Month: April 2019

SolderSmoke Podcast #211 — Malicious Code! Spaace! Vintage Sideband! MAILBAG

27 April 2019

 SolderSmoke Podcast #211 is available

 http://soldersmoke.com/soldersmoke211.mp3

 Pete NOT quitting podcast! Malicious code case RESOLVED!

Ambiguity and the Digi-Analog Divide

 Edwin Howard Armstrong biography

SPAACE!
Apollo 11 50th Anniversary
Oscar 100 in Geostationary Orbit. Why can’t we have one too?
Farhan puts AISAT in orbit. FB!
Space is difficult
SSTV from the Space Station

 Pete’s bench report.

Vintage Sidebanders
Recording of Midwest Vintage SSB “tune up session”
Vintage rigs that sound bad
Distorted views on “distortion”

Bill fixing old Bose Wave Radio

 NOT GOING TO DAYTON. AGAIN! But SolderSmoke rep will be there

 75 meter secrets of success (timing is everything!)

MAILBAG

 Steve N8NM sends me FB National Dial
Steve N8NM aspires to complexity — enough of this simple stuff!
Dave W2DAB goes to Columbia U session on Armstrong, sends FB book.
Jim W4JED — reports of QCX sideband a bit exaggerated. Where is Allison?
Rob Powell wins beret challenge. VK2TPM and VK2BLQ also win. CONGRATS!
Colin G3VMU sends nice 1930s radio picture
Alan WA9IRS sends diagram of digi radio signal flow. CLEAR AS MUD!
Chris KD4PBJ Grandmother worked at Hammarlund.
Steve NU0P sends info on Art Collins and the Apollo moonshots.

Nobel Prize winner Joe Taylor, K1JT, Talks to a Radio Club

Really great to see this session with Nobel Prize winner Joe Taylor, K1JT.
I liked his comments on his use of his retirement office at Princeton, University.
I also liked his slide on how far below the noise level you can go with various modes.
And then there was his reminder to 1) RTFM and 2) be sure to check the EME delay box so that your software will get the timing right when working earth-moon-earth.

“Pulsars keep good time.”

A Beautiful Variable Capacitor (from Pete)

Is this a thing of beauty, or what? Pete sent this to me back when I was having trouble finding a “smooth running” variable cap for my HRO dial receiver. It has a standard Jackson Brother’s reduction drive attached to the shaft, followed by a really cool gear arrangement. Note the spring loaded teeth on the big gear — that is to keep the gears tight when turning in both directions.

As was the case with the HRO dial that Armand sent me, the beauty of this part will cause me to build something with it, really just for the purpose of putting it to use. We’ve been talking about double or triple conversion superhets with 100 or 50 kHz final IFs. At those frequencies you can get good selectivity with LC filters. As with the Drake 2-B. Steve N8NM is sending me a dial that will go well with this part. That will add to the already abundant mojo/juju. I feel a VFO in the works. Thanks to Pete for being so supportive of my luddite analogism.

Homebrew Your Own Remote Head (with a 3D Printer) (Video)

After I issued a luddite complaint lamenting the arrival in ham radio of appliance-like “remote heads”, Ed KC8BSV pointed out that at least one guy — Joe VE1BWV — is HOMEBREWING his own remote head. (You must admit, this sounds really weird.) I still haven’t completely got my head around this, but Joe’s video (above) is really impressive.

We’re living in the future my friends!

 Remote your heads! With 3D printers!

Our Dismal Digital Future?

I’m sure some would find this device appealing — to each his own. But I don’t like it. It seems to mark another step down the path toward the complete appliance-ization of ham radio. Note how the control head is looking more an more like something for your car audio system, or your cell phone.
YUCK.
Count me out.
Just say NO!
Menus are for RESTAURANTS!
RIGS NOT RADIOS!
HDR FOREVER!

https://qrznow.com/barrett-4050-hf-sdr-transceiver/?fbclid=IwAR1LEoJ-nyeRKuzEu9tNdHcb1rRlTaD3zWnFDuIPrEdQ3cgytMU0hbQxOoc

Digital Engineering vs. Analog Engineering

In a book review Thompson makes this observation about the digital-analog divide:

One difference might be that human beings can deal with ambiguity, and computers really can’t. If you’ve done any Python [coding], you make the tiniest mistake, and everything stops immediately. That’s what makes it different even from other forms of engineering. When you are trying to fix a car, if you fail to tighten a bolt on one wheel as tight as it should be, the entire car doesn’t stop working. But with code, an entire app, an entire website can go down from the misplacement of a single bracket. I think that’s the one thing that sometimes scares writers away, because they are more accustomed to working with ambiguity.

 https://arstechnica.com/gadgets/2019/04/how-the-new-art-form-of-coding-came-to-shape-our-modern-world/

I am definitely more accustomed to working with ambiguity. All of my rigs are filled with ambiguity.

Understanding Digital Radios

Alan WA9IRS writes:
Hi Bill,
Thought I would drop you a brief note. I have been catching up on my listening to past issues of Soldersmoke podcasts and was particularly interested in the discussion between you and Pete concerning the simplicity associated with non-digital, integrated circuits and microprocessors and all of the rest of the very small miniaturized circuit elements. You rightly pointed out that you desired (along with a lot of the rest of us) to fully understand what was going on in a circuit and for that reason desired to maintain the simplicity of transistor and discrete components in your design and build projects.
I agree with you completely but offer the alternative to the simple circuits in the form of the attached simple diagram of the signal flow path in a digital radio. I found this some time ago in a digital electronics magazine and thought you and Pete would find it interesting. Perhaps this might be something to spring on Pete on 4-1-2018.
Take care and thanks to both of you for many pleasant and thoughtful hours of enjoyment listening to Soldersmoke!
All for now, 73,
Allan, WA9IRS
My response:
Thanks Allan, Very illuminating. It is all clear to me now. I feel so much better. FB OM. 73 Bill


Circuit for Farhan’s Satellite — Arduino in SPACE

Farhan sent me the schematic of the AISAT amateur digital satellite that went into orbit on April 1, 2019 from India. He notes that the circuitry is very simple. Indeed, it reminds me of the very simple but effective circuitry we saw in satellites in the early days of the space age. Beautiful simplicity, with an Arduino on-board. And it is great to see that Farhan did not forget the low pass filter. FB OM.

Packets from Farhan’s Space Ship

Farhan’s AISAT flew over this morning. Using HD-SDR software, an RTL-SDR Dongle, and my Dominican Republic refrig tubing quad I was able to capture some the packets. Above you can see one of them, floating like a flying saucer in the waterfall. Pretty amazing that that signal came from a machine put in space by our friend Farhan.

Congratulations to Farhan on New Amateur Satellite Launched 1 April

This is not an April 1 trick. Farhan and Exseed Sat have put another bird in orbit.
Details here:
http://amsatindia.org/

 This site in Argentina gives pass information:
http://amsat.org.ar/pass?satx=aisa1

 I will be listening tonight!

Congratulations Farhan!

More info:

https://www.isro.gov.in/launcher/pslv-c45-emisat-mission

https://makeinhyderabad.com/private-satellite-with-hyderabad-origin-aisat-starts-off-well/

Malicious Code in the Si5351 — Pete quitting podcast

Those of you who have been reading Pete N6QW’s blog (and all of you should be reading it!) will have seen a recent post about his efforts to modernize (digitize) the VFO in an old tube-type Ten Tec Triton IV model 544. Pete complained that –oddly — in spite of replacing the old analog tube-type VFO, the rig with a modern, rock-stable Si5351 VFO, the old rig CONTINUED TO DRIFT. That had Pete and a number of us scratching our heads. How could that be?

Pete then completely removed the Si5351 VFO from the old boatanchor. Sitting on his bench, all by itself, THE DAMN THING EXHIBITED ALL THE CHARACTERISTICS OF ANALOG VFO THERMAL DRIFT. Wow! Why? Pete was really pulling his hair out on this one.

We immediately began to see if others were getting the same results. Nope. None of our Si5351 VFOs were doing this. This was REALLY strange.

At this point we had to turn to a real Arduino expert, a guy who I had met during my time in Italy: Luigi Bugiardo from the Arduino research center in Bocalupo, Calabria. Pete gave him remote access to his computer and he began to poke around.

It didn’t take long. Luigi quickly found the problem: He found several lines of malicious code “embedded in the Si5351.h and si5351.cpp files –sort of lurking out there and not easy to spot.”

Pete then removed this code and — BINGO — no more drift.

Now I know some of you guys are thinking that this was just a bit of harmless fun. But Pete is really angry about this. He feels like he has been played for a sucker by some ham who was pretending to collaborate with him. Pete sees this as yet another violation of the unwritten ham code of conduct. To him this is another intrusion of computer/hacker noob hazing into the ham radio world. And worst yet, he thinks this malicious code came to him because of this involvement in the podcast and his blog — that participation resulted in the widespread exposure that got him into this mess.

Pete is so upset that he has vowed to drop out of the podcast and shut down his blog.

So come on fellows. It is time to ‘fess up. If you did this, or if you think you know who did this, please send an e-mail to me at soldersmoke@yahoo.com I think being able to pinpoint the prankster will help Pete deal with this whole thing, and hopefully get him back into the SolderSmoke…