Manufactured by Sony, Tokyo.
The small Sony ICF-7600D was released to the market in 1983 and it was a successor to the Sony ICF-2001, the very first double conversion superhet with digital PLL frequency synthesis in pocketbook format. In the years before, WRTH still rated the „travel-friendliness“ by the fact if a receiver would fit under an aeroplane seat, the small Sony receiver does fit in the coat pocket. It had a digital frequency display, a BFO for easy SSB reception and ten station memories.
In contrast to its predecessor, the plastic cabinet of the ICF-7600 DS is anthracite-coloured. The set, which measures 18 x 12 x 3.5 cm, weighs in at 650 g and is the size of a paperback book; Sony supplied a grey felt bag for protection. The set is best operated in a lying position, so many listeners have been tinkering with it, and plexiglass stands have been made especially for the Sony 7600 series.
The telescopic antenna can be swivelled onto the top of the unit, a jack socket allows the connection of an external antenna, just above it is the tiny attenuator switch. The ICF-7600 DS does not have an RF gain control, which can lead to overloading when used with long-wire or broadband amplifying active antennas.
The left half of the front panel is taken up by the loudspeaker grille, the frequency and time display and the power switch are located in a field at the top right. The lower part of the right half of the front panel is occupied by the numeric keys for memory recall or direct frequency entry and the AM / FM / EXECUTE keys.
At the top right, there are three large buttons that switch the receiver on or off and activate the sleep timer. A slide switch on the top of the set serves as main switch, preventing the radio from being switched on unintentionally in the suitcase by pressing the ON button. When the tiny TIME-SET button on the back of the receiver and the hour or minute button are pressed at the same time, the time can be set. The time display of the 7600D can be switched from 12h to 24h format by means of a small switch in the battery compartment. If the SET key and the hour / minute keys are pressed at the same time, the alarm time is entered; the „Standby“ key activates the timer mode, and the travel alarm clock is set.
Below the clock display - in contrast to many expensive tabletop receivers, both time and frequency can be read simultaneously during reception - is the frequency display, which unfortunately does not have a backlight. The frequency is displayed in 5 kHz steps; for frequencies within the limits of a short-wave broadcast band, the corresponding metre band is also displayed. A small red LED next to the display serves as a field strength indicator and lights up in case of strong signals. The set is switched on by pressing the ON button. If there is no reaction from the radio, the MAIN POWER slide switch at the top face must be set to „on“. Now a hiss should be audible from the loudspeaker. To enter a reception frequency, first select the band range with the AM (long/medium/shortwave resp. 153 - 29'995 kHz) or FM (VHF broadcast band) key.
The reception frequency can be entered directly with the number keys and called up with EXECUTE. For example, the key sequence AM - 6 - 1 - 5 - 5 - EXECUTE calls up Austrian Radio with its morning broadcast from Vienna.
To store an active frequency, press the ENTER key and one of the numeric keys at the same time; to recall the stored station, just press the corresponding numeric key later.\ A +/- or up/down switch on the left is used to tune the receiver up and down in 5 kHz steps. If you also press the small Band Select button, you immediately jump to the lower limit of the next shortwave broadcast band. The ICF-7600 DS also tunes the 21m band.
A search function is activated if the Start-Stop button is pressed, the receiver stops at the next station with acceptable signal strength, and continues searching automatically after 1.5 seconds if the Stop button is not hit.
Other important controls are located on the side faces of the set. On the right is the volume slider, a tone control switch and the operation mode switch. In the normal position, this small switch sets the receiver to be tuned in a fixed 5 kHz channel spacing; in fine tuning mode, the frequency can be adjusted continuously between the 5 kHz points, the frequency on the display is not altered. So in case of interference from an adjacent channel, use the FINE position to tune down one or two kHz and thus make the signal more intelligible, but the operation frequency matches the displayes frequency only in the middle position of the knurled fine tuning wheel.
In the SSB position, the BFO is activated, and the small knurled fine-tuning wheel must be tuned to zero beat. This allows reception of amateur radio and single sideband stations. On the left face of the unit, you will find the power supply socket (pay attention to the typical Sony plug dimensions and polarity!), an earphone and a tape recorder jack.
The small ICF-7600DS is powered by a total of 6 UM-3 batteries, two of them for the memory and clock functionslast a long time. The other 4 batteries for radio operation last for about 12 hours. To save batteries, the supplied mains adapter AC-240 can be used. At the time of its release, the reception performance of the Sony 7600D was outstanding for a small receiver; even today, the set is an above average portable radio. The suboptimal sensitivity is less noticeable in Europe with its density of high power transmitters and high field strengths than in Africa or the Pacific region. With the built-in IF filter, transmitters in 5 kHz channel spacing can be separated well, especially when fine tuning is used and the set is tuned 1 - 2 kHz low or hig.
On long-wire antennas, the small Sony tends to overload, and also broadband active antennas seem to me not suitable. I had no problems connecting my 20 m antenna via a Yaesu FRT-7700 antenna tuning, and the Sony set also copes well with signals from the magnetic antenna GS-2 from Grahn.
To dispose of only 10 station memories caused me some trouble during my holidays, but I managed to keep track of the memory contents. The timer/sleep function is practical; if you can do without an illuminated display at nighttime, the Sony ICF-7600D can replace a travel alarm clock.
Compared to the original ICF-7600D, the catalogue price of the Sony 7600 DS has been reduced from about 600.- to about 400.- sFr. The fine tuning option - for many years not available in microprocessor controlled portable receviers - and SSB reception with an astonishing performance and technically advanced construction made the 7600D to be my favourite travel receiver. It was succeeded by the ICF-SW7600G, which had a performing synchronous detector as an additional feature, the dimensions and other functions remained the same.
Double conversion, digital PLL frequency synthesis.
The set is equipped with semiconductors.