SolderSmoke FDIM Interviews: Hans Summers G0UPL Talks about the QDX and His New Balloon Tracker

 

Thanks to Bob Crane W8SX for getting us this wonderful interview with Hans G0UPL.  Its really amazing to hear Hans talk about how many QDX rigs and Baloon Trackers have been sold by QRP Labs, and how quickly they sell.  Really great.  Hans's comments on the realities of the parts shortage was also very interesting. 

Listen here (about 7 minutes):  http://soldersmoke.com/2022 G0UPL.mp3

U4B Balloon Tracker 

SolderSmoke FDIM Interview with Farhan VU2ESE -- The sBITX is Coming!

Bob Crane W8SX --  our correspondent in Dayton/Xenia --  once again collected interview with FDIM presenters. Thanks Bob!  Here is his talk with our friend Farhan:  

http://soldersmoke.com/2022 VU2ESE.mp3

Here is a great post on the sBITX (May 30, 2022) from Farhan's web site: 

https://www.vu2ese.com/index.php/category/uncategorized/

Here is Farhan's amazing presentation on the sBITX at the 2021 FDIM: 

https://soldersmoke.blogspot.com/2021/11/farhans-amazing-knack-story-from.html

JFET (Junction Field Effect Transistor) Video -- Part 1

Good video.  I like how he related the real-world device to the Igs graph. Also, note the big variation in MPF-102 parameters.  Stay tuned for Part 2. 

Phase Noise and all that

Our friend Dave K8WPE has been listening to old podcasts.  He recently came across those in which Pete and I were talking about phase noise.   He asked for some resources on this topic.  Here is what I sent him: 

 Receiver performance expert Robert Sherwood explains it this way: 

Old radios (Collins, Drake, Hammarlund, National) used a VFO or PTO and crystal oscillators to tune the bands. Any noise in the local oscillator (LO) chain was minimal. When synthesized radios came along in the 70s, the LO had noise on it. It is caused by phase jitter in the circuit, and puts significant noise sidebands on the LO. This can mix with a strong signal outside the passband of the radio and put noise on top of the weak signal you are trying to copy. This is a significant problem in some cases: You have a neighboring ham close by, during Field Day when there are multiple transmitters at the same site, and certainly in a multi-multi contest station. You would like the number to be better that 130 dBc / Hz at 10 kHz. A non-synthesized radio, such as a Drake or Collins, has so little local oscillator noise the measurements were made closer-in between 2 and 5 kHz. 

http://www.sherweng.com/documents/TermsExplainedSherwoodTableofReceiverPerformance-RevF.pdf

Rhode and Schwarz have a good oversight video with great graphs that explain the fundamentals,  See above or here:  https://www.youtube.com/watch?v=hfgaEjf1154 

I think a lot of the fretting about advanced receiver performance measurements are really kind of over-the-top, and mostly of interest to advanced builders who want the very best performance from their receivers.  Most of the rest of us are happy if we can hear the band noise and separate the desired signals from the QRM.  But I must admit that as time goes on, I find myself getting more and more finicky.  I start to worry about gain distribution and dynamic range.  But I don't worry so much about phase noise because I am more of an LC oscillator guy and don't make much use of the PLL devices (like the Si5351) that do produce more phase noise. 

I've had many articles on the blog about about phase noise.  Here they are: 

https://soldersmoke.blogspot.com/search?q=%22phase+noise%22

The Amazing Workshop and Test Gear of Tony Albus PE1ONS

This is almost too much.  This makes me want to go out and buy some more test gear, maybe another scope, or a spectrum analyzer, or at least another DMM.  I mean Tony has at least three of everything. 

This is really amazing.  Tony is obviously a test gear guy, but he also has a ham call PE1ONS.  He says he is not too active, but we should encourage him to get more involved with ham gear.  We need guys like him working on ham gear.  And he seems like such a happy person.  

Here is his QRZ.com page: https://www.qrz.com/db/PE1ONS

Here is his awesome YouTube channel: https://www.youtube.com/TonyAlbus

Marconi the Fascist

For obvious reasons Marconi stories pop up in my news feeds.  This morning an article  from Wales reminded me of a very dark and disheartening aspect of Marconi's life:  his fascism and his participation in the persecution of Jews. 

There have been at least 14 stories in SolderSmoke extolling the technological virtues of Marconi.  I even met his daughter Elettra while in Rome and wrote it up for the blog.  But it is just wrong to sing Marconi's praises while ignoring his fascist involvement. 

His fascism wasn't even separated from his radio work.  He won fascist honors and he won his appointment to Mussolini's  Academy of Italy  because of his radio work.   Take a look at this quote: 

He became President of Mussolini's Academy of Italy -- and it was in that position that he participated in the persecution of Jews.  He was a member of the Fascist Grand Council.

If you have doubts about this, just take a look at the short clip (above) from Marconi's 1937 funeral procession.  Note the fascist salutes, note Mussolini himself marching in the procession. 

The article from Wales: 

https://www.pressreader.com/uk/south-wales-echo/20220527/281590949186995

More background here: 

https://www.theguardian.com/world/2002/mar/19/physicalsciences.humanities

A Modern Mechanical Television -- Nipkow Discs and Arduinos Lead to a Mechanical Color TV (video)

I had, of course, heard about the mechanical TV systems that pre-dated the CRT-based "electronic TV" invented by Philo Farnsworth.  But I never really understood how they worked until I saw this Hack-A-Day article by Jenny List.  And wow, I see it now.  Nipkow discs.   Color TV.  Parts made in a 3D printer. Excellent. 

Here is Jenny's post:  https://hackaday.com/2022/05/27/3d-print-a-colour-tv/

Here's the IEEE Spectrum article by Markus Mierse (the brilliant fellow who built this amazing device): https://spectrum.ieee.org/mechanical-tv

Be sure to watch the video (above).  Take a look at the awesome quality of the 32 line color TV picture. And check out Marcus's amazingly beautiful construction.  (Note:  Built on a wooden base). 

Marcus Mierse's Modern Mechanical Color TV

"Experimental Methods in RF Design" LADPAC Software Available FREE!

We've frequently said that is pays to check the W7ZOI web site.  Tony G4WIF did just that and pointed us in that direction, noting that the LADPAC "Ladder Package" software is now available for download from that site. 

Homebrewers will really want to have that package on their computers.  There are all kinds of useful programs in that package:  software for designing crystal filters and feedback amplifiers, a program that allows you to think systematically about receiver gain distribution and dynamic range, and many other useful things.  

You can get the program here: 

http://w7zoi.net/emerrata.html

Also on Wes's site is this May 22, 2022 picture of Farhan VU2ESE with EMRFD co-author Bob Larkin, W7PUA. 

Thanks Wes! 

"Hobby High" from the Lamarkaan Radio Club and The Hindu magazine

 

https://www.thehindu.com/opinion/open-page/hobby-high/article65375392.ece?fbclid=IwAR01JGwweZuJEH1Pg15rREybZqfqKUjU3ZLbGn-xhOYZVlFPs7yN_FbJoX4

This is a really nice look at hobbies and their role in life. It is very relevant to discussions of The Knack. 

Many of the quotes resonate with me, especially those about how hobbies -- in our case ham radio -- provide an important source of enthusiasm.  I remember an old timer in Rome telling me that at age 85, he jumped out of bed each morning, heading to the radio shack with enthusiasm. 

I'd add that ham radio adds elements of permanence and continuity in our lives. For many of us, we've been working on radios since our early teens.  I have in my shack gear that I've had for almost 50 years! Amidst the vicissitudes of life, it is really nice to have things with this kind of permanence. 

Thanks to Atanu Dasgupta of the Lamakaan Amateur Radio Club of Hyderabad for alerting me to this article.  OM Atanu wrote: 

My friends, acquaintances and members from my extended family often ask me how I spend my time and keep myself busy throughout the day. When I say I pursue a hobby called Amateur Radio (Ham Radio) and I spend more than 8-10 hours in a day for that purpose, I don’t find many takers. Many of them feel that I must be earning handsomely by devoting my energy and time as seriously as pursuing a regular work-from-home regime for some corporate entity. Sometimes even my domestic help express doubts, albeit in a decent manner, about my devotion to something in life without any financial gain and expect a wage-hike for them against my ‘extra earning’. After all how can a hobby (pastime) can keep someone so engrossed physically, mentally - on the computer, over thick books/ magazines , on the work table at the radio shack, on the floor for some odd metal works, on the rooftop with antennas, over the Radio-on-air, over phone etc - without some pecuniary benefits? Recently a brilliant essay by Himani Datar on ‘hobby’ in the Hindu Magazine (https://www.thehindu.com/.../hobby-high/article65375392.ece ) has been very impressive and appears to be a savior to all concerned like me. The essay brings out all in favour of all hobbies and hobbyists and I feel more confident now about my course of engagement on a long-term basis.   

Atanu's Shack

Marohu: The Dominican Telescope with a 25 inch Mirror Originally Made for JPL

 

https://dominicanrepubliclive.com/development/dominicans-built-the-largest-telescope-in-the-region/?utm_source=rss&utm_medium=rss&utm_campaign=dominicans-built-the-largest-telescope-in-the-region