SolderSmoke Daily News

A Homebrew Receiver from Hidehiko JA9MAT

2026-07-23T05:21:35.454-04:00

We recently complained that no SolderSmoke Direct Conversion receivers have been built in Japan. So far, no Japanese SS DC Receivers have been built, but Hidehiko JA9MAT has gone a long way in addressing this complaint. In the video above you will see a 40 meter receiver using a PTO and a LONG tuning shaft. There is a wooden base. I see at least three 3D printed coil forms. Hidehiko explains that this receiver has "SA612(DET) + 2N3904 x 2 (Franklin VFO) based with Long Shaft PTO." FB Hidehiko! More from him in the days ahead.

Filters: Crystals, LC, Mechanical, SAW, etc.

2026-07-22T05:19:36.044-04:00

I thought this was an interesting look at filters and crystals. And even mechanical filters. Remember: Those little SAW containers became the lapel pin symbols of the FMLA.

I know there are readers who object to anything produced using AI. This video is in that category. But those who object would presumably have accepted the videos or other content found through the use of a search engine, right? Perhaps those who object to this kind of material should just turn off their computers, wait for the next delivery of QST or 73 Magazine (!) and hope that no AI tools were used in their production. Also, I would point our that reading this blog is entirely optional.

VK3ACU Builds a Transmitter for 3.579 MHz

2026-07-21T05:33:41.433-04:00

Colorburst, my friends. CBLA stuff from OZ. A chip in the mix. Thanks to Paul VK3HN for sending us this.

Comments on the SolderSmoke Direct Conversion Receiver from Andri in Bandung, West Java, Indonesia

2026-07-20T08:29:04.988-04:00

Congratualtions to Andri, of Bandung, West Java, Indonesia. Andri successfully built the SolderSmoke Direct Conversion receiver. (See the the Short below for a video of his receiver in operation.) Like many, he had some trouble getting the AF transformer -- so he took one out of an old Japanese transistor radio. He needed the FET for the PTO, so he made due with a surface mount part. All this by someone who does not have a ham license. I think he deserves a license, solely based on his successful build of this receiver. He has done something that most hams will never do: He has homebrewed a receiver. Thanks Andri!

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Comments from Andri:

I am just a newbie and not a ham radio operator, so I don't have a callsign. I do enjoy building electronic things though even though I have no background in electrical engineering.

It was a nice rewarding experience building this receiver. The challenging part was sourcing some parts which are hard to come by here in Indonesia such as the toroid cores, JFET and audio transformer. So I substituted FT50-6 with FT50-2, T50-43 with ferrite core for SMPS, and I use an SMD JFET instead.

Thank you very much for the detailed instructions on how to build this radio. Without them I would be lost. Ham radio has always been intriguing to me, but I never got into it because it is a prohibitive hobby.

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Bandung Wiki: https://en.wikipedia.org/wiki/Bandung

137 Direct Conversion Receivers -- Recently Built in Bandung, Indonesia. But none in Japan, None in China, None in Africa, and only 1 in all of Latin America!

2026-07-19T05:11:49.085-04:00

RX built in Bandung Indonesia -- Andri used an AF transtormer from an old Japanese receiver.

Why have NO receivers been built in Japan? And none in China. Only one in all of Latin America. Not one in all of Africa.

Please let us know if you spot any errors, or if we have inadvertently missed anyone. Don't worry about being late to the game -- the challenge continues. All of the info is still available.

As of July 21, 2026 0930Z:

So far, total receivers built: 137 (129 plus 8 honorable mentions). Total Count: 137. Receivers built in 19 countries.

NE3U (KY4EOD) Matt

KQ4AOP First ham signals ever heard!

N9TD Derek

AC3NG Ryan

VK3TPM Peter Marks

W4KAC Ken

W4KAC Ken built a second one!

N2EPE Erik

VA3NCA Wayde (Canada)

KI5SRY Mark -- Gears on PTO screw

KA1MUQ Frying pan receiver

AA1N Adam

ZL1AUN Aaron -- Using SSB transmitter -- (New Zealand)

W8UC Never before homebrewed.

VK4PG Phil -- Nice case, "really pleased"

G7LQX Working well, video of CW and SSB. -- (England)

KE2AMP John Spring on PTO screw -- great

N9SZ Steve nice receiver

KD9NHZ Piotr Nice one

KE8ICE Calvin, Very cool receiver.

WV3V Jayson! Got it done!

GM5JDG Martin. -- (Scotland)

KF8BOG Jim: A long struggle, but success.

Chris Wales Fantastic video. -- (Wales)

YD9BAX Wayan! Homebrew transformer! (Indonesia)

N0NQD Jeff

WN3F Roy -- Made new stickers!

AB5XQ Bill
KB7ZUT Andy
AA1OF Jer

VictorKees Holland (Netherlands)
KC9OJV John -- Manhattan-style convert
WZ5M 1, 2 or maybe even 3 receivers!
K1KJW Jim in Vermont
KC5DI Dallas -- friend of WZ5M
Gary Australian -- Wooden PTO form (Australia)
LU2VJM Juan in Argentina -- (Argentina)
K1OA Scott "Most fun in 50 years"
KC9DLM Ben -- Had EFHW problems
PH2LB Lex Yellow, Glue Stick -- (Netherlands)

AI6WR David
G6GEV Dave (It was a blast!) (England)
KC1ONM Wayne MakerLabs NH
KB1OIQ Andy MakerLabs NH
KA1PQK Jay MakerLabs NH
W1TKO Mike MakerLabs NH
K5KHK Karl
SM0TPW Mikael -- (Sweden)
KI7LKB Brian (coat hanger tube)
M6CRD Chris (England)

W2DAB Dave in NYC
W4JYK Wes of VWS
KA4CDN Mike of VWS
M7EFO Adrian
VK5RC Rob (Australia)
KD8KHP Dave
VK1CHW Chris (Australia)
KA0PHJ Brian
W0IT Louis
W1PJE Phil

W2AEW Alan
KN6FVK John (Barkhausen-Be-Gone Spray)
VU2JXN Ramakrishnan -- (India)
AA0MS Doug
9V1/KM7ABZ Paul -- (Singapore)
VK2BLQ Stephen -- (Australia)
N3FJZ Rick
Daniel VE5DLD -- (Canada)
Student 1 Student of VE5DLD
Student 2 Student of VE5DLD

Student 3 Student of VE5DLD

K7WXW Bill

NK3H Mitch

KN4ZXG Ted

WA1MAC Paul

N4AVC Chuck

K3IY Kevin

N6ASD Ashish in Bangalore (India)

W1DSP Rick

WD4CFN Steve

KM5Z Mike

KF5DAN Dan

Fritz Fritz

N9OK Joe

WA5DSS Bill

K0GDB Grant

G0JNR Shane Glow-in-Dark Coil Form

KK7BCO Tobias

K2BVR Bob

Robert Sutton

K5YFO Dave (Texas)

KD4PBJ Chris

KN4GAH Chris -- EE perspective

F1GMA Philippe -- (France)

W2TEF Todd

EI9ITB Karl -- (Ireland)

VU2TUM Puneit Singh (India)

AA7EE Dave Richards

KI5VIR Jay

CT7AXD Graham -- Promoted from Honorable Mention! (Portugal)

G3MOT Josh (England)

KW4H Steve

NJ7V Charlie (RedSummit)

N2ETZ Denny

AB9LM James

W9XT Gary

G0PJT Alex

KF8FZZ Tyler

N7HPR Steve (Instructor) (N7HPR Group)

Clark (N7HPR Group)

KQ4ZHO Kurt (N7HPR Group)

KQ4OBR Brian (N7HPR Group)

KR4CUF Justin (N7HPR Group)

Amanda (N7HPR Group)

David (N7HPR Group)

KM4AED Jamey (N7HPR Group)

KN4MVH Larry (N7HPR Group)

N5GVW Dick (N7HPR Group)

W7KAL Kal

KC9LFP Joe

SP9DEL Marian (Poland)

LB8VA Ivar (Norway)

AA7FO Chuck Adams!

WE6Z Doug

N7MN Jason
VA2GJ Gerald in Quebec
N6HA Bill
Andri Bandung, West Java, (Indonesia)
Scott K6AUS
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Honorable Mentions:

*AA7U Steve No PTO

*VK7IAN Ian -- No Manhattan boards -- (Tasmania)

*KC1FSZ Bruce's build on a PC board

* DL1AJG Andreas -- (Germany)

* Matthew Student of DL1AJG

* Arash Student of DL1AJG

*KA4KXX Walter -- FB 20 Meter version

*M9KCA-ST2NH Nader - LM386 in place of AF amp

Why is AM on 3885 kHz?

2026-07-18T04:47:41.156-04:00

It is Saturday morning, 0500 EDT. I am tuned to 3885 kHz, listening to the Old Military Radio Net. It is on 3885 kHz. Why this frequency?

Wikipedia: https://en.wikipedia.org/wiki/SCR-536

Gemini explains:

The frequency 3885 kHz is inextricably tied to one of the most iconic military radios of World War II: the BC-611 Handie-Talkie (part of the SCR-536 radio set).

Manufactured by Galvin Manufacturing Corporation (which later became Motorola), the BC-611 was the world’s first ubiquitous handheld, two-way AM transceiver. It was the "walkie-talkie" you see clamped to the ears of infantrymen in every classic WWII movie.

The technical marriage between this specific radio and 3885 kHz came down to how the military deployed them and what happened immediately after the war:

1. The Channels Were Commandeered

The BC-611 could operate anywhere from 3.5 to 6.0 MHz by swapping out internal plug-in coils and quartz crystals. Because the U.S. government temporarily shut down all civilian amateur radio operations "for the duration" of WWII, the military freely assigned tactical frequencies right inside what used to be the ham bands.

For company and platoon-level communications, 3885 kHz became a standard assigned military channel.

2. The Great Surplus Avalanche

When WWII ended, the military had hundreds of thousands of BC-611 units, along with mountains of spare FT-243 crystal units, sitting in warehouses. The government liquidated them to the civilian market for pennies on the dollar.

Hams returning from the war snapped them up. Because these units were strictly crystal-controlled (you couldn't just spin a dial to change frequency), you were locked onto whatever crystal was inside. Since a massive portion of the surplus BC-611 inventory came pre-installed with the military's 3885 kHz crystal and tank coil, thousands of hams suddenly possessed portable AM rigs fixed precisely to that exact spot on the dial.

3. A Lasting Living Tradition

Even though a BC-611 only pushed out a fraction of a watt of AM power (using a tube filament battery and a 108-volt B+ battery), hams quickly realized that if they gathered on 3885 kHz, they could hear each other locally. Operators with larger, higher-powered home stations began parking on 3885 kHz as well, just to act as "big ears" to pick up the faint signals of the handheld walkie-talkies.

That specific frequency choice was entirely forged in the surplus markets of 1945 and 1946. Eighty years later, the tradition is so deeply ingrained that military radio collectors and vintage AM operators still hold a massive, synchronized check-in on 3885 kHz every year during the Dayton Hamvention weekend.

How Were 3.579 MHz Crystals Used in Color Television Sets?

2026-07-17T05:04:32.125-04:00

Gemini explains:

In NTSC analog color television, the 3.579545 MHz crystal was the heartbeat of the entire color decoding system. Its primary job was to act as the ultra-precise frequency and phase reference needed to recreate the colors you saw on the screen.

To understand why it was used, you have to look at how color television was engineered to be backward-compatible with older black-and-white sets.

1. The Challenge of "Squished" Color

When the NTSC standard was developed in 1953, engineers had to squeeze color information into the existing, crowded black-and-white television channels without causing interference.

To do this, they decided to transmit color using a color subcarrier centered precisely at 3.579545 MHz.

Luminance (the black-and-white brightness detail) was sent normally.
Chrominance (the actual color information) was modulated onto this 3.579 MHz subcarrier.

The color signal used Quadrature Amplitude Modulation (QAM). In QAM, the amplitude of the 3.579 MHz wave determined the saturation (how vivid the color was), and the phase angle of the wave determined the hue (whether the color was red, green, blue, or yellow).

2. Restoring the "Suppressed" Carrier

To prevent the 3.579 MHz color signal from creating distracting, wavy line patterns on older black-and-white TV screens, the carrier wave itself was suppressed (removed) before transmission. Only the "sidebands" (the actual color data) were sent over the air.

Because the carrier was suppressed, the TV receiver had to completely recreate that 3.579545 MHz wave locally to decode the color.

If the TV's locally generated wave was off by even a tiny fraction of a degree in phase, the colors would shift wildly—faces would turn green, and skies would turn purple. This is where the 3.579545 MHz crystal came in.

3. Locking to the "Color Burst"

Because the transmitter and the television set had to be perfectly synchronized, the TV station sent a tiny, brief reference sample of the original carrier wave at the start of every single horizontal line on the screen. This was called the color burst.

The color burst was a short packet of just 8 to 9 cycles of the 3.579545 MHz wave.
It was placed on the "back porch" of the horizontal blanking pulse, immediately after the horizontal sync pulse.

Inside the television, the 3.579545 MHz quartz crystal was the heart of a local crystal oscillator circuit. When those 8 to 9 cycles of the color burst arrived at the beginning of a line, a Phase-Locked Loop (PLL) or injection-locking circuit compared the incoming burst to the TV's local crystal oscillator. It adjusted the local oscillator's phase to match the burst perfectly.

Once locked, the crystal oscillator kept ringing cleanly and steadily across the rest of the 63.5-microsecond horizontal scan line, giving the TV a flawless phase reference to demodulate the red, green, and blue color components from the video signal.

The Legacy of the "Color Burst" Crystal

Because millions of color TV sets were manufactured every year, factories produced these highly precise 3.579545 MHz crystals in astronomical quantities.

This mass production made them the cheapest, most widely available crystals on the surplus market. Consequently, generations of engineers and radio amateurs adopted them for unrelated projects—such as building QRP transmitters (often on the 80-meter band, where the second harmonic of 3.579 MHz sits nicely at 7.159 MHz), clocking early microprocessors, or generating telephone DTMF touch-tones.

The 43.333 MHz Crystal in my Nuvistor Converter was Bad. But WHY did I Find Another One in my Junkbox?

2026-07-16T05:57:38.912-04:00

Gemini explains why:

As a radio amateur, you have likely run across these crystals in countless parts bins, swap meets, and vintage schematics. The reason 43.333 MHz crystals are so common comes down to a classic, elegant piece of frequency math that bridged the gap between early VHF operation and standard HF rigs: the 2-meter to 20-meter transverter/converter.

The 2-Meter to 20-Meter Magic Number

Historically, amateur radio operators wanted a way to receive and transmit on the 2-meter band (144–146 MHz) using their highly sensitive, existing 20-meter HF receivers (14 MHz) as a tunable Intermediate Frequency (IF).

To mix a 144 MHz signal down to a 14 MHz IF, you need a highly stable 130 MHz local oscillator (LO):

\text{144 MHz (RF)} - \text{130 MHz (LO)} = \text{14 MHz (IF)}

Creating a stable, fundamental-frequency quartz crystal at 130 MHz was physically impossible for decades because the quartz wafer would have to be sliced microscopically thin and would easily shatter.

Instead, designers utilized a robust, lower-frequency third-overtone crystal operating at 43.333 MHz. When you multiply 43.333 MHz by three in a simple tripler stage, you get exactly the 130 MHz LO signal needed:

43.333\text{ MHz} \times 3 = 130\text{ MHz}

Why They Flooded the Market

Because the 2m-to-20m conversion was the gold standard for VHF operation in the 1960s, 70s, and 80s, these crystals were mass-produced. They were the heart of legendary gear like the Drake SC-2 receiver converter and dozens of homebrew transverter designs featured in the ARRL Handbook and 73 Magazine.

If a ham wanted to monitor the popular 146.94 MHz repeater frequency of the era, they would use a 2-meter converter with this exact crystal, allowing them to tune their HF dial to precisely 16.94 MHz.

Other Multiplier Matches

Additionally, 43.333 MHz has convenient harmonics for other bands. For instance, multiplying it by 10 yields 433.33 MHz, which sits perfectly inside the 70-centimeter amateur band and the widely used 433 MHz ISM band (common for low-power key fobs, weather stations, and remote controls).

Whenever you see a strangely specific, non-integer crystal frequency like 43.333 MHz, 38.667 MHz (used for 2m to 10m conversions), or the famous 3.579545 MHz color burst crystal, there is almost always a legacy of mass-production and clever math behind it!

The Smith Chart -- Veritasium Explains its Origins and How it Works

2026-07-15T12:55:39.596-04:00

This is really interesting and represents one of the best explanations of the Smith Chart that I have seen.

One quibble: In the beginning, they make it sound like all refelcted power in a transmission line is lost. That is not really true. Much depends on the frequency, the type of line used and the length of the line. The video presents this "SWR loss" as being very significant, and many hams seem to think that any SWR worse than 1:1 will kill their signal.

Look at the question that I put to Gemini:

I am a radio amateur. My SWR meter shows an SWR of 2:1. I am using 50 feet of RG-58 coax to a dipole antenna. The dipole is cut for 40 meters and I am operating on 40 meters. My rig is putting out 100 watts. How many watts are being reflected? How many watts are being radiated?

Gemini calculated:

Assuming your SWR meter is located at the transmitter and shows exactly 100 watts of forward power, 11.1 watts are being reflected at the meter, and approximately 76.1 watts are actually being radiated by your 40-meter dipole.

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That means that in this scenario, I am putting into the transmission line 100 watts and 76.1 watts are being radiated. That means that the loss resulting from this SWR of 2:1 will be about 1.186 db. With one S unit equaling about 6 db, this is clearly not enough to worry about.

Also, lets remember that we could put a 50 ohm dummy load at the far end of our transmission line and achieve an SWR of 1:1. But that dummy load would not radiate.

Three cheers for Veritasium for doing this Smith chart video.

Thanks to Rogier PA1ZZ and to Mike WN2A for sending this video to me.

Please put below your comments on the video and my observations.

A Nice Workshop (With The Logical Song)

2026-07-14T08:04:57.739-04:00

How to Build a MODERN Electronics Workshop (and How Much it Might Cost) (PLEASE COMMENT)

2026-07-12T05:35:27.451-04:00

First, kudos to this fellow for pronouncing "solder" correctly. The L is silent (sorry to our British readers). He does have an accent, but he is in Texas, and has picked up the CORRECT pronunciation. So kudos.

I really liked the video. It represents a movement into the modern age of electronics. I know that we usually talk about HDR, and homebrew rigs that -- while solid state -- are from the early 1970s. There has been a lot of progress since that time. This video is a reminder of that, and talks about what we can do to participate in this modernity.

Some observations:

-- The microscope. Looks cool, but it is kind of scary...

-- The tiny digital rechargeable soldering iron looks like a great idea.

-- I agree on the mechanical (non chemical) soldering tip cleaner idea.

-- The 3D printer info is very useful.

-- Enclosures? I am still in the 1/8 inch plywood era. I have a ways to go.

-- We could use more info on CNCs.

-- I didn't know that you could get a pick-and-place machine for the home. Probably just as well!

-- I like the thermal camera. I also like his suggestion that you could just burn your fingers!

-- I think an oscilloscpe is a must, even early on. I agree on the need for a multimeter.

-- Indeed, a good PC is a must.

What were your reactions to this video?

My Parks 2 meter Nuvistor Converter, a QST review, and Bio Info on the Tektronix Hams who Designed It (Who is W7UHF now?)

2026-07-11T05:30:17.588-04:00

Denton E. Nelson (amateur radio callsign W7UHF) was an electronics engineer and a notable figure in mid-century amateur radio history, best known for co-founding Parks Electronics alongside fellow operator Loren Parks (K7AAD) [3.1.3].

Tektronix Background

Nelson spent part of his career in the 1950s working at Tektronix in Oregon, where he moved through various roles from assembly into test and production engineering [1.2.2, 3.2.3]. During his time there, he was also an active member of the Tektronix Employees Radio Amateur Club [3.1.2].

Parks Electronics and VHF Converters

In the 1960s, Nelson (W7UHF) and Parks (K7AAD) partnered to build high-performance VHF (Very High Frequency) converters, initially starting their production in Parks's garage [3.1.3]. At the time, amateur radio operators who wanted to operate on the VHF or UHF bands often relied on outboard converters to shift those higher frequencies down so they could be tuned on standard shortwave communication receivers.

Leveraging their rigorous professional backgrounds at Tektronix, Nelson and Parks applied strict commercial test-equipment standards to their amateur gear [3.1.3]. Parks Electronics quickly became famous for its superior "little black boxes" [3.1.3]. Unlike much of the consumer equipment of the era, every converter Nelson and Parks produced was individually tested for precise gain, bandwidth, and low noise figure before it was shipped [3.1.3]. This commitment to quality made their equipment highly sought after by VHF and UHF enthusiasts worldwide [3.1.3, 4.1.6].

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One question about W7UHF: If you go to QRZ.com, you will see that there is still a listing for W7UHF, under the name of Denton E. Nelson. But it is for a Technician license. And it lists a previous call as KD6EFF. Who is that? Could that be OM Nelson's son? The holder is in Silicon Valley, and the license seems like it is about to expire.

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Loren Parks (1926–2023), who operated under the amateur radio callsign K7AAD, was a man of three distinct legacies: he was a skilled electronics engineer who built highly respected amateur radio gear, and a pioneering manufacturer who made millions in the medical device industry. [3.1.1, 3.1.6].

Tektronix and Amateur Radio (K7AAD)

After serving in the U.S. Navy and earning a degree in psychology, Parks moved to Oregon and took a job in the 1950s with Tektronix, the pioneering test equipment manufacturer [3.1.1, 3.1.6]. He was heavily involved in the local amateur radio scene and the company's ham radio club [3.2.1].

Recognizing that operators needed better ways to tune into the VHF and UHF bands, Parks partnered with his Tektronix colleague Denton Nelson (W7UHF) to build outboard receiving equipment [3.2.2]. What started as a garage project became Parks Electronics [3.2.2]. By applying rigorous commercial test-equipment standards to their amateur gear, their VHF converters became famous for their high performance and exceptionally low noise figures. Parks was also a dedicated supporter of the wider ham community, at one point stepping in to purchase and run the VHF'er magazine to ensure the publication survived [2.3.2, 3.2.2].

The Medical Device Fortune

While his amateur radio converters were a critical success among hobbyists, Parks found his vast fortune in the medical field. In 1961, he founded Parks Medical Electronics in Aloha, Oregon [3.1.1, 3.1.7].

Pivoting his electronics expertise, Parks designed some of the world's first impedance plethysmographs and Doppler ultrasound systems [3.1.1, 3.1.7]. These devices are used by doctors to measure blood flow in vascular studies, detect faint pulses, and monitor patients during surgery [3.1.1, 3.1.5]. His company became a global pioneer in vascular diagnostics—making Parks a multi-millionaire in the process—and it remains one of the oldest manufacturers of Doppler systems in the world today [3.1.5, 3.1.7].

The Nuvistor, Thermatrons, RCA, Patents, the Rise of Asian Competitors (and my Parks Electronics 2 Meter Converter)

2026-07-10T09:32:41.385-04:00

Asianometry always does a great job with this stuff, although I find myself grimacing when he speaks positively about Sarnoff. Nevertheless the tube history is good (although he fails to mention that De Forest never figured out how his tubes worked).

I have four Nuvistors! They are in a 2 meter converter from Parks Electronics of BEAVERTON, OREGON. I may have this wrong, but I think the video said the Nuvistors were very expensive. This can't be right. Gemini AI says the 6CW4s in my Parks device sold for $1.50 to $2.50 in 1961.

Three cheers for the Nuvistor! I may try to see if they still work.

A Very Nice Audio Workbench -- With Lots of Great Ideas

2026-07-08T09:54:09.057-04:00

We covered Ben Hase's workbench earlier this week, focusing on his findings about glue, fusible resistors, and relays.

This is a more complete look at his workshop.

-- Very useful were his descriptions of his "daily driver" 'scopes and sig gens.

-- I like the fingers for the patch cords.

-- It was nice that he has one analog 'scope.

-- WOW, HE HAS A KLH RECEIVER. SO DO I! ROGIER SENT IT TO ME!

-- His use of Scan-Snap is potenially useful for us.

-- I like his organization of parts bins.

-- His use of the "tray truck" is ingenious.

-- He has a good chair. I note that he has a physical therapy T-shirt.

-- His obvious devotion to HAKKO soldering tools is understandable.

-- He has the obligatory drawer full of Fluke meters.

We covered Ben's workshop when he was in Manhattan: https://soldersmoke.blogspot.com/2024/06/another-great-workshop.html

It is great to see that he has more room now. His acknowledgment of his wife's support was very nice.

In this video, Ben visits Matt in the Pacific Northwest and swaps ideas on workbench construction: https://www.youtube.com/watch?v=GZ0rupOQKvE

And in this one we see Ben's work on a badly mangled Sansui receiver: https://www.youtube.com/watch?v=3w-wH4CGeT0

With a workshop like that, Ben should be a ham. A homebrewer.

Shuji Nakamura -- Inventor of Blue LEDs -- Takes on Fusion Energy at Age 72

2026-07-07T08:10:55.560-04:00

This blog covered Shuji Nakamura at least twice before -- we reported on on how he had invented the blue LED: https://soldersmoke.blogspot.com/search?q=Nakamura

Now we report on a more recent effort by Nakamura, this one is focused on nuclear fusion.

I think the inspirational thing about the Nakamura stories has to do with his persistence, his refusal to give up, and -- in this most recent story -- his willingness to take on big challenges at age 72.

Three cheers for Shuji Nakamura!

--------------------------------------------------------------------

From a CNN story: https://www.cnn.com/science/shuji-nakamura-lit-up-the-world-and-now-wants-to-power-it-spc

Shuji Nakamura already transformed the world once. His invention of blue light-emitting diodes (LEDs) changed everything about our daily lives.

Computers, phones, big screens, traffic lights and electronic billboards light up because of his invention.

Nakamura earned the Nobel Prize in Physics in 2014, along with two other Japanese scientists, Isamu Akasaki and Hiroshi Amano, for their contributions to his LED breakthrough.

Some experts have hailed his invention as important as Thomas Edison’s incandescent light bulb.

And so, it’s big news when one of the world’s greatest inventors says his next invention will far surpass the importance of his previous one.

His goal: To create a power plant that uses a new kind of high-pulse laser for nuclear fusion, producing an “endless” supply of efficient, clean energy. With nuclear fusion, there is no uranium involved and no chance for a meltdown.

If he cracks the code, its potential is limitless, said Nakamura, a professor of materials and of electrical and computer engineering at the University of California, Santa Barara (UCSB).

At an age when many look to retire, Nakamura, 72, bursts with energy.

“Retirement is very boring,” he told CNN.

‘I became so desperate’

Long before Nakamura earned Nobel recognition, before he was inducted into the National Inventors Hall of Fame, he was maligned and ridiculed — an engineer best known for explosions in his lab and for his lack of productivity.

Nakamura worked at a then-little known Japanese chemical company called Nichia Corporation, in 1979, heading its research and development team, comprised of just two people.

But after about 10 years in, he’d developed only three products — and none sold well. At company soccer and softball games, his colleagues harangued him saying, “Why haven’t you produced anything? You need to quit!”

Afterward, on Friday nights, Nakamura often returned to the office and roamed the halls taking on extra duty as an overnight security guard.

“Yeah,” Nakamura said with a laugh, “I had to check the whole company walking around.”

Feeling isolated, Nakamura developed a mentality of what he calls “invention by anger,” an extreme drive to prove others wrong. All his managers told him the same thing: You must quit.

“I became so desperate,” he said.

A last-ditch effort to save his job

Nakamura grew up in a small Japanese fishing village where he learned to love nature and the color blue because of the ocean.

His experience tinkering, toiling and blowing up stuff in his lab had given him the idea to chase his dream of cracking the code to blue LEDs.Major corporations like IBM, General Electric, Bell Labs, Sony and Toshiba invested millions over the decades trying to solve the mystery. Red and green LEDs were easily mastered, yet the solution to making blue LEDs remained elusive because blue light has a shorter wavelength and requires significantly more energy to emit.

At stake was the potential for a multibillion-dollar industry.

In a last-ditch effort to save his job, Nakamura approached Nichia’s founder and chairman Nobuo Ogawa.

“Can I develop blue LEDs?” Nakamura asked.

He couldn’t believe what came next.

“OK, no problem,” Ogawa said.

Nakamura was given a budget of $3 million, an unheard-of amount in 1988 that represented 2% of the company’s annual sales. Two-thirds of the money was for equipment; the rest was to be spent on studying and learning techniques that could lead to a breakthrough.

‘I feel resentful when people look down on me’

Nakamura then spent a year in a lab at the University of Florida learning about metal-organic chemical vapor deposition, or MOCVD.

At 34, he’d never stepped foot on a plane. He also never had a scientific paper published — a fact that earned scorn in Florida. To those with PhDs in the lab, Nakamura was a nobody with zero academic chops. They treated him like a lowly technician, he said, constantly asking him to fix this and fix that.

He quietly raged. “I feel resentful when people look down on me,” he once said. “At that time, I developed more fighting spirit. I would not allow myself to be beaten by such people.”

Nakamura is a professor of materials and of electrical and computer engineering at the University of California, Santa Barbara. At 72, he has no plans to retire because he feels he's on the verge of his biggest breakthrough to date.
Matt Perko/Univ. of Calif.-Santa Barbara

When he returned to Japan in 1989, more hurdles were thrown his way. His biggest fan, the founder of Nichia, stepped aside as president.

And in his pursuit of a breakthrough, Nakamura chose to go all-in on studying the material gallium nitride as the key to unlocking blue LEDs. Almost every other researcher in the world worked with a different material, zinc selenide.

This became a huge problem, he said, when a renowned researcher held a seminar at Nichia with an emphatic message: gallium nitride was a dead end. Among those in the audience was Nakamura’s new boss.

By day’s end, a hand-written note arrived on his desk, ordering Nakamura to halt all work.

He rejected the order. “I threw it away in the garbage,” he told CNN, smiling.

More notes arrived every few weeks with the same order. He tossed them in the trash, too.

In Japanese culture, he said, it is nearly unheard of to ignore a superior’s orders. In fact, Nakamura stopped attending weekly R&D briefings so that he wouldn’t have to tell colleagues what he was doing.

“I became so angry,” he said, “so that I make the decision” to keep going and keep chasing his dream.

Within months, Nakamura was vindicated. He experienced “the greatest moment of my life,” when he made a simple LED that illuminated with a soft violet-blue light. He wasn’t sure how long the light might last.

He left for the night, and, in the morning, the light still glowed. “It was still very dim, but it’s surviving,” he said. “That moment is very ‘Oh my gosh!’”

On November 29, 1993, Nichia held a news conference that shocked the electronics world. The blue LED had been conquered.

It turned out Nakamura was right: Gallium nitride proved to be the key.

“The tamer of nature and successor to Edison,” Forbes magazine once wrote, “turned out to be an unknown researcher at a Japanese company few had heard of.”

Endless energy as his final chapter

Nichia and Nakamura eventually had a public falling out with back-and-forth lawsuits. The two sides settled their landmark dispute in 2005 — with Nichia agreeing to pay him $8.1 million, far less than the nearly $180 million a Japanese court had ruled Nakamura deserved for his invention.

Almost all of the money, he said, went to “attorney fees and also taxes.”

He prefers not to dwell on that part of his past. He’s proud of what he invented. Plus, he said, “Winning the Nobel Prize was greater.”

“I’m very happy,” he said.

Nichia didn’t respond to CNN’s request for comment.

A recent report by the International Atomic Energy found that if old light bulbs were still used around the world, global electricity needs would be nearly unsustainable — “around 70% higher electricity consumption for indoor lighting in buildings.” The electricity saved on home lighting from LEDs, the report found, roughly equals the power used by the entire country of South Korea.

Nakamura is focused on the future and what he feels will have an even greater environmental impact by producing limitless energy with zero emissions.

To meet this goal, he has formed Blue Laser Fusion, a company that uses his blue LED technology to create laser power that could transform energy generation around the world.

About 99.5% of nuclear fusion research over the decades, he estimated, has focused on using powerful magnetic fields to create endless power. Nakamura believes the answer lies in the 0.5%.

“The story is very similar to the blue LED development,” Nakamura said.

In December 2022, researchers at the National Ignition Facility at Lawrence Livermore Lab in California, a core part of the US Department of Energy (DOE), achieved the first-ever “fusion gain,” a major scientific breakthrough, when a laser-induced reaction produced more energy than it takes to trigger it.

Nakamura was not involved in that experiment. However, he had already begun developing a new high-power laser concept for inertial fusion, drawing upon his pioneering work in LEDs and laser diodes.

He co-founded Blue Laser Fusion in November 2022. The DOE fusion breakthrough further energized him. Nakamura is determined to take what was proven as scientifically possible in the lab and turn it into a functioning power plant.

He said Blue Laser Fusion has seen breakthrough after breakthrough in the years since.

To contain the continuous fusion reaction without burning everything up, Nakamura and his team have created what is called the optical enhancement cavity, which stores the high-pulse laser energy in its optical chamber, then amplifies the laser power by up to 100,000 times, which drives and contains the burn.

“In layman’s terms,” UCSB said in a 2025 news release, “the laser is the hammer breaking into a tiny pellet of hydrogen isotopes (atoms). The chamber is the anvil, keeping everything contained. The result? Genuinely clean, secure fusion energy.”

At this point, it’s far from Nakamura’s goal of limitless energy with far-reaching benefits.

More work is needed. The company is scaling up to meet its goal to construct a 1-gigawatt pilot fusion power plant — big enough to power 750,000 to 1 million homes — by 2032 near Santa Barbara, California.

Will this be his greatest achievement and gift to the world?

“Yeah, yeah,” Nakamura said simply.

Asked how he might react if a young scientist in his lab defies his orders and continues doing whatever he or she wants to do, Nakamura laughed.

His message to young scientists everywhere, he said, is this: “Taking a risk is most important.”

Doing so might just change the world.

How Hans G0UPL Cracked the Code for Stable I and Q from the Si5351

2026-07-06T04:45:39.134-04:00

L to R: Farhan, Roy Lewallen, Eric Guth and Hans Summers

Back in 2018, I remember Farhan telling me that "Hans has cracked the code" getting stable I and Q from the Si5351. But I never really appreciated the importance of this breakthough until I recently started looking at the receiver from Macedonia. Then I asked AI (Google Gemini) for a readout on who was responsible for the I and Q innovation. Here is what I got yesterday from Gemini:

---------------------------------

The credit for solving this problem and unlocking stable, single-chip $I/Q$ quadrature generation from the Si5351 goes to Hans Summers, the British QRP developer and founder of QRP Labs.

While other talented developers in the amateur radio community—most notably Jason Mildrum (NT7S)—wrote the definitive, widely used standard open-source Arduino libraries for basic Si5351 tuning, it was Hans Summers who fundamentally cracked the math required to force the chip into a stable $90^\circ$ phase shift over a wide frequency range without breaking lock.

The Breakthrough Discovery

Around 2014 to 2015, while designing highly compact, low-cost transceivers like the QCX and ultimate VFO kits, Summers realized that standard programming libraries were completely incompatible with generating stable quadrature signals.

He pioneered a completely reversed architectural method to control the chip, which became the blueprint for homebrew SDR builders everywhere:

Flipping the Fractional Math: Standard libraries fixed the primary internal Voltage Controlled Oscillator (VCO/PLL) at an integer value and used the second stage (the MultiSynth fractional dividers) to dial in the exact frequency. Summers realized this broke the phase shift. He discovered that you must lock the MultiSynth divider to a fixed even integer and force the first stage (the PLL VCO) to do the fractional math instead.
The "No Reset" Discovery: Standard practices issued a soft PLL reset command to the chip every time the user turned the tuning dial to ensure clean frequencies. This reset caused the phase relationship to drop out or randomize. Summers proved that after an initial startup reset to align the phases, you can smoothly glide the VCO frequency up and down via the $I^2C$ bus without resetting the PLL, keeping the $I$ and $Q$ signals locked in a perfect mathematical embrace.

Thanks to Hans Summers publishing his detailed engineering application notes and open-sourcing his mathematical methods, developers around the world were able to write the code that modern microcontrollers (like the ESP32 in your receiver) use today to keep the $I/Q$ phase rock-solid as you dial across the bands.

An Interesting Receiver from North Macedonia

2026-07-05T07:38:56.764-04:00

https://hackaday.com/2026/07/02/diy-si5351-radio-tunes-in-sw-mw-and-more/

There are some really cool features in this receiver: There is an ESP microcontroller and an Si5351. There is the rotary digital dial that we had been working with. There is an NE602 mixer and a receiver that is sometimes (SDR mode) direct conversion and other times (Radio mode) a simple superhet with an 455 kHz IF. Wow.

There are really two receivers in this box, and AI kind of confused them. When I asked what the IF was, Gemini told me that there was no IF - it was, they said, a direct conversion reveiver. But no! In the quickly displayed schematics in the video, we see an IF amplifier and what appears to be two IF transformers and a BFO at 455 kHz. So at least in the "RADIO" switch position we see a superhet. The VFO freuency fed into the NE602 is 455 kHz above or below the signal frequency. If they had a BFO on they could listen to CW and SSB in the "Radio" position (it would not be single signal -- there is no sharp filter in there). But even wthout a BFO, in the RADIO mode you could also listen to AM signals using the envelope detector in the IF strip.

Things change when you throw the switch to the SDR mode. Much of the IF/Demodulator board is turned off. The Si5351 now feeds the signal frequency to the VFO port of the NE 602, turning it into a direct conversion receiver. You could feed this signal into your SDR but you would not get image rejection. For this you would need I and Q signals to go to the computer. This receiver provides I and Q output from the Si5351, and it is this that you need to turn that computer into a true single signal, image-rejecting receiver.

Thanks to Hack-A-Day for alerting us to this, thanks to Mirko Pavleski for building this receiver and showing it to us, and special thanks to Hans Summers G0UPL for cracking the code that let the Si5351 produce the stable I and Q signals needed in SDR receivers like this. More on this tomorrow.

A Really Really Complete South African Workshop

2026-07-03T04:56:14.925-04:00

This is really almost too much. But I include it here because it is just an obviously impressive set of tools. There are also many CNC machines (machines that Pete keeps talking about). Finally, this video comes to us from afar, from South Africa. And SolderSmoke remains committed to INTERNATIONAL solidarity. Thanks Ed for this wonderful video.

Vintage Audio Restoration: Glue, Fusible Resistors, and Relays

2026-07-02T06:18:56.305-04:00

This guy is restoring VINTAGE audio gear. It is definitely younger than the Boatanchors we usually work on, but it is a lot older than more recent gear that is made with largely pick-and-place machines and surface mount components. There are mostly through hole components here.

There are some challenges I've never thought about: glue that over time starts to mess up the circuitry. Fusible resistors? Who knew? And then there are relay contacts that go really bad. We use a lot of these kinds of relays.

All in all, there are a lot of good ideas in this video. His other videos are probably worth watching too. I think it will be especially useful for my friend Bob, KD4EBM who does a lot of work in this area.

Please let me know what you think. Comment below.

SolderSmoke Podcast #265: AI Pete, WSPR, sBITX, San Diego, Last Ditcher, NYC, 17-12 Fix, MMM Blasphemy, 6T9er, MAILBAG

2026-06-29T11:04:05.694-04:00

SolderSmoke Podcast #265 is ready for download.

Video Version: https://www.youtube.com/watch?v=-jWYe6NxnJA

Audio Version: http://soldersmoke.com/soldersmoke265.mp3

---------------------

Travelogue: Pete to San Diego, Dean to NYC, Bill stays home.

Field Day Report! Dean? Pete? I had a bad back. Really.

The importance of "taking a break" discussed on "Hidden Brain" podcast.

We need new chapters for the FMLA series. Time to add the CBLA?

AI Pete? http://soldersmoke.com/AIPete.mp3

Dean: WSPR success -- Report

Back on the air with the homebrew sBITX.

VWS WSPR TX and AMP

KK4DAS WSPR Map

Pete: Visit to surplus store in San Diego.

The Last Ditcher CW rig. Frank Jones would approve! Construction technique combining wooden slats and copper clad boards is FB.

Homebrew CW rigs -- update.

Schematics and Co-Pilot

Shameless Commerce Division:

Mostly DIY RF

Become a Patron through Patreon.

Do you want an emailed heads up about blog post and pocasts? Send your e-mail to bill.meara@gmail.com

Please comment on the Podcast (on YouTube or on the blog) and about blog posts (on the blog page). Comments let us know that we are not speaking into the Google void!

Bill: Fixing the receiver in my 17-12 rig. Adding 12 db to the TIA.

The Open Circuits book. Eric is the Eric from CuriousMarc. And he is a ham!

Blasphemy? Bill redraws schematic for Michigan Mighty Mite.

I have 6T9 tube. I don't really want to build a CW transmitter. But I may have to.

Gemini explains "Low Value Content" They see 10,000 posts and assume it is AI Slop.

Mailbag:

Wes: Nice email from W7ZOI.

Peter Marks VK3TPM fixed the index file (with help from Claude).

Peter VK3TPM and Paul VK3HN -- Great comments on AI.

Also Dean KK4DAS and Bob KD4EBM

VK3HN sent FB AI QSL from ZL2BNE (see mine!)

Bruce KK0S sent two FB AI QSL cards.

Rogier PA1ZZ -- Sends "The World of El - AI" IDK.

Ryan KJ7KVD building a Michigan Mighty Mite (I sent parts)

Robert W8MOX heard my beacon from the DR to Annandale Va.

Kirk NTOZ -- The future of ham radio and what went wrong.

Paul KL7FLR -- The Wizard of Wasila -- Finally 3D printed a Toroid winder

Charlie NJ7V -- Doing great work over at Red Summit RF.

Podstatus reports that we are #2 in Ghana! Hooray for us!

Farhan VU2ESE -- LARCSet CW mods!

Walter KA4KXX Homebrew POTA proposal.

Grayson KJ7UM: Likes Helge's Norwegian paraset

Gerald VA2GJ: Including DC RX in Canadian license study materials.

Ron WA6YOU: Spy radios RT-6 and RR-6

Scott K6AUS: https://soldersmoke.blogspot.com/2026/06/update-how-many-drake-2-b-receivers.html We need to send him a 2B!

Bob W8SX: FDIM interview with Hans G0UPL. More to follow.

Update: How Many Drake 2-B Receivers Were Made? Can Someone Send a Drake 2-B to Scott?

2026-06-28T07:29:28.137-04:00

We first looked at this question way back in 2011: https://soldersmoke.blogspot.com/2011/05/how-many-drake-2-bs-german-tank-problem.html

Scott K6AUS has been involved since the very beginning and continues to look at the mathematics:

https://nomadiq.net/blog/post/how-many-drake-2bs-were-ever-made

Scott has given us a very useful update based on additional serial numbers provided by SolderSmoke listeners.

How many? About 11,300. Check out Scott's page for some interesting mathematical details.

Thanks a lot Scott!

BTW: SCOTT K6AUS DOES NOT HAVE A DRAKE 2-B. THIS IS JUST WRONG! HE HAS DONE SO MUCH FOR THIS RECEIVER! HE SHOULD HAVE ONE! IS THERE ANYONE OUT THERE WHO CAN SEND A DRAKE 2-B TO SCOTT?

Bob W8SX Interviews Hans G0UPL at FDIM 2026

2026-06-27T06:20:40.201-04:00

Thanks to Bob W8SX for being the SolderSmoke Correspondent at FDIM again this year.

We will present the audio recordings that Bob did for us. The first of these is with Hans Summers G0UPL.

Bob talks to Hans about the QMX and QMX + transceivers. Hans reports that he has sold more than 16,000 of these transceivers in the last three years. He describes for Bob how he made use of the Hilbert transform, and how the fact that this rig is SDR means that with each firmware update, the user gets essentially a new radio, with features that often did not exist before.

Here is the recording:

http://soldersmoke.com/G0UPL FDIM 2026.mp3

Thank you Bob, thanks Hans, and thank you QRP ARCI.

100 Billion Transistors on One Small Chip -- No Room for Homebrew!

2026-06-26T04:07:58.653-04:00

https://newsroom.ibm.com/2026-06-25-ibm-debuts-worlds-first-sub-1-nanometer-chip-technology

FCC Amateur Radio Exam Question: Draw the schematic for the new IBM sub-1nm chip, showing how it will be used in FT-8 operations.

Mike WN2A suggested I ask AI about a schematic. Here is what Gemini said:

Here is what Gemini said:

Please draw me the schematic (showing the connections of all 100 billion transistors) in the new IBM sub-nm chip.

I would love to help sketch out circuit diagrams, but drawing a literal schematic showing the individual connections for all 100 billion transistors is physically impossible!

To put that number into perspective, if we were to draw a schematic where each transistor was just a tiny 1-inch symbol on a piece of paper, the blueprint would be so massive it would easily cover the entire landmass of the United States.

Modern sub-nanometer chips—like IBM's cutting-edge nanosheet architectures—are far too complex for human hands to map out line-by-line. Instead, engineers use advanced software to design chips hierarchically. Here is how that massive sea of 100 billion transistors is actually organized under the hood:

1. The Building Block: The Gate-All-Around (GAA) Nanosheet

At the microscopic level, these chips no longer use the older FinFET (fin-shaped) transistors. Instead, they use nanosheets, where the channels are stacked vertically like a three-story sandwich. The gate wraps entirely around all four sides of each horizontal sheet, providing maximum electrical control and drastically reducing current leakage.

2. Standard Cells (The Functional Logic)

Instead of wiring 100 billion separate components, computer scientists group transistors into "Standard Cells." These are pre-designed functional blocks like:

Logic Gates: AND, OR, NAND, and NOR gates (requiring anywhere from 2 to 8 transistors each).
Flip-Flops: Memory cells that store a single bit of data (requiring about 20 to 30 transistors).

3. The Macroscopic Layout (Blocks and Cores)

Billions of those standard cells are then combined into macroscopic structural blocks that look less like a traditional schematic and more like a highly organized city map. If we were to draw a high-level schematic of the chip, it would look like a block diagram featuring:

Processor Cores: The massive processing engines packed with arithmetic logic units (ALUs).
Cache Memory (SRAM): Vast grids of 6-transistor memory cells stacked tightly together to hold data right next to the execution units.
Interconnect Matrix: A vertical 3D skyscraper of up to 15 layers of microscopic copper wiring running above the transistors to route data and power across the chip.

If you are working on a homebrew electronics project and want to map out a circuit diagram for an RF amplifier, a QRP radio transceiver, or a simple analog filter, I can absolutely help you draw or troubleshoot those schematics! But for 100 billion nanosheets, we have to leave the drafting to the silicon foundries' supercomputers.

My AI QSL Card: Wood Boxes, a D-104, Books, a 'Scope, the EB-63A, Guapo, our Sticker, and a Cup of Coffee! KK0S's Cards

2026-06-25T07:32:31.211-04:00

Inspired by the ZL2BNE card sent to me by VK3HN, and the excellent question from Walter KA4KXX, I endeavored today to create a QSL card that was sort of like that of OM ZL2BNE.

I kind of like the result:

-- We have the wooden box rigs. I am working on one of them. (That happens a lot!)

-- There is a D-104.

-- We see the EB-63 .1kW Linear.

-- There are books on the shelf: SSDRA, EMRFD and SPRAT in a binder. And we see a book by Hayward.

-- There is an oscilloscope.

-- There is a nice map of Northern Virginia and my Maidenhead Grid Square.

-- We see Guapo, and a cup of coffee.

-- We also see the SolderSmoke sticker.

Here is how I did this:

I used https://www.canva.com/ You have to select the AI option. Then I told it I wanted it to look like the ZL2BNE card (I sent them a copy). At that point you have to start modifying what the AI comes up with. You have to do this many times until you get it sort of right.

Please send me your results!

Here are a couple of QSLs that Bruce KK0S did with ChatGPT:

A Really FB HB QRP QSL Card from New Zealand

2026-06-24T05:18:50.380-04:00

That's the spirit! The solder is melting. Note the oscilloscope. Note the books on the shelf. This amazingly good QSL card was sent to us by homebrewer Paul VK3HN, who made the contact with ZL2BNE.

This card reminded me of my first real DX: ZL2ACP many years ago. 15 meter CW with my new Drake 2B receiver. I had crossed the Pacific before I had crossed the Atlantic. I ran upstairs and woke my parents to tell them of this amazing feat! I still have that QSL card.