Radiot lehden 1/2010 linkit

Sivu 26 National Company
K4KJ A Brief History of the National Company, Inc. John J. Nagle
Bay Specifications and Pictures of National Radio Company Product
Radiomuseum] USA: Radio Catalog for the radio manufacturer National Company, Inc; Malden
W0VLZ HRO Receiver Models
HRO SR
HRO-50
HRO-60
HRO-500
NC-100XA vanha