Portable Receivers '' Tom Thumb 528 '', '' Firestone TT-528 '' and '' Tom Thumb TT-600 Hybrid ''.
Portable radios and receivers.ForeignThe Tom Thumb 528, Firestone TT-528 portable tube radios and the Tom Thumb TT-600 Hybrid tube transistor radio have been manufactured since 1956 by Manufactured by Automatic Radio Mfg. Co., Boston. The models are assembled according to the general superheterodyne scheme, except for the ULF terminal casing. In the first two models of radio tubes there are 5, 3 in the HF part and 2 in the final amplifier. The latest model has 3 radio tubes in the HF part and 2 transistors in the final ULF. The food is different. The first two models use two batteries, 45 and 1.5 V. The latest model has one for 45 and one for 4 V. The first two receivers have a maximum output power of 80 mW, the last 120 mW. Dimensions of radio receivers 152x95x40 mm.
