Rouges Gallery: Three Possible SolderSmoke mics

One of my New Year's resolutions was to finally, seriously pay some attention to the audio quality of the SolderSmoke podcast. With its roots in the scratchy Echolink connections between Juneau and London, audio quality has long been neglected on our show. With some funds donated by kind listeners (thanks guys!) I was this weekend shopping the internet for a suitable SolderMic. I ran into a lot of audio-fool snake oil. Wait a second, I thought, let's do some checks on the many mics I have around me here in the shack. I made comparison tests using three different mics (pictured above): my venerable D-104 chrome lollipop (with a transistor amplifier in the base), the dilapidated computer mic with improvised pop shield that I've been using for the last several years, and a Turner +2 mic that I gutted a while back (the original element was replaced by a cheap Radio Shack electret element, and the on-board amplifier was disconnected). (NOTE: It is a MYTH -- an ugly myth -- that the D-104 is CB gear. We debunked this hideous lie a while back. The D-104 is definitely ham gear! The Turner +2? Well, I don't know about that one. It does look a bit good-buddyish.)

At first, I thought the re-done Turner would win out. Then I thought the computer mic would keep its job. But then -- surprisingly -- the D-104 started to sound REAL good. The D-104 was especially good at keeping AC hum out of the signal -- that was a problem with the other two.

I found that I could get a very nice-sounding audio by running the D-104 audio through some EQ to knock down the little bit of hum that it did pick up, and to put about 30 db of attenuation on my now infamous SSSS whistles. I also used Audacity's noise remover.

So, the next SolderSmoke may come to you via an Astatic D-104. Kind of appropriate, don't you think? What do you guys think? Maybe I should post an audio sample to get some expert opinion before I chrome lollipop #130...

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What should I do with this thing?

Pretty cool, don't you think? I found this among the stuff that arrived from storage. I must have bought it at a hamfest sometime in the distant past. Note the miniature TUBES. Note the place of manufacture: BEAVERTON, OREGON. The internal construction is beautiful, with good shielding between each stage. It has a nice AC power supply. I have no real need for a 2 meter converter... So, what should I do with this? It seems to have the potential to become a QRP transmitter. Or maybe a DC receiver? Or maybe I should just turn it over to AA1TJ for conversion into something really surprising and marvelous.

Einstein and Lead-Acid Batteries

In "SolderSmoke -- Global Adventures in Wireless Electronics" we discuss the way in which Einstein's Special Relativity explains how and why transformers and coils work. I thought it was very cool to be able to see the role of Einstein's theory in our little toroidal transformers. Yesterday The New Scientist (perhaps the best science weekly in the world) brought news that we need to consider relativistic effects if we want to understand how and why our car batteries (and, I suppose, our gel-cells) work:

Thank relativity every time your car starts. Lead-acid batteries get about 80 per cent of their voltage from special relativistic effects.

Check it out (the NS story is short and gets right to the point): http://www.newscientist.com/article/dn19978-car-batteries-run-on-relativity.html?DCMP=OTC-rss&nsref=online-news

Some Tech Humor

Ron Barrett

Apparently Pluto's demotion from planet status might have been a bit unfair. Researchers say that the rival to Pluto that was discovered six years ago is actually smaller than Pluto.

And I thought this BBC skit on computer problems would yield a few chuckles from the SolderSmoke community. (For U.S. readers: Orange is a big ISP/mobile phone provider in the UK and elsewhere.):
http://www.youtube.com/watch?v=kAG39jKi0lI

Grote Reber, Radio Astronomy, and Tasmania

Wow, the website of the National Radio Astronomy Observatory is a real treasure trove, with lots of ham radio info. Check out their page about ham radio's contribution to the exploration of the universe: http://www.nrao.edu/whatisra/hist_ham.shtml

The picture above shows antenna that Grote Reber built in his backyard in Wheaton, Illinois in 1937. It is now on display at the National Radio Astronomy Observatory at Green Bank, West Virginia. That's quite an antenna! Imagine the neighbors' reaction.

NRAO has a page devoted to Grote Reber:
http://www.nrao.edu/whatisra/hist_reber.shtml
I had wondered what had drawn him to Tasmania later in life. Here's the answer:

In the 1950s, Reber sought a field that seemed neglected by most other researchers and turned his attention to cosmic radio waves at very low frequencies (1-2 MHz, or wavelength 150-300 meters). Waves of these frequencies cannot penetrate the Earth's ionosphere except in certain parts of the Earth at times of low solar activity. One such place is Tasmania, where Reber lived for many years. He died in Tasmania on December 20, 2002.

ECHOLINK and WINE: Works very well

I've been away from Echolink ever since my eeemachines PC went toes up and wiped out the Windows XP operating system. Echolink had always been a bit difficult to get running, even under Windows, so when I returned the eeemachne to life with Ubuntu, I never really even considered trying to get Echolink running on it. There is no Linux version of Echolink. But then, yesterday, somehow I got inspired. Something told me I should give Echolink a try using the Linux WINE Windows emulator. After all, I'd found that LTSpice worked great under WINE. I went to the Echolink download site, and hit the button. Ubuntu Karmic Koala (the version I am using) automatically fired up WINE and put the new windows program in the appropriate place. Echolink started right up. That night I was able to check into the Sunday evening QRP group for the first time in years. It was great. Now I'm on Echolink in the morning, talking to hams in Western Australia. The cheers for Jonathan Taylor, creator of Echolink! And three cheers for Ubuntu (especially Karmic Koala)!