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

HF Bandsweep with the Hammarlund HQ-100 (video)

It has been a while since we last did a bandsweep.  Too long.  Here is one using my recently fixed up Hammarlund HQ-100.  Repair details are in recent videos. 

For this bandsweep we cover most of the HF band and even briefly dip down into the AM broadcast band: 

Demonstration of the Hammarlund HQ-100: Radio Marti, 40 meter AM, 40 Meter SSB, 40 meter FT-8, 40 meter CW with and without the Q multiplier, classical music on WRMI, WFAX 1220 kHz AM, WWV 20 MHz, CB!, 17 meter SSB, the 20 meter BS position, the effect of AVC and the Noise Limiter, SSB with the internal BFO and with the Q multiplier as BFO. CW with the internal BFO AND the Q multiplier. 

Be sure to subscribe to the YouTube channel.  

Sticker Shock -- WYKSYCDS Stickers Spotted in NYC and in a Netherlands Pub! Awards!

 

I am awarding the coveted Brass Figlagee with Bronze Oak Leaf Palm to Dave W2DAB, to Lex PH2LB, to Jesse N5JHH, and of course to Pete Juliano, N6QW.  More awards are possible.  http://www.flicklives.com/index.php?pg=215&recno=2590 

Repairing the Sony ICF SW1 Receiver -- Used for Numbers Station Reception? Why no replacement for C-625?

Ten years ago, my friend John gave me this tiny Sony receiver.  It wasn't working.   I tried to fix it but quickly discovered that the tiny size of the device made repair difficult.  All you needed to do was to swap out some leaking electrolytics, but they are surface mount electrolytics -- replacing them is not for the faint of heart.  Kits are available, but again, this is not easy. 

In 2020 I got one of the kits, but didn't try to use it until yesterday.   It only supplied six of the electrolytics.  In the video above, they discuss replacing seven electrolytics, including the one that seems to be placed in the round black holder. C-625.  Why didn't my kit include a replacement for that one?  Could it be that this capacitor was not one of the leaky SMD caps?  

Replacing these caps really wasn't easy. At one point I inadvertently removed not just the bad cap, but also a nearby surface mount resistor.  Luckily the schematic showed it to be 0 ohms.  That was easily replaced.  I lifted one of the pads on one of the other caps -- I just slid it back into place and hoped for the best. 

BTW, I just today discovered that this little receiver may have been used late in the Cold War by those who needed to receive messages from the infamous Numbers Stations: 

 https://www.cryptomuseum.com/spy/sony/icfsw1/index.htm

500 WYKSYCDS IBEW Stickers Arrive in Europe! Order yours today! Free!

Lex PH2LB in the Netherlands has gone the extra kilometer for the IBEW.  When he saw the stickers that had been placed in New York City, he asked for the design.  I sent him the files that  Jesse N5JHH (designer of the stickers) had sent to me.  Very quickly, Lex had 500 of these stickers printed up and ready to go (see above).  His shack now serves as a veritable beachhead in Europe for the IBEW and the CBLA.  Thank you Les!   

Les has even set up an on-line order form for those who seek to assist in the noble campaign to spread the word about our cause: 

https://ph2lb.nl/webshop/sticker.php

Les is making the stickers available for free -- all you need to do is pay the postage. 

Please be sure to send us pictures of the stickers after they have been placed. 

And let's not forget that the quote on the sticker is from Pete Juliano, N6QW. 

Here is one that recently showed up in Blacksburg, Virginia (zoom in on the green utility box): 

And here is Lex's very interesting site, with his Knack Story:  https://www.ph2lb.nl/blog/index.php?page=history