KO7M's Two Cubs (Piper and MFJ)

Jeff, Ko7M, travels around in this very cool Piper Cub. He has floats for it so he can land on water. He sometimes listens to SolderSmoke as he flies. Which brings us to his second Cub:

KO7M has built his first QRP rig!

Thursday, February 19, 2009 4:11 AM

From:

jeff

To:

n2cqr@yahoo.com

Bill, what have you done... You are killing me out here... :) You may recall, I am ko7m out in the Seattle area and I wrote recently about flying around with soldersmoke playing over my aircraft audio system.

Well... I have been systematically listening to every soldersmoke episode from the beginning... Not a small task... :) I am currently up to episode 80, so I am closing in on the prize of being current.

BUT!! You have completely afflicted me with the need to build something... Most of my ham life however I have been mostly an appliance operator it seems though I built a lot of tube equipment in my younger years, burned a lot of fingers and once launched myself across the shack when I took hold of a 750 volt plate circuit.

Therefore, I am not up to the task of designing something from scratch, but ya know... I just HAD to build something and NOW, so I went with a kit. So, not exactly knack-ish but ya gotta start somewhere, eh?

I went with the little QRP transceiver from MFJ called the "MFJ Cub". I picked up a 40 metre version of this little gem, plugged in my MP3 player with my current episode of soldersmoke and started GENERATING solder smoke! This little kit went together very easily during moments when I had a few minutes to work on it.

Well, this evening (it is now 01:00 PST) I finished up with my last little bit of solder smoke generation and the little rig is done. Now for the REAL smoke test...

Since I don't have a current limiting power supply, I went with a little nine-volt battery for the smoke test. The little power LED lit up and I heard a pop in the headset, nothing was getting warm, so things looked good. We went to the full 12 volt supply and I went through the alignment process by first setting the product detector's operating frequency to fall within the CW filter passband. I then used my Icom receiver to set the VFO operating range since I don't have a frequency counter. I then peaked the receiver bandpass filter for best sensitivity and lastly set the BFO to the correct sideband.

For the transmitter, I first set the carrier offset to about 600 hz from the received signal and peaked the transmitter bandpass filter for maximum RF output. I only have a simple SWR bridge for indicating a relative output level forward and reverse. Lastly, I set the power output level to about what I estimate should be about one watt.

Whoo hoo! Pulled off the dummy load and plugged in the G5RV and antenna tuner and started tuning around the low end of 40 metres and there were signals everywhere. Nice receiver in this rig. The tuning is a little fast, but managable. Seems to be very sensitive. I happened to catch the end of a CQ call as I was scanning around the band and when he signed I gave him a call.

To my complete surprise, he came back to me and gave me a 459 report... From Japan! I bagged a JA1 on my first QSO on a rig I built myself (or at least assembled). There is nothing better, I tell ya! I attached a screen shot of the Solar Flux level for my first QSO.

So... I am afraid to say you have reinstilled the need to melt solder in me after an absence of over 30 years. It is a disease I tell ya! I have located copies of both Solid State Design and Experimental Methods, which are both on the way and I am eagerly looking forward to figuring out what the next project will be.

The knack is returning...
Kind regards,
Jeff Whitlatch - ko7m

The Kettering Group: Satellite Pioneers

A while back we were talking about the Italian brothers whose satellite observation work got them caught up in some international intrigue early in the space age. This morning I came across some web pages about The Kettering Group, a group if intrepid British lads who were in the same game. Heartwarming stuff. I wish my school had been like theirs! Read about them here: http://www.svengrahn.pp.se/trackind/getstart/oldcyts.htm
More info here: http://www.svengrahn.pp.se/trackind/trackin1.htm#KEttrack

Clockwork CW: The Path to Minimalist QRSS?

Well, maybe not using that one. But something like it. The idea -- mentioned recently on the podcast -- is to use a mechanical clock mechanism to generate the CW for a QRSS beacon. This would allow us to get the transistor count for our beacon down to one. For some odd reason, some of us find this appealing, especially when you consider that the transistor count on the receive side is in the tens or hundreds of millions. One is the magic number. You can see how this project brings together two of the biggest littlest recent trends in the QRP radio: QRSS and minimalist radio.
It's kind of scary when you Google something and are referred back to your own blog. That's what happened to me on this subject. Back on May 28, 2008, this was posted (by me!) as a comment to one of the beacon-related posts:

Hello Bill and Others:
A few years ago, a buddy had made a neat keying operation made by taking a
one RPM clock motor and had it rotate a printed circuit board disk that had
the callsign etched on it several times sequentially. Clock motors are
made to run continuously for years, and it stood up with just an
occaisional cleaning of the wiper arm with spray cleaner.
All the best to all!
73 de Lee Smith VE4ANC

This message from Lee was a response to a January 1999 question from me. So we are sort of re-inventing the wheel here.

Of course, there are some QRSS beacon circuits out there with VERY low transistor counts. Hans Summers has one on his site that used a bi-stable multivibrator to generate a pattern for QRSS. That would yield a total transistor count of 2 or 3. But we are going for one single transistor. And I kind think we should look for something that will allow for the transmission of callsigns.

Here's an e-mail exchange from the Knights of QRSS mailing list that may generate some ideas:

Re: [Knightsqrss] Junkbox + soldersmoke = pattern generator

Saturday, March 7, 2009 10:43 AM

From:"Paolo Saia"

To:"n2cqr"

Very nice idea Bill. After tiny solar mepts this could been our next QRPP/ET challenge .
73 de Paolo IZ1KXQ
--------- Initial Header -----------

From : knightsqrss-bounces@cnts.be
To : knightsqrss@cnts.be,"Soeren Straarup" xride@x12.dk
Date : Fri, 6 Mar 2009 21:48:55 -0800 (PST)
Subject : Re: [Knightsqrss] Junkbox + soldersmoke = pattern generator
It would be fun if the clock were a "wind up" type. And for extra credit: Power the transmitter with the energy from the same spring mechanism (or other wind-up device) that powers the clock!
ET PHONE HOME!
--- On Fri, 3/6/09, Soeren Straarup <xride@x12.dk> wrote:

From: Soeren Straarup <xride@x12.dk>
Subject: [Knightsqrss] Junkbox + soldersmoke = pattern generator
To: knightsqrss@cnts.be
Date: Friday, March 6, 2009, 3:30 PM
Hi list,
Hans Summers has made an astable multivibrator as pattern
generator.
Bill Meara has thought about making a analog clock.
Alan Yates loves my idea of an exercise bike pattern
generator.
Though i'm open for suggestions. No pics, pc or
any other programmable
devices.

Rules of design:
1) KISS
2) Should be in most junk boxes
3) Pattern should be easily changed (diversity, more
homebrewers)
4) KISS
This is for a simple Pixie2 TX modified to be a QRSs TX.
Stability? SSShhh.
Vy 73 de OZ2DAK
Soeren Straarup | aka OZ2DAK aka Xride

Lots of Great Old Radio Books FREE!

Our man in Helsinki, Greg, OH2FFY, reports that "Armstrong: A Man of High Fidelity" is available free online. We talked about this book in a recent SolderSmoke. I checked it out and found the online version to be very easy to read. I suggest you click on the "flip" version -- you get a very nice display that is much like looking at a real book. Here's the link:
http://tinyurl.com/cvc4qd
That link led me to Project Gutenberg where I plugged in the word "radio" and was instantly given a list of really nice old books, including the Radio Amateur's Handbook by A. Frederick Collins of Congers N.Y. (my home town). Here it is:
http://www.archive.org/details/theradioamateurs06935gut
Thanks Greg!

Italians at the Forefront of QRSS

In SolderSmoke 102 I mentioned that Italians are playing an important role in QRSS. Alberto, I2PHD, is certainly one of the key people. His software is behind most of the grabbers that we all use. THANKS ALBERTO! Here's his bio:

Born in 1944, in Lucca, Tuscany, Italy. Got a Doctorate Degree in Physics at the University of Pisa. Since then worked for IBM, with various responsibilities. Radioamateur since 1966, active on most bands, from 160m to 23cm. Lately experimenting with 137 kHz, recently allowed in Italy with 1W ERP.

Studying and applying DSP and digital techniques in general. Author of Winrad, SDRadio, Spectran, Jason, Argo and Hamview, widely diffused programs for SDR (Software Defined Radio), spectral analysis and real time filtering of audio signals, received with a radio and routed to a PC equipped with a soundcard.

Despite the age, open to learn new techniques and theories. *Not* a tube (or valve, depending on the side of pond you are reading this) nostalgic.

73 Alberto, I2PHD

Home page http://www.weaksignals.com

ET Phone Home! With Minimalist QRSS!

I knew that Alan Yates, VK2ZAY, was just the man for this project. Alan and I met up several years ago when Billy and I spotted and built his Trivial Electric Motor (we still have it, and occasionally fire it up to amaze visitors). On SolderSmoke 102 I mentioned the possibility of a one transistor QRSS transmit station. Obviously this would require some sort of mechanical keyer. I thought of a clock drive. Alan pointed out the in the 1982 Steven Spielberg movie, ET had used a saw blade as his mechanical modulator (see above). Alan also had some intriguing ideas of his own:

G'day Bill,
Thanks again for noticing my QRSS signal making it through to Europe.

Your talk about mechanical solutions for QRSS modulators immediately
made me recall "E.T. the Extra-Terrestrial". The "Phone Home" device he
built had a modulator based on a sawblade IIRC - its been years since I
watched that 1982 classic.

One easy hack might be to use an AC synchronous motor out of a gobo
rotator (for example, I got one out of a fibre optic christmas tree that
expired from overheating). Its reduction drive results in a fairly slow
rotation which might drive a modulator plate. You could do the pickup
optically using a LED/photodiode (or transistor, or even an LDR I guess)
transmission pair. Electrical contacts would work too, but doing it
optically probably means it would have a longer life.

A tape loop system might also be practical and would allow long
modulations to be encoded at reasonable tape rates. A syncro-drive gobo
has to be turned fairly slowly and pushes the "density" of the data
fairly high so the mechanical or optical sensor gets harder to just
throw together. I am sure a clockwork driven disk could be made to
work, it just might have to be fairly large.

Mechanical readout might be a microswitch and holes in the plate, or
even using PCB material with the pattern on it (etched or masked), and a
brush contact. To minimise wear a brass small roller held against disk
with spring tension would work. Oxidation on aging might become a
problem - yeah the more I think about it I am liking optical better.

You can also do it electrically using a diode matrix which can be read
out with some counters. Of course that defeats the original purpose
which was to make a single transistor QRSS beacon with a mechanical
modulator.

One completely insane idea that just occurred to me is to build a slow
mechanical oscillator (say driven by a Stirling Engine or a Curie Point
Pendulum heated by a small candle) and modulate the RF oscillator with
that. The mechanics or thermal system might directly effect the RF
oscillator frequency. Who will make the first candle-powered QRSS
beacon with thermopile PSU? :-)

Regards,
Alan
http://www.vk2zay.net/

Homebrew WSPR from W3PM

Recently I've been reading with envy the WSPR reports from K6HX. Mark tells how he walks into his shack each morning and is greeted with signal reports from around the world. Beautiful maps are presented, with lines arcing from Southern California to distant islands in the South Pacific. I burn with envy. I want to WSPR too! But I have no SSB gear for 30 meters, and unlike our beloved visual MEPT QRSS, WSPR requires SSB gear.

I had mentioned all this on SolderSmoke, and this morning Gene, W3PM, came to the rescue. He sent info on a really interesting and very simple SSB transceiver. Take a look at the block diagram. On transmit it is essentially a DSB rig with a filter at the operating frequency to knock down the unwanted sideband. On receive it is a Direct Conversion receiver preceded by a narrow filter that allows the WSPR frequencies through. It uses the familiar SBL-1 mixer. The filter has only one crystal. And --icing on the cake -- Gene built his version in modular form, with each module in an Altoids tin. Clearly, this is the WSPR rig for us!

Gene provides a very nice write up on his project here:
http://www.knology.net/~gmarcus/WSPR/wspr2.pdf

Gil Cartoon of W7ZOI on the Mountaintop

Steve, WA0PWK, sent this one in. He found it in an old issue of "Hints and Kinks." Note the callsign on that FB HB portable rig. Wes tells me that this cartoon was actually a Doug DeMaw initiative. Doug took an older cartoon by Gil, W1CJD, and put "W7ZOI" on the rig. The drawing appeared next to a short article by Wes about an electronic keyer using a pair of 741 Op Amps. Wes also reports that his kids got a real kick out of it -- his son Ron was taking an elective printing course in Jr. High School at the time, and printed up a bunch of W7ZOI QSL cards featuring the modified Gil cartoon.

I thought that Steve, N0TU (now WG0AT !), would find this especially interesting.

SolderSmoke Podcast #102

For the podcast go to:
http://www.soldersmoke.com

For the new SolderSmoke Store:
http://www.cafepress.com/SolderSmoke

In SolderSmoke 102:

In the shadow of Vesuvius...
...then back to the "laboratorio."
-------------
QRSS musings:
1 transistor for transmit, 100 million for receive.
We need a low tech beacon generator -- maybe mechanical clock driven?
QRSS on "Hack-A-Day."
VK2ZAY QRSS booms into Europe.
Soul in the New Machine: Billy's oscillator.
ON5EX's grabber on SolderSmoke blog.
Italians at the forefront of QRSS.
--------------
T-shirt news: "Menus are for restaurants!"
"QRSS Ops Do it Very Slowly"
--------------
Using iGoogle for ham radio.
USENET is going strong!
Back on Echolink.
--------------
Minimalist Radio:
The Gnat! The NS-40!
I add a second transistor to my ET-1 (and hang my head in shame).
--------------
MAILBAG:
Jim, AL7RV, developing smoke generator for LTSpice.
Randy, K7AGE, sent Empire of the Air video -- Thanks!
Jim, K9JM, prescribes higher Q for regen rx. "Never will be a 2B!"
Rye, K9LCJ, "Low Space Means Fine Teletype."
Alan, W2AEW, Listens to SS while on the road with Tektronix.
Dave, W8NF, "Armstrong, A Man of High Fidelity." Indeed.
Mark reports W7ZOI releases new EMRFD software.
Jonathan, KB1KIX, Shep fan, has good Smith Chart stuff on his blog.
Jerry, NR5A, building a QRSS beacon.
George, K8VU, Dilbert has "utter social ineptitude."
David, VK6DI, moving East.
Paul, K3PG, took Willamette project on ski trip.
Steve, WA0PWK, Gil cartoon about Wes.
---------------------------

Out of the Ozarks... The NS-40!

I think this new rig is really interesting. NS stands for "No Simpler." It has only 14 parts. The coils are etched into the PC board (see above) -- I've never seen that before in an HF rig. It runs Class E and puts out 5 watts! The Designer is David Cripe, NM0S, and a kit is available from the 4 States QRP Club for only $30. Look here for more details:
http://www.wa0dx.org/wa0itp/ns40.html

Out of the Sonoran Desert... The Gnat!

We've been away for a few days, down in the shadow of Vesuvius, but I'm back in the shack now, and this morning I've been looking more closely at the latest creation out of the Sonoran Desert:
Chris Trask, N7ZWY, has given us the design for an amazing rig he calls "The Gnat" (Chris has a deep interest in the flora and fauna of the Sonoran Desert.) Like the ET-1 and FETer, The Gnat is an HF transceiver using only one active device. Chris uses a 2N2222 transistor. But unlike the other one-device rigs, The Gnat uses no switches or relays for T/R transitioning -- his rig goes from Receive to Transmit just by pushing the key down. The receiver is, of course, a regen. And get this: The Gnat can produce somewhere in the area of .5 watts to 2 watts of RF. Wow, that's one big bug! There's definitely a lot of Knack in The Gnat. Check it out:
http://www.home.earthlink.net/~christrask/Gnat%2040.pdf

QRSS on HACK-A-DAY

Eliot over at Hack-A-Day was kind enough to run an article about our QRSS exploits. I figured this aspect of the hobby would be intriguing for the more computer oriented folks who visit that blog. Judging from the comments, I think I was right.
Check it out:
http://hackaday.com/2009/02/22/qrss-radio-amateurs-slow-speed-narrowband/