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Monday, July 28, 2008

Rome Workbench

Here is the workbench, now located in Rome. If you look closely, between the two shelves on the wall you can see my "tool hanger." It is just six inches of insulated wire on which I hang diagonal cutters, pliers, wire strippers, etc. You can also see my little HAMEG 'scope.

Saturday, July 26, 2008

Dan's Small Parts Back in Operation

http://www.danssmallpartsandkits.net/

Dan is a great source of parts for Knack victims. Check out his catalog -- take a look at his special deals.

Wednesday, July 23, 2008

VE7SL Identifies Mystery Military Radio

That's the one. That's the radio that Giorgio, I0YR, and I have had our eyes on. I found it in a local charity shop (location to remain secret, pending final transaction!). The one I found had no identifying plates, but with the scant info I provided in SolderSmoke 88, Steve, VE7SL, figured out what it was, and sent this picture to confirm. Not a BC-348, but instead a USMC BC-312.
UGLY BEAST! Not my kind of rig, but Giorgio may want it. Thanks Steve!

Check out Steve's web page: http://www.imagenisp.ca/jsm

Monday, July 21, 2008

Shep, SETI, Radar, Spark Coils

In this episode Shep builds a 2 meter rig to talk to locals, but picks up signals from much farther away. Musings on extraterrestrial DX. Also, our hero gets zapped by a spark coil.
As always, it takes Shep a while to get going on the ham radio stuff, so you might want to fast-forward through the groovy 1965 small talk at the beginning. EXCELSIOR!
Here is the mp3: Shep, 1965, 2 meters, SETI, Spark Coils.

Sunday, July 20, 2008

The SolderSmoke Microphone

As promised, here is the infamous SolderSmoke microphone, featuring duct tape, and supported by a Radio Shack "Third Hand."

Check out the "popping on the letter P" audio filter I made out of a bathroom drain filter, a baby wipe, and duct tape. The previous effort using some foam from an old Walkman headphone is also visible.


Kind of appropriate, don't ya' think? I think this simple filter has helped with the audio problem.
(Let me know what you think.)

Saturday, July 19, 2008

SolderSmoke #88

July 19, 2008

http://www.soldersmoke.com

My walk to work in Rome
The BEST Jean Shepherd ham radio episode
My talk with Jean Shepherd
NR5A's beacon
200 Knights
QRSS of .3 wpm = 1.3 Hz bandwidth
IZ4BFA in stereo CW
K1JT - The Knight with the Nobel Prize
WSPR
Drain cap audio popping filter
Help ID a BC-348
Dan's Small Parts to return
The British Amateur Television Club: Knack to the Max
ADVERTS: N3ZI's Freq Counters, Gadgeteer Books
MAILBAG: Home Counties QRP Club, LU1CBL's BA Beacon,
I2NDT's Thailand Beacon, KI4UZI listens at Cape Kennedy,
KD0BIK's podcast, AF4UI's LC meter, KD4EBM on Coherent CW,
ZL3TKA IS NOT CRAZY, 7J1AWL reading "Crystal Fire,"
M0JFE wants HB phone, VK7AX rebroadcasting SolderSmoke in
Tasmania, M0NDE caught The Knack at age 6.

Friday, July 18, 2008

The QRSS Knight with the Nobel Prize


We are in some very distinguished company on the QRSS "Knights" mailing list. Joe Taylor, K1JT, is active in the group. Joe won the Nobel Prize in Physics in 1993. His biography includes references to ham radio that will warm the hearts of all Knack sufferers: K1JT's bio

This year, Joe created a new piece of software that is being used by many of the Knights. It has a name that will appeal to QRP'ers. Here is a description:

WSPR is the name of a computer program.
It is pronounced "whisper",and stands
for "Weak Signal Propagation Reporter";
it implements transmitting and receiving
functions for a digital soundcard mode
called "MEPT_JT", which stands for
"Manned Experimental Propagation
Tests, by K1JT".

WSPR generates and receives signals
using structured messages, strong
forward error correction,
and narrow-band 4-FSK modulation. Its
principal design goal is reliable
copy at very low signal levels. In
practice it works well at
signal-to-noise ratios down to -27 dB in a
reference bandwidth of 2500 Hz.
Joe recently released a new version of WSPR, so if you are going to give this a try, make sure you do so with the most recent release. You can download WSPR 1.0 (r972) from

http://physics.princeton.edu/pulsar/K1JT/WSPR100.EXE

Sunday, July 13, 2008

The BEST Jean Shepherd Ham Radio Episode

Mark, W8MOJ, found this one a while back, but then somehow we lost it. This morning I found it again. Jean Shepherd talks about ham radio homebrewing, regen receivers, searching for parts at radio row, building stuff in the basement, secretly studying for his ham license during civics class, and one of his teenage ham friends who, in his basement, secretly built a.....

"Other kids would draw Christmas trees and sailboats... I would draw schematics of phone transmitters."

Don't miss this one! Here is the link to the mp3 file: Jean Shepherd, January 24, 1973


N3ZI's $9.99 Counter Kits

Doug, N3ZI, was one of the intrepid participants in the ARRL Homebrew Challenge competition. FB! He is now making available some very inexpensive digital frequency readout kits. Jerry, NR5A, sent me one. (Thanks Jerry!) Obviously this is a kit useful to Knack victims.

Here is the web site for the kits: http://www.pongrance.com/

Saturday, July 12, 2008

UK Amateur TV: KNACK TO THE MAX

You will really like the video archive of the British Amateur Television Club. Start out with the "Bob and Brian" show. It is as if "60 Minutes" did a segment on THE KNACK. Don't miss the excellent antenna lecture by Dud Charman, G6CJ. He used small-scale antennas at UHF to demonstrate the principles behind directional antennas. All of the videos in the archive are very good. Thanks BATC!

Here's the link: http://www.batc.tv/channel.php?ch=1

Wednesday, July 9, 2008

My Beacon (MEPT) Circuit

Guys have been asking to see the schematic for my 30 meter QRSS MEPT beacon. Here's the oscillator circuit. This actually started out on a plane ride. My son Billy and I were talking about electronics. I drew a basic schematic for an oscillator, and we built one when we got home. It originally used a 20 meter crystal. At one point we were playing "find the oscillator" -- hiding it somewhere in the house, and tracking it down with a Sony shortwave receiver. Now, with some modifications, it is the first stage in my 30 meter MEPT beacon.

An ugly schematic for a rig built with the ugly construction technique. Nothing fancy here. Two feedback amps and a PNP transistor as a switch to key them. I let the oscillator run continuously. (Let me know if you can hear the "backwave"!) About 20 mw out. As you can see, it doesn't take much to get a QRSS signal on the air.

Tuesday, July 8, 2008

Shepherd Learns Morse and Discovers Ham Radio


Here is another gem from Jean Shepherd. He describes his discovery of CW at age 6 or 7, his first shortwave receiver, and his discovery of amateur radio. Plus, some Army Signal Corps madness.

Click here for the mp3 audio file: Shepherd, Morse, Ham Radio

Sunday, July 6, 2008

SolderSmoke #87

July 6, 2008     

http://www.soldersmoke.com

On the beach at Fregene
-----------
QRSS Mania:
Calibration problems solved
First reports received
The Fun of Grabbers
Checking your signal via Blackberry
The Joy of Milliwatting
Chirp, Click, Drift in QRSS
Temperature sensitivity
Bury that Beacon?
Why so little US QRSS?
More US Grabbers needed
AA1TJ/QRSS?
----------
Elser in "History of QRP in US"
New Slides, WAC on ClustrMap!
MAILBAG: G0FUW reports EI9GQ victin of Knack
KC0PET on understanding our circuits
ON4FW sends FB pictures
KG6TCJ on QRSS calibration
W7ZOI on FD and calibration
W4NI on measuring harmonics
PE1OIT on GPS calibration technique

Saturday, July 5, 2008

The QRSS View from ON5EX -- July 5, 2008


I wanted to give you guys a sense of what you can see on the QRSS Grabbers. The grabbers are just the output screens from the Argo or Spectran (or other) software that have been placed on-line, updating every few minutes. In the screen shot above, you can see the sophisticated signal of Eddie, G3JZO, pounding into Belgium (this is the Grabber of Johan, ON5EX). My much more basic effort is visible as a line of Morse Code just below Eddie's sig. Above Eddie you can see the "snake CW" of IQ4FJ. Along the bottom right of the screen, you will see the square wave signal from the 5 mw solar powered beacon of Paolo, IZ1KXQ (scroll down a bit to see his rig, and his schematic). I think the vertical stipes must be lightning.

Check out I2NDT's Grabber Compendium (but be aware that not all of them are on 24/7):
http://digilander.libero.it/i2ndt/grabber/grabber-compendium.htm

In this screen shot from I2NDT's Grabber, you can see the effect of me turning the air conditioning on in my shack. I have added a bit of insulation (an ARRL Handbook placed on top of the beacon box!) and things seems to have stabilized. With the entire "QRSS band" only 100 hertz wide, it doesn't take much to slide your signal all the way across the band!

Friday, July 4, 2008

Cleaning up my QRSS Signal

This week I worked to improve the quality of my 30 meter QRSS signal. At first I was pleased to just be in the band and visible on the grabbers. But soon I grew jealous of the very clear and clean dots and dashes of IK0IXI and others. My droopy dashes ("Italian tears") were getting embarrassing. Making matters even worse, when conditions were good, very noticeable key clicks became visible on the grabber screens. These became known among the Knights of QRSS as "shop hooks." I thought they made my signal look like some sort of Arabic lettering. Clearly something had to be done.

Yesterday I put a seven volt zener diode voltage regulator in the oscillator circuit. I also drastically reduced the size of the the capacitor that connects the oscillator to the first RF amplifier. This seems to have done the trick. The clicks are gone and the dashes no longer droop. Power out is now down from 200 milliwatts to 20 milliwatts. That's fine -- this puts me in the power range favored by the Knights.

The narrow-band nature of QRSS work makes imperfections very visible. A chirp or click that would be undetectable on ordinary CW becomes very apparent in QRSS. This morning when I adjusted the air flow from the shack air conditioner, I inadvertently sent the stream of cool air toward the beacon transmitter. With the On5EX beacon on my screen, I could almost immediately see the resulting frequency change!

The on-line grabbers are really fantastic. They give you and almost real-time ability to check band conditions. Almost all day I can see my 20 milliwatt signal arriving at ON5EX. Depending on time of day, you should be able to see my signals here: http://www.on5ex.be/grabber/grabber.html Look for me around 10140060 (+/- air conditioning).

Why isn't there more QRSS activity in the USA? Why are there so few American grabbers?
Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column