Hiccups in SolderSmoke 139

First there was the whistling of my SSS sounds (a speech defect that I had been blissfully unaware of due to a nullifying case of tinnitus!) Then, in SolderSmoke 139 the long-suffering SolderSmoke listeners had to put up with hiccups. Yea, around 53 minutes into the show there began an annoying series of hiccups. Being an essentially analog kind of guy, I'm sort of pleased to point out that these are DIGITAL hiccups, apparently introduced by the Audacity software during the actual recording (not when I converted the show to mp3). I've been having more than my normal share of road-kill computer problems lately. The laptop I'm using to record the show ate a couple of the recent episodes before I had a chance to upload them (I had to do them over -- that's very frustrating). So this time I was recording the show on a thumb drive. Apparently it was filling up as we got close to the end, which led to the hiccups. The worst part was that a hiccup came just as I was delivering a key quote from The Woz. (I'll post it.)

If anyone has any gear laying around that might with these problems, please send it my way. Obviously I could use a bigger thumb drive. An external sound card might be nice. I could probably use another laptop also...

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30% off on SolderSmoke, The Book. December 7

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http://soldersmoke.com/book.htm

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Messaging ET (METI), and Silicon-based Life Forms

My fellow beacon fans will like this one. The ultimate (REALLY ultimate) beacon! http://www.newscientist.com/article/dn21236-lets-build-a-beacon-to-tell-aliens-who-we-were.html?page=1

And then there is this article about silicon-based life forms. (At first I thought they were talking about us!) http://www.universetoday.com/91449/why-silicon-based-aliens-would-rather-eat-our-cities-than-us-thoughts-on-non-carbon-astrobiology/

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SolderSmoke Podcast #139

December 3, 2011

http://soldersmoke.com/soldersmoke139.mp3

Halloween, Thanksgiving, and Billy's Birthday (on the range!)

Astro-Knack: CCD camera in the telescope. Solar astronomy.

Winter approaches: Shack heating by Heath, Halli, Hammarlund and Drake.

2B troubles on 17 meters.

Rig Re-Cycling: Rebuilding 17 meter rigs from the last solar cycle.

Azores DSB re-build: Oscillator troubles then adding a JBOT.

Manhattan style construction and the need for urban renewal.

Book Review: Steve Jobs. (Woz has the Knack!)

MAILBAG

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Electronics"http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20

An Inspirational Homebrew Motor from Spain

Bruce, KK0S, alerted me to this inspirational masterpiece from Spain. It is, as he points out, one of a number of really great videos about top level homebrew craftsmanship from Europe (remember the French homebrew tubes?).

Other comments from Bruce:
Did you notice that the calipers and micrometer this guy was using were seriously old-school. Totally manual readout. Not even a dial on that set of calipers! On top of that, his little lathe was manually fed. Notice in one of the shots, he is shown turning the cross slide feed wheel. No CNC anywhere. I can't be positive, but I don't think the lathe had a digital position readout either. This man is a machinist in the truest sense of the word. The Knack not only lives - it thrives!

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Secret Listeners -- The Voluntary Interceptors

Jim, AL7RV, and several others sent me the link to this really interesting video about the British radio amateurs in WWII. Real "stiff upper lip" spirit in this video. Musn't grumble! Great stuff from Great Britain: http://www.eafa.org.uk/catalogue/5108

That regen receiver they showed looks a lot like the beast that I brought back from the UK with me. Once again, I am hearing the siren song of the diabolical regens....

Progress continues on my Indian-ized Azorean DSB transceiver (with JBOT amp). I now have the amp nicely stabilized (thank God!). Now I just need to get the output from the balanced mod close to the 1 mW PEP level needed by the amp. Should be done soon. And my cold seems to be going away, so maybe I'll be able to share my tales of JBOT derring-do in a podcast this weekend.

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics"http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20

30% off on SolderSmoke, The Book. Cyber-Monday Sale. November 28

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics"
http://soldersmoke.com/book.htm
Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke
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A Re-balanced Modulator for my Re-cycled Rig

My effort to bring my Azorean 17 meter DSB rig back to life continues. This is proving to be harder than I thought. I'm still taming my version the JBOT amp. It still seems to break into oscillation -- I think the oscillation freq is around 1 MHz. But I am making progress.

I had to go back and work on the balance modulator circuit. I really like the simple two diode singly balanced mixer circuit. But my original Azorean board had, like the oscillator board, been through a few too many rounds of modification and repair. I decided to start over. See above. I even came up with my own little innovation on this circuit. Doug DeMaw's original design called for a 100 ohm pot at the junction of the two diodes, with the signal coming off the tap. You adjust the pot to balance the circuit and null out the carrier. But I didn't have a 100 ohm pot. Lots of 1K controls were available, so I put in two 50 ohm resistors in place of the pot, then put the 1k pot between the diodes, with the tap to ground. This balances things out nicely. See below.

I hope to get a podcast out next week, but I've been suffering from a nasty headcold that would have introduced all kinds of weird audio effects.

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The Bar of King Arduino

I'm not sure what I would do with an Arduino, but articles like this definitely make me want one! Here's one passage:

To make the board, the group had a specific, student-friendly price as their goal: $30. "It had to be the equivalent of going out to dinner at a pizza place," Banzi says. They also wanted to make it quirky, something that would stand out and be cool-looking to erudite geeks. If other boards were often green, they’d make theirs blue; while some manufacturers economized on input and output pins, they’d add plenty to their board. As a final touch, they added a little map of Italy on the back of the board. "A lot of the design choices are weird for a real engineer," Banzi says with a knowing laugh, "but I’m not a real engineer, so I did it in a silly way!"

Here's the article. Note the origin of the name of the device.

http://spectrum.ieee.org/geek-life/hands-on/the-making-of-arduino/0

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Steve Smith (on the left) and Bill (with the filter)

Steve "Snort Rosin" Smith has been keeping me on the side of the angels (and the FCC regs) in the area of harmonic filtering. Today he sent me this Steve and Bill cartoon. Thanks Steve. Just what I needed as I prepare for my next attempt to get my JBOT (with filter!) to behave. Wish me luck!

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Amplifier Woes -- Help me! Help me!

When I look in the mirror and I see a haunted, obsessed look in my eyes. My wife senses that there is something wrong in the ham shack. She is right. I have an amplifier that wants to be an oscillator. Help me exorcise these gremlins! Guys, this problem is holding up the production of the next SolderSmoke podcast.

My JBOT amp works fine into a dummy load, but when I connect it to an antenna, it gets unstable. Here are some more details of the symptoms:

I am running the JBOT with a 5 element (two toroids, 3 caps) low pass filter (designed by Doug DeMaw and approved by Steve Smith).

With the antenna connected, all is well UNTIL I raise the power out (by varying the input) beyond about 1 watt. Below one watt, the amp is working fine, and it stable. As soon as I hit the 1 watt point, the amplifier seems to break into oscillation. This does not happen into the dummy load.

The antenna is a simple dipole fed by coax. It shows a low SWR. Even when I put an antenna tuner between the amp and the antenna and bring the SWR down to negligible levels, the instability problem persists.

With the amp disconnected from all other circuitry other than the antenna and the power supply, if I just touch the input capacitor, it breaks into oscillation. This does not happen when the amp is working into the dummy load.

I've bolstered the power supply filtering and decoupling. No luck. I tried some de-Qing of the transformers. No luck.

Any suggestions?

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Backyard Solar Astronomy

Over the weekend I took a break from JBOT amplifiers and did something I've been meaning to do for a long time: solar astronomy. I pulled out my old 4.5 inch Tasco reflector telescope and aimed it at old sol. I know, I know, this can be dangerous, but we were careful -- note that Billy is standing on the other side of the business end of the telescope. In his hands is the paper onto which we projected the solar image. I'd always wondered how I would get the sun into the telescope's field of view without risking my eyesight by using the finder scope. This turned out to be no trouble at all: I just looked at the shadow cast by the tube of the telescope and --using the shadow as my guide -- moved the tube until it was lined up with the sun. We snapped a picture of our results. I think our crude effort compared very favorably with the picture from NASA's Solar Dynamics Observatory. You can see the same sunspots in each image (ours is reversed because we were using a reflector). These images are from 12 November 2011.

Our picture

NASA's picture

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