Cloud Chamber Finale

 

Today's aparatus (above).  Chamber is larger and I left the bottom sealed.  It sits directly atop a chunk of dry ice.  The spongeat the top is soaked in alcohol. 

This is a one minute clip.  It does seem a bit like watching paint dry, but you will see many atomic particles moving through the cloud. If you look to the right side of the screen you will see that the cloud has started to rain alcohol.  I will put additional clips on the Patreon site. 

Harry Cliff's wonderful book mentions the origins of the cloud chamber. 

Click for a better view. 

Click for a better view/

Here's an interesing site on cloud chambers: 

https://www.hep.phy.cam.ac.uk/scatter/cloud.html#:~:text=Operate%20the%20chamber%20in%20a,approximately%20parallel%20and%20horizontal%20beam.

And here's another one: 

https://scoollab.web.cern.ch/cloud-chamber#:~:text=The%20cloud%20chamber%20was%20one,dry%20ice%2C%20and%20Isopropyl%20alcohol.

I think that is all I will do on the cloud chambers.  This was a lot of fun, but I am running out of dry ice.  There is, however, a lot of room for improvement and experimentation here, and a project likes this puts you in touch with the earliest days of particle physics (as Harry Cliff explains above). Good luck on 1.22 nanometers! Please let us know how you do. 

Here is one more look at the "output" of my cloud chamber.  This is a ten minute video.   You can see many traces in this. Check it out: 

More Cloud Chamber traces. April 26, 2024 (youtube.com)

Thank you Charles Wilson.  And thank you C.L. Stong. 

Re-building the Islander DSB/CW Tube Rig in Cuba

The VFO Board

The "motherboard" for an Islander

Islander boards recently obtained in Cuba by CO7WT

Pavel CO7WT is making great progress in re-building an Islander DSB rig, the same kind of rig that got him started in ham radio, and that was so popular in Cuba years ago.  Here are some background blog posts on this rig:  https://soldersmoke.blogspot.com/search?q=Islander  In essence, the Islander was the earlier tube DSB/CW rig; the Jaguey was a later, solid-state DSB/CW rig. 

When they get this Islander going, hams outside Cuba should definitely try to work this re-creation of an important rig. 

Thanks Pavel for all the information.  I will share with the group info that Pavel sent about temperature stabilization techniques used on this rig.  

Pavel CO7WT writes: 

Great news, today I received the package from my colleague in zone 6.

Two original islander motherboards and one from the vfo!

I'm doing a search among old technical friends in the city and in the country to see if I can put together at least a transceiver motherboard.

Audio triode-pentode is easy, as is tx pentode and audio double triode.

The difficult ones would be the 6cb6 and 6bz6 of the receiver... At least according to what I have polled among my local friends...

Tomorrow some friends are going to start looking for bases and valves that can be used to build a trx islander.

All out of pure nostalgia. I intend to make it qrp, that is, up to the output pentode, which there is between 3-5W of power, that is enough for me.

I am looking for alternatives for small sources, perhaps I will use switching for the filaments and we will see what I can get for the 180-250v of the plates.

Earlier: 

CO7WT here, built a pair of the Islander back in the time, the most scary part was the power supply.

The 600V is 300ish V from the transformed DOUBLED stright from the transformer and if you look closely on the diagram the doubling capacitor need to be of good quality otherwise it will explode in the spot.

As you can imagine, using scrapped parts means that very often this capacitor explodes, even after a few months of duty, that was a common problem.

We used to use 47uF/800v from Germany that was almost easy to obtain, but exploded like fireworks a given day.

Later I learned that if you put a resistor of about 1k 5W in series and work it for a while like this [no real voltage at the end] it will behave in the future and this trick saved many, a trick that was shared with Coro CO2KK and he found the explanation on the taming/training of the dielectric after storage/inactivity will prevent it from exploding.

I think he made mention this on a DXers Unlimited program...

Big Success with Cloud Chamber

 

My Cloud Chamber

It was time to take a break from building SSB transceivers.  I wanted to build something completely different.  I went with something that I've wanted to build since I was a kid. Sometime in the late 1960s, I read about a Wilson Cloud Chamber in the book "The Amateur Scientist" by C.L. Stong  (my mom got the book for me, at great sacrifice).  

You have to make a little cloud in a chamber.  When an atomic particle flies through (as they do!) it will leave a little trace in the cloud.  Cool.  Literally cool: This is a dry ice diffusion cloud chamber.  You make the cloud by putting isopropyl alcohol in blotter paper at the top of the chamber. You then cool the bottom part (a lot) using dry ice. The alcohol evaporates, then is cooled into a cloud by the low temperature of the dry ice. Fortunately, my local supermarket has started selling dry ice (it was harder to come by when I was a kid).  For the chamber, I used a plastic container from the same superpmarket. For the light source I used a little LED workshop flasllight.  

I saw traces immediately, while I was setting the thing up.   

Here are two videos of what I saw during that first hour:  

This one minute video shows the traces I saw.  Look for the little whisps of "smoke": 

(2125) Traces seen on day 1 - YouTube

This one shows a few more traces, but then BOOM at about 27 seconds.  Check it out.  What is that?  (Thinking about it some more, I think this may have just been some higher humidity air leaking into the chamber and condensing suddenly.) 

(2125) Day 1 with Cloud chamber - YouTube

Here's the C.L Stong book.  My project begins on page 307

http://www.ke5fx.com/stong.pdf

So what band would this be?  Something in the nanometer range, right? 

Here is a video showing what you see in a large cloud chamber: 

https://www.exploratorium.edu/video/cloud-chamber

EXCELLENT Video Series on RF Amplifier Design

Run, don't walk, to this video series by RF MAN.   He is truly, THE MAN!  Pete N6QW found this series, passed it to Dean KK4DAS, who alerted me.  Thanks guys. 

This is a six part video series on how to design an HF 50 watt RF linear amplifier using our beloved IRF-510 MOSFET.  Each video is about 30 minutes long. 

The author (who is this genius?) makes great use of LTSpice.  I have been using this software for years, but still I learned a lot by watching these videos:  AC Analysis.  How to change the values of the things you are measuring.  Even something as simple as drawing a wire right through a component to get leads on both sides.  This is really useful stuff. 

RF Man goes through the whole design of the RF amplifier.  He describes how to use LTSpice to determine input and output impedances (he does this with a NanoVNA in another video).  He talks about the use of negative feedback, and temperature compensation.  There are swamping resistors as Q killers.  This is all great, real-world stuff.  

Especially useful for me was his presentation on how to do "two tone" IMD tests.

  

There is a lot to learn here.  RF Man has a really wonderful way of explaining complex theory, and demonstrating complex tests.   This series makes me want to build a MOSFET amplifier.  

Look for the six parts of this series.  Here is RF Man's YouTube channel: 

https://www.youtube.com/@rfmanchannel6915/videos  

Thank you, RF Man! 

The War of the Worlds -- In CW -- By Chuck Adams AA7FO

This is for CW fans, or for those wishing to improve their CW skills.  You can now listen to the entire H.G. Wells book in CW, thanks to Chuck Adams, AA7FO. 

This seems very timely becasue my son and I are watching the NETFLIX version of "The Three Body Problem" by Cixin Liu.   This deals with an entirely different war of the worlds.  

Check out Chuck's CW version of the book.  Thanks Chuck! 

https://www.aa7fo.com/war-of-the-worlds.html

Deep Space Station 43 -- Canberra, Australia

 

https://spectrum.ieee.org/apollo-era-antenna-voyager-2

From the IEEE article: 

The dish’s manufacturer took great pains to ensure that its surface had no bumps or rough spots. The smoother the dish surface, the better it is at focusing incident waves onto the signal detector so there’s a higher signal-to-noise ratio.

DSS-43 boasts a pointing accuracy of 0.005 degrees (18 arc seconds)—which is important for ensuring that it is pointed directly at the receiver on a distant spacecraft. Voyager 2 broadcasts using a 23-watt radio. But by the time the signals traverse the multibillion-kilometer distance from the heliopause to Earth, their power has faded to a level 20 billion times weaker than what is needed to run a digital watch. Capturing every bit of the incident signals is crucial to gathering useful information from the transmissions.

The antenna has a transmitter capable of 400 kilowatts, with a beam width of 0.0038 degrees. Without the 1987 upgrade, signals sent from DSS-43 to a spacecraft venturing outside the solar system likely never would reach their target.

https://spectrum.ieee.org/apollo-era-antenna-voyager-2

The Rad Receiver from N6GWB

Geoff N6GWB and his eldest have produced a really wonderful receiver, and have joined the elite ranks of those who have built their own receivers.   Congratulations to both!  ( Be sure to watch the video below.)

Geoff writes:

Though I built it, my eldest has retained naming rights.  Behold the Rad Radio Receiver, an Soldersmoke inspired build.  It’s a 40m DC reciever.  I had planned on making this a truly 50-50 N6QW N2CQR build, but I needed to get it done for a show and tell this Wednesday.  I have N6QW dual JFET RF amp and mixer modules.  I have the N2CQR ceramic ocillator circuit from the 2017 DC receiver project.  I had planned on including the all analog audio amp from the more recent N2CQR DC project, but alas, time got the best of me.  I was hoping to make the whole thing all-analog.  (I thought the all analog would get me more “hard work” kudos at the show and tell.) I ended up including a LM386 audio amp making this a bit of a cyborg.

I have included pictures of the receiver open and closed.  The closed pic includes bespoke decals.  I have also include a brief movie demonstrating the audio.

Many, many thanks for the inspiration and knowledge!

Geoff

N6GWB

A QRP Quiz Question

 

I have the answer from an excellent and authoritative source.  

Here is the question:  The rig I bought for one dollar at Winterfest was produced by MXM Industries of Smithville Texas.  What does "MXM Industries" mean?  Why was this the name of the company? 

Homebrew-to-Homebrew Contact on 17 meters with DL2RMM (Video)

 Here is short clip of a very cool HB2HB contact on 17 meters.  Thanks Jens! 

Check out his QRZ page here: https://www.qrz.com/db/DL2RMM

Woebot -- An AI-Based Therapy Bot for Us?

 

This was on 60 Minutes last night.  Of course it made me think of our many "Tales of Woe."  Perhaps this could be of use to us.   But I wonder how the bot would react to our typical problems: 

"I am feeling bad about myself becasue my RF amplifier keeps going into oscillation.  What should I do?"

"My opposite sideband suppression is inadequate because my filter skirts are too wide. What is your advice?" 

"My LC VFO drifts slightly and my SDR-using friends taunt me about this.  I feel dejected.  What should I do?"  

"The Raspberry Pi in my SDR rig is hallucinating and I can't find the needed wisdom files. Is there a support group for this?" 

"I have discovered spurs in the output of my transmitter.  They are 60 db down, but I still can't stop thinking about them.  What should I do?"

I can't help thinking that if Jean Shepherd had access to something like this, his Heising modulator trouble might not have spoiled his date with the girl from his school.  

What do you guys think about the Woebot?  

The Doug DeMaw Article that got me into Homebrew Double-Sideband

Just click on the images for a better view

Pete WB9FLW asked for this.  This was an important article for me -- it paved the way for my entry into homebrew phone gear -- this article was the basis for my first DSB transmitter, built in the Azores. 

I think Doug was a bit optimistic in saying that SSB operation was possible with this rig.  Maybe it was possible for Doug, but for most of us DSB is just a LOT easier to get going than SSB.  (I know that some people don't believe this, but I note that most of these folks have built neither DSB nor SSB rigs.  It always seems easier before you start to melt solder.)  

Be sure to check out the 10 meter DSB rig recently built by Mike WU2D.  He has 6 or 7 good videos on this project, including this one: https://www.youtube.com/watch?v=xThoAMv4zrw

Another CW Contact with the SupeRX/TX 40 (Video)

I changed the crystal in the transmitter.  I got a different rock from Mouser and am now on 7030.  

Wednesday April 3, 2024. On 40 meters in the afternoon with Mike KM4KY in North Carolina.