Yamaha PC-9
The Yamaha PC-9 "Natural Sound Portable Compo" was manufactured in 1982. It's basically a re-styled Sanyo C7 in a darker color. Notice that the Yamaha's volume knob is larger than the Sanyo's, which is a welcome change. This model is very heavy (about 25 lbs) because it consists of 3 separate components (tuner, tape deck, and power supply), each of which has a metal case. These components are held against the speakers by a sturdy metal bracket that the handle snaps into. The woofers are 12cm and the tweeters are 4cm.
The service manual can be purchased HERE.