How to Homebrew your own Transistors

No store-bought transistors for these guys -- they homebrew their own point contact transistors using a bit of Germanium from a diode.  This makes me feel like such an appliance operator.   

This video is in Polish, but The Knack is a universal language, and this guy obviously speaks it.  Turn on captions, then opt for auto-translate to English.  You will then get English subtitles and Bob will be your uncle.  

I really liked this one.  This fellow has obviously DONE this;  his video is filled with both practical tips and theoretical explanations.   He talks about the virtues of beeswax, and about how to borrow red nail polish to mark the collector lead.  FB. 

Here's the channel:  https://www.youtube.com/@Marcin_Marciniak

In their next episode they promise to build a radio receiver using the homebrew transistors.  That'll be great. 

Thanks to Marcin and company, and to Jenny List of Hack-A-Day who alerted us to this. 

Marcin is a ham  -- SP5XMI:  https://trafficlist.altervista.org/radio-officer-friend/marcin-marciniak/

But who is the fellow who built the homebrew transistor? 

Mr. Carlson Makes a Thermatron Power Supply for a BC-348

When I was 14, I had to make a power supply for a Heath HW-32A.   Mine ended up working, but it was nowhere near as nice as Mr. Carlson's BC-348 supply (shown in the video above).  I didn't have a sand blaster, nor a drill press, nor much of anything else, really.  

But hey, don't real boatanchor hams use Greenlee chassis punches?  What's with the drill press and the hole saws? 

Note that Mr. C takes care to make sure that the rectifier tube is in the proper angle FOR OPTIMAL VIEWING.  That's some serious attention to detail OM.  And whoa, DELICATE SURFACE MASKING TAPE from 3M?  Respect!  Also, era-specific looming material. 

His point about the importance of the cardboard washers in the power transformer was really useful.  I hadn't thought about that. 

Here are the two previous BC-348 videos: 

https://www.youtube.com/watch?v=nX87kwSshZ8

https://www.youtube.com/watch?v=Zqe6CBe0iGs

Thanks Paul! 

SolderSmoke Quiz Question: Who is the actor in this Bell Labs video?

He appears at 8 minutes, 17 seconds.  And he is somehow in the YouTube title frame.  I think I know who it is.  Any ideas?  (DON'T LOOK AT THE COMMENTS!) 

 

"Matter Waves" -- A 1961 Bell Labs Film

I continue to mine the AT&T video archive.  Here's a really wonderful 1961 film showing how particles really are waves also.   The simplicity of the gear that the Bell Labs folks used to demonstrate this is really admirable.  I would love to see the preceding film (the one that shows how light waves are really also particles). 

Arthur C. Clarke Talks about Satellites, SETI, Remote Work, and Wrist Radios (1976 Video)

He was, of course, right about the impact of satellites, but he was the inventor of the geo-stationary concept.  I wonder how he would react to the low-earth orbit Starlink system we are now using. 

He coments about how contact with extraterrestrial civilizations could come at any time, but notes that false alarms are common -- this made me think of recent explanations of the famous "Wow!" signal. 

His "Communicate don't Commute" idea seems to foreshadow the "remote work" via  Zoom that kicked in during the pandemic.  

And he talks about Dick Tracy-like wrist radios.  I sort of have one now (thanks to Elisa), in the form of my Apple Watch.  But it may be that putting a camera in there would be a bit too much... 

"The Far Sound" -- Bell System Video from 1961 -- Good Radio History (video)

This is a really OLD video, but there is a lot of great material here: 

-- Tubes.  (Valves or Thermatrons)

-- Coax.  

-- Frequency Division Multiplexing. 

-- Negative Feedback and the fight against distortion. 

-- Transistors and early experiments with semiconductors.

-- Fiber optics and Masers.

-- Satellite communications.

-- Early hopes for video communications.

The video is, by today's standards, extremely misogynist.  And the sound experiment with the poor woman wearing a male head was just weird.   But still, an interesting film. 

Thanks to Mark KM4GML for reminding us of this wonderful Bell Labs (AT&T) video archive. 

https://www.youtube.com/@ATTTechChannel 

 

Harry Caul had THE KNACK -- Movie Review -- "The Conversation" --1974 by Francis Ford Coppola (Harry Caul based on W3VCG)

 

I give it FIVE Soldering Irons! 

I found it on Amazon Prime.  The workshop scenes remind me of ham workshops.  The movie character Harry Caul was based on real-life Marty Kaiser.  Was Marty a ham? 

POSTSCRIPT (August 23, 2024):  Yes, he is a ham!   W3VCG!   FB.  Here is his web site: 

http://www.martykaiser.com/fbi1~1.htm

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

http://www.martykaiser.com/odyssey2.htm

Thanks to Roy WN3F for reminding me to watch this film.  Roy found a clip that is reminiscent of hamfests: https://www.youtube.com/watch?v=joM5VDCIQg8

How Big is a Photon? (Video)

As I have mentioned in the podcast and in blog posts, I have a lot of trouble picturing HOW 20 meter photons somehow fly off my antenna.   I understand how EM WAVES are generated.  But there doesn't seem to be any corresponding explanation for how the photons are generated.  

This video looks at a related question:   How BIG are the photons of visible light?   I am not sure this is all correct (and neither, apparently, is the creator of this video) but it is very interesting.  

Comments are welcome.  

The Tropics Defined: Sun Directly Overhead on July 31 in Punta Cana DR

July 31, 2024  12:30 Local Time

Check out the shadow at my feet.  The sun is directly overhead.  This happens here on July 31, shortly after noon.  We define "the tropics" as the area of the earth at which -- as some point in the year -- the sun will be directly overhead.   Here we are at about 18 degrees North latitude, so for us, the overhead date is July 31.  We are definitely in the tropics.  A good graphical description of what is happening appears here: 

https://www.suncalc.org/#/18.5548,-68.3853,12/2024.07.31/12:37/1/3

A Wonderful Aeronatical Mobile Contact

 29 July 2024

20S 0943Z 0543L K8JSM/AM Sean, pilot on a 757/300. En route from San Francisco to Orlando with 246 souls on board, including a bunch of kids going to Disneyland.  Was 35,000 feet over Louisiana (12 miles East of Shreveport) when I first spoke to him.  (He had been in QSO with Andrew VK6IK in Western Australia.  I could hear Andrew also.) Sean was using the 400 W Rockwell-Collins transceiver on the plane (that's his picture of the control panel, above), with the antenna vertical in the back vertical stabilizer (rudder). I told him I was running 20 watts from a homebrew rig to a vertical ¼ wave ground plane antenna about 70 feet up; he speculated that the fact that we were both vertically polarized must have been helping.   Sean said he also pilots 767s transatlantic. 

I really had two contacts with him,   Around 0600 local he was calling CQ and no one was answering.  So I called him again and we continued:  I told him about the Aeronautical Mobile contact I had had from Samana.  I also told him about my contacts with MIR and RS-10 (and the RS-10 robot!) from the Dominican Republic 1992-1996.  I told him that Elisa had been present for many of the contacts with Norm Thagard on Mir station (Elisa walked in the HI7 shack at around this time – Sean said hello.)  Sean said he has been a ham for a long time – since before he was a pilot.  He has built a 2 meter “tape measure and PVC”  antenna.  I told him we have a little aircraft radio and use it to listen to the tower at Punta Cana airport, and to aircraft calling the regional ATC in Santo Domingo.  Sean says he too has a little airband receiver and often uses it to listen to airplane tower traffic.  Sean said the airline encourages this kind of contact because it is a way to keep pilots alert on long overnight flights (other pilots have other activities to do the same).  As we spoke he was waiting for a meal (salmon).  He mentioned that he could see the constellation Orion out the window;  I told him I had been looking at Orion in low in the East just before talking to him.  In the end, Sean  had to sign as the plane crossed into Florida and aircraft pilot duties took precedence.  

More info on Sean here: https://www.qrz.com/db/K8JSM     

Thanks Sean!

A Message from Walter KA4KXX -- On Bias Setting, the Joys of Al Fresco Rigs, Lawn--Sign Radio Base

 

Dear Dean KK4DAS:

...

3) Note that a rule of thumb I have used successfully in adjusting RF Power MOSFET

bias is to increase the voltage in 100mV steps, measuring the RF Output Power 

each time, and stop as soon as you start to see significantly diminishing returns.

4)  Although I did mention a plexiglass cover (the idea was from the Electroluminescent 

Receiver in photo below) in a 2017 entry I made on my QRZ page, I never built one, because I  have found a cover of any kind to be unnecessary and even detrimental based on operating portable outdoors in a public park with my rigs once every month for 10 years.  

From these experiences I have enjoyed the wonderment and respect I have received 

from fellow hams as well as passersby who have universally admired my creations. 

If the truth were known, my homebrew Alfresco transceivers might be the most 

photographed radios in all of ham history!  

Therefore, the only box I bring to my ham radio outings is for my lunch, because nobody

really gets excited about photographing just another box.

However, I do use plastic carrying cases per the photo for any rigs I carry 

in the trunk of my car.  If it rains, the top of the carrying case can be used as a 

temporary cover, so I know contacts can be made in a light rain because I have done it.

[Of course, credit card hams are not capable of operating portable even on a cloudy day

or their $$$$ radios would suffer from high humidity disease and need to be sent 

back to the offshore factory for $$$ refurbishment!]

5)  Lastly I will mention that I have never used any type of wood for a radio base because

wood is too heavy (and 1/8 inch aircraft plywood is too expensive), and the strength of

wood is not necessary to support a measly 5 pounds of electronic parts. 

Instead, per the photo, I have used Coroplast yard sign material (usually two sheets

with the channels crosswise then taped or glued together with the top covered using copper tape) common school science fair poster board, or good heavy duty cardboard such as from a TV set box.

Either light or heavy-duty double-sided tape and 4-40 or 6-32 nuts, bolts, and washers (sometimes oversized) are used to hold everything on board.  Occasionally L brackets, standoffs, hot glue, and foam or balsa wood support pieces are also utilized. 

In summary, keep up your good work as the new star on the Soldersmoke Podcast and 

please be certain Bill pays you as much as Pete.

72,

Walter

KA4KXX

Some Pictures of SolderSmoke Shack South

That's me at the operating position.   Window looks out to the terrace and to the ocean to the East, the  Mona channel.  The shack is on the top (seventh) floor. 

Here is the view from the terrace, looking South.  The big terrain feature is Cabo San Rafael. 

From the terrace looking North. 

Looking East into the morning sun 

From the terrace looking West. 

Antennas will go up there.  Perhaps solar panels too.  

A bog portion of the shack is a workbench with tools and test gear.  

Yesterday an old friend from Santo Domingo, Luis Ernesto HI8LEZ stopped by.  Thirty years ago we were pioneers in the use of amateur radio satellites from the Dominican Republic.  Luis Ernesto is in the book!