Solder Smoke Cologne! New!

As mentioned in SolderSmoke 104. Check it out! Here is the link:

Solder Smoke -- From the Men at Work Collection

Troubleshooting and Simulations

Alan, W2AEW, roams the Northeast USA as a Field Application Engineer for Tektronix. This week he sent me an e-mail with some words of wisdom about simulations and troubleshooting. Thanks Alan!

An excerpt from Alan's e-mail:

Funny you mentioned about LTSpice, and wanting to have that puff of soldersmoke whenever you place a component. It reminds me of something that I'd often tell new-hire engineers. Many times, engineers fresh out of school have never touched a resistor - they've often spent their entire education doing bookwork and simulations. I would always caution engineers about this, and try to illustrate that the simulation is only as good as the model you give it. If you ask the simulator to exercise the model in a way it wasn't designed for, it won't tell you that, it will just lie to you. YOU have to be smart enough to recognize the lie. For example, the simulator has no problem putting 10,000 amps through a 1N914A diode - it doesn't know that you'll let the smoke out of it! The simulator must be considered a tool, just as you VOM, scope, counter, finger, nose, etc. are all tools. Each can give you valuable information (and can lie to you). You have to learn to know what you can believe, and what you have to question - and you need to develop ways to look at strange behavior in a number of ways to figure out what is happening.

It reminds me of a story that Jim Williams wrote many years ago (you mentioned Jim Williams in a previous SS episode). He described how, as a child, he was playing with circuits at his neighbor's, and using his (neighbor's) oscilloscope to examine a circuit he was working on. He was getting all kinds of strange behavior, and couldn't make heads or tails of what he was seeing with the scope, VOM, etc. The neighbor (who was definitely afflicted with the Knack) came by and, with moistened fingers, probed around in his circuit for a few minutes. He then grabbed a small value capacitor and soldered it judiciously in the circuit, and everything worked fine. Jim was flabergasted and demanded an explanation. The neighbor said that he suspected that the circuit was oscillating at several hundred MHz, and used his finger's capacitance/loss/etc. to damp this behavior. He continued to explain that since the oscillation frequency was so high, the scope couldn't "see" it. Jim complained that this "wasn't fair"! The neighbor concluded the lesson about how important it is to not-only understand what our tools can do for us, but it is really more important to understand their limitations - because it is when we ask a tool to do something that it can't do, it often won't complain, it will lie. The same holds true for nearly every tool we use, and is a lesson well learned. This story is included in his chapter entitled "Should Ohm's Law Be Repealed?" in his book, "Analog Circuit Design: Art, Science and Personalities" from 1991.

Alan has a lot of great stuff on his web site. Check it out:
http://www.qsl.net/w2aew/

Marconi's Big Ears

Thunderstruck by Erik Larson has countless gems about Marconi. I thought I would share one with you this morning.

When Marconi was born on April 25 1874, an elderly gardener saw the new baby and exclaimed, "Che orecchi grandi ha!" ("What big ears he has!") Marconi's ever protective Irish Mom, Annie, took offense and replied:

"He will be able to hear the still, small voice of the air."

Indeed.

Thunderstruck!

Chris Trask, N7ZWY, recommended this book. I'm really enjoying it. Maybe too much: I was reading it on a crowded Rome bus this week, and was so absorbed by the chapter on Marconi's first efforts to transmit beyond line-of-sight that I didn't notice the pickpocket. He got my little radio receiver/MP3 player. The radio gods let me down that morning!

Homebrew CPU

Since we were talking about minimalist computing, I thought you guys would be interested in Steve's homebrewed CPU project, aka the Big Mess of Wires. Inspirational stuff! Check it out:
http://www.stevechamberlin.com/cpu/about/

Minimalist Computing from New Zealand

My Toshiba Satellite Pro 400CS went toes up in 2006 after many years of service. It died with a horrible grinding sound from the hard disc. I tried to bring it back to life, and bought a replacement HD, but I never could get it going and the project got sidetracked... until an e-mail from Kevin, ZL3KE, (see below) got me back in the old computer repair business.

With long-distance help from Kevin I
1) Got a boot-able DOS disc, which got me to an A:
2) Partitioned and formatted my HD which got me a C:
3) Loaded DOS drivers for my CD ROM drive which got me a D:
4) Used the CD-ROM drive to load Windows 3.1 which really brought this thing back to life.

I usually dislike working on computers, but with Kevin's help and encouragement, this project was fun. And I can now use some old programs that I haven't been able to use since the advent of Windows 95, like my favorite astronomy program "Distant Suns." I'm also running ON7YD's excellent QRSS transmit program.

I always liked the audio features of this computer. With a bit of driver downloading, I now have sound. There are some nice audio clip files in this (birds chirping, machine guns, another gong!)
that may find their way into the podcast.

Any thoughts on what else I can do with this machine? Any other Windows 3.1 applications?

Here's the message from Kevin that re-started all this:

Minimalist/QRP computing

Friday, March 6, 2009 1:09 PM

From:

"Kevin Ravenhill"

To: soldersmoke

Hi again Bill,

I was amused to hear your comments about QRSS and the ever-so-slight
discrepancy between the number of transistors needed for Rx and Tx...

Maybe it's time to introduce the concept of the "QRP Computer" - using
older/slower hardware generally regarded as obsolete, but otherwise
perfectly serviceable and having a much smaller carbon footprint than the
latest 2.5GHz+ machines! This is something which I've been working towards
for some time.

I'm typing this on an old 233MHz Pentium laptop (Toshiba Satellite Pro
480CDT), with 64MB of RAM, a 3.8GB hard disk and an 800x600 screen,
running a cut-down version of Win98SE with all web integration (IE etc.)
stripped out. This will happily run pretty much all the radio software I
need without complaint (such as MMTTY for RTTY, MMSSTV for SSTV, Digipan
for PSK31, Argo, Spectran, IZ8BLY Hellschreiber, WSJT v4, etc).
Just about the only thing lacking is WSPR, which I would very much like to
run but I think it probably needs more resources than this machine has
(Joe Taylor, are you listening? ;-).

The rationale was/is to find the simplest, smallest, most bloat-free
programs to accomplish what is needed (minimalist computing, in other
words) - and it must all be freeware or similar - bells & whistles are
frowned upon, and definitely no commercial stuff allowed! I wouldn't say
I'm 100% there yet, but the journey so far has been interesting and
rewarding.

Although this was originally intended to be a dedicated machine for radio,
I now find myself increasingly using it for things like web-browsing and
email as I find the whole "no bells & whistles" experience quite
refreshing (I use Popcorn email and a minimalist, no-javascript browser
called "OffByOne" - my browsing needs tend to be fairly basic and I tend
to regard any website which uses Java/Flash etc. as not worth the effort).

I think Mike AA1TJ's quote on his "Reggie" page is quite apt here: "In
anything at all, perfection is finally attained not when there is no
longer anything to add, but when there is no longer anything to take
away...."

72/3, Kevin
ZL3KE

The MOSquito -- More Minimalism from Catalonia

Joan and Eduardo -- the guys who brought us the Flea -- have come up with another very interesting insect: The MOSquito. A single IRF510 does all the RF work. There is a computer involved, but it looks to me like it just does some audio DSP. The video is in Spanish, but all true Knack victims will be able to follow it. More info their web site:
http://ea3ghs.googlepages.com/mosquito
Enhorabuena Joan y Eduardo!

Going Solar! Solar QRSS!

Bright sunny morning here in Rome. I was talking to Nigel, M0NDE, on Echolink and he mentioned his efforts to keep his new shack completely "off the grid." That got us talking about the video I posted yesterday (scroll down) about making solar panels from donuts and tea, and the next thing you know, I'm connecting my Volkswagen solar panels (see above) to my QRSS beacon. No longer will my 50 milliwatt transmitter be contributing to the destruction of the planet! I feel better already.

Homebrew Solar Panels from Donuts and Tea!!!!

So all you appliance ops out there using STORE BOUGHT commercial solar panels should hang your heads in shame!

Eldon's Acquatic "ET PHONE HOME!" Machine

Man, the authorities would DEFINITELY blow this thing up if they found it! Check out Eldon's innovative effort to keep the transistor count to ONE and to use mechanical means to generate his QRSS callsign. "COMING SOON TO A GRABBER NEAR YOU!"

Here is the e-mail from Eldon describing his creation. Using the saw blade was a nice touch!

Bill, In keeping with the spirit of QRP, QRSS and the minimalist HB challenge of ET-Phone-Home I have enlisted one of my single-transistor-nine-volt (2N3904) QRP rigs. With the best that I can measure, this system has a DC "input power" of 6.84mw into a 16 inch loop antenna of 30 AWG copper coated-steel MIG welding wire. On previous experiments, the Tx was easily detected from 1500 feet away from on my grabber. Longer DX experiments have not yet been conducted. Note as per the photos, I have cheated a little, the Tx rig that I selected to used, was from a previous project, and has an additional active element, a five volt regulator (LM7805) for oscillator stability and battery longevity (i.e the 9 volt battery voltage can decrease down to 7 volts and oscillator requires only 1.8ma before the Tx frequency goes unstable). Bill, The QRSS frequency modulation technique that I used is the same that I suggested for you to invert your FSK MEPT transmitter signal - for up frequency modulation - increase the "capacitance to ground at the collector" of the oscillator ( which I think cancels some of the normal colpitts crystal oscillator capacitance - and therefore the frequency goes up with increased capacitance ). My modulation requirement does not need a "gimmick" as you have used, because of my use of direct mechanical capacitance coupling (as described below). For modulation my system uses about 8 gallons of water in a 6 inch reservoir with trickle flow bypass regulation around a weighted falling piston, which pulls on a string, which turns the encoder. The piston is large "Whole Fancy Indian - Cashew - Premium Quality, All Natural" nut container ( obtainable from the actual Kirkland Costco store ) with Velcro (loops) Sticky tape wrapped around the top and bottom bulges providing the snug fit and trickle flow metering in the water column. About 8 lbs of weight was added to the nut container to provide the necessary potential-energy storage. This system of metering and energy storage provides for a run-time of about 10 minutes, before a mechanical reset is necessary ( note to potential builders, performance and timing formulas are not included within this document ). Following ET's example, the encoder is a 10 inch multi-cut rotating disk encoder - model number 9-32636 (only obtainable from Sears) augmented with "replaceable-movable-removable" coding elements attached with tape. Before the coding elements were installed on the modulation encoder, the system produce a QRSS "Saw Tooth" waveform (what else would you have expected?), which was initially used just for testing (see: the additional oscillator mounting hole on the substrate, closer to the pivot point ). Note, this encoder technique requires no actual physical or switch contact with the Tx. Only a ground and collector capacitor plates were extended from the colpitts oscillator to form the modulation active elements. I originally was planning to encode my own call - "WA0UWH", but the encoder blade could not hold that much data. A blade upgrade is being considered (i.e., 12 inch). For now, I have chosen something shorter and simpler to encode (as ET would have suggested), I will use my QTH as the name of the nearest major landing-site in my area with high intensity approach lights - SEA (Seattle International Airport), besides it was much easier to cut from PC stock - 5 dots and a dash. Note: the selected message can be shortened by folding the unused elements onto the center of the modulation blade (Note to self - other messages could be encode using the same elements and a similar folding technique, that is "ET" could be encode from the "SEA" elements ). The resulting modulation is not as square as traditional QRSS3 digital driven keyers, but, . . . it is very distinctive. The FIRST major modification to this system was the addition of a rolling cart for transport, I had to move the reservoir to a stairs where I could get above it, to pull up and reset the modulator piston, which by the way requires about a 20 lb pull for about the same duration as the run time (about 10 minutes). The NEXT major modification WILL BE a maximum flow (3/4 inch) tickle flow "bypass" pipe via a control "valve" to aid in the reset process ( for the European critics, I do not think this should be mistaken nor counted as an active QRP element ). This will make the resetting process go much smother, quicker, and should require much less external "arm strong" input power (question: where does the input power go?? warming the water??). The MEPT QRSS operation is simple; Raise the piston (lock it in place), Wind up the draw string around the pulley, Install the encoder disk, Release the lock, and then Wait for the DX grabber reports? Note: a complete set of construction, operation photos and grabber images will be added to my Gallery when time permits: http://qrss.ebcon.com/WA0UWH/Photos/ NOTE: For others HB'ers interested in this project, Kits WILL NOT be made available. Bill, watch for my signal on the 30M grabbers - it should be very recognizable as my signal will have a bit of a "Saw Tooth", waveform component. More details may follow as the project progresses (to where, I am not sure, but I do know that this is enough of this!). Bill, It has been fun !! 73's - Eldon - WA0UWH - alias "SEA" Phone Home BTW: No actual grabbers were harmed while collecting data for this document, but a 30db attenuator was added to the antenna connection on my SA602 DC receiver for its near field overload input protection.

Mechanical Memory Keyers

Billy and I went to the Rome flea market this Sunday and picked up a clock motor that may become the core of a mechanical keyer for the single transistor QRSS MEPT beacon we've been talking about. Unfortunately ours is battery powered -- we couldn't find any wind-ups that had a second hand.

I got an intersting e-mail on this subject from Gene, K8EE:

Mechanical Memory Keyer

Monday, March 16, 2009 6:44 PM

From:

"Gene Mayler" To:

n2cqr@yahoo.com

Hi Bill,
Just wanted to let you know that I built a mechanical memory keyer
back around 1960. It was very similar to the one you suggested in the
last "Solder Smoke." I built it for the radio club to use on Field Day. It
It used a phonograph motor to coupled to a mechanical variable speed
drive. A circular piece of PC board was attached to the output of the
VS drive. Patterns were etched on the PC board for the CW
messages, one to call CQ, one for the contest exchange and one to say
"tnx QRZ ...."

Of course, the variable speed can be achieved with a D.C. motor instead of
the mechanical VS drive. Todays computer software can create much
better artwork to etch on the PC board.

Unfortunately, I threw the thing out in the trash a couple of months ago. I
wish I still had it so that I could send you a picture of it. Oh well. What's
done is done.

Tell the guys that it CAN be done and it HAS been done.

73,
Gene Mayler - K8EE

SolderSmoke 103: Piper Cubs and MFJ Cubs

http://www.soldersmoke.com

In the SolderSmoke 103 Podcast:
15 March 2009
Beware the Ides of March!
Ostia Beach and Ostia Antica
248 Knights of QRSS. And Wizards!
ET Phones Home (with QRSS?)
Possible new grabbers in VK6 and Dubai
Telescope, Satellites...
REAL QRP QSOs on 80 and 40
Saving an old Toshiba Laptop
ECHO-QSO WITH JEFF, KO7M:
-- Piper Cubs and MFJ Cubs
-- Satellite QSOs
-- LT Spice and test gear
MAILBAG:
Gene W3PM listens from QE2, HB WSPR rig
Jim AL7V sending parts for my W3PM rig
Jim AB3CV's color burst Gnat
Jason NT7S on Tektronix guys and SolderSmoke
Kevin ZL3KE on old computers
Paul M1CNK's DDS 30-based QRSS beacon
Soeren OZ2DAK on exercise bikes to power beacons