A radio hat is a souvenir tube radio receiver of direct amplification , made in the form of a hat . Released in the USA by Merri-Lei Corporation in early 1949 and sold for $ 7.95 under the name "Martian Radio Hat"
Electronic lamps, a loop antenna, and a tuning knob were an important element in the appearance of the receiver. The hat was available in eight colors.
Description of the circuit
The receiver is assembled on two finger pentodes of direct glow. The first lamp, type 1S5 (domestic analogue - 1B1P), is a detector , and the second, 3V4 is a low-frequency amplifier , to the output of which headphones are connected. For consumer safety reasons, the anode voltage was chosen to be very low - 22.5 V (usually the battery tube receivers operated with anode voltage from 70 to 120 V). The elements of the radio hat are placed on a flexible T-shaped polymer board; it was inserted into the top of the hat. The loop antenna simultaneously serves as the inductor of the input oscillating circuit . The tuning knob was brought out onto the tulle, between the lamps sticking up. The capacity of the anode-filament battery is enough for 20 hours of continuous operation of the receiver. The battery was connected to the receiver with a cable, it had to be carried in a pocket.
Links
- Radio hat (English) // LIFE. - 1949. - P. 155-156 .
- Sun hat has built-in radio (Eng.) // Popular Science. - 1949 .-- P. 119 .