Ade Weiss's New Book

Big news on the QRP/homebrew literature front. One of the titans of the genre, Ade Weiss, has released another amazing book about our hobby. I really enjoyed Ade's first history of QRP, and, because it covers a more recent period (1968-1981), I think this new this one is even more interesting. I took a portion of it with me on the train yesterday (and will be doing the same for the rest of the week!) The book is a wonderful technical history. It is filled with interesting stories and with very illuminating schematics and technical discussions. Ade takes us through the exciting early days transistor transmitters and direct conversion receivers. There is a lot of discussion of the commercial rigs that we've come to know and love -- lots of HW8s and Argonauts. And Ade has made it all available as a free download! Thanks Ade!

http;//www.QRPdxPropagationAntennas.com

ADE WEISS'S NEW HISTORY BOOK -- PDF DOWNLOAD:

http;//www.QRPdxPropagationAntennas.com

THE FIVE-WATT QRP MOVEMENT IN THE US, 1968-1981

by Adrian Weiss W0RSP (ex-K8EEG),

author of

JOY OF QRP: STRATEGY FOR SUCCESS

HISTORY OF QRP IN THE US, 1924-60

IONOSPHERIC PROPAGATION, TRANSMISSION LINES, AND ANTENNAS FOR THE QRP DX’R

The Milliwatt: National Journal of QRPp

TABLE OF CONTENTS

Part 1. K6JSS and the 100-watt QRP ARCI ………………………………….......... 1

Part 2. QRP/8 Newsletter, QRPP CORNER Column, and THE MILLIWATT:
The Beginning of the Five-Watt QRP Movement in the US ... 3

Part 3. The QRP World Outside the 100-watt QRP ARCI ………………….... 22

Part 4. The QRP Takeover of the 100-watt QRP ARCI. ………………….......85

THE MILLIWATT QRPp DXCC and MILLIWATT DXCC Trophy List..........105

Adrian Weiss W0RSP’s Bibliography: Selected Technical Articles. 109

EPILOGUE: W0RSP Retro-ARRL-DX-Contest 2/18-19, 2012 Log, PIX....111

***************

IF you are interested in where our niche in the hobby came from, and would

like to read about the developments in technology caused by the transistor

and IC, and see many then-new but still-used circuits, and learn the

history of the commercial evolution of QRP gear from Ten-Tec, MFJ,

Heathkit and others, then this book is for you!

It is 115 PAGES in length in PDF FORMAT--

FREE!!! DOWNLOAD (32MEGS, ~ minute +/-) FROM:

www.QRPdxPropagationAntennas.com

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

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29% Off on SolderSmoke Book! Leap Year Sale!

Leap Year Sale at Lulu on "SolderSmoke -- Global Adventures in Wireless Electronics"http://soldersmoke.com/book.htm

Hubble Ultra Deep Field in 3D

This is about 2 years old, but somehow I missed it. It is really beautiful, and it helps keep things in perspective.

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Winterfest!

Billy and I went to the Vienna Wireless Association's Winterfest hamfest yesterday. We had a great time and met many SolderSmoke fans. Above you can see me and Randy, N3UMW, the designer of our SolderSmoke logo. Thanks again Randy!

There's Charles, AI4OT. Charles bought a copy of the SolderSmoke book at last year's Winterfest. This year he dropped by to show us his tiny Steve Weber QRP rig in an Altoids tin. FB! And he was kind enough to talk-up the book, helping me make a few sales! Thanks Charles!

We managed to get rid of a bunch of junk, and only bought one item of new junk (a Hallicrafters S-38E receiver). And we got to show our friend (and aspiring homebrewer) John what a real hamfest is all about.

Thanks to the VWS for another great 'fest.

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The ZL2BMI DSB Transceiver

Oh man, I've been a fan of this rig for many years. I first read about it in the pages of SPRAT. Today I stumbled across what appears to be an on-line version of the instruction booklet prepared by Eric Sears, ZL2BMI. Lots of lore in there. Lots of soul in this rig.

This site has three documents describing the rig. All three are a lot of fun: http://www.mightymessage.com/

Three cheers for Eric Sears! Hip-hip...


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Two Workbenches and a Mini Solder Pot

KC9LIF's bench

Hi Bill,

FB...What a great addition to your work bench. Congrats, you will put it to good use! I remember that scope when I worked at the Nuclear Physics Research Department Cyclotron at Indiana University about 30 years ago. It was the top of the line and worked great!! I lucked out by getting a Techtronics 2213 60Mhz dual trace at a Hamfest for a great price a few years back. Luck like that comes to those that wait. I recently gave my work bench a face lift... BTW, the bench doesn't look that nice now...

73,

Kent KC9LIF

Dino's bench

Bill -
Ray VK4ZW's "solder pot" idea is a good one....for another version check out Doug Hendrick's tech note at his Hendricks QRP site:

http://www.qrpkits.com/files/MiniSolderPot.pdf

Congrats on the new scope! We have finally moved to our "place in the sun" and I had the opportunity to double the size of my workbench.
73 - Dino KL0S



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Fat Tubes-day!

I couldn't resist using that title. Stephen from the UK sent me this link to Jeff Duntemann's site about Compactron tubes. Many possibilities here. I think I have a 6T9 in my junk box. These are kind of like tube versions of ICs, but with the advantage of being understandable.

http://www.junkbox.com/electronics/CompactronTubesIndex.shtml


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New Oscilloscope!

That, my friends, is a genuine dual-trace, 100 MHz Tektronix oscilloscope. Wow, a new day has dawned on the N2CQR workbench! The 'scope comes to me as a result of the generosity of friend who, like the guy in the old "Millionaire" TV show, prefers to remain anonymous. He claims this is an equipment trade, but the terms were so one-sided (in my favor), that this was really a gift.

As you can see below, the 'scope fits perfectly in the center position on the shelf above the bench. I've already put it to work -- here you see it looking at the output from the VFO of the kick panel rig.

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Book Sale!

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http://soldersmoke.com/book.htm

A Soldering Tip(!) from Australia

Ray notes that it should be mm not cm

Bill,

I heard you discussing the gadgets that you have in your shack on a recent SolderSmoke podcast particularly the small flame device that you use to remove the enamel from copper wire. I have found the following to be a fantastic way to remove the enamel and tin the wire at the same time. I was alerted to this process by Grant, VK4JAZ, who saw it on the Hendricks QRP Kits site.

Get hold of a basic soldering iron, usually around $10 - $20, and take out the solder tip (you don't need to buy a new iron if you have a spare tip but I find the separate iron allows me more flexibility during construction). Drill a hole in the base of the tip, about 5 - 10 mm, and place the tip point first into the soldering iron. The hole can be filled with solder when the iron is hot and all you do is put the enameled wire into the solder. The heat removes the enamel and the wire is tinned at the same time. The burnt enamel floats to the surface and all you need to do is skim it off before tinning another wire: Simple and neat.

Vy --... ...--,

de Ray VK4ZW

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Words of Wisdom from Farhan

I read the mail of the BITX20 group. Here is some good advice from Farhan:

I have often seen builders finishing an entire build, then powering it
up to face the frustration of a dead circuit. I suspect that the
trouble is with our kit building mind set. As a kit builder, we assume
that if it has worked well for a few hundred others, there is no
reason for it to not work for us. But the truth is more sobering ...
Of the hundred odd components, any of them could get swapped by
another, or a bad solder, wrong polarity, etc. can all conspire to
thwart your attempts. The bitx manuals are really some of the best
produced in the recent years and yet, even with leonard's videos,
troubleshooting kits is a challenge.
I am proposing a more elaborate, slower but surer approach to building the bitx.

It is as follows: build it one stage at a time, use one stage to test
the next. For instance, one could start with the bfo first. Just a
single transistor with the crystal. Then use an RF probe to check the
rf output. If there is no output, then sort that out before proceeding
to the next stage. With the addition of the buffer amp, the output
should go up. Then one could proceed to the audio amp. Injecting audio
from your mp3 player or computer could check that it works. Next,
replace the audio source with the mic amp, this tests the mic amp.
Now, if you add the two diode modulator, you should be able to receive
the dsb at 10 MHz on your HF transceiver.

This approach tests each stage individually and in isolation before
proceeding to the next. It also provides wholesome education to the
builder. In software industry, it is called a 'test driven
development' method of developing software.

In the end, this approach is no slower than the current approach,
except that surprises are not kept for the last.

I am sure that some of us can come out with a sequence of stages to
build where each stage is tested using the previous stage.

As much as bitx is about building it cheap, it is also about learning
your radio from inside. Bitx is also education on the cheap, don't
give up that opportunity.

- farhan VU2ESE

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Kick Panel Rig: EXPOSED!

There it is, sans kick panel. You can see the breadboard (a real one!) on which it is built. The box in the center has the oscillator circuitry (currently on 75 meters, but subject to change); the box is elevated a few inches by two pieces of wood -- I do this so that the frequency control will be a comfortable distance from the table! HB-ergonomics! The AF (mic) amp is in the lower left (just a 741 op amp). You can see the adjustment pot of the balanced modulator behind the mic amp. The low pass filter of the PA is visible on the right (rest easy Steve Smith!). The switch on the right is T/R. The red switch is "spot" (or in the UK "net").

I thought I was having some trouble with RF getting into the mic amp. The audio out from the mic amp looks a bit distored when I have the oscillator and PA circuits fired up. I worked on it for a while, beefing up the decoupling on the 12 volt lines, but that didn't change things. I've decided not to worry about it, because the output signal from the final looks clean, and the signal sounds good on my trusty Drake 2-B. It may have been a test gear problem -- the 'scope probe may have been picking up some RF and may have been uglying up the AF wave form.

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Kickin' the Kick Panel to 40?

Thanks for all the suggestions re what to do with the kick panel rig. Steve "Snort Rosin" Smith (pictured above) suggested getting a 9 Mhz crystal filter and building an SSB rig for 75 and 20 meters. I was tempted Steve, but remember, simplicity is a virtue, and DSB makes a transceiver REAL simple.

Craig and OM KWJ suggested 10 meters. I hear you, but I'm looking for a rig that I can use for pre-dawn rag chews, and at that hour 10 is often a white noise generator.

Bruce wants me to put it on 475 KILO hertz. I dunno about that one Bruce -- sounds kind of lonely!

As I thought this over, I remembered a comment from the true guru of DSB: Peter, VK3YE. In one of his inspiring videos, he mentioned that 40 meters is his favorite band for DSB rigs. It is 0545 local and I am hearing a lot of activity on 40. It all sounds very friendly. Some DX coming through... I could make a stable VFO for 40. Then I add a little DC receiver and I'm in business. So I'm leaning towards 40 meters at this point.

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Back to the "Kick Panel" DSB Rig

OK, so now that the 17 meter rigs are fully operational, I am turning my attention to another homebrew rig from days gone by: This is what I call my "kick panel" DSB transmitter. You see, the metal cabinet is made from a piece of metal intended for placement on the bottom part of a door -- so that people (in a pub, I suppose) won't wear out the door with their feet. I built this rig in my attic shack in London. The breadboard on which it is built is from a Dyas store in Windsor, England. The top of the box comes from a computer I found discarded on the mean streets of South Kensington. I think I originally built this thing for 40 meters, but later switched the VFO and the low pass filter to 80 meters. This rig is discussed in the opening pages of the London chapter of "SolderSmoke -- Global Adventures in Wireless Electronics."

The oscillator is running as it should and the RF amplifier chain (my design) is amplifying (and not oscillating!). The balanced modulator is doing its balancing act quite nicely. The only problem seems to be with the the little op-amp that have in there for the AF -- it seems to be distorting the audio quite a bit. That shouldn't be hard to fix.

There is room in the box for a simple Direct Conversion receiver, so this box will become a DSB/DC transceiver.

But here is my problem: I find myself unenthusiastic about working on a rig for 75 or 80 meters. On the one hand those frequencies are good for me -- I'm an early riser and I need a rig that I can use in the hours before sunrise. But 75/80 always seems to be an unfriendly place -- lots of frequencies that seem to be "claimed" by groups who don' t seem interested in meeting newcomers, not a lot of people calling CQ...

I can put this rig on another HF band. 40 seems nice, but I have plenty of old boatanchor stuff that covers 40. I don't need another 17 meter rig. I already have a homebrew 20 meter DSB rig. How about 12 meters? Or 10? I know they are both dead in the early morning, but better times are coming, right? What do you guys think? To what band should I kick the kick panel rig?


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The New 17 Meter Phone Station

There it is. The SSB station has moved from the workbench to the operating position. I have it situated above the DSB rig, but both of them are hooked up and ready to go. My crystals (and the FCC) allow me to go from 18.110 to 18.128 with the DSB rig. The SSB rig goes from 18.128 t0 18.168 Mhz.

I've been having a blast with this setup. I'm running into old friends who I haven't talked to in one (or in some cases two!) solar cycles. I talked to Lee, G0DBE this morning -- our last contact was June 2000 (just before our departure from the U.S.) Yesterday I talked to Jorge, HK4CZE -- I hadn't spoken to him since 1995! Lots of U.S. contacts too. People really like it when I turn off my linear and go to 1 watt; they can almost always hear me with the 1 watt.

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Beautiful Videos from the Space Station

http://eol.jsc.nasa.gov/Videos/CrewEarthObservationsVideos/

The link above takes you to a really spectacular collection of videos taken recently from the International Space Station. Great stuff. Be sure to check out the aurora. And the stars as they become visible over Canada. The St. Lawrence seaway is very apparent in the Mexico to New Brunswick video. In that one you can also see where the Rockies really start to rise (not so many lights). Over the Great Plains you can see where the main North-South and East-West highways are (straight lines of lights!).

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Knacktivity in the White House: The Mashmallow Cannon

I thought this was a lot of fun. And in another video I saw that the kid was using an Altoid tin to hold the batteries that power the trigger.

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The Parasaki: DL3PB's Amazing All Diode Transceiver

JBOD! FB!

Hi folks,

I'd like to share with you a long-cherished dream, that recently came true, forty years after I came to read about hams using tunnel diodes to make QSOs when I was aged twelve or so:

Finally I managed a first skywave QSO with my PARASAKI-transceiver, an 'all diode' rig: Christophe/F8DZY replied to my very first call on 20m band in REF-contest last weekend. I was running 2mW into a temporary vertical dipole on my balcony. Distance between us is 918km - obviously OM Christophe has excellent ears.

Those interested in the cruel details of my circuit, please find attached a schematic and a photo of the pretty ugly setup. The circuit is designed straight-forward with exception of the parametric VXO, derived from Mike/AA1TJ's famous Paraceiver design. (see http://fhs-consulting.com/aa1tj/paraceiver.html )

The low impedance of the high peak-current tunnel diodes make it very difficult to built a really crystal controlled oscillator rather than an LC-oscillator, synchronized by the crystal more or less, at least on the higher SW-bands. The Parametric VXO provides a crystal-stable, chirp-free signal on expense of an output power of two milliwatts only instead of ten, but with an amazing spectral purity, no need for a low pass filter or such. Of course it sounds pretty cool making a QSO with a 'bunch of diodes' and a parametrically excited crystal, but believe me or not, I'd preferred to bring that full ten milliwatt into the air - on the other hand that approach allowed to tune the rig a bit ( ~ 5kHz/per xtal), which turned out to be much more valuable than a few milliwatts more while being 'rock-bound'.

The receiver in its 'gain-less' version works fine for strong signals - while listening to QRP(p) stations, the moderate gain of the audio amplifier helps a lot. A comfortable frequency shift between receive and transmit is realized by the 5µH inductor at the LO-port of the mixer, with little effect on sensitivity.

Thanks for the bandwidth, OMs, won't bother again you with such mails, unless I make a cross-pond QSO with that rig ( not that likely ) or any skywave QSO with homemade semiconductors ( probably impossible )...

72!

Peter/DL3PB

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Building a Wright Model D

There is a lot of Knack-like activity in this project. I think you guys will like this show. I'm not sure the Hulu link will work outside the U.S.

http://www.hulu.com/watch/23333/nova-wright-brothers%E2%80%99-flying-machine

There is also a lot of good background info here:

http://www.pbs.org/wgbh/nova/wright/

And as long as we're talking about Knack-related aviation, here's a great article about an avionics engineer who has made a big difference in the world:

http://seattletimes.nwsource.com/html/businesstechnology/2017426408_bateman05.html

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SolderSmoke Podcast #141

http://www.soldersmoke.com/soldersmoke141.mp3

February 5, 2012

Recording on repaired computer
RG-174 shield wires: "Murphy's Whiskers"
"The Radio Art"
"Non e radioamatore se non gli fuma il saldatore!"
Does soldering a soldering iron disturb the universe?
HCJB: Home of the Quad, but DX Party line is over
Butane, Loctite, Scotchbrite, Velcro, and Gorilla tape
Getting the 17 meter SSB station going -- trials, tribulations, triumph! MAILBAG

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QROoooooooo!

Here's a rig that will never be featured in SPRAT or QQ! Welcome to the Gates HC-114: http://www.transmitter.be/gat-hc114.html
(Stephen, G7VFY, sent me this, so blame him if this exposure to QRO causes any psychological trauma.) I note that the rig does have a five element low-pass filter.

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The Knack, defined

Of course, our British cousins will have some problems with this. (We already have some lexicon problems there -- I can sense many of them wincing every time I say "SodderSmoke"!) But I'm sure they will be understanding here. And indeed, the Knack can sometimes leave you Knackered! (BTW: I currently have an annoying little soldering iron burn on the tip of my right finger.)

Hi Bill,

Maybe I'm not the first to think of these two words, but here goes:

Knacking v/n. as a noun, the act of artfully and cleverly designing, building from scratch, or repairing devices using, usually electronic in nature, specifically amateur radio related...not related to hacking As in: "My knacking was a success and I finally got my Drake 2B working on 30 meters" Somewhat redundant, since knacking IMPLIES extreme cleverness, knacking ALWAYS has a successful result, by definition!

as a verb (as in "Googling") to artfully and cleverly design, build, or repair a device, normally electronic in nature as in "I was knacking my JBOT amp yesterday and successfully added a new low pass filter" Implies high level of cleverness and determination and a modicum of luck


knacker n. one who artfully and cleverly designs, builds or repairs electronics, especially amateur radio related, implies high level of accomplishment and can be used by knackers to describe themselves without embarrassment or outright bragging. Knackers do not need formal training in electronics to fully qualify. Knackers always know who they are and can be identified by burn scars on their fingers from soldering accidents.

Keep your great blog and podcasts going.

73

Steve Silverman
KB3SII

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Hard Core! Wisdom and Ideas on Toroids

Gerard ZS5AAC

This morning the BITX20 mailing list has an interesting discussion of toroidal cores. I especially like Gerard's use of the cores from old CFL bulbs. Farhan wraps it up with a great explanation of why we use ferrite cores in broadband transformers:
------------------------------
Over the years I built quite a few BITX's. In the beginning I used the
toroids salvaged from CFL lamps. These worked quite well for the mixer
coils. For the filter coils I used 6mm bakelite slug tuned coils that were
stripped from old PYE radios. Wonder if anybody else experimented
along the same lines. I build my BITX's Manhattan style and they work from the start with few minor tunings. Happy BITX'ing, Gerard, ZS5AAC.
---------------------------------------
Bob
The purists may attack us on this, but what you propose is very
possible. I have been using a wooden-core toroid for several years as part of an antenna tuner.

http://qrp.webhop.net/Pictures/Webcam-1293651325.jpeg

http://qrp.webhop.net/Pictures/Webcam-1295140555.jpeg

I'm also using small plastic and wooden beads as toroid cores for
several other projects. Half inch long sections cut from thick-wall (schedule-40 or schedule-80) PVC pipe also makes good toroidal forms. Beauty of using non-metallic cores is that the core can be split to allow winding wire through the slot without having to thread it through the hole.

http://qrp.webhop.net/Pictures/Webcam-1289957121.jpeg = 1.4 uh

Bending an inductor back on itself in toroidal form concentrates the
magnetic field in the center, whether the core is metallic or non-metallic. This gives you similar self-shielding properties when using either type core material.

With non-metallic cores you no longer have to worry about core saturation, so running high current finals is not a problem.

Key to doing this is being able to measure inductance of 5 turns, 10 turns,
and 20 turns, so you can calculate and plot the effective AL of your wooden core toroids. Once you know this value you can make up a chart to tell how many turns are required for a specific inductance.

Twisting wires together to make a transmission-line for bifilar or
trifilar windings is interesting because the impedance of that transmission line might affect performance of your transformer. It may require a bit of experimentation with an SWR bridge to tell when you have the best balance between twist pitch, wire diameter, and insulation thickness.
Arv - K7HKL
---------------------------------------------

Robert, Arv,
There are two types of coils used in the bitx - the broadband
transformers and the RF coils in the bandpass filter and oscillators.
You could easily substitute the rf and vfo/bfo coils with just about
any kind of coil - as long as you are hitting the same inductance and
Q. But there is a catch : a few years ago, I finally got down to
measuring the Q of the nylon tap washers that I had originally used.
The q was quite modest at 70. Wes made independent measurements with similar results (his paper is on www.w7zoi.net under technical stuff). In short, for good performance use good old air coils wound on a
cylindrical formers if you don't use toroids.

About the broadband transformers. These need a material that has very
low loss, very high permeability. The reasoning is like this :
1. We need an transformer's inductance such that the reactance is
at least 200 ohms at the lowest frequency. This puts the inductance at
around 30uH at 4MHz.
2. If we achieve 30uH through lots of turns (say 100), each turn will
exhibit capacitance with it's neighbor and the large number of turns
will add up the capacitance so that the coil will provide enough
self-capacitance to resonate at an unintended frequency in HF leading
to pretty bad mixer performance.
3. The only way out would be to achieve the required reactance with
lower number of turns. This means using ferrites.
- farhan VU2ESE

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Success on Seventeen Sideband!

Wow, sometimes scratch-built homebrewing can be a frustrating masochistic activity. Who among us at one point or another hasn't sat back from the bench and wondered why he didn't take up stamp collecting? But then sometimes the radio gods are smiling on you, the smoke stays inside the components, the antenna rope doesn't break, oscillators osc and amplifiers amp and all is right with the universe. I had one of those days yesterday.

The RF feedback measures I described earlier took care of that problem very nicely. Conditions on 17 were not that good yesterday, but as soon as the sun was up I started hearing stations. I called Phil, K5ACR, in Oklahoma and he came right back to me. He said the signal sounded OK, but he thought I might have been driving it a bit too hard. I backed off a bit and he said it sounded very nice.

Our weather was really disturbingly pleasant yesterday (we're not supposed to be out in T-shirts on January 31). I took advantage of it and went out with my fishing pole and sling shot (the neighbors love it) and got a line over just the right branch. This allowed me to turn my low-to-the ground 17 meter inverted Vee into a proper dipole, up about 15 meters or so.

Back to the shack and K5USI said I was booming into Mississippi's Gulf Coast. I turned off my 20 watt linear and he could hear me just fine barefoot. Then I worked K2BQ in Florida. All stations report that the signal sounds very nice.

I remembered that I did a QST article about this transmitter a few years back. I can't find it on the web, but here is an old page that describes it as it was in the last solar cycle:
http://www.gadgeteer.us/17SSB.HTM

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics"http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20

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Save 20 percent through February 3. Through the Lulu site you can get the book in the print or e versions.

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Our book: "SolderSmoke -- Global Adventures in Wireless Electronics"http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20