Here is a true worldwide best-seller.
When everybody was trying to make the perfect portable hifi combo, Sony came up with the HELI and at last took over the market it strived to catch up with (or create) since the mid 1970s.
The FH sold like hotcakes : it was small, truly portable (for a 1982 system :), not all that bad sounding and was topped by the cute as can be PS-Q7 quarter-sized turntable which became one of Sony's better remembered component.
Two FH power-blocks could be used : EBP-78 for outdoor use and AC-78 for indoor.
If specs for the ST-78 tuner, TA-78 amplifier, TC-78 recorder and PS-Q7 turntable weren't exceptional, they were nevertheless quite respectable for a portable hifi set. The APM speakers are the SS-78
Sony produced an astronomical amount of later FH systems ; apart from the similar FH-7 MKII, none managed to be as cute a bestseller as the orginal HELI / FH-7.
As several other Sony products, the FH-7 arrived at the right moment, with the right features and the right design - come to think of it, this doesn't happen very often, Sony or not.