From that slightly awkward time that lies between the fully analog and fully digital eras come the Pioneer SX-3700. It was 1980 and digital displays were just catching on and Pioneer sought to capitalize on the movement with its Fluroscan technology. The SX-3700 produces 45 watts per channel and incorporates a direct coupled amplifier design.
There is a variant of the SX-3700 labelled the SX-820. Apparently it is a European version but has a black dial face and white Fluroscan. A couple other SX-3000 series receivers also had European variants in the SX-620, SX-720.
The Fluroscan display shows the tuning for the AM or FM bands depending upon AM or FM selector button is pushed. The analog dial shows both FM and AM tuning as well. The power output meter is also a Fluroscan display. Pioneer utilized a 3 gang FM tuning capacitor and quartz servo lock technology to create a very good FM tuner section. The Fluroscan FM display is backed up by a quartz crystal oscillator that provides a stable time base so that the correct numbers will always be displayed for a given frequency selection. The display is also 5 digits as opposed to many other manufacturers that used only four digits. Pioneer referred to all of this as their P.D.Q. or Pioneer Digital/Quartz tuning technology.
The SX-3700 was a mid range receiver and had bigger brothers in the SX-3800 and the SX-3900. But, those receivers had more complicated designs and are more difficult to work on than the SX-3700.
If you like the Fluroscan display then the SX-3700 (or SX-3800, SX-3900 depending upon your budget) might be the way to go. They do look very nice in the dark and are a good representation of the technological shift from analog to digital. They are also very good performers and can be found for a price that is within most budgets. A fully serviced unit will sell for around $300 while the average working unit will sell for $150 to $200.