Category Archives: Radio Modifications

A very simple mod for your PowerMate controller

My Powermate USB sporting a white rubber band grip.

My Powermate USB sporting a white rubber band grip.

After publishing the post about my PowerMate USB controller, Mike Ladd replied on Facebook:

“Do what I did a couple of years ago and add a lobster claw rubber band to the [PowerMate] tuning wheel.”

In case you’re not familiar, Mike is referring to the thick, wide rubber bands that are placed on lobster claws to hold them shut. Mike included the following video; you can see that the rubber band fits perfectly around the top of the tuning knob, giving it a little extra grip.

https://www.youtube.com/watch?v=gtlDMSpaj4c

This same type of rubber band can often be found in the produce department of grocery stores as it’s used to hold bunches of broccoli, asparagus and other produce together.

Many thanks for the tip, Mike!

Moshe restores a Ben-Gal “Duet-Stereo”

Ben-Gal-Duet-Stereo-Full

Many thanks to SWLing Post contributor, Moshe, who writes:

About 2 weeks ago, a very good friend called me and exclaimed, “you just have to see this radio…I’m keeping it for you!”–so, I drove to his aunt’s house and saw this beauty.

After hauling the radio to my place, I started to check it out, to see what would be needed for restoration; it was working, with bad contacts, poor frequency response and low output.

I took hi-res pictures of this radio, some during restoration. Now the radio sounds great. It has been recapped, a couple of bad resistors and bad wires replaced, contacts have been cleaned, and some good cleaning for the chassis as well.

Ben-Gal-Duet-Stereo-Board3

Ben-Gal-Duet-Stereo-Rear2

Ben-Gal-Duet-Stereo-Front-Detached

As I wanted to keep the original appearance of the chassis, I kept the original filter capacitors on board, but disconnected them from the circuit, added terminal strips and new capacitors from underneath.

Ben-Gal-Duet-Stereo-Board2 Ben-Gal-Duet-Stereo-Board1

The radio uses an EF85 tube as the RF stage. With the addition of a grounding connection and random wire antenna, it’s very sensitive on shortwave.

Ben-Gal-Duet-Stereo-FrontPanel

About the Ben-Gal Duet-Stereo:

It was made in Israel by Ben-Gal, a label inside shows it was made at 12th of December, 1965.

It is a console model with record player. As the model name suggests, the amplifier and record player are stereo (though the tuner is not…).

The radio has longwave (marked in meters), mediumwave (marked in meters) and 3 shortwave bands (with megacycle and meter band marks).

The shortwave bands overlaps with each other, so cover is continuous:

  • SW3 2.3MHz to 6MHz,
  • SW2 5.5MHz to 15.5MHz,
  • and SW1 14.5MHz to 23MHz.

Ben-Gal-Duet-Stereo-Open

Many thanks, Moshe, for sharing photos and this description of this beautiful Ben-Gal Duet-Stereo. I bet the audio fidelity is amazing. My father has a 1960’s console–with a similar configuration–made by Admiral, though it was limited to mediumwave and FM reception. Some day, I will try to restore it to its former glory!

Thanks for the inspiration, Moshe!

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

Sony-ICF-SW100In 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-NonWorkingYou 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.

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)

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.

Listening to the 'SW100 before I pack it for my next trip.

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

Sony-ICF-SW100-Open2As 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.

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

RTL-SDR-001SWLing 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.

Sony ICF-S10MKIII 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.

Silicon Labs DSP chip homebrew receiver

DSP-HomebrewThe 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.

Review of the SSTRAN AMT3000 AM transmitter kit

SStram-AMT3000-Board2

Regular SWLing Post readers know that I’m a sucker for vintage radios––especially those of the WWII era. Indeed, I’m pretty much a fan of anything from the 1930s and 40s. I love the technology of that era and have an affinity for the culture and history, especially film and music.

Last year, I acquired a beautiful Scott Marine Radio Model SLR-M––a receiver that quickly became the centerpiece of my modest vintage radio collection.

Scott-Marine-SLR-M

Scottie (yep, I call her Scottie) produces beautiful, rich audio from her internal speaker. It’s truly an amazing piece of over-engineered technology that still sounds this good after 70 years.

Edythe Wright

Edythe Wright

Only a week or so after plugging Scottie into an antenna, my wife and I picked up a $1 CD at a church yard sale. The CD featured big band music from the late 30s/early 40s. Though we already had much of the music on the CD, we bought it anyway to keep in our car. One beautiful fall day, I was driving down a rural road and had the CD playing when a Tommy Dorsey recording of “The Music Goes Round And Round” with Edythe Wright on vocals, began playing. It had been ages since I heard this song…I then wondered how many GIs might have heard this song during WWII via GI Jive or the Armed Forces Radio Network. Perhaps they heard it on the Navy version of my Scott Marine radio, the Navy REH?

It was then I decided to finally pull the trigger and order a proper low-power AM transmitter for our home––something with which I could broadcast period music via my vintage gear.

There are a number of AM transmitters on the market, but the one that always stands out from the crowd is the SSTRAN AMT3000. My buddy, The Professor, has one and uses it to consume much of his digital audio content including podcasts and Internet radio stations. He sang the AMT3000’s praises, and I trust the Prof; he’s something of a medium wave guru.

Thing is, the AMT3000 only ships as a kit. In the past, this had stopped me from ordering the transmitter as I figured it was more than my beginner kit-building skills could manage. But after building David Cripe’s Ozark Patrol regenerative receiver, and loving the experience, I felt confident enough to make the order.

And, boy, am I glad I did!

The SSTRAN AMT3000 kit

The kit arrived within a few days of ordering it. Upon unboxing it, I felt like I had gotten my money’s worth, as it was packaged carefully in a quality box: components were clearly labelled in their own poly bags, the board was clearly marked with component numbers and the assembly/instruction manual was in a plastic binder, all clear and straightforward.

SSTRAN suggests taking your time building the kit, as there are a lot of components to solder, and you risk making mistakes that aren’t necessarily easy to remedy if you rush through the process. I tried to follow this advice––well, I intended to follow this advice. Thing is, I find it very difficult to put down a kit once I’m in the zone, so I zipped along a bit more quickly than I intended.

But it helped that SSTRAN took out a lot of the head-scratching and guesswork; the process couldn’t have been more smooth. I carefully checked and double-checked each component and marked it off the assembly list. First, you install all of the resistors, then capacitors, and on to other components. Other than having to hunt for some of the component locations on the board, it really was quite simple.

SStram-AMT3000-Board

I started building the kit on a Friday afternoon and actually finished it the following Saturday morning. Much to my delight, after performing the tuning procedure, the transmitter worked on the first go. Whew!

Powerful (low power) broadcasting

SSTRAN-AMT3000-2

The AMT3000 can be configured to work with the supplied simple wire antenna, which will essentially broadcast AM to radios throughout your home, or it can be configured for a Part 15 compliant outdoor base-loaded vertical antenna which will extend your range up to 3/4 of a mile, should your shack be down the road or in an outbuilding.

For the moment, I have my transmitter set up for in-house broadcasting only.  If I ever want to build the base-loaded vertical, I only need to make a simple modification to the board to do so.

SSTRAN-AMT3000-3

The supplied manual does a great job of explaining the best ways to maximize your signal, reduce any electrical hum and tweak your audio fidelity.

I’ve been using the AMT3000 nearly every day since I finished building it in mid-November. It seems to have a 100% duty cycle, does not overheat, and has no drift.

It produces high fidelity audio with a flat frequency response––and of course, with modulation and compression controls, you can tailor the audio to your particular taste.

Result?  It sounds amazing piping WWII-era tunes through my Scott Marine SLR-M, Hallicrafters SX-24, and SX-99 and my Hammarlund SP-600.

As a bonus, I can hook my shortwave receivers up to the AMT3000 and listen to received audio via other radios throughout my house. Many times, I’ve listened to live broadcasts of ERT Open on 9,420 kHz via my kitchen AM radio…Very cool!

I also hook the AMT3000 up to my shack PC and stream my favorite internet radio station: the UK 1940s Radio Station via TuneIn radio. Absolutely brilliant!

I set my transmitter to 1410 kHz, and have left it there.  You’ll need to do a medium wave (AM) survey to find the clearest spot on your AM dial. I’m sure results will vary, depending on the level of medium wave broadcast activity in your area.

Here’s what my Scott Marine SLR-M sounds like playing “March of the Toys” by Tommy Dorsey and his Orchestra via the SSTRAN AMT3000 (note that this was recorded with just an iPhone, so audio fidelity is somewhat lacking):

Conclusion

SSTRAN-AMT3000-1

If you’re looking for a high-quality, low-power legal AM transmitter, I highly recommend the SSTRAN AMT3000. Even if you’re a novice kit builder, with time and patience, you can successfully construct the AMT3000, too. If I did it, you certainly can!

If you’d prefer buying a pre-assembled AMT3000, they do occasionally turn up on eBay. Click here to search.

As for me, I’m happy to have achieved my modest goal of being able to broadcast 1930s and 1940s music to vintage radios of the same era.

SSTRAN sells the AMT3000 directly on their website. Click here to view.


SSTRAN AMT3000 Models and Prices (via SSTRAN)

AMT3000
10 kHz channel spacing for use inside North and South America. Includes enclosure and 120 Volt AC Adapter. The single surface-mount IC is pre-soldered on the board.
Price: $92.95

AMT3000-9K
9 kHz channel spacing for use outside North and South America. Includes enclosure and 120 Volt AC Adapter. The single surface-mount IC is pre-soldered on the board. *
Price: $92.95

AMT3000-9KNT
Same as AMT3000-9KSM, except the US-standard 120 Volt AC Adapter is not included. **
Price: $88.95

Pete gives Kaito high marks for customer service

PL-880 (1)

SWLing Post reader, Pete Jernakoff (K3KMS), writes:

“I purchased two PL-880 radios from Amazon about a year ago and before the soft muting issue became a hot topic. Both of my radios (8819 firmware version) suffered from this most annoying problem but it wasn’t until I started reading your excellent blog that I learned of the cause.

About two weeks ago, I called Kaito Electronics USA and asked if they could upgrade the firmware on my two radios to the 8820 version. The person I spoke to said (paraphrasing) “Sure! Send them to us any we’ll perform the upgrade for free. All you do is pay for the return shipping.”

So off the radios went to Kaito. About 10 days later I had them back with the new firmware installed. The return shipping was $10. Weak MW and SW signals are now easy to listen to: no soft muting issues at all. Kudos to Kaito for agreeing to perform the upgrade for me. My dealings with them were thoroughly pleasurable.”

Thanks for sharing that great experience, Pete! You’re right–the 8820 upgrade is certainly worth the shipping costs and I’m happy to hear Kaito makes the process so easy.

Don’t know the firmware version of your PL-880? Click here to learn how to display the firmware version.

For more information on PL-880 soft muting, click here.