Free Electronic Books Online!!!

Alan WA9IRS alerted me to this technical treasure trove. Pete Millett is an engineer who, in his spare time, scans and uploads books about electronics that are no longer under copyright. Great stuff! Thanks Alan! Thanks Pete!
http://www.pmillett.com/technical_books_online.htm

WebSDR Receiver Goes to Six Bands

Those intrepid digital hams at the University of Twente have temporarily put their WebSDR receiver on six bands (we should lobby to make the expanded freq coverage permanent). It is really great. I love the waterfall display. Audio quality here is excellent. (I'm listening to 75 meter SSB now.) Check it out:
http://websdr.ewi.utwente.nl:8901/

You should also check out PA3FWM's SDR page: http://websdr.ewi.utwente.nl:8901/
Very interesting. I thought picture above should be entitled "The Ultimate Dead Bug."

I have successfully completed troubleshooting my old (1983) frequency counter (found some bad CMOS gates), and I just finished assembling Doug N3ZI's very FB freq counter semi-kit (thanks Jerry!)... Now I'm listening to the Web SDR receiver... The SoftRock40 kit seems to be calling me.... I feel myself being pulled into the digital vortex! Quick, someone throw me an analog life saver!

Skn Flick Trailer

Steve, N0TU, has a really good one minute video that will (I think) be the lead-in for a longer flick on Straight Key Night. Inspirational stuff. Makes you want to warm up filaments and pound some brass. Thanks Steve!

The Beacon on the Echo Satellite

W8KHK gave a very nice Christmas present to the AMfone group. Check out the pictures (and descriptions) of the beacon transmitters that went into space on the ECHO satellite in 1960. Echo was the big inflated silver ball -- it was nicknamed "the satelloon." I was struck by how much the exterior of this rig looks like the solar-powered QRSS rig of Paolo, IZ1KXQ.

FROM W8KHK's POST: Here are a few more pictures of the ECHO beacon transmitter. These are identical to the actual flight hardware, used for testing and measurements. They now reside at the W2DU Florida QTH, and while the batteries have long since expired, if the solar cells are illuminated by a 100 watt bulb, or the actual sun, you can receive the transmitted beacon signal at 108 MHz. Low Tech by today's standards, but in those days it was hard to find transistors that would work above audio frequencies. Photo 21 shows a complete beacon system. To the bottom left is another transmitter, before potting. To the bottom right is another transmitter, potted and ready to be incorporated in the styrofoam "dish" assembly. Photo 22 is a close-up of the two transmitters from photo 21. Photo 23 shows an entire dish assembly, prior to potting in styrofoam. This space project, and many other early space projects from the Astro Electronics Products division of RCA will be chronicled in the soon-to-be-published Reflections III by W2DU.

MERRY CHRISTMAS FROM ROME!

SolderSmoke 97

http://www.soldersmoke.com

December 21, 2008
Tiber flooding, Italian @ (snail!)
--------------
DSB 80 "Kickpanel" project:
Rig reform
Harder than SSB?
Do we need to match diodes?
Terminating balanced modulators
An antenna for my "spot" ("net") circuit, LED
Thinking of speech processing
Driver hotter than final
---------------
MEPT QRSS:
VK2ZAY crosses Oz on 470 micro-watts
Using 9H1LO's grabber engine as time machine
My beacon box: 10 and 30 in same enclosure
Knights QSY to lower bands (temporarily)
---------------
Theory:
Thanks for beta independence help
Why does feedback lower distortion?
W3JDR's Ne602 modeling
Grinding resistors for precision
Broken counter leads to learning logic
--------------
Miscellaneous:
Wes updates site
Kanga USA is back
There is no SPRAT 13
AA1TJ's lightbulb rig
---------------
MAILBAG:
Lyndon smells the smoke
Roger KA7EXM goes to Aikhabara
Mark KI7N hits Singapore's radio row
Bob KD4EBM's feedback on feedback
Mike KC7IT fixes Christmas lights with 'scope
Frank VK2AKG on YouTube solenoid concert
Mike AA1TJ working on return loss bridges
John K7JM says SS blog makes DXCC
Jerry NR5A on Solder-SETI, b'day
Ron WB3AAL 1K QSOs from AT
Alan N8WQ: Tree battery!
Jeremy N1JER and QRP-L QRSS group build

MERRY CHRISTMAS AND HAPPY NEW YEAR TO ALL!  

Homebrew Antikythera Mechanism

AA1TJ's Lightbulb Transmitter!!!!

This is a really excellent example of ham ingenuity. Michael, AA1TJ, has built an 80 meter CW transmitter from the components in one of the compact florescent light bulbs.

http://mjrainey.googlepages.com/dasderelicht

Free Logic Simulator

My frequency counter is broken, and this is providing an incentive for me to learn about logic, JK Flip Flops and all that. Hack-A-Day alerted me to what looks like a very useful simulator program (free download).

http://sol.gfxile.net/atanua/index.html

MAKE Resistor Video

MAKE made even the humble resistor interesting. Thanks again Make!


MAKE presents: The Resistor from make magazine on Vimeo.

SolderSmoke 96

SolderSmoke 96
December 8, 2008

http://www.soldersmoke.com

Moj Music
Rome winter: Snowcapped mountains, Starlings
Billy’s Blog – Please visit!
“Make” redeems itself with LED video
80 DSB rig: LTSpice, Design, Diplexers, Decoupling
Properly terminating balanced modulators
The virtues of feedback
80 meter DSB QRP (in a contest)
Reading Recommendation: January 2009 “Air and Space”
Jupiter and Venus aligned
Saturn picture with (sorta) homebrew rig
Ben’s Balloon Beacon
Laurence KL1X in N. China – will set up QRSS grabber
MAILBAG
Roger K7RXV and Bob KD4EBM on SolderSmells
Jerry NR5A has WSPR-mania
Scott KD5NJR on “Soul of a New Machine”
Bob K7HBG “Real radios have knobs”
Akshay VA7AAX 15 year-old listener, homebrewer

Check out our neighborhood and flea market

Go to Google Earth, or even just to Google Maps (available without download from the Google home page) and search for this: Piazza di San Cosimato, 00153 Rome, Italy. Look for the "Street View" button and click on it. Now you can explore our Piazza.

GM8EUG sent me this great link for a 360 degree shot of the neighborhood flea market. Let the picture fully download, then click on it and you will be able to look around (and up and down!) Click on this:

http://geoimages.berkeley.edu/worldwidepanorama/wwp305/html/ToniGarbasso.html

Pictures of Saturn with a (sorta) Homebrew Rig

The e-mail and picture I received from Randy N3UMW could easily launch me (and perhaps others) into some adventures in the fascinating world of electro-astronomy. I have a telescope. I have an old webcam. I have some PVC...

Randy's message:

Attached is a photo of Saturn that I took with a modified webcam through an 8 inch scope in my very light polluted back yard near Washington DC. I can normally only make out a dozen stars due to all of the nearby street and porch lights. Luckily this does not affect the viewing of planets.

Taking the photo was very easy. You simply remove the webcam lens and add a telescope adapter (can be made from PVC tube), then you take a 2 minute movie through the webcam and use free software to align and stack each frame of the video. The end result is a hundred times better than what you actually saw. It's funny that a cheap scope and cheap webcam can equal what the observatories were doing 20 years ago! The attached photo was my second attempt.

Damien Peach uses this same method with better hardware in better locations and takes fantastic photos. See them at http://www.damianpeach.com/

N1VF's MIT Balloon Beacon Transmitter

1.5 watts out on 30 meters with total cost of 25 dollars. Here is the transmitter that Ben, N1VF, and friends are using for balloon operations.
For more details see: http://web.mit.edu/bgelb/www/balloon/hfbeacon/

Billy's Blog

The fellow who helps me introduce SolderSmoke mailbag ("That's awesome!") has launched a blog. Billy would really get a kick out of getting some visits and comments. Thanks!
http://thebillymearapage.blogspot.com

Very interesting video on the LED

I've made some disparaging comments recently about the MAKE blog. I noted that they seemed to be drifting away from soldering irons and toward knitting needles. But they have redeemed themselves with this excellent video on LEDs. It even features HOMEBREW LEDs!!! Thanks MAKERs!


MAKE presents: The LED from make magazine on Vimeo.

Update: My Kickpanel Amplifier

Here's an updated schematic for the amplifier chain I've been working on.

Here's the latest version of the Spice file: Bill's Kickpanel Amps

I'd appreciate feedback and comments on this project. Do I need more de-coupling on the first three stages? Am I running too much current through Q3? Should I alter the load on Q3?

SolderSmoke 95

SolderSmoke #95

Get the podcast here

November 23, 2008

Amp design adventures with Spice, EMRFD
WANTED: NE602 Spice model
Pictures (from pirates?) in 80 meter waterfall
Problems space with tools and solar panels
QRSS news: W1BW 50 mw heard in VK6 and VK7
WSPR QRO controversy
IK0IXI's video on HB 8 band SSB rig
Ordering parts -- the aroma factor
1 uF caps OK for HF bypass?
Reading Recommendation: December 2008 Discover Magazine
MAILBAG:
Thanks for help on CD for Mike's wife
Paul WA1MAC: Chapstick PTO, alternate use for political lawn signs
Aisea 3D2AA: Listening from Fiji. Just retired, has Softrock kit
Bob NT7S: Has setup SolderSmoke Facebook
Steve G0FUW: Bath Build-a-thon January 17, 2009
Roberto XE1GXG: Getting married, took detour to radio row
Ben N1VF: An old friend from Vienna Wireless Society
Steve "Snort Rosin" Smith: Wants real gong, "Once upon a clip lead..."
John VK3AJG's FB SSB rig
Steve KG6NRM TAK-40 Pic project

VK3AJG's Homebrew SSB Rig

Here is John Price VK3AJG's very FB homebrew 80 meter SSB transceiver when it was in the "boards on the table" phase of construction. As many of you know, it is very rewarding to make your first contacts with a new rig when it is in this condition.

You can read more about John's rig here.

A Cry for Help -- SolderSmoke Responds

Here at SolderSmoke, we often get letters from the relatives of Knack victims. This week we received a particularly impassioned plea for help. I thought readers would be interested in this case, and in the advice we gave:
----------------
Bill,
I usually don't listen to Soldersmoke, but my husband is a ham, so I overhear it from the other room on a fairly regular basis. OK, he listens to each show over and over at least 4 times. I hear him in there laughing--in his workbench area. I think the show's a good thing for the most part, and seems to keep him occupied when I don't need him to lift something heavy.
But today I am writing to you about a matter that has grown serious. A matter that can be overlooked no longer. So many of these radio hams seem to look up to you, Bill--so I am going directly to the ringleader to see if anything can be done. I have changed some names to protect the hapless victims.
I am referring to the blight called Shack Creep. It comes on quietly, but Shack Creep can be upon you before you have a chance to escape.
I'm getting ahead of myself.
In our home, it all started about 5 years ago. Charlie, my husband, had been tinkering with an old radio he found at a garage sale and he'd set aside a corner of the dining room for his small toolbox, soldering equipment, and a small box of things with wires sticking out. I noticed a piece of string or wire or something clotheslined across the room, attached to my macrame plant hanger. ''That's just temporary. I need to see if this thing works.'' Within a few weeks, though, I started to notice the card table expanding into a full-fledged workbench. The single wire that had dangled from the plant hanger had become a bundle of fat cords and wires going out the window and under the edge of the carpet to places unknown. From nowhere sprouted bins and boxes marked, 'Tubes-might work,' 'PCB scraps-keep,' 'Misc-to be sorted' and even more boxes haphazardly stacked with wires and braided cables jutting out every which way.
My dismay was only assuaged by the joyous but manic gleam in his eye as he uttered cryptic phrases like, "that's nearly four thousand miles a watt!," and "a ceramic resonator should never behave this way!"
I started finding oddly-shaped electronic parts in his pants pockets, on top of the dresser, and Arnie, our Irish Setter was recently caught with a doorknob capacitor in his slobbery jaws, headed out to play.
Bill, I love my Charlie, and I know this radio thing makes him happy, but you just have to say something to stop this tsunami of tangled wires and electronic bric-a-brac that threatens to unravel our happy home! For crabgrass we have pesticides. For roaches we have the roach motel--but nothing seems to be able to stem the tide of Shack Creep. Help!
Yours truly,
Anonymous

----------------------------------------

Dear Mrs. Charles:

Thank you for your e-mail. We here at SolderSmoke receive many messages like yours. I am happy to try to help you with your problem, but it is very important that you approach this problem with an open mind, and that you fully accept all of the advice that I am about to offer.

First, you must understand your husband's condition. What you refer to as "Shack Creep" is almost certainly the medical/psychological condition called "The Knack," also known as "Dilbert's Disease." This condition has plagued radio amateurs for many decades, but was first scientifically identified by Dr. Scott Adams during the late 1990s.

Dr. Adams wrote that The Knack is "a rare condition characterized by an extreme intuition about all things mechanical and electrical... and other social ineptitudes."

There is no cure for The Knack, but there are things that you can do to help your husband deal with the symptoms. Here is a list of steps that Dr. Adams and our team of researchers recommend:

-- Accept your husband's condition. Don't try to get him to change his ways, or get him interested in other things. Don't suggest that he switch to stamp collecting or gardening. He can't. He is a victim. He has a disease. Learn to live with it.

-- Victims of this disease usually exhibit a form of nesting behavior. In or near their homes they set up something that they call "the shack." Then they fill this "shack" with bits of wire, electronic items, tools and ham radio magazines. Often -- as in your husband's case -- the shack begins to fill to the rafters, and may actually overflow into other parts of the house.

-- Your reaction to this nesting behavior is very important. First, realize that your husband NEEDS to have a shack. Never suggest that his area be converted into a sewing room, or a TV room, or anything else. Knack victims are extremely territorial regarding their shacks, and will find these kinds of suggestions very upsetting.

-- Realize too that your husband NEEDS to spend a lot of time in his shack. And we mean a LOT of time. Shack therapy is an important part of our program for dealing with this condition. When your husband is in his shack, he should not be interrupted with requests to walk the dog, or take out the garbage or mow the lawn, etc. Our research has found that "honey-dos" significantly reduce the beneficial effects of shack therapy.

-- Knack victims need to consume beverages while in their shacks. Coffee -- lots of coffee -- is what they need.

--Social contact with other Knack victims is also very important, so you should NEVER object to his participation in hamfests or radio club meetings. Think of these events as group therapy sessions.

-- As a Knack victim, your husband NEEDS to work on electronic equipment. This equipment is often big, ugly, and expensive. Most health insurance plans will not cover the purchase of this equipment, but nevertheless, you should see it for what it is: a medically necessary part of your husband's treatment program. This is very important: You should never complain about the amount of money being spent on radio equipment.

-- Shack victims need encouragement from their loved ones. When your husband is struggling with an electronic project, it is best for you to avoid phrases like "Haven't you got that crazy thing working yet?" or "When will that stupid gizmo of yours be finished?" Instead, offer positive feedback: When he shows you something that he has been working on, use phrases like: "Excellent soldering!" or "Great circuit board layout!" Every once in a while, you should declare your husband to be "A true electronics genius," or "A wizard." Knack victims like to hear that.

-- Realize that there is no cure for The Knack. There are only therapies that help victims deal with the symptoms.

I want to also take this opportunity to let you know that we are also thinking of initiatives that we could propose to the new administration on behalf of Knack victims. For example we are considering a push for designated "Knack Victim" parking spots near RadioShack stores, and perhaps airfare subsidies for annual trips to Dayton, Ohio.

I hope you find this information useful and that you will take our suggestions to heart.

Sincerely,

Bill

Amplifier for 80 Meter Rig

Here's the LTSpice schematic for an amplifier chain that I've been building. (It might be hard to see, but maybe you can download it and look at a larger version.) Four stages, all feedback amps. The first three are class A, the final is Class AB. About 45 db total power gain -- it takes the .0001 watt (peak) from my balanced modulator and amplifies it to about 3.2 watts.

So far it seems very stable. Notice that I don't have any decoupling networks on the first three stages (other than a .1 uF cap to ground on the +13V supply rail. I tried to continue without decoupling on the final, but I got instability, so I added a 10 uH RF choke and a cap to ground as a decoupling network to the final stage. Instability disappeared. Do I need more decoupling on the other three stages?

The last two transistors are disgnated at 2N3053 and 2SC2075. That's what I'm actually using, but I haven't figured out how to get these parts into LTSpice, so I'm actually using 2N2222 models in my simulation.

Here is the actual LTSpice file: Bill's Kickpanel amplifiers

I'll talk about this project on SolderSmoke tomorrow. Comments welcome.

IK0IXI's Homebrew QRP SSB XCVR (8 bands!)

SolderSmoke #94

http://www.soldersmoke.com

SolderSmoke #94

November 2, 2008
Halloween in Rome, Autumn rains
Building Class A Amps with Spice, Copper, SSDRA, EMRFD
Wes on oscillator output wave forms
Inspirational article in "Air and Space" Magazine
Book Review: "My Detachment" by Tracy Kidder
Autumn SPRAT
SPECIAL REPORT FROM G-QRP MINI-CONVENTION
Aliens on 80 meters
MEPT: Can you see me?
Softrock 40 Group tries to digitize N2CQR
Homebrew solar panels
Request for assistance.. .
MAILBAG:
Alan Yates in cahoots with AA1TJ
Les gets our logo on I-tunes
Paul WA1MAC gets 2 2Bs
Scott KD5NJR on KSC honeymoons
Bruce VE9QRP on new free QUCS simulator
Keith G0CZR on bubble wrap insulation
Bob KD4EBM on green laser dangers
John VK3AJG designs 80 meter SSB rig
Todd KE7KXI on Knack relapse, old electronics smell
Jerry NR5A BACK IN ACTION!
Bob N7ZF on SolderSmoke Facebook

Homebrew Solar Panels

I hate to tell you, but all you guys who are using STORE-BOUGHT solar panels are a bunch of APPLIANCE OPERATORS. Time to roll your own, and REALLY make your own electricity.
Woody, KF4TQJ, sent me this interesting link on how to make your own solar panel:
http://www.thesolarplan.com/articles/your-own-solar-panel-collector.html
Before you get carried away by homebrew enthusiasm, scroll down a bit on that page and check out the cost estimates for large scale application of this technology.

See if you can see my signal 10140055 Hz

If Italy is in daylight, you should be able to see my 50 milliwatt FSK signal on one of the European on-line grabbers.

IK0VVE has a nice grabber aggregator site that includes a sun clock. Here it is:
http://www.ik0vve.net/mept6.aspx

Just see if the sun is shining here, then scroll down and take a look at either PA1SBD's site or ON5EX's. Sometimes I can also be seen on I2NDT's.

You should see my signal around 10140055 Hz. It looks kind of like a square wave. Read the Morse along the bottom (my FSK is upside down).

For extra credit, see if you can see Paolo's solar beacon. It too looks like a square wave, but with no Morse. He's running 2.5 milliwatts.

Please let me know if you succeed in seeing our sigs.

Arduino -- Italian Open Source Hardware

Scott Haley in Tulsa alerted me to this very interesting article in Wired magazine. How do you say Knack in Italian? Check it out: Wired article on Arduino

Aliens on 80 meters!

Graham, G3ZOD, was looking at the 80 meter band using the on-line SDR receiver in the Netherlands (http://websdr.ewi.utwente.nl) This is what appeared on the screen. Looks like you can work some real DX on 80 these days. The big issue will, of course, be DXCC credit. And I imagine getting a QSL card might be a bit tricky.

The Flea: Minimalist QRP from Catalonia

Here is a really interesting little rig from Joan, Ea3FXF, and Eduardo, EA3GHS. They have a very nice web site with more info, including SPICE simulation files and SPICE waveform results.
Check it out: http://ea3fxf.googlepages.com/flea

Lasers, LEDs, Tin-foil Hats, and QRP

Yesterday I got a very interesting message from Rye, K9LCJ. The map of Tasmania comes from the Modulated Light DX portion of the KA7AOI site (below).

Hi Bill:

I really enjoy your Solder Smoke show and news feeds. Great stuff that has got me back into ham radio again. Your note about optical comms got me fired up enough to add some notes that you might not be aware of.

There is a substantial worldwide community playing with optical communications and they have achieved some amazing records using simple off the shelf components – mostly big Luxeon LEDs which have some (debatable) advantages over Lasers. The most sophisticated component in typical systems is the Fresnel lens – which can be obtained at office supply stores or ebay as “page magnifiers” for a couple of bucks.

There seem to be about four major groups:

The Radio and Electronics Association of Southern Tasmania has an active bunch and they have achieved some great distance records with (QRP) LEDs. They have also been bouncing signals off of geographic features to establish communications paths. They are also doing some cloud/sky bounce things that are quite amazing. The REAST web site has lots of well documented test data that’s really interesting to read.

K3PGP has an exceptional web page full of test reports and construction details. His K3PGP preamp/receiver (and variants) are the basic building block for most systems. It uses a $1.00 pin diode, a MPF103 FET and a handful of common parts to get some almost fantastic performance.

Yves, F1AVY has a strong theoretical background and has been doing interesting stuff in France for quite a while and his web page has lots of interesting technical details.

Clint, KA7AOI has a very comprehensive web page. Clint holds the record for long distance communications (173 miles) and describes much of his equipment and testing. There is also a bunch of historical material that is very interesting.

There are probably a bunch of folks I have forgotten, but all of them are noted in the many and varied links found on these web sites.

I think that the most interesting thing about the activities is how the teams have adapted available technology to an interesting problem. Much of the work resembles current amateur weak signal activities. In fact, Spectran and WSJT are part of almost every activity. Much of the work is unique outside of the academic community and might even be called groundbreaking in some areas.

We have a small group here in the Raleigh North Carolina area, but so far we haven’t done anything of note other than build equipment and play in the local park. The fact that this sort of thing must be done outside at night draws all kinds of attention – some of which is not necessarily good. …a bunch of strange looking guys running around in the dark with strange flashing red lights…. I have a special cap that I wear for the occasions.

Keep up the good work.

Rye Gewalt

K9LCJ

Laser QSO and Visual EME with laser!

Bob, Kd4EBM, sent me some really good info on laser safety. Bottom line: For the time being anyway, Billy will be limited to the <5mw href="http://www.earthsignals.com/Collins/0036/index.htm">http://www.earthsignals.com/Collins/0036/index.htm
Their rig is pictured above.

And here is one that is really mind blowing: A while back we discussed the laser reflectors left on the moon by the Apollo astronauts. Well, apparently there is an intrepid amateur out there who has been shooting his own lasers at the Sea of Tranquility, and seeing reflections come back. Visual EME. Check it out:
http://www.k3pgp.org/viseme.htm

Thanks Bob!

SolderSmoke #93

Oops, forgot to put this on the blog on Sunday:

http://www.soldersmoke.com

SolderSmoke #93

October 12, 2008
HB Pi Network Tuna (with mystery)
Hamfest report from Belgium
Space Hackers removed from YouTube
Verdict on Judica Cordiglia brothers
FB Italian ham magazines
I shift to FSK on 30 meters
Gimmick capacitors
QRSS QSY woes
SolderJoke
MAILBOX:
Jerry NR5A Back in action
Scott KD5NJR on Space Hacker controversy
Steve WB6TNL on the different flavors of solder smoke!
Paul WA1MAC labled PC boards with SSDRA page numbers
Ramakrishnan VU3RDD getting back on the air
Jim K9JM had 60 POUNDS of 2N2222
Jim AL7R listening from Yuma
Wes W7ZOI on plumbing washer toroids
Paul WA5WCP on laser safety
Terry G4GHU also went to KSC on honeymoon

The Da Vinci QRSS Code

Here is my 30 meter QRSS frequency standard using paper for insulation.

I SHIFT TO FSK ON 30 METER QRSS

The online grabber of Johan, ON5EX, provided instant gratification this morning. Right after I finished some modifications that I hoped would result in a Frequency Shift Keying signal on the 30 meter visual QRSS band, looked at the grabbers and found this. That's me. It is a kind of "upside down" FSK. Look along the bottom of the square wave and you can read the CW.

I used a fairly standard approach to get the FSK, but with a twist: I added the usual LED and a cap to the oscillator circuit. Now, on key down, the positive voltage from the keyer causes the LED to conduct, putting the additional cap into the circuit. But here is the twist: for the capacitor, I just used some of that twisted-up two conductor insulated wire that often comes with cheap old (mono) ear phones. In the old days this would have been called a "gimmick" capacitor. I started out with 3 or four inches. Using Spectran to monitor the amount of shift, I just cut off bits of the wire until the shift was at the desired 5 Hertz. I just clipped away at the wire until the shift looked about right.

The rig is now key down all the time, and even though power out is still only about 20 miliwatts, I have the final in Class A, so I actually had to put a heat sink on it. But there is still no need for a muffin fan, or liquid cooling or anything like that!

Five hertz isn't much of a shift. I think I can hear it, but barely. Shows up nicely on the grabber screens.

It was a lot of fun to start out with a vision of what I wanted the signal to look like, then actually make it happen.

Flea Market Find -- Pi Net Tuner -- With a Mystery

Last Sunday's "Flea at Trastevere" (I'm the only one who calls it that) was a huge success for me. Minutes after arriving, amidst all the junk, Billy and I found this homebrew Pi network antenna tuner. The guy who sold it to me told me he had built it himself. The workmanship is top-notch. The quality of the parts is superb. There's a built in SWR meter and a 10 db attenuator.

When I started drawing out the schematic I noticed something weird: As the front panel indicates, it is a Pi -network, but for some reason the builder has the input variable cap floating. The physical connection to the chassis is via insulators. The other variable cap has the standard mechanical and electrical connection to chassis ground. That input cap needs to be grounded too, correct? Why would this builder -- who obviously knows his way around a soldering iron -- go to the trouble of allowing that input cap to float?

"Space Hackers" removed from YouTube

They say the videos were taken down because of some Intellectual Property issue. That's their story, but I've seen the X-Files, and know that something more sinister is probably at work here. Kay, WD0BDK, suspects the Russians -- the thinks they are mad at us for making fun of the Woodpecker!

(Note to lawyers: I did not post the videos on YouTube.)

Skepticism about "Space Hackers"

Many of us really enjoyed those videos about the two Italian brothers from Turin and their homebrew space monitoring program. But there is some controversy about some of their claims:

http://www.svengrahn.pp.se/trackind/Torre/TorreB.html

Controversy or no controversy, I still liked the videos and admire the efforts of the two intrepid brothers from Torino.

SolderSmoke #92

The latest SolderSmoke podcast:

http://www.soldersmoke.com

September 28, 2008
TOPICS:
The Flea at Trastevere
QRSS 2N2222 goes toes up. Why?
Da Vinci Code MEPT Frequency Standard
Wind Powered QRSS
QRSS Whispers reflecting off airplanes
Transformer troubles at CERN
Arnie's cool Cuban hack
Woodpecker update
A SolderSmoke charity project
Another engineer joke
Kanga USA BACK IN BUSINESS!
The Joy of Fixing Things
Jim Severns - KNACK VICTIM
A Homebrew Italian Space Program
MAILBAG: G0FUW in Gibraltar
VU3RDD in Southern India
KB1QVO on laser comms
K4BVL likes our audio
VK3PB on Italy's "Space Hackers"
W0DAB on free online MIT courses
DL4MGJ on fixing 2B parallax
WB6NTL on transistor failure mode
AF6C on crystal ovens
G3ZTB likes Shep

A Homebrew Italian Space Program

Peter, VK3PB, alerted me to the six YouTube videos about the Judica Cordiglia brothers of Turin, Italy. These guys were young and enthusiastic amateurs when the space race began in the late 1950s. They quickly developed some very impressive monitoring facilities that allowed them to listen to both US and Soviet space missions.

Watch these videos and you will not only get a look at the technical work of these intrepid and skilled amateurs, but you will also get a sense of the many intangible things that make Italy such a special place. You'll get a sense of the human warmth, the friendship, the enthusiasm and fun that characterize life here.

They had the foresight to film a lot of their youthful technical adventures. The videos take us back to the Italy of the late '50s and early 60's. (That roof that they built their antenna on looks EXACTLY like mine!)

Don't miss these videos. They are really wonderful. Here are the links (if you have trouble, just search YouTube for "Space Hackers 1/6" "Space Hackers 2/6" etc.

http://www.youtube.com/watch?v=1F_67UAaG70
http://www.youtube.com/watch?v=N-y2DuYNxm4
http://www.youtube.com/watch?v=s8sElZpvzRU
http://www.youtube.com/watch?v=wcGPXZPYHNs
http://www.youtube.com/watch?v=A9kiSMcrqRg
http://www.youtube.com/watch?v=WUT-eZH0860

Rudy Severns

Allan, WA9IRS, sent me the link to a really interesting article about guy who is obviously one of us, a victim of The Knack. Here is how the article begins:

An innovator in power-supply design who anticipated the trend toward higher frequency switching, an illuminator of power-supply topologies, and one who introduced many engineers to the promise and perils of power MOSFETs, Rudy Severns has made diverse contributions to the power electronics field in a career spanning five decades as an engineer, author, instructor and consultant.

On the 50th anniversary of his first jump from a biplane, Rudy Severns went skydiving yet again, pushing his lifetime total to somewhere in the vicinity of 500 jumps. Throughout his career, he took breaks for months-long sailing voyages, which usually necessitated a job change on his return. When it was time to fulfill his military obligation, a young Severns parlayed his experience as a radio operator into a stint with the Army's Special Forces, where he learned the skills of unconventional warfare.

Here's the link to the article: Rudy Severns

IZ1KXQ's Wind-Powered QRSS Beacon

Paolo, IZ1KXQ, is the fellow who brought us the 5 mw QRSS MEPT beacon powered by small solar cells (see an earlier blog entry). He is now experimenting with wind power. FB Paolo! We hope to see your windy signals soon.

Cool Cuban Hack

Arnie posted this on QRP-L. I thought it was a pretty ingenious way to work around
an unavailable part. FB Arnie!

My TS820 non QRP, but capable of QRP operation transceiver. ... has a similar type of female 9 pin socket to connect or not connect the external VFO. I needed a plug when not using the external VFO, and it was made using a Russian 6H2P dual triode that had a bad filament... I very carefully broke down the glass using nichrome wire at red hot temperature and then a thermal shock. The glass bulb broke nicely in a rounded even circle !!! Then I proceeded to remove the soldered connections to the two triodes... removed them , and soldered the wires required for the jumpers as specified by TS 820 manual... After checking that all was OK, then I poured Araldite epoxy to fill the glass ... It worked very well, and the only cost was the small amount of valuable epoxy ( not easy to find locally, and extremely useful for repair jobs and pasting the islands of the Manhattan style homebrew printed-nonprinted circuits !!! 73 and DX Arnie Coro CO2KK

Beacon Final Amp Goes Bad

All of a sudden the power output meter on my 30 meter beacon (MEPT) transmitter stopped jumping up and down. The oscillator was still running, and the keyer was working, but output had obviously dropped considerably. I started troubleshooting and my attention started focusing on the 2N2222A in the final. The stage runs Class A, with long QRSS key down periods. The emitter resistors get a bit warm. I replaced the transistor with a new 2N3904 and -- BINGO -- output was back up in the tens of milliwatts.

I did some tests on the 2n2222A. With a VOM I looked at forward and reverse bias resistance across both junctions, comparing the part from the rig with a new part from the same batch. In the transistor that went bad there is a lot more reverse bias current across the base-collector junction.

So, what happened? Any ideas?

This was one of those very satisfying repairs in which you quickly zero in on the problem, change one part, and then put the gear back into action. The victory was made even sweeter, when, a few minutes after I put the rig back on the air, I noticed my QRSS CW signal on I2NDT's online grabber.

I'm almost finished with my 10.140070 frequency standard. Armed with that, I'll be free to experiment with FSK keying (without fear of being unable to find my way back to the 100 Hz -wide QRSS frequency band). 73 from Rome

SolderSmoke #91 STEREO SPECIAL

Be sure to listen to episode 91 of the SolderSmoke podcast:

http://www.soldersmoke.com

September 14, 2008

TOPICS:

Sardinia!
ON5EX's QRSS MEPT leads us back to bike riding
Watching Jupiter, listening for Jupiter
KF6KYI's I-tunes QRSS
Stan, 9H1LO's new grabber
Laptop motion detectors as earthquake detectors
Nuclear fusion in the shack
Philo T. Farnsworth
Building a QRSS freq standard
SPRAT CD
Forget about stocks: SSDRA now selling at $399.89
SolderJokes
QST articles on-line! FB!
Jim Williams and the joy of fixing things
STEREO SPECIAL: Roger Hayward's new binaural DSB project
Antenna woes
MAILBAG:
G0WAT on HOGCON 2008 (21 Sept in Herts.)
AJ8T on Russian rovers with laser reflectors
KA9OOI on language and low pass audio filtering
WB6TNL says NO to rat neurons in QRP gear
KB6QR "beknacked" vice "knackered" ?????
NR5A has a Drake 2A
7J1AWL on the air from Vietnam
KC0PET goes solar
OZ1CJX Bad case of Knack, may need professional help
K8WPR says Knack keeping him away from wild women, bars
AJ8T on CK722 museum
AG5RS works Texas balloon from Dubai (via net)
KI4SGU POW radio parts
N8WQ on schematic drawing program
KF4LMZ has QRSS-itis, finds 10.140 rock in CB rig

The Joy of Fixing Broken Gear

Alan, WA9IRS, sent in this really great link about Jim Williams, an engineer who writes for EDN. In his article Jim captures better than anyone the joy of repair.

Those taking up an engineering degree online can use the tips included in his book.

Check out his article: "Try Fixing it Yourself."
And if you like the article, check out Jim's book: Another Look at Analog Circuit Design

N2CQR in Sardinia

There was no SolderSmoke podcast last Sunday because at our normal
broadcast time we were on an overnight ferry from Rome to Sardinia.
Beautiful island! I have a little SW rx with me, and this
Blackberry. And SSDRA.... But not much radio work this week.

Stars are beautiful here. Milky Way is BRIGHT! View was especially
good from the ship when we were way out in the Med. 73 from Sardinia!

Bill

--
Sent from Gmail for mobile

Large Hadron Rap

We don't really cover rap music here at SolderSmoke, but we make an exception for this one. More than 400,000 downloads so far.

Shooting Lasers at the Moon

Ron Sparks, AG5RS, sent us this very cool picture. My kids take great delight in shooting those tiny red laser pointers out the window, and as described in SolderSmoke we actually built a simple laser communications system. But so far we haven't achieved the kind of "beam shooting into the sky" effect pictured here.

Here are Ron's comments.:

"It was interesting for you to mention the lunar laser reflector. It had a very special impact on my life. You see, I grew up in Texas at about the midpoint of the 600 mile line between NASA Clear Lake and the McDonald Observatory in the Davis mountains and was in High School when Neil Armstrong walked on the moon. I had the pleasure to visit both NASA and McDonald at that time and had direct contact with some of the people responsible. I have actually put my hands on the controls for the laser in the attached photo. More importantly, the control box was opened up for me so I could see all the gizmos inside."

Check out the website: The Lunar and Planetary Institute

The website has some interesting info on the width of the laser beam when it reaches the moon, and how they use the data to measure the distance. Sounds vaguely QRSS-ish:

"Laser beams are used because they remain tightly focused for large distances. Nevertheless, there is enough dispersion of the beam that it is about 7 kilometers in diameter when it reaches the Moon and 20 kilometers in diameter when it returns to Earth. Because of this very weak signal, observations are made for several hours at a time. By averaging the signal for this period, the distance to the Moon can be measured to an accuracy of about 3 centimeters (the average distance from Earth to the Moon is about 385,000 kilometers). "

CLASSIC GERMANIUM

Ted, AJ8T, alerted me to this very interesting page.

"The CK722 holds a unique place in the history of the transistor. Introduced by Raytheon in early 1953, the CK722 was the first low cost junction transistor available to the general public. It was an instant success. Countless "build it yourself" articles were published in the popular electronics press and electronics/hobbyist magazines describing how to use the CK722 to build all types of devices such as radios, oscillators, electronic voltmeters, photoelectric alarms and hearing aids. Eager to learn about the exciting new transistor technology, the public responded enthusiastically to the CK722 - hundreds of thousands of these transistors were bought by experimenters, radio hams, engineers and others interested in this technology over the next few years. In addition, there is a sentimental aspect to this device. Many of the talented and dedicated professionals and amateurs who have been responsible for the tremendous rise of the electronics industry over the past four decades can still remember the time when, as a young hobbyist, they were able to scrape together enough money (maybe through saving allowance or cutting the neighbor's grass) to buy that first CK722 - can you still recall the smell of solder and the absolute delight of hearing a local radio station coming through "loud and clear" on the newly constructed one transistor radio powered by, of course, a gleaming, bright blue CK722? This webpage and book have been constructed to help preserve the special legacy of the Raytheon CK722."

Check it out:

http://www.ck722museum.com/

AG5RS works Texas Balloon BLT-24 from Dubai

Payload Master Mike WA5TWT and the main payload for BLT-24

From our man in Dubai, Ron Sparks, AG5RS:

Hi Bill,

Yesterday was the annual South Texas Balloon Launch Team launch BLT-24. It went quite well and I was able to participate even from Dubai. This year they got an IRLP to Echolink to Repeater hookup going and I was able to Echolink to that ground repeater, then do a QSO across the balloon crossband repeater. So my signal went by "the tubes" all the way to Clear Lake Texas, then by radio wave up to the balloon at 90,000 feet and back down to everyone in about a 300 mile circle of Texas. Pretty neat. At the same time I monitored the APRS packets coming out of the balloon via the APRS web page in Finland, so I was able to have a map on the screen with real time GPS data from the balloon while I was making the QSO.

You have really bitten me with the QRSS bug and I want to build a beacon to carry up to A61Q's house and install. Sadly I don't know where to get any components here in the UAE (Soldersmoke listeners might know where to point me for local purchases?). So, I am putting together a "Bill of Materials" and will order it from Mouser in the US and have it shipped to me. I just know Murphy will probably cause me to miss one resistor or something and then have to wait another two weeks and pay for that much more cardboard to be shipped -- sigh.

All the best.

73, Ron, AG5RS
---------------------
Ron also asks if anyone has any advice on how a foreigner might get a ham license in Dubai.

Philo T. Farnsworth -- Radio Hero

I briefly thought about a title for this blog entry that would declare Philo T. Farnsworth to be a Knack victim, but in his case that just seemed a bit flip. Read Chapter One of Paul Schatzkin's excellent book and I think you'll see what I mean. What an impressive guy.

Chapter One Of "The Boy Who Invented Television":

http://www.farnovision.com/tbwit/chapter1.html

On the Air (QRP) from Vietnam

Our friend Jonathan, 7J1AWL, managed to overcome the bureaucratic barriers, and was on the air from some really beautiful locations in Vietnam.
Check out his pictures and videos: XV2OC
I really like the shot of Oscar in the helmet.

NUKE KNACK!

Sure, some of your guys have solar panels and wind-powered generators, but how many of you have NUCLEAR FUSION goin' on in the shack? These guys do. They DEFINITELY have The Knack. Be sure to watch the video in which the guy admits that he has an agreement with his wife to replace the house if he actually blows it up!

Check it out: Wall Street Journal Fusion Article

This all reminds me of a wonderful book I got as a kid: "The Amateur Scientist" by C.L. Strong. "Build a Homemade Atom Smasher" was one of the projects. Homebrew X-Rays were also in there.

Jupiter

This image (by Michael Weasner) is very similar to what we see when we look at Jupiter through our six inch reflector telescope. Billy and I were up on the roof last night, looking at Jupiter and the moons. Sky and Telescope magazine publishes a nice chart showing how the moons will be configured each evening. Arnie Coro, CO2KK, in the most recent edition of Radio Havana Cuba's "DXers Unlimited" program mentions how easy it is to receive radio signals from Jupiter. I haven't tried that yet, but as a Knack victim, I feel the urge to do so.

We also watched OUR moon rise over Rome, and saw a satellite pass overhead. Saw some neat double-stars, and I taught Billy about averted vision.

Carl and Jerry: KNACK VICTIMS!

These guys definitely have The Knack. Check out Jeff, K7JPD's Carl and Jerry web site:
http://www.copperwood.com/carlandjerry.htm

Digital Designers Discover Hands. Wayne Green

Sent in by Mike, kc7IT, here is an interesting article on how software guys are being encouraged to build things with their hands:
http://www.nytimes.com/2008/08/17/technology/17ping.html


Sent in by our musician, Mark "Moj" Johnson, W8MOJ, here is an update on Wayne Green of "73" magazine fame:
http://www.computerworld.com

SolderSmoke #90

http://www.soldersmoke.com

August 17, 2008

August in Rome, Italian beaches, Circeo
Hardrock Cafe, My Sharona, The Knack
The Planet Mechanics
VK6DI on QRSS
Listen to me talking to Jean Shepherd (1976)
SolderSmoke (sort of) in Australia in 1944
Herman Munster is not an appliance op...
Book Review: "The Science of Radio"
August QST: KD1JV's rig, pneumatic switching, QRP WAS
Conrad's Garage, KDKA, K4HU (SK)
Kits and Parts by W8DIZ
Working on 80 meter DSB rig
Computer fixed, counter still dead
MAILBAG:
7J1AWL in Vietnam
Jerry, NR5A, gets a Drake 2A
KB1DRK recommends Spitfish
SM5QU on Apollo Backpack Radios (AM!)
AC7ZN reports WB8LZG has aerielitis
W8NF on Dorkbot (Knack?  or no Knack?)
G0FUW to speak at Basingstoke 1 September
M0JRQ on the meanings of "knackered"

Conrad's Garage -- Birth of KDKA -- K4HU, SK

Harry Mills, K4HU, passed away recently. Harry was 100 years old and was active on the ham bands right up until the end. National Public Radio featured Harry and his ham station in an "All Things Considered" segment about early radio. It came out in 2001. I don't know how I missed this one -- it is really great. Have a listen: NPR program on KDKA, K4HU

Bicycling across 30 meters

I was having lunch today, thinking about ON5EX's QRSS bicycle. I've showed it to my wife and kids -- we all think it is really very clever. But then I realized that at the same time I've been admiring Johan's bicycle artistry, I've been using his online grabber: http://www.on5ex.be/grabber/grabber.html

I wondered how he transmits and receives at the same time. Then I noted the black stripes on the grabber screen, each about one bicycle long. Clever fellow!

Inspired by Johan, I have put my humble QRSS3 CW MEPT back in the band. I'm at around 10140070, visible on Claudio's grabber now. Reports would be appreciated.

"It's always a hazy day on Titan."

Now for some real DX. The Cassini probe is exploring the moons of Saturn. Above you see a picture of the planet in eclipse -- the sun is behind it. Click on the picture to make it larger. Look closely between the rings at around the ten o'clock position. That's us. That's Earth.

"New Scientist" has a really amazing video on the mission's highlights: http://space.newscientist.com/article/dn14276

Bicycle Riding on 10140010 Hz

Sure, you can talk on SSB.... but can you ride a bike on SSB? Apparently you can on QRSS!
Who is the mystery rider on 10140010?

VK6DI Comments on QRSS Bandwidth, Modulation

David, VK6DI, is one of the Knights of QRSS. He sent in this very nice note about bandwidth and modulation methods in QRSS. Thanks David!
-------------------------
Yes, QRSS3 bandwidth is indeed 0.34 Hz. ON7YD has an excellent 'CW bandwidth' reference at

http://www.qsl.net/on7yd/136narro.htm#Bandwidth

Clearly 'hard keying' rather than 'soft keying' of a CW (or FSK) transmitter will increase the transmitted bandwidth. In a practical sense QRSS transmissions key the carrier at such infrequent intervals that an occasional key click every 3 seconds (for dots) or 9 seconds (for dashes) should be of little consequence QRM wise, and especially so when using QRPp. Ideally however it is preferable to control the carrier's rise and fall times during keying. Sometimes just simple R-C filtering is used for carrier wave-shaping, however 'Raised Cosine' rise and fall times such as used for PSK31 are optimal, albeit much more difficult to produce. 'Raised Cosine' shaping also seems to make good 'intuitive sense'. Hence some compromises as to carrier wave shaping are usually the order of the day.

A convenient way to become familiar with QRSS's bandwidth requirements is to run the program "Spectran" (by I2PHD & IK2CZL), and to then observe the preset QRSS parameters. Spectran is available for download at -

http://www.weaksignals.com

As with the program Argo, Spectran also has a series of predetermined settings for all standard QRSS speeds. Those settings have been optimized for best results when receiving QRSS. This is an extremely important factor for most beginners. Whilst it is true that the more sophisticated FFT programs offer tremendous flexibility of user settings, they also carry a proportionally higher risk of operator confusion.

To obtain further insights into QRSS bandwidth requirements try running Spectran and then select a 'Mode' via drop-down menu -



Now observe the "Show Controls" menu -



Note that 11050 / 32768 = 0.34 Hz FFT bin bandwidth. Each bin will take 32768 / 11050 or about 3 seconds to fill, and 3 seconds is the duration of a QRSS3 dot.

Similar calculations can be obtained for other QRSS speeds - QRSS10, QRSS30, etc. Note that both bin size and waterfall scrolling speed are factors that will determine the final visual S/N ratio. For that reason it is best to stick with easy to use programs such as Argo when beginning QRSS activities. Many seasoned QRSS operators use Argo with excellent results, as you can observe on many of the on-line grabbers.

QRSS10 is not considered usable on HF. It is impossible to keep even the most stable transmissions to within a few QRSS10 FFT bins at the receive end of the path due to continually varying ionospheric conditions that will disperse the signal. The final 'visual S/N ratio' is dependent upon capturing as much energy in as few FFT bins as is possible.

QRSS3 on HF over long paths often results in an ambiguous visual display following QSB. For example - a dash may appear as a series of dots. Is the character below an "O" or a "Z"?



Switching to QRSS6 and FSK-CW seems to partially resolve this problem, but not completely. Slower ID's will obviously allow more time to "visually integrate" the signal. That is, to make a 'decision', as to whether the portion just observed on-screen was a dot or a dash. The trade off (as always), is the rate of information transfer. QRSS6 transmissions are best received as QRSS3 in this instance, and look fine on the QRSS3 grabbers. FSK-CW transmission has additional advantages, apart from any perceived improvement in signal readability. FSK-CW is very easy to generate from an existing QRSS keyer, and cheap Red LED's when reverse biased seem to function adequately as Varactor diodes for FSK modulation purposes. A shift of about 5 Hz is all that is required. The best advantage with FSK-CW however, comes from not having to key the transmitter's carrier on and off. That helps with transmitter frequency stability when interstage isolation from the Crystal oscillator may be poor, as is often the case with simple transmitter designs.

There is certainly room for more experimentation with Visual Modes. The sheer variety of approaches to the modulation problem can be quite interesting to watch at times, but in the end the same old constraints remain. Dual freq CW (DFCW) is yet another option, and has the advantage over QRSS Morse that both dots and dashes can be the same length. So ID's are faster than for normal QRSS.

Ref - http://www.w1tag.com/Modes.htm#DFCW_ENTRY

One final factor not always appreciated by newcomers to the 'slow modes' is that the 'visual gain' advantage of QRSS over that of traditional speed Morse does not arise from the use of narrow receiver IF filters as might be expected. The advantage results from the narrow FFT bin size (Resolution) within Argo / Spectran - namely 0.34 Hz at QRSS3 speed. Narrow filters may be useful to exclude strong QRM that otherwise might impact the receiver's AGC, but they make no difference to the visual S/N ratio. (All else being equal.)

Unfortunately I think that it is fairly unlikely that I will see very many EU signals until conditions improve. So far this year I have caught only one EU signal. Conditions have been really poor these past 12 months or so. When the sunspots return I'm sure everybody will see many new EU and US stations. DL6JAN has previously made it down into VK with 5 mW, along with many other stations that were running 50 mW to 200 mW or so, and all with minimal antennas.

Ref - http://www.proehl-elektronik.de/qrss/dxrprt_e.html

Good luck with your QRSS experiments, I hope you will continue to have fun with the mode.

Regards,

David, VK6DI.

VK6DI Web page:      http://tinyurl.com/lp2vv

VK6DI Captures:      http://tinyurl.com/2lxyy5