Sony ICF SW100 (Review) PDF  | Print |  E-mail
Written by Bryce Ringwood   

This was a single-chip radio manufactured in the 1990s and early 2000s. It was marketed as a "world-band receiver". It covers 150kHz to 30MHz and FM from 76MHz to 108MHz. The set decodes stereo transmissions. The set is remarkable for being slightly smaller than a pack of 30s cigarettes. Power is derived from 2 x AA alkaline batteries. I have not managed to get NiCad or NiMH rechargeable batteries to work, but it did work well on rechargeable alkaline manganese "Grandcell" batteries. I once left the batteries in a bit long, so I had to take the set apart to clean it . I vaguely remember one large  proprietary chip.


On/Off       - Button which can be locked.
Tuning      - Fine/Coarse using up and down buttons. There is no tuning knob. The radio scans to find a station
Numeric Keypad - Used for direct tuning and memory access
Direct       - Enter frequency directly
EXE          - Used to terminate execution  (of data entry, say)
DX/Local - Input attenuator for strong signals
News/Local doubles as FM Mono/Stereo in FM mode
SSB          - Toggles between Am, USB and LSB
SYNC       - Synchronous detector for AM - removes distortion from signals suffering from selective fading
AM/FM       - Mode switch
AM Band   - Takes you directly to an AM broadcast band (as they were in 1994, of course)
+/-              - Memory page Up/Down

SLEEP      - The set is also an alarm clock. Press to stop waking you up
ERASE      - I really don't know what this does (Maybe erasing a station from memory)
ENTER      - Nor this. I fiddle with it to get the time right for my time zone. Entering a station into memory maybe ?)
Label Shift - Used when entering the names of stations in alpha mode etc.

There is a crude "tuning indicator" and low battery warning, as well as mode indicators. 

The frequency display is large and easy to read. It is also used to display time. (The set displays world time in all zones.) Frequency is displayed to the nearest 1 kHz..
The set has a built-in 1" speaker.

If you have one of these and it becomes faulty, I'm not sure there is much you can do about it. The ribbon cable can be replaced. If you break the case, its a mission to repair it.

The set is a fully synthesized double superhet receiver. In this design, the local oscillator frequency (see article on superhets) is divided down in stages and locked to a master crystal oscillator. If the local oscillator attempts to drift, then a phase detector stage generates an error voltage which brings it back on frequency.  We can look at this in a later article.

The set can be used with an external "active aerial" (which I have never used, or seen). It is also supplied with a handy clip-on long wire antenna - all of 5m or so.

Finally, the set can store 50 stations in 10 pages of 5 stations each. (All you have to do is to remember where you stored them!)


This set has excellent audio quality if played through headphones. It really is HiFi - and you can use it as a tuner, since there is "line out". Using the clip on antenna, I have heard plenty of DX on this set, and, of course, it resolves SSB with ease - but only to the nearest 100Hz. I haven't used the synchronous AM detector much, but when I needed to, it did its job of making the signal intelligible. The set is small and light enough to be carried anywhere - which is its undoing, since it can be dropped or otherwise damaged.  The chances of a set like this having been "improved" are quite small, I would imagine. You can enter the names of stations on the LCD after you have entered them into memory.

There have been criticisms that the set is not sensitive, and certainly I find it perhaps a little less sensitive than the Barlow Wadley, for example, but there can't be much difference between them. In common with most solid-state receivers, it will overload (and might be damaged)if you put a full-size antenna on to it. Obviously, the tiny speaker can't give great sound. Battery life is between 18 and 23 hours using alkaline batteries, compared to over 2000 hours using standard batteries for the Zenith Royal 1000, and probably something similar for the Barlow Wadley. For many people, this set would be challenging to use, but it is really quite straightforward compared to some other small radios. Don't be put off by the lack of a tuning knob. The set does not have RDS possibly because Japan has not introduced RDS to its FM broadcasting. (So I'm told).

This radio does what it sets out to do and has most of the features of large table radios. At the time of writing, SONY are still marketing the slightly larger SWF7600GR designed in 1977, but well worth considering if you are looking for a shortwave radio.


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