Podcast QRM Culprit Found: WBIG-FM 100.3 MHz

Listeners noticed that recent SolderSmoke podcasts had some other audio playing faintly in the background. At first I though this must have been AM broadcast band breakthrough, so I built a little crystal radio, only to discover that the powerful AM stations here were not playing the ZZ-Top style classic rock that I was hearing in background noise. Bert, WF7I, suggested that I listen carefully to the QRM for a call sign. I tried that this morning. I couldn't get a clear call sign, but I picked up the unmistakable rhythm of Peter Frampton's "Do You Feel Like We Do?" Fortunately that song is 1) infrequently played and 2) quite long; I had enough time to take a spin around the FM radio dial. Sure enough, I caught the tail end of the Frampton song on WBIG-FM 100.3 A quick check of the web shows that this is a 50,000 watt station that has its transmitter within about 1 kilometer of my house. Bingo.
The mic cord is just about 1/2 wavelength. That would put the high voltage nodes at the ends, right? I notice that the interference drops noticeably if I wind up the cord, and increases a lot if I stretch out the cord.
I can hear some other stations in there also (one country station). It may be that there are multiple FM stations broadcasting from that antenna site. I can see the tower's red lights blinking from my front lawn.
Thank you Peter Frampton!

Regen Madness

How many times have I said "never again, no more regens"? I guess I need a twelve step program or something like that. This latest bout of regen fever started with the King's Speech movie. So I blame the Brits. All of them. Then this Belgian guy with the video comes along (see above). Now I find myself drawing out a schematic for the old regen that I picked up years ago at the Kemption Park rally in London. Someone please, STOP ME!

Job Opportunity: MAKE needs THE KNACK

Sounds like the folks at MAKE are looking for someone with THE KNACK. Check it out:
http://blog.makezine.com/archive/2011/03/awesome-opportunity-to-work-with-make.html

HomeBREW (literally!) Your Own Microphone!

During those dark days in which I was using my Astatic D-104 mic for podcast purposes (not a popular move) I checked on the mic element inside my chrome lollipop and found it to be the original crystal "Rochelle salt" element. I remember wondering about the Rochelle salt: What the heck was that? Well, this morning, the hippie technologists over at the Make blog explained it all to me via the above embedded video. It turns out that you can MAKE piezoelectric Rochelle salt crystals in your kitchen using -- get this -- soda ash, coffee filters, and -- wait for it: CREAM OF TARTAR sauce! I'm not making this up.

The Hobbit Hole

In the interest of preserving what I suspect will become an important piece of amateur radio history, I'm posting some pictures of the underground radio shack and workshop of Michael, AA1TJ.

Michael describes the facility this way: The shack is under two feet of snow at the moment, but from the surface it looks for the most part like any New England spring-box cover that you come across while walking in the woods. Only, when you lift this cover you discover Dr. Evil's secret underground radio laboratory, a re-creation of Hogan's Heros radio station, or what I affectionately refer to as the "Hobbit Hole."

The two of us burrowed down 13 feet, breaking up boulders the size of a VW Bug as we went. Aside from the pick and shovel work, I used both one and two-handed sledges along with an assortment of rock chisels and pry bars. Everything came up in 5 gallons buckets.

The lower-level slab used hand mixed concrete. The walls are 12" thick insulated masonry blocks; a Canadian-made product called, Sparfill, that's unfortunately no longer available here. We called in Ready-Mix for the concrete roof. The interior dimensions are a luxurious 2m square.

As luck would have it, I had just taken some photos of the interior for my pal, DL3PB. Please find them attached. Actually, in one bench corner you'll see the 2,400RPM AC induction motor and 400 pole stepper motor that I plan to use in the "Full Monty" version of the present project.

Mike has a wonderful posting on his blog today: http://aa1tj.blogspot.com

Shuttle and Space Station (and Sunspot)

Check it out! The ISS and the Shuttle Discovery captured by an amateur astro-photographer as they passed in front of the sun, with major sunspots nearby! Catalin Fus of Krakow, Poland, had his solar-filtered telescope trained on sunspot 1166 on March 7 and recorded this amazing conjunction. Thanks Catlin and thanks to spaceweather.com.

I had the whole family out in the front yard after dinner last night. ISS and the Shuttle made spectacular pass over the Washington DC area. We saw both rise up from the Northwest and then blink out after passing overhead. The shuttle (I think) was about one minute behind ISS.

40 years of Spice

Bob, W8SX, sent me an interesting article from EDN on the recent commemoration of the 40th anniversary of our beloved SPICE program. Check it out:
http://www.edn.com/blog/IC_Design_Corner/40584-SPICE_a_40_year_old_open_source_success_story.php