The portable multi band receiver with it's horizontal dial drum and the band selector switch to operate the turret tuner at the roght small face has a quite similar external appearence to the late Zenith "Trans Oceanic" radios.
The portable receiver comes wit ha black plastic cabinet, a carrying handle and a cover, which can be flipped down and pushed in the pottom part of the receiver when it's in use (I found this cracked in several CRF-5090, I have seen...). The dimension's of the radio are 34 x 25 x 16 cm and it's weight 5,7 kg.

The CRF-5090 can be powered from 110 or 220 V mains, from a car battery with 12 V DC (a special sony plug is used, the socket has two connectors for 220V AC and another two for the DC input) or from eight UM-1 mono cell batteries.

The telescopic antenna is mounted at the top face of the radio, near the caryying handle.

The top part of the front panel is taken by the horizontal frequency dial drum, the band selector acting on the turret tuner mechanism is located at the right small face. Small plastic pointers can be used to remember the location of Your favourite stations on the dial, a red LED glows on the dial pointer, when the signal strength of a signal is sufficient. At the right of the dial window, You find a nice analog signal strength meter.
All controls are located in another horizontal row, at the left You find the main power switch and an earphones jack, further right the squelch and BFO controls and the R.F. gain control, in it's normal position, the R.F. gain is controlled automatically. At the right, You find the rotary controls for tone and volume and the switch for AFC active in the FM broadcast band only.
The tuning knob with a concentric fine tuning control is located next to the oval speaker in the bottom part of the front panel.

The operation scheme of the CRF-5090 is no thrills: Set the power switch in the "ON" position, adjust the volume, select the desired band with the band selector at the right side of the radio and tune to the desired frequency... This task is not so easy, as the frequency dial resolution of the receiver is quite poor, on each band, You might find several shortwave broadcast or amateur bands. So guessing, listening to a spoken identification or an interval signal is the way to identify a frequency. All receivers with a digital frequency counter are much easier to tune, but this was the state of the art for a domestic world band radio when the CRF-5090 was new.
The is the possibility to tune in CW or single sideband signals in the amateur radio bands, the set comes with a BFO and even manual R.F. gain control, but tuning is quite cumbersome and the receiver is not that stable.

In the AM bands, the CRF-5090 acts as a single conversion receiver with an intermediate frequency of 455 kHz, in the FM band single conversion with i.f. 10,7 MHz.

In summary: the Sony CRF-5090 is a collectors piece in a classic design similar to the one found in late Zenith "Trans Oceanic" receivers. It comes with a much better built quality then similar looking later world band radios from far east prosuction such as different Koyo receivers.
The CRF-5090 comes with Air Band coverage as an additional feature, this will be the reason this set has not been sold very often in Western Europe. The CRF-5080 is a similar set without AIR Band coverage.
Martin Cook from New Zealand wrote an excellend article about the repair of the warped CRF-5090 dial; obviously, many CRF-5090 have this problem with the warped drum dial.