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Thursday, April 17, 2025

"Seems Like Radio is Here to Stay" -- Old Radio, Radio Magic


The first 12 minutes of this podcast are pretty good.  I think it captures well the wonder of radio -- magic carpets, signals taversing the Himalayas and all that -- but the presentation is kind of confused.  The PRX podcasters keep saying that it was recorded in the 1930s, but then we hear references to the Nuremburg trials and the possibility of sharing the atom bomb. So there is some confusion in the presentation. 

https://podcasts.apple.com/us/podcast/champions-of-old-radio/id453044527?i=1000702716017 

Can anyone find the original recording from the 1930s about the wonder of radio, without the references to things that happened in the late 1940s? 

Thanks to Rogier for sending this to me. 

Norman Corwin

Wednesday, April 16, 2025

Homebrew vs. Kits -- The influence of Russian Homebrewers

 
Click on the image for a better read. 

Like Kirk, I too was influenced by the Russian and Eastern European homebrewers.  As a kid, every issue of QST seemed to contain (especially in the "How's DX?" column) pictures of intrepid Russian homebrewers seated next to their HOMEBREW stations.  I wanted to be like them. 

When I first launched the Direct Conversion Receiver Challenge, someone decided that it would be better to make the receiver into a kit. He criticized me for deciding to keep this project homebrew. There seemed to be a lack of understanding of the difference. This morning I got an e-mail from Kirk NT0Z. He attached his column from the February 2013 issue of Monitoring Times. I think he captures very well the difference between kits and homebrew. An excerpt from the column appears above. I need to get a portrait of UW3DI to hang above my workbench. Thanks Kirk.

Here is more info on the UW3DI transceiver:

Monday, April 14, 2025

DJI Drones -- How it All Began (with a shout out to Frederick Terman)


Lots of interesting stuff in this video, including a short clip of non-other-than Frederick Terman, of Stanford University and Silicon Valley.  Like many of you, I have Terman's "Radio Engineer's Handbook" on my shelf. 

Sunday, April 13, 2025

The Amazing Technological Development of DJI Drones


Yes, the ability to hover is a really big deal. 

Kalman filtering.  Who knew? 

GPS, compasses, intertial navigation, redundancy.  Great stuff. 

NZ showed DJI that quadcopters were the way to go.  

The importance of brushless motors. 

It is really amazing how quickly quadcopters took over from ordinary helicopters.  The regs in the DC area that prevent us from flying quadcopters here were probably developed BEFORE the quadcopters were developed. 

I still wonder about why we still fly normal helicopters:  Take you hands off the controls of a helicopter and it will soon start to flip and fall.  Take you hands off the controls of a quadcopter and it will just hover in the sky.  When the batteries get low, it will return to the start point and land.    

I have a video taken by my Hanmilt drone on my Patreon channel.   I have already bought a DJI Mini 4K to fly in the DR. 

Friday, April 11, 2025

Mike KA4CDN's Engraved SolderSmoke Direct Conversion Receiver -- Another VWS RX!


Mike KA4CDN is an experienced homebrewer and a member of the Vienna Wireless Society.  He took the SolderSmoke challenge and built the direct conversion receiver.  Congratulations Mike, and welcome to the Hall of Fame!  

Mike writes:

The goal of the project was mainly to test my conversion of my Ender3 3D printer into an engraver for making PC boards. Thank you Bill and Dean for leading the project. It had been a while since my soldering iron was hot on an RF electronics project. It is amazing how fast I get rusty and forget stuff. Now I'm going to pick back up on my crystal filter that I started I think two years ago
 ;-(  Awesome! 


For more information on how you too can build the receiver: 


Join the discussion - SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

 

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

 

SolderSmoke YouTube channel:

Thursday, April 10, 2025

The History of MOSFETs -- Let us Remember the 40673. The IRF510. And others...


Lots of great history explained in this video.  I found myself thinking about our beloved 40673 dual gate MOSFET: 

https://hackaday.com/2016/03/21/the-curse-of-the-40673-zombie-components-that-refuse-to-leave-the-building/ 

And, of course,  about the IRF510.  

Monday, April 7, 2025

Asianometry on MOSFETs, MESFETS, CMOS and Moore


Asianometry does a pretty good job here.  I am sure people will quibble about some of his descriptions of radio, AF, and RF.  But overall, pretty good.  I did see what looked like a direct conversion receiver in his block diagrams, but it was described as a superhet.

I was also struck by what looked like the lack of shielding in the modern cell phones.  Some hams seem to believe that we cannot live without shielding.  But apparently we can.  

I also like how the bloc diagrams have the LO feeding mixers both on the receiver side and on the transmit side.  I realize that you can do this by switching the LO, but I like to feed both mixers at the same time.  

Asianometry talks about the need for inductors in the chips, and how this was often a show-stopper.  This made me think about the Gilbert Cell that we find in our beloved NE-602s.  Wasn't Barry Gilbert trying to create a balanced mixer that would not need coils? 

Finally, there is a nice review of the history of Silicon Labs.  I was hoping to see the Si570 and, of course, the Si5351.  But no, these seem to have come later than the slide used by Asianometry.  

Sunday, April 6, 2025

The Hall of Fame -- Completed SolderSmoke Direct Conversion Receivers (So far --- more to come!)

Dean KK4DAS's Receiver

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 (see below). 

So far 53 completed receivers, with 4 honorable mentions:  

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    
KI5SRY          Mark -- Gears on PTO screw
 
KA1MUQ       Frying pan receiver
AA1N              Adam
ZL1AUN         Aaron -- Using SSB transmitter
W8UC             Never before homebrewed. 
VK4PG           Phil -- Nice case, "really pleased"
G7LQX           Working well, video of CW and SSB. 
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.    
KF8BOG          Jim:  A long struggle, but success.  
Chris Wales    Fantastic video.  
YD9BAX        Wayan! Homebrew transformer! 
N0NQD        Jeff 
WN3F              Roy -- Made new stickers! 
AB5XQ            Bill  
KB7ZUT          Andy  
AA1OF            Jer

VictorKees        Holland
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
LU2VJM          Juan in Argentina
K1OA               Scott "Most fun in 50 years"
KC9DLM         Ben -- Had EFHW problems
PH2LB             Lex  Yellow, Glue Stick

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

W2DAB           Dave in NYC
W4JYK            Wes of VWS
KA4CDN          Mike of VWS
-------------------------
Honorable Mentions: 

*AA7U            Steve No PTO
*VK7IAN        Ian -- No Manhattan boards 
*KC1FSZ        Bruce's build on a PC board
*CT7AXD       Graham -- different AF amp
-----------------------------------------

Candidates for the Hall of Fame: 

SA5RJS              Rasmus
KA9TII               James
W2AEW             Alan
AA7FO              Chuck 
K7WXW            Bill 
W1PJE               Phil  MIT
VA3ZOT           Tony  Surface Mount -- Honorable Mention? 
KM5Z              Mike Yancey
AB2XT             John (Done, just need the video)
M7EFO            Bingo
KO7M              Jeff (Piper Cub)
K7WXW          Bill 
KD4PBJ           Chris

For more information on how you too can build the receiver: 


Join the discussion - SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

 

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

 

SolderSmoke YouTube channel:

Thursday, April 3, 2025

Wes W4JYK's FB SolderSmoke Direct Conversion Receiver by a Vienna Wireless Society Makers Group Member


I was very glad to see Wes W4JYK finish this reciever.  Wes is a member of our local radio club -- the Vienna Wireless Society, and is part of the club's Makers Group.  

Wes writes: 

The DCR is up and running.  Listened to East Cars Net along with a few other stations.  Very cool! and good project.

Thanks Wes and congratulations on entering the Hall of Fame!
-----------------------------------------

For more information on how you too can build the receiver: 


Join the discussion - SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

 

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

 

SolderSmoke YouTube channel:



Dave W2DAB's NEW YORK CITY Homebrew SolderSmoke Direct Conversion Receiver. Manhattan Construction IN MANHATTAN! FB!


Dave W2DAB is a long-time friend of the SolderSmoke podcast.  When Steve Silverman was moving out of NYC, Dave went on the subway down to lower Manhattan to retrieve (for me) Steve's HP-8640B signal generator. And that thing is heavy!  Months later I picked it up from Dave.  Dave is also rumored to have participated in some of the SolderSmoke sticker operations in New York City.  I will neither confirm nor deny his participation.   

Dave obviously did a beautiful job on this receiver, and it sounds great.  Dave's reception is hampered by his high-rise location -- he is currently limited to the use of a mag loop.  I thought about suggesting that Dave take his receiver down to Central Park or to the banks of the East River, but I worry that this device might be too much even for the famously tolerant residents of the Big Apple.  

By the way, that station Dave heard was Percy, KF2AT, right up the road from him on E 106th Street.   

Dave writes: 

The really nice part of this project is that it’s so broken down that I can understand all of the parts and I can keep working on this to make it better and better. Improvement and patience are necessary traits for successful home brewing.  I don’t rule out a Park DCR Activation, as I like to say Manhattan construction is so much more interesting done in Manhattan.

(Percy KF2AT is also in Manhattan.) 

Thanks a lot Dave, and congratulations,  Welcome to the Hall of Fame!  

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

For more information on how you too can build the receiver: 


Join the discussion - SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

 

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

 

SolderSmoke YouTube channel:


My Hanmilt HK 22 Drone -- Video and a still picture


This is the beginners's drone that I was using in the Dominican Republic this past winter.  It was really great.  The hover capability was amazing -- this made it very easy to learn to fly.  If it looked like I was getting into trouble, I would just go up a bit, hover, and figure out what to do. Obviously I could not do this with a fixed wing R/C plane.  Photography was excellent. See picture below -- I took this shot from my drone this winter.  I have a video on the Patreon channel.  

I flew this thing dozens of times, and only had one crash.  It was very minor.  I am still using the original propellers. 


The brand names change on these things very quickly, and Hanmilt might not be available anymore. But there are a lot of drones like this.  I paid about $100.  

I think my next drone will be a DJI drone.  But this will have to wait until I return to the Dominican Republic in June (I am in the FAA's "No Drone Zone" around the national capital.) Here is a really interesting video on DJI: 

Tuesday, April 1, 2025

Chris M6CRD's FB SolderSmoke Homebrew Direct Conversion Receiver


Chris M6CRD built a really nice looking recceiver.  And it sounds great too, both on CW (above) and SSB (below). 

Chris writes: 

Hi Bill.  It is using an audio transformer on the output but its an ebay one of unknown impedance. The description said 1.3k:8r but I have my doubts how accurate that is. The radio runs fine after I quenched some initial oscillation with larger caps on the power rail of the audio amp, its just a little quieter than I suspect it should be with the correct transformer. 

I told Chris that Dean and I had also had some early trouble with AF transformers of questionable specifications.   But in any case his receiver was clearly inhaling very nicely. 

Congratulations Chris.  Welcome to the Hall of Fame!

  

For more information on how you too can build the receiver: 


Join the discussion - SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

 

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

 

SolderSmoke YouTube channel:

Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column