Inhaltsverzeichnis
Sony CRF-220
Manufactured by Sony, Corp., Tokyo.
In the early seventies, Sony launched the „giant“ portable radios CRF-220 and its twin with an additional VHF band CRF-230. Like the later receivers of Sonys CRF series - the top of the range Sony sets were much more expensive than average sets and sold only in small numbers.
Technical data
- Frequency range: FM broadcast band, LW, MW, 20 x SW (1,6 - 26,1 MHz)
- Frequency display: Analogue display, approx. 10 kHz
- Frequency memory: none
Power supply
- Mains operation: 110, 127, 220, 240 V
Dimensions
- 452 x 325 x 190 mm, weight 13.8 kg
Accessories
- Car battery adaptor DCC-126
Operation
The high end portable receiver comes in a cabinet covered with black leatherette, with a sturdy carrying handle at the top, a protective transport cover can be removed, it is equipped with a metal disc world-time converter and compartments for a logbook and documents.
With its 45.2 x 32.5 x 19 cm, the set is even more voluminous than the already bulky Grundig Satellit 3400, and although it can be carried by the carrying handle, this „portability“ refers more to moving it to another shack than to its usefulness as a „portable travel companion“.
On the top face of the unit, the ends of a telescopic antenna for shortwave reception on the left and of two telescopic antennas for VHF reception on the right pop out at the push of a button; when the antennas are pushed all the way in, they are optimally protected from damage.
The top third of the front panel is taken up by the loudspeaker, the controls are arranged in two horizontal sections, the bottom row contains connectors and switches for less frequently used functions.
In the centre of the front panel, at the left, the signal strength instrument and at the right, the frequency dial windows are located. The S-meter is calibrated in S-units, a toggle switch below it activates the dial illumination and a second one sets the instrument to battery voltage control.
To the right of the S-meter the selected shortwave band segment is displayed, the 500 kHz ranges are selected with a powerful rotary switch on the left face of the receiver. To determine the frequency, the displayed frequency on the SW 2-19 dial, which runs vertically from 0 - 500 kHz, is added to the frequency in the display window: in the example shown, the receiver is set to 5.800 + 450 corresponding to 6.250 MHz. If you are tuned to a station on a known frequency, the dial can be calibrated to signal maximum.
The large pushbuttons below the corresponding dials activate the shortwave ranges SW2-19, and the tuning knob is the one below it. The dial accuracy is probably around 10 kHz, which is usually sufficient to identify a station.
In the middle dial window, the vertical dials for SW1, medium and longwave are located, frequencies can be read with acceptable accuracy - again the band range is activated with the large button below and the large tuning knob below tunes the band. There is no separate fine tuning knob.
Located at the far right are the dials, band selector buttons and the tuning knob for the VHF broadcast band. In the lower row of controls, below the S-meter, are the tone controls for treble & bass, the volume control and below that the RF gain control, with the control pulled out, MGC i.e. manual control of the RF gain is possible.
At the bottom row, you find the headphone / earphone jacks on the left (the Sony can handle both diameters of plugs, it's just ingenious…), and below the SW tuning knob, the BFO control for CW and single sideband reception. A small switch activates the BFO, the desired sideband can be set with the control.
Switches under the middle tuning knob activate special functions in the AM range: in the LOCAL position, an attenuator is activated, the switches for ANL (noise limiter) and the two IF filters, in the SHARP position, adjacent channel interference can be suppressed well.
Below the right FM tuning knob are the switching elements for VHF squelch and automatic frequency correction AFC.
The rear panel has a switch to select between the internal and external antennas and screw terminals for the LW-SW1, SW2-19 and VHF antennas. Also on the rear panel are headphone and tape jacks, a five-pin diode jack to connect the set to a tape recorder and the typical Sony four-pin external voltage jack for connecting the mains cable and probably also a DC voltage.
Operation in the FM broadcast band, LW, MW and SW1 is largely self-explanatory. Set the power switch to „ON“, adjust the volume, press the button below the corresponding frequency scale and turn the tuning knob until the station is heard…
In the shortwave ranges, the desired band segment must be selected with the rotary switch on the left face of the receiver while the SW2-19 key is pressed. Before trying to tune in an out-of-band frequency, it is worth to calculate if the frequency is covered. For example, since the 31m band covers 9.500 - 10.100 MHz, the BBC on 9.410 MHz or ERT Athens are left out. Otherwise, for example to tune in to Austrian Radio Intl. on 6.155 MHz, tune to the 49 m band starting at 5.800 MHz, set the dial to 355 (5'800 + 355 = 6155), and you should hear the signal from Vienna - it sounds more complicated than it is in reality.
Similar calculation skills were still necessary some years later with the smaller Sony sets (ICF-5900), Panasonic RF-2200, etc. In the contemporary Grundig Satellit receivers or Braun T-1000 with their non-linear dials, also some guesswork was necessary, and not everybody could afford a Collins R-390A with the mechanical digital display, which was perfectly accurate.
In Summary, the Sony CRF-220 is a collector's set for people with space, due to the high price tag, only few sets made their way to shops in Germany and Switzerland. To search in a broadcast band, my CRF-220 performs well, a station on a known frequency can be tuned with acceptable accuracy. However, the shortwave coverage is not continuous, out-of-band stations, certain amateur radio ranges and marine radio ranges are left out; the set has acceptable stability for SSB reception, operation with an RTTY/CW converter is possible in the case of strong signals. And I will hardly ever take my CRF-220 with me when travelling…
Technical principle
Double conversion superhet, linear dials on 500 kHz shortwave band ranges.
Components
The set is equipped with semiconductors.
