Listen to Latest SolderSmoke Podcast

Thursday, March 31, 2011

SolderSmoke Podcast #132


http://soldersmoke.com/soldersmoke132.mp3

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?)
73 Magazine
QSO with Mike Bryce WB8VGE
Knack Job Opportunities at Make and Hack-a-Day
Chemical Tailoring of Crystal Mic Audio Response
Pi Day!
Sling Shots, Fishing Poles, and Antenna Launchings
MAILBAG!

A Language Guide for the International Brotherhood of Electronic Wizards

Hello Bill,

I heard mention of your book, Soldersmoke - Global Adventure in Radio Electronics, on the G-QRP reflector and bought it on a whim. Since it arrived I have not been able to put it down. What a great read! Very enjoyable and an inspiration. I say that because my homebrewing had taken a bit of a back seat while other hobbies - flying RC gliders, ballroom dancing etc - came to the fore. But after reading just a few chapters of your book, the old soldersmith in me was stirred and I had to go and make something.


Like most Hams I am the 'caretaker' of a huge stock of components - well let's face it we are really just looking after part of the world's supply of components for the other guy who might need them! - I decided on a simple phase shift oscillator for 600 Hz and soon found a circuit from my old collection of circuit drawings. I had all the parts and quickly soldered it together. Sadly my elderly 'scope confirmed that it was not working and after a bit of head scratching I decided to make it up on a construction board. In the process I realised that my design had included components of the wrong values and if it had oscillated at all, it would have been in the MHz region! The final product worked a treat and I cobbled together some photos (in the attached PDF) to send to my radio pal - Roger DL3RMU - in Berg Bacchaussen in Bavaria. From your podcasts, I suspect you are a bit of a language wizard as well, but just in case - "Jede Schaltung braucht eine Lichtdiode !!" means, 'Every circuit needs an LED!' and "Erfog!" means 'success!' The result was a lovely 600Hz sine wave at nearly 5V p-p. Not exactly wizardry but very satisfying. Now wouldn't it be great if I could get it to oscillate at RF frequencies!?


Roger DL3RMU and I have shared an hour long, weekly, CW QSO since early 2005. Just to make it that bit more interesting we do it in German! Helpfully CW overcomes my pronunciation problems. This all started with my realisation that my urban location and limited antenna space restricted my effective operating range for a number of reasons. I am not a great linguist but I have always been interested in languages and I figured that while I might not have much reach, I could have a lot of fun trying out CW QSOs both QRO and later QRP in the language of the other guy rather than 'rubber stamp English'. To my surprise my rusty schoolboy French and slightly better German were well received. I met Roger a few times on the air and we decided to keep a weekly sched. I decided to give European languages a real go, so I cobbled together a handful of common phrases from dictionaries and online language resources to get by, before embarking on a more ambitious project: a set of translations for every European language.


Originally I wrote to the radio societies of every European country to seek help but this was not an effective approach. So I then contacted every non-English member of WACRAL (to which I belong) and asked them if they would kindly translate roughly 50 common QSO related phrases into their mother tongue. To my delight and surprise the response was great and a number of guys helped put together the translation files. There are now 15 European languages on my fledgling website. I call the website, 'Parlez Vous QSO' and it can be found at: http://web.onetel.com/~stephenseabrook/. I really ought to find out how to get a proper domain name sorted out (any advice welcome!) but it is easiest to find by typing 'Parlez Vous QSO' into your search engine. The site itself somehow caught the attention of a number of enquirers, some of whom simply emailed me the translations in their own language! This is the sort of 'fraternity of amateur radio enthusiasts' that makes our hobby great! There are quite a few 'missing' languages but the pleasure of being able to communicate - even falteringly - in the other guy's language is great and I am delighted with the response I have had from the guys on the other end of the QSO.


My construction was mainly limited to station accessories: PSK interface, RTTY interface, CAT interface and various test equipment before I got into QRP. I built a FoxIII, MFJ Cub for 20m and a couple of Christmas' ago a K1. What a great radio! I never cease to be amazed that if the station Icom 706 or the Kenwood 570D fails to yield a QSO with lots of Watts, a changeover to the K1 often finds a QSO within minutes! How can that be!?


Keep up the good work on Soldersmoke. I thoroughly enjoy the podcasts and look forward to the sequel to the book!


kind regards


Steve Seabrook M0ECS

Sittingbourne

England

Wednesday, March 30, 2011

Save 20% On SolderSmoke and Other Books

Through tomorrow -- save 20% Coupon Code: SPLISH
http://soldersmoke.com/book.htm

CFL Light Bulb Schematics

Lots of good parts in those new fancy bulbs! This site provides schematics for the major brands. Very useful. Try not to eat the mercury in the tubes.
http://www.pavouk.org/hw/lamp/en_index.html#bigluz20w

Tuesday, March 29, 2011

Drect Conversion Receivers in New South Wales



Dear Bill,

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:

http://www.youtube.com/watch?v=rF1WoPDajsU

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.

best 73's

Peter, VK2TPM

Sunday, March 27, 2011

My Other Car was Homebrewed with Junkbox Parts!

At the SolderSmoke Store we have a bumper sticker to that effect.

Here's a guy who actually did it!
http://jalopnik.com/#!5785679/homeless-man-builds-his-own-car-out-of-junk

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

SolderJob! Professional Knack and Hack Opportunity!

Oh man, this one is tempting. Almost makes me want to give up up the diplomat gig and move out to San Mateo... Check this out guys. This looks like a great opportunity for one of us. From the always awesome Hack A Day site:

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?


http://hackaday.com/2011/03/24/hackaday-is-looking-for-a-full-time-project-builder-video-host/

Thursday, March 24, 2011

Back to the Future: Packets from the Space Station

Readers will have noticed that I have an affinity for beacons. All kinds of beacons: WSPR, QRSS, 10 meter CW... (Tony Fishpool says I have broadcaster tendencies.)

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

SolderSmoke baby-wear!

A podcast listener sent in this picture of his beautiful baby daughter with a piece of clothing from the SolderSmoke Store that seems to be a bit QRO!

Monday, March 21, 2011

80 milliwatts to New Zealand (and Italy)

I realize that having your QRSS signal show up on a distant grabber is no big deal, but this was the first time I've seen the signal from my little DaVinci Code rig make the trip to ZL. You can see my shark fins in the screen shot above. It was just before dawn here, so gray line must have been helping. A Solar Flux Index of 92 also helped. My shark also made it across the Atlantic (and half the Med!) Mauro IK1WVQ's grabber made this nice capture (looks like this was around dawn at his location):

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

From the good folks at Sierra Radio (our sponsor):

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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-circuit programmers and a set of easy to follow instructions and design examples that are useful for the ham radio operator.

For more info:

http://www.hamstack.com/hamstack.html

Friday, March 18, 2011

Another Mighty Mite Success Story!

Bill:

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.

73,

Neil

--
Neil Caudill
KB1UAL

Free Shipping on SolderSmoke -- The Book

Use Coupon Code Ground 305 and get free shipping on "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm

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

WSPR Direct Conversion Receiver: On the Air and Online

In a testament to the sensitivity of the WSPR system (and I mean that in the technical, not the emotional sense) I got a couple of reports indicating that my very QRPp WSPR signal was, well, a bit obnoxious. I think part of this results from the fact that I'm one of the few people using a double sideband transmitter -- the lack of filters makes my signal look a bit different. But I do have an AC hum problem that shows up on receive screens. And because I haven't worked out the circuitry to allow the WSPR software to move my little transceiver from transmit to receive, I'd been leaving it in 100% transmit mode. I can understand why people didn't really like that.

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
http://wsprnet.org/drupal/wsprnet/map
just type N2CQR in the box that asks for the call.


Wednesday, March 16, 2011

20 years after construction... Mighty Mite Makes Contact!

Bert, WF7I, sent us this report from the nuclear reactor building at UVA. You can almost feel the excitment! Congrats Bert!

Bill:

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.

72/73!

Bert WF7I

Tuesday, March 15, 2011

The Return of the Michigan Mighty Mite

Michigan Mighty Mite -- N2CQR/HI8 version

Bert, WF7I, (our correspondent at UVA Charlottesville), wrote yesterday about his past and recent adventured with a little rig that got a lot of us started in the scratch-built homebrew game: The Michigan Mighty Mite. I built one in the Dominican Republic, probably in 1993. I never worked anyone with it, but was really pleased to get the thing oscillating. I still have remnants of it (sans crystal) -- see above. Bert's e-mail and AA1TJ's recent derring-do make me want to dust off that little single FET transceiver for 3.579 MHz that I built in Italy. One QSO would make me happy. At least this minimalist stuff is keeping me away from the regens...

Here's a good article on how to build one:
http://www.qsl.net/wb5ude/kc6wdk/transmitter.html

Here's a site from Dave, WA5DJJ, who built a bunch of these rigs:
http://www.zianet.com/dhassall/Michmitymite.html

Bert's e-mail:

Hey Bill.

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
Kenwood TS-2000, 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.

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.


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.


72/73,

Bert WF7I

Monday, March 14, 2011

Happy Pi Day! (3.14 Get it?)

http://www.collegehumor.com/video:1948828

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

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

Saturday, March 12, 2011

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.

Thursday, March 10, 2011

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

Wednesday, March 9, 2011

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

Tuesday, March 8, 2011

Watch the Shuttle fly with the Space Station


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.

AA1TJ's Dream: No Tubes, No Transistors... ALTERNATORS!

Treat yourself today to an experience in radio enthusiasm and innovation: Go to AA1TJ's blog and read about his latest creation: The Schmidtschem. Michael begins his post this way:

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

Crystal Radio Sleuthing

As part of my effort to stamp out broadcast interference to the SolderSmoke podcast, this weekend I reassembled the crystal radio that Billy and I had built in London. It is REAL simple: Just a parallel LC circuit with a germanium diode detector and some high impedance phones. (I also put a chunk of galena and a cat's whisker on the board -- that's for when I get the urge to form my own PN junctions.) As expected, I immediately heard two AM broadcast stations: WFAX 5 kw 1220 kHz (religious) and WUST 20 kw 1120 kHz AM (mostly foreign language). I found out the hard way that these stations reduce power at night: I was bragging to my wife about the EXCELLENT reception I'd been getting on the crystal set, but when, after dinner, I brought her into the shack for a demonstration, she could barely hear anything. Oh well...

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

The Knack in Mexico, Engineer and Inventor

Our correspondent in Guadalajara, Roberto XE1GXG, had earlier posted a comment on Guillermo Gonzalez Camarena, an inventor who worked on color TV. This morning I had the chance to check out the Wikipedia article on OM Guillermo. I was struck by the telltale signs of The Knack. This is further proof that the phenomenon is truly global. Excerpts from the Wikipedia article:

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...
On August 31, 1946, González Camarena sent his first color transmission from his lab in the offices of The Mexican League of Radio Experiments, at Lucerna St. #1, in Mexico City. The video signal was transmitted at a frequency of 115 MHz. and the audio in the 40 meter band.

He died in a car accident in Puebla on April 18, 1965, returning from inspecting a television transmitter in Las Lajas, Veracruz.

A field-sequential color television system similar to his Tricolor system was used in NASA's Voyager mission in 1979, to take pictures and video of Jupiter.[1]

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

The King's Speech Regen

In SolderSmoke 131 I talked about this old homebrew receiver. I picked it up at a radio rally in London and almost sold it at a hamfest in Virginia. A fit of UK nostalgia provoked by a screening of "The King's Speech" caused me to hold onto it. Now it is luring me into two areas that I don't really want to get into: high voltage and regeneration. But here we go... I turn now to our British cousins: What can you tell us about this receiver? 1920s? 30's? What tubes should I be looking for? How would they have powered this receiver? Does anyone have a schematic that might describe this device? (Or something close?)


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Thursday, March 3, 2011

SolderSmoke Podcast #131

SolderSmoke Podcast #131
http://www.soldersmoke.com/soldersmoke131.mp3
28 February 2011

--Winterfest!

--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
--MAILBAG

Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column