Category Archives: Radios

A repair story: Vlado’s fix for the classic Sony ICF-SW100

In June, I made a small leap of faith and purchased a (dead) Sony ICF-SW100 from Universal Radio (see the listing on right).

ICF-SW100-Used-NonWorking You see, for many years, I’ve dreamed about owning this wee little receiver, now a classic among tiny radios, but used ones are typically too expensive for my modest budget.

This time, seeing the ad at Universal, I spoke with Universal Radio directly to obtain more details about their defunct unit; while they simply didn’t know what was wrong with the Sony, they were able to very accurately describe its cosmetic and functional condition…I took a deep breath, and decided to take a chance on it anyhow.

In full disclosure, I have a secret weapon in my camp: my talented friend, Vlado (N3CZ), who is not only the most adept electronics engineer/technician I’ve ever known, but one who truly welcomes a challenge. The thought had occurred to me as I admired the wounded Sony, Wonder if Vlad would like to take this on–?

The answer, of course, was Yes! So I dropped the DOA Sony off at Vlad’s home last week. He disassembled the radio, only to discover that my ICF-SW100 was a victim of the (dreaded) damaged ribbon cable.

A short history of the Sony ICF-SW100 and SW100S

These radios are indeed brilliant, incredible performers for their miniscule size. Yet the first generation of ICF-SW100 radios–those produced before the fall of 1997–have a design weakness: the ribbon cables which connect the upper and lower portions of the radio’s clamshell design eventually fail. Multiple openings and closings bend and cut the cables, rendering the otherwise remarkable little radio useless.

SWLing Post contributor, Dan Robinson, recently shared his knowledge about the ICF-SW100 series. Dan notes:

SW-100 Seekers Beware

As shortwave veterans know, the classic SONY miniportables — SW-1, SW-100(S) and SW-07, represented some amazing technological achievements. SONY managed to shrink some fantastic technology into these receivers, including (with the last two in the line) — SYNC capability. The SW-07, which was the last of these receivers, still brings some high prices on Ebay.

But if you are searching for the ICF-SW-100S there are some things to consider and beware of. As everyone knows, the SW-100 suffered from the well-known ribbon-cable failure problem. SONY addressed this problem in later serial numbers, and changed the design of the radio case.

Modified SW-100s have a notch where the top cover meets the base.

There are some dishonest sellers out there who are trying to pass off older version SW-100s as modified ones. Usually, the tip-off is that the photograph in the Ebay auction will be dark or out of focus, so it’s hard to tell if the radio is the modified version or not.

It has become quite rare to find an original SONY modification kit, which includes a new top cabinet of the SW-100. And some sellers are trying to get as much as $300 for these, though they rarely sell at this level.

This repair kit was on eBay at time of posting.

ICF-SW100 modification kit found on eBay at time of posting.

It’s also becoming rare to see SW-100S radios new-in-box. I had two of these, sold one and kept the other.

If you’re after one of these marvel radios, do what everyone should do when considering items on Ebay — ask many questions about [the] cosmetic condition, accessories, serial numbers, etc.

Universal Radio, a trustworthy seller I know, had fully disclosed the model number and problems with this radio, so I knew exactly what I was buying. Dan has a very good point, though: unless you know the seller to be honest, do your research and ask questions!

The ailing ICF-SW100

Vlado discovers the faulty ribbon cable (click to enlarge)

Back to my ailing unit: Vlado delivered the news about the ribbon cable via text message, and though I was well aware that the chances were high that was the ribbon cable, I was a little bummed, to say the least, to get the formal diagnosis.

Why? As Dan mentions above, you’ll find that the SW-100S upgrade kit Sony produced in the 1990s is no longer available new; sellers typically list these kits at prices in excess of $300 US. Out of my budget.

But Vlado, ever the intrepid engineer, had no idea I would be disappointed with this news; he was just giving me this FYI via text. Indeed, he seemed entirely unfazed, as in, hey, no serious internal damage here…

Another hour passed. Then came another message from Vlad; this one simply said: “Call me.”

Oh no, I thought. But I called, and Vlado answered cheerfully, “Hello? Tom, is that you? Sorry, I can’t hear you very well because your SW100 is playing too loudly. Hang on–let me turn the volume down!”

Vlad installs the replacement ribbon cable (click to enlarge)

“What!?!” I responded, in utter disbelief.

Yes, he’d got it working! It seems that Vlad had unearthed an old DVD player in his garage that he’d kept merely for parts. He opened it up, identified a ribbon cable with the right pitch, then cut and folded the cable to fit into the SW100. Ingenious!

That’s Vlado for you!

And should I be interested in replacing this used cable with a new one–or in repairing other Sonys–Vlad directed me to eBay listings for new cables which only total about $20, shipped. Truthfully, I’m in no hurry, as this one is functioning perfectly and changing out the ribbon cable seems to have no effect on stored memories, etc. With a single affordable eBay purchase of multiple cable sets, it occurred to me that Vlad would have enough replacement cables to repair the SW100 many times over…

So I bought the cables. (This one for the narrow cable and this one for the wider one.)

My “new” Sony ICF-SW100

Needless to say, I’m very pleased with my “new” (to me) SW100. It’s a little masterpiece of receiver engineering in such a tiny package. And since the ICF-SW100 is unquestionably the smallest portable I own–and is one of the few I own with a proper line-out jack–it may very well become my go-to radio for one bag travel.

It’s in the bag: listening to the ‘SW100 before I pack it for my next trip!

Stay tuned the review…

Vlado’s radio E.R.: the doctor is in

As I’ve said, Vlad is one of the most adept repair technicians I’ve ever known. At my prompting, he’s kindly agreed to let me promote his services here on the SWLing Post. Vlad acknowledges that he “likes a challenge,” adding that he enjoys nothing more than making repairs even when”parts are scarce” and radio”surgery” is required. Moreover, his bench fees will be quite reasonable, especially considering what you receive: new life for a failing radio. So, if you’ve got an ailing rig on your hands, and don’t mind waiting for Vlad to get to it, send it to his radio emergency room, where radios (like my Sony) have life breathed back into them once again.

Long live the Sony ICF-SW100! And long live Dr. Vlado, who makes this possible with his creative (and nearly miraculous) repairs.

To contact Vlad, simply contact me with a description of your radio and its problem and I’ll put you in touch with Vlado.

eBay sighting: Braun “Wall Unit” by Dieter Rams

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Dieter Rams’ office with mounted Wall Unit. (Source: Campsite studio)

Many thank to my buddy, David Korchin (K2WNW), who sent the following eBay link:

Dieter Rams masterpiece Braun “Wall Unit” Wandanlage TS45 TG502 reel L470 PCS5

While I love Dieter Rams’ designs, and no doubt this is a very rare piece in “almost perfect shape,” it is certainly well-beyond my budget at $11,000 US plus $600 shipping.

Admittedly, though, if I were building a modern house and wanted a feature piece of functional artwork, the Braun Wall Unit may very well fit the bill. Most of Rams’ designs certainly seem to hold or increase in value over time.

For now, I’ll just admire this design from a distance. Curious if it’ll fetch its BuyItNow price. Thanks again for sharing this one, David!

Guest Post: Richard tests the frequency stability of the Tecsun PL-880

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Many thanks to SWLing Post contributor, Richard Langley, for the following guest post:

Frequency Stability of My Tecsun PL-880

Recently, while recording the audio on a particular SW frequency unattended over night, I decided to set my Tecsun PL-880 in USB mode with the 3.5 kHz RF bandwidth setting as I had previously noticed splatter QRM from a station 10 kHz below my frequency of interest. I adjusted the frequency to the nearest 10 Hz for natural-sounding voice. On playing the recording, I was disappointed to find that the signal had drifted in frequency and although speech was still recognizable, music was distorted.

I decided to try to measure the stability of the receiver by recording the Canadian time signal station CHU on 7850.00 kHz in USB mode (CHU has no LSB component) over night for over nine hours. The receiver was operated with just its telescopic whip antenna indoors and the audio was recorded with a Tecsun ICR-100 radio recorder / digital audio player. I wrote a Python script to compute the audio spectrum of each one-minute segment of the recorded files using a fast Fourier transform (after removing a DC component). The script then looks for the largest peaks in the spectra centred on a specified frequency and prints out the frequency (to the nearest Hz) and amplitude of the peak. In case the signal has dropped below audibility, a threshold is set and if the detected peak is below the threshold (likely just detecting the random noise background), it is skipped. The specific centre frequency I was looking for was 1000 Hz, the frequency of the tone used to mark each second of the CHU broadcast except when the voice announcement and digital signal are transmitted. In AM mode, the spectrum would consistently show a peak at 1000 Hz but in SSB mode, the peak will vary depending on the receiver frequency setting and the actual frequency of the receiver’s oscillator.

The plot below shows the received CHU one-second tone frequency as a function of time (UTC) from when the receiver was first switched on.

StabilityPlot-CHU1000hz

It shows the tone frequency started out at about 1046 Hz slowly dropping in the first half hour to about 1012 Hz and after about an hour stabilized to 1011 Hz ± 1 Hz for the better part of an hour. (This shows that you may have to allow a receiver to “warm up” for perhaps up to an hour before attempting anything close to accurate frequency reading at the order of 10 Hz.) But then, over the course of the next seven hours when the signal was audible, the frequency slowly rose ending up at about 1034 Hz. The variation might be affected by the ambient air temperature (but this should have been nearly constant), air flow around the receiver, and perhaps the charge level of the receiver’s battery. On several occasions, I have turned the receiver on (after being off for many hours) and seen a CHU frequency offset of only 10 or 20 Hz. So, I intend to repeat this experiment sometime to check on the day-to-day frequency stability. This frequency stability measurement technique could also be used with WWV/WWVH by recording the 440, 500, or 600 Hz tones broadcast at different times during the broadcast hour.

Of course, it’s also possible to check the receiver’s frequency offset in real time by switching between AM and SSB modes while adjusting the receiver frequency in 10 Hz steps until the signal sounds the same in both modes. There is also freely available computer software for various operating systems that can display a real-time spectrum of audio passed to it through a microphone or line input. So, a CHU or WWV/WWVH test using such software could also be performed in real time. And alternatively, by tuning say exactly 1 kHz away from the transmitted carrier frequency in SSB mode, the software can be used to measure the audible heterodyne frequency to better than 10 Hz — even 1 Hz. This frequency can then be added or subtracted as appropriate to the dial reading (assumed accurate or with a noted offset) to get the exact transmitted carrier frequency.

By the way, it is possible to calibrate and reset the PL-880 using the procedure documented on the SWLing Post (click here to view).

As a side benefit of the analysis I carried out, we can also look at the quality of the received signal over the recorded interval. In this case, it is a measure of the level of a particular audio frequency rather than the RF signal+noise level we usually get from the receiver S-meter or other signal strength display. This is illustrated in the plot below for the CHU recording. As you can see, reception was mostly quite good between about 02:00 and 04:00 UTC and then became fair but above threshold level until about 05:30 UTC.

The signal was then essentially inaudible up to about 08:00 UTC when with bouts of fading it became audible again for an hour or two with sunrise approaching.

— Richard Langley

Guy discovers the $13.99 Basbon DS-858 shortwave radio

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SWLing Post contributor, Guy Atkins, writes:

I spotted this new listing on Ebay today, and was wondering if it’s a new model, or perhaps a repackaged Tecsun PL-606? It’s lacking the rotary tuning knob and has a smaller display than the 606 however. It also has two rows of main buttons rather than three:

http://ebay.to/1KGjfrN

Curiously, the seller doesn’t even list the brand name in their auction title; it’s only noted in the pictures. However, “Basbon” isn’t exactly a brand of communications receivers with a long, proud tradition :^)

For $13.99 including shipping the the USA it’s hard to go wrong, so I’ve ordered one.

[…]Three features that caught my eye with the little Basbon radio are that it’s DSP based, it has LCD backlighting, and shortwave frequency coverage down to 3200 kHz. There are 20 memories and a sturdy-looking whip antenna that rotates 360 degrees, too.

I can’t wait to get ahold of this and open it up! I wonder which SiLabs chip it uses?

Thanks for the tip, Guy! I’m also very curious about this little portable–indeed, curious enough, I purchased one, too. Guy and I will compare notes and I’ll post an update after I receive the radio. It’s being shipped via ePacket from China, so transit time will be roughly two weeks if not held up in customs.

Frankly, my expectations are very low, but like Guy, it’s a little too tempting at $13.99 shipped!

Click here for a direct link to the Basbson DS-858 on eBay—click here to search for the DS-858 should the current item number expire or sell out.

Dr. Phil’s radio articles: portable SDR and pocket DX

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SWLing Post reader, Dr. Phil, recently contacted me regarding a collection of articles he’s written about DXing and radio modifications.

His site actually has a number of useful articles that I’ll plan to convert to future posts, with his permission.

I asked Dr. Phil for links to two of his most popular publications. He replied:

My two big recent articles are shown below. One is about “Pocket Radio DX”: using under-$20 radios to DX (started in 2003). Click here to download as a PDF.

The other is about using an $18 NooElec TV-tuner as a MW and shortwave receiver. Click here to download as a PDF.

Brilliant! Thanks so much for sharing these, Dr. Phil!

I actually have a Sony ICF-S10MK2, which I consider to be a capable and useful little AM/FM receiver for the sub $20 price. I’ve also been very tempted to purchase an RTL-SDR dongle, so I may go ahead and bite the bullet on one of the NooElec SDR dongles.

Mike’s thrift store find: a Panasonic RF-888

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Mike's Panasonic RF-888 (left) and his GE Super Radio II (right)

Mike’s thrift store Panasonic RF-888 (left) and his GE Super Radio II (right)

SWLing Post contributor Mike (K8RAT) writes:

I happened upon a good find of a vintage radio recently when I visited my local Goodwill store in a small city in Ohio.

Among the electronic equipment on a shelf I discovered a Panasonic RF-888. I was not familiar with this radio. The large speaker along with switches and knobs for features found on the better radios impressed me.

The price on the sticker read $3.50. I paid at the counter and motored away not knowing what a bargain I had received.

The RF-888 audio is very good on FM and good on AM. Sensitivity and selectivity are very good on both bands. The tuning meter is useful.

I recommend visits to local second-hand stores. You never know what you might find.

Mike, K8RAT

Many thanks for sharing this story, Mike, as it provides a good lesson for us all: never pass by a thrift store! I’ve never had the good fortune of finding a gem like the RF-888–or a Sony ICF-2010 like Vlado–but I shall keep searching.

Panasonic RF-888s sell on eBay for $100 US and higher–at $3.50, I’d say Mike snagged a deal.

Silicon Labs DSP chip homebrew receiver

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The Silicon Labs Si4730 series DSP receiver chip powers many of the portable shortwave radios currently on the market.

Manufacturers are not the only ones implementing the chip in receiver design, however; radio enthusiasts are too.

I recently discovered this short video by a Japanese hobbyist who implemented the Si4734 in his receiver design:

While I don’t speak Japanese, the author also has a webpage of detailed design notes you might check out (click here to view). I used Google translate for a rough English translation of the page.

Have any readers made a homebrew receiver from a Silicon Labs DSP chip? If so, please comment!

Click here to download the Si4734 product information sheet.