for Issue #6
(Having trouble seeing the entire issue? See the note at the bottom of this page for possible cause.)
contributing authors have once again overwhelmed us and allowed us to produce a
terrific issue of Homebrewer Magazine. Contained in more than 500 pages of full
color, high resolution graphics, we have a mixture of easy and complex, quick
and extended, antennas and radios, digital and analog … something for everyone
to build, and educational for everyone even if you don’t build up a given
highlight of the issue, and the cause of a great deal of excitement in the QRP
community during August-September, is something called the SoftRock-40
Receiver. This little 1”x2” board from designers Tony Parks KB9YIG
and Bill Tracey KD5TFD plugs into the USB port of your computer and works
together with a powerful software application from FlexRadio called
“PowerSDR” to provide a 40-meter receiver with absolutely stunning
performance. The exciting quadrature
sampling detector enables the software on the PC to pull out signals as low
as 40 dB, thus rivaling some higher-end commercial receiver performance.
Beford, N1RX provided a nice service to many on QRP-L by experimenting
with a different crystal to move the SoftRock to 30 meters. He obtained
some crystals in quantity and supplied them at cost to SoftRock owners wishing
to modify their kit … and Bruce wrote up a nice article for Homebrewer
explaining how he went about designing the mods.
speaking of quadrature sampling receivers, we had a surprising contribution from
a pair of wonderful designers from Finland, Juha Niinikoski OH2NLT and
Matti Hohtola OH7SV. These guys designed and built an award-winning, 0-8
MHz DDS-based QSD receiver called the JUMA-RX1 that has nice
specifications – and I’m currently in the process of building this one up
Defined Radio (SDR) radios are becoming quite popular these days, much due to
the excitement and interest generated by FlexRadio Systems’ SDR-1000
transceiver. We had a review of this radio way back in in Homebrewer issue #1,
but QST recently published a wonderful review of this same radio and
covered the many new features that have been added since we saw it here. So in
joining with the surge in popularity of SDR, we re-published our original SDR
review written by designer Gerald Youngblood K5SDR. We also have included
the well-done QST review. And lastly we have added the technical overview of SDR
technology that software radio guru Bob McGwier N4HY did for us in the
Atlanticon 2004 Forum. This is a one cool collection of SDR reference material!
the time this issue gets into your hands, the AmQRP likely will have announced
details and availability of the DDS-60 Daughtercard. The article in this
issue describes how we extended the frequency range of the original DDS
Daughtercard by going to an AD9851 DDS chip and including the DDS Amp project
right on the main DDS card itself. We went to using the AD8008 op amp to provide
a nice, flat signal level right out to 60 MHz, and we retained the use of the
SMT trimpot to allow output level adjustment. Then as a builder option, we
provide DS-1804 digipot to allow the external controller software to also change
the output level. Pretty neat!
along the line of DDS signal generation … two DDS chips have got to be better
than one, right? Lyle Johnson, KK7P
thinks so, and he provided an article describing his DDS2 dual chip design
that forms a building block for a software defined radio clock generation
circuit. By operating two RF clocks of the same frequency but having 90-degree
phase difference, one has the start of some great signals to drive QSD and QSE
circuits on an SDR radio.
are also fortunate to be able to include KK7P’s Atlanticon presentation
of Digital Building blocks for Analog Radios. He received rave reviews
from the Atlanticon audience this past spring, and now you’ll have a chance to
see into the mind of one of the brightest QRPers in our midst.
designer of the famous HAMCALC program, George ‘Murph’ Murphy VE3ERP
worked with W2AHW to produce a design of a miniature magnetic loop called
the Octaloop. Imagine having an Small Transmitting Loop (STL) antenna for
80m that is only 52” in diameter! Murph and Harold provide some clear and easy
plans on how this can be effectively accomplished.
PIC-based weather station article series from Dave Ek, NK0E has spanned
two magazines and 5 years’ time. We’ve provided here in this issue of
Homebrewer the full series of PIC-WX articles and software so you can
easily build up the project without referencing many back issues.
are so fortunate to have the homebrewing expertise and talent of Paul Harden, NA5N
with us as a regular contributor to Homebrewer Magazine! Paul’s “Handyman
Series” this time overviews the homebrewing techniques of Manhattan
construction and you’ll be absolutely thrilled in reading though his
installment. Outstanding stuff!
years ago, we introduced Craig
Johnson’s PIC-EL project board along with the start of the Elmer 160 PIC-training
course for hams. The “Pickle” board was very popular as it had lots of
useful peripherals that we QRPers and homebrewers could use in actual
applications on the bench. Not the least of them is the DDS Daughtercard, and
because of it many people are now using the PIC-EL at heart of a precise RF
signal generator sitting on their benches. Since the AmQRP recently spawned
another run of the PIC-EL as a partial kit (board plus several hard-to-get
components), and KangaUS stepped up to make up bags o’ parts for the remaining
components, Craig and I felt it more than appropriate to collect the PIC-EL
documentation, add a little more to it and publish it all here together for
Homebrewer readers. Enjoy!
Ottenberg, WA2DJN is a regular contributor to Homebrewer Magazine and he
prides himself in finding simple ways to produce useful instruments for the
workbench. This time Dave found a nice test oscillator circuit and he packaged
it in a plastic tube for use as a signal injector.
fairly-regular contributor to our Homebrewer journal is Phil DeCaire, WB7AEI.
This time Phil explores the ever-present world of Low Pass Filters
and provides us with some useful tools, simple equations and practical examples
in their use.
Holton, N1NB spent a lot of time with KK7P and me in designing the AF-908
DSP audio filter. In doing so, he became very familiar with the Micro908
hardware and software capabilities and he applied it in solving a challenge we
made at this past Atlanticon: stabilize the Crystalizer! Steve designed a simple
interface for the Micro908 to control the Crystalizer and wrote a nice
program using a thermister in a control loop to keep the Crystalizer frequency
right on the mark. By the way, he
won first prize at Atlanticon for his effort here!
Bresedin, UA9LAQ contributed two articles to Homebrewer this time, and in
his own unique style provides us with some of his wonderfully-stated designer
wisdom. His overview of his 20-meter
receiver, and a walk-through of an experimental 2-meter antenna
provide a delightful and informative read.
Everhart, N2CX has been doing the design series called Power Meter
Cookbook for a number of issues. He
is now getting to the point in this current installment of getting us past the
“analytics” stage and on to practical incarnation of his designs. You can
wire up the circuits he provides this time and make some great headway on better
understanding the theory presented thus far.
are very fortunate to have received permission from Murph VE3ERP to
include his ever-popular and ever-improving HAMCALC program set on the
Homebrewer CD-ROM. You can find his
latest program (#78) in the Software section of this CD.
Assistant editor Nancy Feeny NJ8M also felt that it would be
useful in each issue to have a walk-through of one of HAMCALC’s features in a
real-life example, and she’s provided a nice tutorial on designing a power
supply with the appropriate programs in HAMCALC.
are some good projects that just never lose their value over time, and it’s
curious how some designer/authors always tend to be the source of those
projects. Jim Kortge, K8IQY designed the Precision VXO project
some years ago and presented it at Atlanticon to a very eager audio.
Then in the following months he provided the design for a mating Crystal
Measurement fixture to give us homebrewers some real useful capabilities on
the bench. We present both of these
instruments again in the Homebrewer pages … if you missed building them the
first time, here’s a chance to reprieve yourself!
the last issue, Al Gerbens, K7SBK introduced his Excel macro
“program” called AA908 Plot Gen that took the raw data file produced
by a scan of the Micro908 Antenna Analyst and displays a wonderful plot of the
SWR, resistance and reactance. Never one to be satisfied with something that
works (like all of us, I think!), Al made a raft of feature additions that
further increase the usefulness of this tool.
Joe Everhart’s N2CX
Test Topics and More (TTAM) column this time around shows some basic
electronics that are relevant for more than just test equipment. The “Designed
for Test” section shows how to use a 75-ohm attenuator with other equipment
and cables designed for a 50-ohm impedance using a so-called minimum loss pad.
Joe’s “Coming to Terms” section deals with series and parallel equivalent
circuits, a topic that comes up now and again, particularly in conjunction with
impedance matching. “Stimulus and Response” talks about power attenuators
– how to design them and how to size the components that make them up.
columns are the staple of most magazines and Homebrewer readers are able to be
regularly exposed to the experience, wit and storytelling grace of Richard
Fisher KI6SN and Arland K7SZ. Through the KI6SN “QRP
Operating” column we get a view into some of the Field Day experiences
that some guys had this past
summer. Then in two K7SZ “Tuning Up” columns this time we learn how Digital
Dickey was converted from an analog world, and how that same analog world (a
la that troublesome Argonaut) nearly did him in.
Newman, N2CQ once again gives us a 3-month forecast of QRP Contesting
events, including links to all the associated rules web pages. As an added
treat, Ken supplied us with the full 5-year set of results from the
Homebrewer Sprint event that he runs during the spring and fall of each
year. What a great compilation of contesting results!
are very proud to present a first-of-its-kind (to the best of our knowledge) in
our QRP publishing world by producing, editing and publishing an instructional
video within the “pages” of Homebrewer Magazine. Joe Everhart N2CX and I
(N2APB) collaborated to present a 45-minute video overviewing the technical
aspects of the Micro908 design. This WMV file is able to be viewed in the
standard Windows Media Player (or equivalent) on most computer systems, and we
think you’ll enjoy actually seeing the designers describing their
is another great bonus feature in Homebrewer this time that you can’t find
anywhere else. We had an opportunity to interview the designers of the
SoftRock-40 (Tony and Bill) and we provided this hour-long audio file
on the Homebrewer CD for your listening pleasure. So not only can you read about
this popular little rig, but you can hear from the designers in their own words
about the project, the process they followed in developing it, and some of the
future directions they’ll next be taking the SoftRock.
Be sure to listen in on this interview!
are very thankful to Chuck Adams, K7QO for allowing us to include his
comprehensive Morse Code Training Course in this issue of Homebrewer
Magazine. Chuck is actively involved in training ham clubs in the proper
learning and use of Morse code, and he is quite an accomplished in this
communications mode. The K7QO Code Course consists of 149 MP3 files located on
this CD, plus some expert guidance provided by Chuck and several related
SOFTWARE on CD
is a ton of software programs, source code, and other files relating to
the articles and projects presented in this issue of Homebrewer. The best way to
see and use these files is to use your file browser to navigate to the CD drive,
and then into the Software folder. You will either see a folder with the name of
the individual software program, or a zip file that contains a compressed file
of all the related files for that named topic. These files will best operate
when copied to your computer’s hard drive. (Also, you should not attempt to
run a program while it is still contained in the compressed zip file container
– you will get unexpected results.)
programs and files included in the Software folder this time include: HAMCALC
78, PIC-EL design and software files, GCGC (Great Circle), WA0SVL Conversion
utilities, AA-908 Plot Gen, source code from all the PIC-WX articles, Serial DDS
source code, Link908 source files, SoftRock-40 and PowerSDR source and
installation files, software files for the JUMA-RX1 Receiver controller, TC908
Temperature Controller software, … and more. This folder is a software
homebrewer’s treasure trove!
the Why QRP? presentation is included
for your use at local club meetings. Lastly, as before, we have included the detailed
Kits folders including all manuals, schematics, software, pcb layouts, etc., for
current and popular QRP kits that have been produced over the years. This is a
great reference bank of technical homebrewing information!
Opening This Issue?
Several people have commented that they "only see the first 7 pages of the Homebrewer Magazine". The whole magazine is really there, trust us! The first, automatically-opened file is a 7-page PDF file called intro.pdf that serves as an introduction to all the contents of the CD and provides launch point hot links for the main PDF file of the magazine (e.g., when you click the photo of the cover) and other contents. If the hot links are not being interpretted by your operating system or Adobe Reader, try using your file browser (Windows Explorer, or equivalent) to view the file contents of the CD drive when the disc is inserted. You will see the main PDF file for the magazine called HB6.pdf and you can manually click on it to open and view all 509 pages. Similarly, you can navigate around the other CD files to access the rest of the wealth of information on the CD. Good luck and let us know if you have any problems reading the magazine.
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Page last updated: October 22, 2005