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

Loops and QRSS

On QRP-L there has recently been some discussion of the effectiveness of small loop antennas. Some hams in Northern Italy are doing something very interesting in this area. They have two identical QRP (1 watt) QRSS transmitters on 30 meters. They are keyed simultaneously, but one antenna is connected to a standard vertical antenna (with a very good radial system), while the other goes to a small, resonant CFA loop. By looking at the various QRSS on-line grabbers out there, you can get a real sense of how the two antennas perform. I just took at look at VK6DI's grabber -- I could clearly see the signal from the vertical, and could see quite a bit of the signal from the loop (see above at around 10140040 -- the loop signal is a few Hz above).

Claudio, I2NDT, has a good web page describing the experiment:

http://digilander.libero.it/i2ndt/pagine/Dual%20Beacon.htm

Herman Munster gets license, works Italy!

Nick, KA1BQ, alerted me to this one. I don't think Herman really had The Knack ( he seems more like an appliance operator to me), but he did work Italy, so it merits mention here.