Helge LA6NCA Builds a One Tube CW Transceiver -- And Makes a Contact!

Helge has done it again!  He has shown us the benefits of homebrew CW.  And he has done it with one tube.  FB Helge. 

Of course, I really liked the wooden box.  His is a lot nicer looking than mine.  I also liked how he carefully laid out the parts -- I seem to be stuck in my 13 year-old "build then design" mode.  Helge's way of doing it is better: design, build.   In that order! 

Some will quibble about a lack of 700 Hz offset between transmit and recieve.  With a VFO rig, this could lead to the stations chasing each other across the band.  But Helge is crystal controlled here, so I don't see a problem.  Is that right?  Please comment below. 

Thank you Helge for another great rig, a great schematic, and for showing us your obvious joy at reaching 400 km across the sea to your friend in Norway.  FB! 

The Roman Space Telescope

The New York Times reported today that you would need HALF A MILLION high definition TVs to display just one image from the Roman Space Telescope in full.  Wow. 

The telescope will be at L2. 

 https://en.wikipedia.org/wiki/Nancy_Grace_Roman_Space_Telescope

KW4H -- Steve -- "Knobs > Menus"

 

I really like the "KNOBS are greater than MENUS" sign.  For years we have been saying that menus are for restaurants.  FB Steve.  

Steve's resotation man-cave is very interesting, as are the rigs he has on the shelf or on the bench.  Lots of good work is obviously being done there.  

I also have one of those KP4USA QSL cards. Steve and I got into ham radio at around the same time, so it is possible that he was on the other end of that QSO.  I will check. 

Check out Steve's QRZ page: https://www.qrz.com/db/KW4H

W9TH - Jeff -- Shames Me Into Building a 6T9er -- "You Have No Excuse"

 

First off, that my friends is a ham radio shack.  Note the many books.  And the many Heathkit HW-8s and at least one HW-7. There is a 'scope.  And sig gens.  And a vise!  This is a thing of beauty.  

Jeff sent me a KiCad circuit board for an 6T9 transmitter.  He heard me moaning about it on the SolderSmoke podcast.   As he notes, I no longer have an excuse not to build this things.  The Radio Gods are demanding it.  Who am I to say no? 

Check out Jeff's QRZ page: https://www.qrz.com/db/W9TH

And his website: http://w9th.com/     (QRP before QRP was cool!) 

Thanks Jeff! 

"Solvitur ambulando." Latin for "It is solved by walking."

We've been proponents of this idea for a long time:  Essentially it is that sometimes you have to at least temporarily put a hard technical problem on hold.  Sometimes you need to just STOP working on the problem, put the rig on the shelf, and go out and take a walk.  Or, perhaps, a hike. 

In the travel section of the New York Times today, I found this phrase from Latin: "solvitur ambulando."  It was in an atricle by one of my favorite authors, Paul Theroux. One of his his novels, "The London Embassy" was eerily true to life, and had me thinking that the house he described was, in fact, the house in London that I was living in.  Paul has been at it for so long that, frankly, I thought he was gone.  I was delighted to learn that he is not, and that he is still writing books. 

Theroux wrote, "Is something fuddled in your mind? Searching for an idea? Then lace your boots, leave the house, and set off alone: Chances are you will find the answer along the way.  This remedy (attributed variously to Diogenes the Cynic and St. Augustine) is one that all true piligrims know, and in many respects serious hikers are the modern embodiment of medieval pilgrims."  

Indeed, if the solution is fuddled in your mind and you are searching for an idea, take a break, do something different.  Take a walk: "solvitur ambulando." 

Keeping the Voyager Spacecraft Alive

 

https://www.nytimes.com/2026/08/18/science/nasa-voyagers-big-bang.html?unlocked_article_code=1.8VA.nYO7.tliu0Kleh5vJ&smid=url-share

Here is a really nice New York Times story about NASA efforts to keep the Voyager spacecraft alive.  They are approaching 50 years old. They are very far away.  They are running low on the plutonium that keeps them warm and powered.  The fuel for the thrusters is starting to clog the pipes.  But NASA recently carried out a "Big Bang" effort to extend the life of these two spaccraft. 

One of the 25 year-old engineers admitted that he treats the Voyagers like he treats his aging parents -- problems do crop up.  But then he was reminded that his parents had been born AFTER the launch of the Voyagers.  

The animation above shows where the two spacecraft are, and where they have been. 

Solid State Transformers -- Are the small DC supplies from Amazon small versions of what we need?

The algorithm seems to KNOW what I have been reading.  This week the New York Times Sunday magazine had a really frightening story about the vulnerabilities of the U.S. electrical grid.  The big vulnerability is the large transformers.  They are very very hard to replace.  Replacement takes years.  If something were to happen to only a few of these transformers, the U.S. could be plunged into an apocalyptic power outage.  This is not theoretical stuff.  People in the U.S. have been taking out transformers with high powered rifles.  What is that old saying about people who live glass houses?   Well it appears we live in one. 

The NYT article ended with one optimistic note:  Solid State Transformers.  These are being used in the AI Data Centers.  Asianometry took a look at these devices -- I really like his YouTube channel, but I think he missed the big down-side of old clunky tranformers: their extreme vulnerability.  

One additional ham radio note:  Pete N6QW, Grayson KJ7UM and Helge LA6NCA have recently been using very small high voltage power supplies.  Back in the day,  thermatron rigs required much larger transformers.  Are these tiny DC supplies small versions of the Solid State Transformers discussed in the NYT article and the Asianometry video?   

First Earth-Moon-Earth Echoes: 1946 from New Jersey on 111.5 MHz using Military Radar Gear

https://www.nationalww2museum.org/war/articles/project-diana-moon-and-soviet-union

https://en.wikipedia.org/wiki/Project_Diana

Maxwell's Equations Explained

I really liked this one, and the follow-on videos show a lot of promise.  The maker starts with the four equations that we see on T shirts.  He admits that at the time he first saw them, he did not understand.  But in this video, he digs in, and finally gets it.  The connection between Maxwell's equations and C (the speed of light) are especially well presented.  

There is a document that goes quite a bit further, and explores the connections between Maxwell's equations and quantum mechanics.  It is by that wonderful physicist Freeman Dyson. It is entitled "Why is Maxwell's  theory so hard to understand?" Check it out: 

https://davidtong.org/pdfs/teaching/electromagnetism/dyson.pdf

The Solar Eclipse in Spain, Balloons, and Veritasium

This was all pretty cool.  There was a lot of good scientific info.  I had noticed the crescent shapes on the ground during earlier solar eclipses (from tree leaves!), but I never knew WHY we were seeing them. Thanks for the explanation Veritasium.   

There was also a cool balloon launch and recovery, and some great video recovered from the balloon. 

It looked like everyone had a great eclipse in Spain. 

SolderSmoke Podcast 266: TROUBLESHOOTING! Test Gear, LA6NCA, ZIA Rig, Australia, Nuvistors, 75 AM, MAILBAG

SolderSmoke Podcast # 266 is available. 

Video version: https://www.youtube.com/watch?v=_hbLmsFxzx4

Audio version:  http://soldersmoke.com/soldersmoke266.mp3

Travelogue:   Dean to Boston, Bill to Glenmore in Maryland.  

Discussion of AI, data centers, and ham radio. 

Dean's Bench:  

--  Troubleshooting 

--  Why we emphasize building in stages

--  Understanding what your test equipment is telling you

--  Measuring everything and expecting precision from analog circuits.

  

--  Recent examples from our Discord channel, examples were my rigol scope was lying to me.

Pete's Bench:  

-- Helge LA6NCA's Rig

-- Troubleshooting when the data fools you:  The ZIA rig. 

SHAMELESS COMMERCE DIVISION: 

-- Mostly DIY RF. 

-- Please continue to comment on blog posts. 

-- Please think about becoming a Patreon sponsor/ 

Bill's Bench:  

-- Working Australia on 20 and 17 SSB. 

-- Putting 80 meter antenna back up.  But high (August) noise level on 75. SOLVED! 

-- Nuvistor adventures with 1964 Parks Electronics Converter. 6CW4s. 

-- Thinking of audio derived S-meters. 

Mailbag: 

Grayson KJ7UM -- admiration for Helge LA6NCA. 6L6 Rig. 

Hidehiko JA9MAT's super regen, And FT-101 VFO Box. 

Chuck WB9KZY on older UK covert listening devices. 

Paul VK3HN:  Australian CBLA rig. 

Andri in Bandung, Indonesia -- Built a SolderSmoke DC receiver. 137 built so far! 

Mike WN2A liked 3885 kHz post (not everyone did -- AI Slop?) 

Walter KA4KXX liked piece on G0UPL breaking the I and Q code of Si5351.

Bob KD4EBM and Peter VK3TPM on AI. 

Ryan KJ7KVD will build MMM when family duties permit. 

Chris KD4PBJ noted SolderSmoke on a ham radio sign sheet.  FB.

Eric 4Z1UG -- Interviewed Will N5OLA (Heathkit Guy) https://www.qsotoday.com/podcasts/n5ola

K6AUS seeking understanding on mixers.  FB! 

K6AUS:   Did Drake make any 2Bs with serial numbers 3000-4000? https://nomadiq.net/blog/post/how-many-drake-2bs-were-ever-made

I am still looking for a Drake 2B for K6AUS.

NT0Z -- Kirk.   A big fan. Thanks. 

Why is Lahti on the Dial of the Receiver? Where is Lahti?

I have seen Schenectady and even Springfeld (see below!) but Lahti was new to me. I spotted it yesterday on the dial of the receiver that the fellow from the UK was fixing. Lahti? What was that? 

Turns out, this is a European Longwave thing. 

Gemini explains: 

When you see Lahti printed on the dial of an older radio, it is typically marking a Longwave (LW) broadcast frequency rather than a shortwave frequency.

The presence of Lahti on the dial relates to several historical factors:

• The Lahti High-Power Station: Located in Lahti, Finland, the national broadcaster Yle operated a massive, high-power longwave transmission station on "Radio Hill" (Radiomäki) starting in the late 1920s. Because of its central location and immense power (reaching up to 200 kW in later years), its signal could blanket all of Finland and carry across northern Europe.

• Dial Navigation: On older European and world-band radio dials, manufacturers frequently printed the names of major high-power European broadcasting cities (such as Lahti, Rome, Berlin, Moscow, or Droitwich) directly onto the glass or metal scale. Because consumers tuned radios by city or wavelength rather than just abstract kilohertz numbers, these city names served as benchmark reference points for specific frequencies (such as Lahti's long-standing assignment on the longwave band, which eventually settled on 252 kHz).

• The Era of "All-Wave" and Multi-Band Radios: Older vintage receivers—particularly those manufactured in Europe or targeted at international markets—often featured multiple bands spanning Longwave, Medium Wave (AM), and Shortwave. Even if a radio is broadly referred to as a "shortwave" or multi-band radio, its dial layout almost always incorporated the Longwave band where powerhouse European utility and broadcasting stations like Lahti lived prior to the widespread decommissioning of European LW transmitters in the late 20th century.

The old dial on my wife's grandfather's receiver

Fixing up a Nice Old (but not TOO old) Receiver in the UK -- What would you have done? Please comment below.

Crikey! Blimey! The parts are wonky!  Then he fixes it and they are all lovely!  These are some great descriptive words that you just won't hear in a U.S. workshop.  Pity.  

I liked the receiver.  I had never seen one of these. 

The Ultrasonic cleaner was nice.  As was the oven.  

His repair of the switches was very cool.  I like his technique for repairing the many leads that got broken. 

When he started unplugging the plugs on the boards, I got nervous.  Pull out the cell phone and take some pictures first!  

Opening up those old pots was really going the extra mile.  I would have just squirted some deoxit in them.  

He ended up changing almost all the caps on the AF amplifier board.   The Capacitor Police would indeed been annoyed.

Great job.  It was fun watching him work.  But what would you guys have done differently?  Please comment below. 

Thanks to Rogier PA1ZZ for sending me this. 

Some Great Workshop Ideas from Germany -- What do you think? Is there any overkill? Should I stick with the baby-wipe boxes?

Here we continue our series on workshops.  This one is in English, so most readers will not need any closed captions nor translation.

There are a lot of good ideas in this video.  I found myself thinking about my shack in Virginia and the one in the Dominican Republic.  My parts strorage is very outdated.  Here in Virginia I make use of old cardboard shoe boxes, and plastic "baby wipe" boxes (they are really old).  I may need a 3D printer.  

Check out this fellow's YouTube channel: https://www.youtube.com/@greatscottlab  

Paul Taylor VK3HN Talks about Hombrew and SOTA

 

https://www.youtube.com/watch?v=Rkd1o2PQI9M

It was great to see Charlie NJ7V of Red Summit RF interview Paul Taylor, VK3HN. 

Paul has been a friend for many years.  He is one of the FB ham radio operators and homebrewers from Melbourne, Australia.  

Paul has been on the SolderSmoke podcast and blog so many times, with so many rigs and so many summits: https://soldersmoke.blogspot.com/search?q=VK3HN

You should listen to Charlie's interview with Paul.  It is filled with good ideas and inspiration. 

Thanks to Charlie and to Paul. 

A German Builder Makes a 2 Meter Receiver - Warts and All!

First, you probably need to turn on closed captioning, and select autotranslate, probably to English.  This video is worth it. 

This fellow takes on the self-imposed challenge of homebrewing a 2 meter FM receiver.  He builds it on a copper clad board, using what looks like dead-bug construction techniques.  

He is not a radio amateur.  But he should be one, just by virtue if his work on this receiver. 

The board looks a lot like one of our projects.  He even points out the large number of parts that have been removed from the board.  You get the sense that he shares in our common frustration with circuits that for some unknown reason just won't work.  I found myself worried that he might opt to remove ALL the parts from the board -- that is our homebrew nightmare.  

Fortunately, he does not reach this extreme.  He gets the thing to work.  It is still not perfect.  He will go back to it later.  Good idea.  Take break.  Walk the dog or something.   Insight will come.  

It is really great and refreshing to have this kind of "warts and all" "blow by blow" description of a build projects.  Too often the books present projects as if they worked the first time the builder put them together.  This happens very infrequently -- the process described in this video is closer to the norm. 

And it is great to have this project come to us from Germany.  SolderSmoke is dedicated to INTERNATIONAL homebrew radio.  

He uses an MC3361 chip as the demodulator. Here is the data sheet: https://www.nxp.com/docs/en/data-sheet/MC3361C.pdf

Thanks to Rogier PA1ZZ for sending this. 

Here is the builder's YouTube channel: https://www.youtube.com/@12null02

Chappy Happy Builds a 25 meter Direct Conversion Receiver using a PAL VFO -- And There Is Distortion of AM SW Broadcast

First, it is a good day when I find a new Chappy Happy project on YouTube.  Thank you Chappy Happy! You make us happy! 

Second, even before I watched the full video, I could recognize the PAL VFO.  This is an old CB device.  You will find them at hamfests.  I picked one up several years ago, knowing that I will someday use it as a VFO or for VFO parts.  It is, after all, an LC VFO, and it is to be celebrated and used.   

Chappy Happy turns his PAL VFO into a simple direct conversion receiver for the 25 meter SW broadcast band.  He is on the west coast of North America and uses it to listen to Radio Japan. He uses a J310 RF amp and an NE602 Gilbert Cell mixer. 

That is great, but there is a big problem in using a direct conversion receiver to inhale AM signals: Unless you can get the frequency AND the phase of the VFO to be exactly the same as the carrier, you will have distortion. You will not have this problem if the signal is SSB, but you will have it with AM or DSB.  

I think I can hear the distortion on the Radio Japan signal.  Can you hear the flutter?  That is what happens with an AM signal being received on a DC receiver.  This is why Doug DeMaw frequently warned that you could not listen to a DSB signal on a DC receiver without significant distortion.  

What do you guys think?  Can you hear the distortion?  Should Chappy Happy turn this receiver into a simple superhet, perhaps something like the Q-31? 

Here is a video of my Q-31 super het for the 31 meter SW band: 

Again, thanks Chappy Happy!  Please keep those projects coming! 

Open Sauce 2026 in San Francisco

CuriousMarc and team were heading to this event.  We look forward to their report.  In the meantime other reports are coming in.  

I do see mention of the WSPR Balloons that circumnavigate the globe.  Want one. Also, I saw at least one CubeSat. 

I wonder (not really) if my homebrew SSB transceivers in wooden cases would make the cut. 

The SolderSmoke homebrew direct conversion receiver (with DISCORD support group!) might fit. 

Using a 5 inch Naval Gun Mount as a Rotor and Being Asked by NASA to Listen for Artemis -- Why no lightning strikes?

Wow, this is very cool.  I don't have a 5 inch naval gun mount.  And NASA has never called me for any reason.  This is all almost too much.  Watching it all, I feel an urge to go UHF.  

Here is the QRZ.com page for Pete N0OY:  https://www.qrz.com/db/N0OY

The deuce and a half mobile rig is really nice, as is the bus with equipment for 10 GHZ that has been to the shores of the Arctic Ocean.  Wow. 

Pete N0OY talking about the deuce and a half:  https://www.youtube.com/watch?v=Xx3P04f4OUY

 Pete talking about WARC Balloons: https://www.youtube.com/watch?v=t_WgszOTrT8

Working Pete on 10 GHz Rainscatter -- 91 miles!   https://www.youtube.com/watch?v=iwoSNoawVJk

N0OY 2021 New Years Day Open House:  https://www.youtube.com/watch?v=kNW1nW238mM

One big question:  Why has Pete had no lightining strikes, even when he has been trying to get them?

Also, why are so many great radio amateurs named Pete? 

Thanks Pete

Will N5OLA (the HW-101 Guy) Interviewed by Eric 4Z1UG (Please comment!)

 https://www.qsotoday.com/podcasts/n5ola

This interview was a lot of fun.  I too was smitten at an early age by the HW-101.  I still have one on my operating table.  We are all lucky that Will is working in an innovative way on these old rigs.  Who can forget his shocking water and soap (followed by South Texas sunshine) approach to cleaning these often cruddy old rigs?  Thanks Will and thanks Eric for doing this interview.  

Please post your comments below.