Sony's ICF-7600 series. The survey!
This review was compiled with the assistance of the World Radio TV Handbook, Amsterdam. Radio Netherlands has no financial connection with the WRTH, nor with Sony, the manufacturer of this receiver.
IntroductionNote that this following review does NOT include the current ICF-SW 7600G, but refers to the now-discontinued sets in the ICF-7600 family.
Whilst Sony can justify its reputation for original thinking, the marketing managers in Japan were not very thoughtful when it came to dreaming up a new type number in the 1980's. If you search old stock or second hand stores, you'll find that Sony had models called the ICF-7600A, ICF-7000AW, ICF-7600-D, and ICF-7600-DS on sale in many parts of the world. These are completely different compact travel portables. There is also an ICF-7601 which sounds like a follow-up to a 7600 type radio. In fact it is (an improved ICF-7600A) but it is not better than the ICF-SW-7600. Confused? Judging by phone calls to our radio station so is the non-technical general public. For reference, here is a summary of the 7600 family.
ICF-7600ACompared to similar priced sets from other companies offering out-of-band SWBC coverage, the old ICF-7600A is now out-of-date, and not to be recommended. However, although production discontinued some time ago, old stock is still found in shop windows of Europe, the Middle East and parts of South-East Asia.
ICF-7600DIn 1984 Sony came out with a set called the ICF-7600D in most parts of the world, with the exception of the North American market where it became known as the ICF2002. It was completely different to the older ICF-7600A, but the similarity in type numbers caused a great deal of confusion in the European and Asian market place. The ICF-7600D was later slightly re-worked from a cosmetic standpoint, i.e. the colour changed to a gun-metal grey. In August 87, the name was changed to the ICF-7600DS and the price lowered in Europe (currently around US$ 300 although this is still more expensive than North America). In the USA and Canada the ICF-7600DS is called the ICF2003 to help reduce the grey-import problem.
The appearance in June 87 of yet another completely different receiver with the number ICF-7600DA didn't help matters. Some European Sony dealers tell us they applied to Tokyo for permission to market it under a different name but this was refused. In North America the same receiver was called the ICF-7700 (pictured above). This portable had both a digital readout, and a complex liquid crystal display to simulate an analogue dial. However, because the radio also had a number of design flaws, it has now been withdrawn. One of the most serious problems was the inability of the receiver to tune in steps finer than 5 kHz.
Operation. The ICF-SW7600 has a straight-forward design and operation. To tune to 9895 kHz for instance, you press the AM button, the numbers 9 8 9 5, and then the AM button again. This executes the tuning request and the receiver tunes to that frequency. The keys on the keypad are well spaced out, so there is no chance of accidently pressing two keys at once. The more expensive ICF-2001D has a small blip on the key for the figure 5. This is useful for visually handicapped users in helping them to feel which key is which. There is no blip on the keypad of the ICF-SW7600. The set jumps up and down the dial in 3 kHz steps between 150 - 531 kHz, 9 or 10 kHz steps between 531 - 1615 kHz ( this is selectable by a small switch in the battery compartment) and 5 kHz between 1615 - 29995 kHz. The steps on FM are 100 kHz. Finer tuning on shortwave frequencies is desirable, and possible. A switch on the side can be set to activate a small thumb-wheel control for fine tuning +/- 7 kHz. Adjusting the thumb wheel has no affect on the frequency display. It is therefore a good idea to keep this thumb wheel in the middle of its track or the set is permanent off-channel by a few kHz. In the case of strong mediumwave stations this means it is possible to tap in 657 kHz but by turning the thumb wheel to one end the radio is actually monitoring the channel below, namely 648 kHz.
Sony improved the Single-Sideband (SSB) reception on the ICF-SW7600 when compared to the ICF-7600DS. It now has a selector for upper or lower sideband. Adjustment of the SSB is via the fine-tuning thumb wheel. This is adequate for SSB transmissions you find on the amateur radio bands. But the control is not stable enough for radio teletype reception, or the technique of listening to one sideband of an ordinary broadcast signal (ECSS). But then this radio is not in the price range of the serious hobbyist and therefore should not be expected to offer these facilities.
The liquid crystal display is clear, showing the time when the radio is switched off and the frequency when switched on. The radio has a timer function, and can be set to operate a tape recorder. Note that the radio will switch a low control current not the mains supply. There is a output jack marked RECORD which has a very low level output. If you were using a WALKMAN type recorder, you'd need to connect the record out to the microphone input. Better results are obtained by connecting the headphone output to the line-input of the tape-recorder. This allows stereo recording on FM, although the speaker of the radio is then muted.
The set offers 10 memories which are programmed by pressing and holding the enter key, and then selecting one of the keys from 0 through 9.
PerformanceWe made the following measurements on the sample:
Frequency Range Sensitivity (in microvolts) for 20 dB S+N/N 2 - 6 MHz 2.1 12 - 17 MHz 10.6 Bandwidth Dynamic Selectivity +/- 5 kHz 26.0 dB +/- 10 kHz 46.0 dB +/- 15 kHz 51.0 dB Blocking level 4.2 mV Image Rejection -16 dB (at +/- 910 kHz) Intercept Point -5 dBmThese results show good shortwave performance for a radio of this type. We noted that an external long wire antenna is NOT recommended, especially in parts of the world with a high shortwave transmitter population (e.g. Europe). In more remote parts of the world a simple long wire antenna might be required for improved reception of higher frequencies. Any overloading when using the telescopic whip antenna can easily be reduced by collapsing the antenna somewhat.
The ICF-SW7600 is selective enough for international radio listening. The option of a second, narrower filter would have been handy. This is currently being offered on a similar priced receiver from the Sangean company, the ATS 808.
FM performance is fine, and the addition of FM STEREO via the headphone socket is a definite plus. It seems strange though that the stereo signal is not available at the RECORD output.
A two position tone control is active on both AM and FM..it simply cuts the treble response when activated. The audio on the ICF-SW7600 is better than on the previous ICF-7600DS, offering better lower frequency reproduction and higher volume output. The DX/LOCAL switch gives about 18 dB of signal reduction when activated. We found it useful on mediumwave in Europe.
The radio has a cleverly designed ON/OFF switch which can be locked. This is useful when the set is packed in a suitcase and you don't want it to spring to life when knocked about. The radio works off 4 penlight batteries. A full set of batteries gave us 18 hours of good FM reception at reasonable listening volume. The batteries should be kept in the radio at all times, even when an external power supply is connected. This ensures that the stations programmed in the memory are retained. You have around 4 minutes to change the batteries before the radio resets itself.
ConclusionThe "7600" family did lead to confusion because the improvements were masked at the dealer level by people who could not easily spot the differences. That said, the ICF-SW7600 is a well designed shortwave portable receiver ideally suited to international radio listening. It is a clear improvement over the ICF-7600DS, both in terms of better design and improved performance. However, the current model ICF-SW7600G, is an even better radio and because of recent price cutting campaigns, may be a better bargain than old stocks of the ICF-SW-7600
Reviewer: Jonathan Marks and Diana