Popular Wireless, August 9, 1930.

Valves Advertised:

HL210, H210, L210, HL410, H410, L410, HL610, H610, L610, P215, P410, P610, P2, P240, P425, P625, P625A, S215, S410, S610, PT240, PT425, PX4 & PT625.