US transistor portables, the 7BT-10K had an aluminum chassis with socketed transistors and LOTS of space there between the components!