Thursday, March 31, 2011
April 1, 2011
Fickle Finger of Fate: Lamp falls on QRSS Crystal
Another heroic computer repair
Sleuthing for RFI with Crystal Radios and Peter Frampton
The seductive allure of the British Regen
Watching the Space Station and the Space Shuttle
Packets from SPAAAACE
Don Vorgaard and the birth of SSB (and DSB!)
Electric Radio Magazine
SPRAT and the ZL2BMI DSB Rig
Jerri Elsworth's 555 contest (Did I win?)
QSO with Mike Bryce WB8VGE
Knack Job Opportunities at Make and Hack-a-Day
Chemical Tailoring of Crystal Mic Audio Response
Sling Shots, Fishing Poles, and Antenna Launchings
Wednesday, March 30, 2011
Tuesday, March 29, 2011
You might vaguely remember I sent you some audio for Soldersmoke a year or two back that was recorded at the New South Wales home brew group here in Australia.
The home brew group is wonderful: it's not a club. you can't join. no-one is in charge. Every so often we have a "challenge" (which is not a competition - no-one wins).
Anyhow, recently the "challenge" was to home brew a direct conversion receiver that could be used to listen to the sunday morning broadcast here on 80m 3959KHz.
On Sunday we got together to present what we'd come up with. Alan, VK2ZAY, does great work but couldn't come so he sent in a video of his creation.
I videoed the proceedings, badly edited it, and stuck it up here:
This challenge was good because it was achievable by dunces like me and because the objective was the same for everyone - listening to a certain broadcast. I hope the video might encourage new home brewers.
Keep up the great work, I watch your blog and always enjoy a new podcast.
Sunday, March 27, 2011
Here's a guy who actually did it!
BTW: There is FREE SHIPPING from the SolderSmoke store through today: Be sure to order $30 or more through Sunday and use code: 2DAYFREE
Friday, March 25, 2011
Hackaday.com is looking for an experienced hacker/writer to join our team doing original hacking and modding projects on video. Are you energetic, outgoing, and passionate about hacking/modding? Can you solder AND explain what you’re doing and why? Come join our team and modify/hack/create things daily with a professional film crew to be aired on HackADay, then post a writeup detailing how you did your hack. Let your mind run wild, combine Mythbusters with Ben Heck, can you do it?
Thursday, March 24, 2011
My favorite was a VHF Digital Satellite beacon. Out in the Azores, I had my old Kantronics KPC-3 Terminal Node Controller hooked up to a 286 computer and a Realistic HTX-202 HandiTalkie. Antenna was a ground-plane made from a coat-hanger. My rig would burp out packets all day long, and occasionally either PC SAT or the International Space Station would fly over and relay my signal to stations on the European continent or, sometimes, on the east coast of North America. I had APRS data in my packet, including a nice little island with a palm tree icon which would show up on the on-line APRS maps.
Well, after watching the Space Station (and the Shuttle discovery) fly over a few weeks ago, I got the urge to get back into the outer space packet game. Last weekend I dug out the old HT and KPC-3. I even found the cables. For the computer I put to work the OLD Toshiba Satellite Pro (appropriate, eh?) that Kevin, ZL3KE, had helped me revive.
Yesterday before going to work I noticed that there would be a nice pass of the Space Station at around 0750 local. I took a little mag mount antenna and left it on the ground in the backyard. I tuned the HT to 145.825 MHz and fired up the Windows 3.1 terminal program on the Toshiba.
When I returned 10 hours later... SUCCESS! Lots of space packets on the screen: KB1GVR, W1TMS, W1CGT, W1GSH, VE2TMW...
So far I'm only receiving, but soon I hope to be sending
PACKETS TO SPAAAAAACE!
Tuesday, March 22, 2011
Monday, March 21, 2011
I measured the voltage at the antenna terminal this morning. Less than 2 volts peak. Assuming a 50 ohm load, that's about 80 milliwatts. This is all especially gratifying because yesterday I was out in the backyard with a slingshot and a fishing reel, putting a bit more wire into the trees. It worked!
Here's the transmitter and the schematic. FSK is from a simple two transistor multi-vibrator (G0UPL's circuit -- you can see it in the lower left):
Sunday, March 20, 2011
Want to learn to design and program with microcontrollers?
Want to add “smarts” to your next ham radio project?Whether you are new to microcontrollers or an experienced designer / programmer, the HamStack is a great platform for your next project. Based on the Microchip PIC architecture, the HamStack can be programmed in C or Basic.
Many people ask us how to choose the best hardware and software tools for developing ham radio projects with microcontrollers.
Up to now, there really has not been a great answer to that question.
So, in traditional ham radio fashion, we put a system together. We call it a HamStack.
The HamStack platform combines popular PIC microcontrollers, a set of circuit boards, great C and Basic language compilers, in-
For more info:
Friday, March 18, 2011
I started listening to Solder Smoke this winter, and I'm now up to episode 81. Since I'm new to homebrewing, I wanted to say that I enjoy the discussion of good projects to start on for homebrewing equipment, particularly the discussion of the Michigan Mighty Mite, which I understand was your first HB TX project. After hearing you mention the transmitter on the show, I looked it up on the Internet and found the schematic. A few hours later and I was on the air. My first contact with it was with KB1TSG, Jim in Randolph VT, receiving a signal report of 449. From my QTH in Monroe, ME that's a distance of 186.5 mi ( 300 km) as the crow flies.
I've learned a lot listening to Solder Smoke over the past two months and listen to it while in the car, at work, and while walking my dog on the back roads of Maine. Thanks for such a great educational and entertaining show.
Don't just buy "SolderSmoke -- Global Adventures in Wireless Electronics"
but check out these other fine Knack-related publications:
http://stores.lulu.com/6sj7comics ("Lid, Kid, Space Cadet" "Sky Buddies" by Jeff K1NSS
http://stores.lulu.com/ian_g3roo (Ian, G3ROO's amazing antenna book)
http://www.lulu.com/copperwood ("Carl and Jerry" books -- scroll down a bit)
http://stores.lulu.com/soldersmoke (SolderSmoke and Bill's other book)
Thursday, March 17, 2011
So, on the theory that it is better to give (reports) than receive, and in keeping with the old idea that all ham radio stations should from time to time RELEASE the push to talk switch and LISTEN, I have magnanimously taken my homebrew DC/DSB WSPR system into receive mode. I'm in 0% transmit. I'm listening all the time, and automatically uploading reports on the stations I hear. Pictured above is the map from WSPR system page showing my spots from last night. Below you can see what my own WSPR system display shows. (I need to adjust my W3PM oscillator a bit. I may be a few hertz off and I am probably missing a bit of the 200 hertz wide WSPR band).
I was pleased to see W3PM's call on my map. An article by Gene provided the inspiration (and much of the circuitry) for my WSPR rig.
My receiver is very simple: The RF from the antenna goes through a low-pass filter directly to an SBL-1 mixer (thanks to Jim -- AL7RV). There it mixes with LO energy from the W3PM Colpitts oscillator. From there it goes to the KA7EXM discrete component AF amp.
You can watch -- almost live -- the stations I am receiving by going to
just type N2CQR in the box that asks for the call.
Wednesday, March 16, 2011
I'm ecstatic to report that my MMM made its first QSO, after almost 20 years, last night at the University of Virginia ham club at the nuclear reactor! I worked W4OEQ, Tom in McMinnville, TN. He gave me a 459 report. I was running about 300-500 mW (hard to tell with our meter) out of the MMM into our inverted vee up high in the trees of Observatory Hill at UVa. I also have three witnesses to the event: our club president, Mark KJ4IEA; club Treasurer Will, KI4LGE; and member Alex, KJ4YWP. I received a round of applause from our group after the QSO was complete!
It was a very satisfying moment to be sure. Not only to make a QSO with this rig from my past and all those memories, but to do it at the re-vitalized UVa ham club, which has its own long, off-and-on history dating back to the 1930s (at least), and to do it with a captive audience! Our club members, mostly younger guys 18-22 years old, have never done CW and always are in a mesmerized/stunned condition when they see me tapping out the dots and dashes, and copying it in my head! Everyone was very silent and focused during the QSO.
Tuesday, March 15, 2011
Here's a good article on how to build one:
Here's a site from Dave, WA5DJJ, who built a bunch of these rigs:
The AA1TJ postings on your blog motivated me to unearth my old Michigan Mighty Mite (the "MMM"). For me there's a lot of history, even emotion, there. I built this little rig with my friend AC7CA when we were both finishing up high school. Neither of us knew what was really going on in this circuit, other than some vague thoughts about resonance and that a transistor amplifies.
What was important to us at the time was more the fit-and-finish of the box that it was in, and making QSOs, rather than working out the theory behind the schematic. I'll email you a photo of the box as it stands now. We got a nice, blue plastic project box from Radio Shack, and figured out that those small iPod (used to be called "Walkman")-style headphone sockets made great crystal sockets as well (they really do). I remember vividly the two of us planning out the radio, I remember trying to work with plastic (not so easy, it tended to melt and scuff up), and attaching the air-variable capacitor (not a small feat with the limited tools available). But the end product looked like a much more impressive rig than it really was. This oversized blue box with a big tuning knob, bright colored red and black banana power terminals, the cool little crystal sticking out of the top, and the Dymo-label tape proclaiming, "Rig Master" (or "blaster", or something similar -- I have to actually go see what it said!). 1/2 W of power came out of this very simple oscillator, just as advertised. But to this day, I don't know if either of us ever even made a QSO with the thing! The thrill was in the assembly of a rig from a schematic in CQ magazine, the fellowship of the two of us working on it, and seeing the thing actually WORK as promised. Time moved on, and it ended up getting shoved to a back corner of my room, and when college and work came along, it almost got totally forgotten and collected dust.
Anyway, the blog postings made me think of low-powered QRP, and I dug it out again, dusted it off, and pulled out some crystals. The thing still works just as it did 20 years ago! I was very happy to see that. I guess one of the advantages to ultra-simple, low part count rigs is that not much CAN go wrong! And if it does, it only costs a few pennies, or nothing, to fix.
The rig went on the air on Saturday night, and it was quite an interesting contrast on the work bench. On one side, my
I called CQ till my hand/wrist was sore, and QSY'd between the 4 freqs I had to choose from, but to no avail. I am not deterred however. This evening, following the W4UVA club meeting, I will hook it up to our 40 m inverted vee high in the woods overlooking the nuclear reactor. It would be fitting if the possible first ever MMM QSO came from this setup. , a state-of-the-art (or nearly so) DSP rig, with the "glowing numerals" and a computer interface. Next to it, the MMM, straight key and a pile of rocks! A single "super antenna" compact vertical was erected on a tripod in my backyard, with a coax coming in to the shack to a switch (functioning as a "T/R" switch, in a way). In one position, my gazillion-transistor appliance rig would function as a ridiculously sensitive and over-the-top receiver for the task at hand. In the other position, my homemade single-transistor MMM would transmit out to the vertical.
Late Sunday night, after I had exhausted myself from "pounding brass", I was reading more from "Solder Smoke -- The Book", and found one picture that really made my day. Sitting in front of your Tandy and just to your left, was a small blurry object. Reading the caption, I saw that it was YOUR Michigan Mighty Mite! What a fitting way to end a wonderful weekend of hamming.
Monday, March 14, 2011
One of the many benefits of having a kid in elementary school is that you are made aware of important days that otherwise might escape your attention. Like today: International Pi Day. While the mathematical connections might be a bit flaky, I liked the above video.
Slashdot put it this way:
I'm not saying it's as good as Lady Gaga or Justin Bieber or something, but it's a great way to get ready for Pi day which is tragically still not a federal holiday. Write your congressman.
Sunday, March 13, 2011
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!
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!
Saturday, March 12, 2011
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.
Thursday, March 10, 2011
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
Wednesday, March 9, 2011
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.
Tuesday, March 8, 2011
The two spacecraft are un-docked but orbiting close together. There is a good visible pass over Canada and the U.S. this evening (see above -- all times EST). Go to http://spaceweather.com/flybys/ to get the times for your location. Hurry, I think the Shuttle comes home tomorrow.
I've dreamed and schemed, off and on, for the last twenty five years over the prospect of constructing a complete, high-frequency (HF) amateur radio station without the use of vacuum tubes or semiconductors... Having considered and subsequently rejected a number of esoteric possibilities, I eventually concluded that a system based on electromagnetic alternators was the most promising.
He has a prototype on the air, using it with a no-gain receiver, and he is making a lot of contacts. Check it out: http://aa1tj.blogspot.com/
Sunday, March 6, 2011
But here's a surprise: These are NOT the stations that are getting into the podcast! With the crystal radio in operation, I did some audacity recording and then quickly checked to see if the breakthrough sounded like what they were playing on WFAX and WUST. NO! The breakthrough was ZZ Top! I'm guessing that the breakthrough was from an FM broadcaster. I note that the length of the cord to the microphone would seems like it would be a nice antenna for the FM broadcast band... What do you guys think?
Whatever the source, I think I have taken care of the problem. I got big ferrite toroid core and wrapped about ten turns of the mic cable through it. No more broadcast breakthrough.
Saturday, March 5, 2011
Guillermo González Camarena (February 17, 1917 – April 18, 1965) (aged 48), was a Mexican engineer who was the inventor of a color-wheel type of color television, and who also introduced color television to Mexico.
Born in Guadalajara in 1917, his family moved to Mexico City when Guillermo was almost 2 years old. As a boy he made electrically propelled toys, and at the age of twelve built his first Amateur radio.In 1930 he graduated from the School of Mechanical and Electrical Engineers (ESIME) at the National Polytechnic Institute (IPN) with an engineering degree; he obtained his first radio license two years later.
He was also an avid stargazer; he built his own telescope and became a regular member of the Astronomical Society of Mexico.
González Camarena invented the "Chromoscopic adapter for television equipment", an early color television transmission system. A U.S. patent application (2,296,019) states:
|“||My invention relates to the transmission and reception of colored pictures or images by wire or wireless...||”|
He died in a car accident in Puebla on April 18, 1965, returning from inspecting a television transmitter in Las Lajas, Veracruz.
In 1995, a Mexican science research and technology group created La Fundación Guillermo González Camarena (The Guillermo González Camarena Foundation), which benefits creative and talented inventors in Mexico.
At the same time, the National Polytechnic Institute began construction on the Centro de Propiedad Intelectual "Guillermo Gonzalez Camarena" (Guillermo González Camarena Intellectual Property Center).
Friday, March 4, 2011
Thursday, March 3, 2011
28 February 2011
--UK nostalgia: "King's Speech" saves British Regen
--Dark Cloud, Silver Lining: ice storm gets us back on the air
--40 meter phone (AM and SSB)
--K2ZA interview: John Zaruba's DX-100
--OUR NEW SPONSOR: SIERRA RADIO SYSTEMS
--SolderSmoke audio woes: interference! Lollipop ditched.
--Buzz Aldrin's lunar seismograph
--Watching the space station fly over Virginia
--Twain, Tesla, Edison and Halley's Comet
--Capuccio on Drugs