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Friday, March 6, 2009

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!

Wednesday, March 4, 2009

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/

Monday, March 2, 2009

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

Sunday, March 1, 2009

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.
---------------------------

Saturday, February 28, 2009

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
Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column