Homebrew Two Dollar Oscilloscope

This is from a short article in the April 1997 issue of Electric Radio magazine. The author is Bob Dennison, W2HBE. Bob is a real genius, and the author of many inspirational articles in ER.

The Sundt Engineering Company of Chicago was advertising this kind of device in the June 1936 issue of Short Wave Craft Magazine. Only two dollars (but that was big money in 1936). From Bob's article: "When the transmitter is modulated with a single audio tone, the waveform of the modulated carrier will be seen. By varying the motor speed (horizontal scan rate) the pattern can be synchronized or made to stand still. Percentage modulation is readily estimated by simple inspection of the display."

So here we have the perfect minimalist 'scope to go with a minimalist AM transmitter!

EME, Bob Heil, and The Grateful Dead

I really loved the TWiT interview with Bob Heil that I posted yesterday. Today we bring you a truly "must see" video on the History of Heil Sound. Really great stuff. Now I know that it was FATE that caused it to be a Peter Frampton song (using a Heil Talk Box) that helped me solve my RFI problem.

Bob Heil seems a really great guy. I liked the bio that he has on his web site.
http://www.heilsound.com/amateur/aboutus/index.htm

Name: Bob Heil
Bob Heil
Position: CEO/Founder
Started in: 1940
Bio: Bob's life mission is to have fun and bring LOTS of people along for the trip. Bob barely got through grade school and then started making more money than his teachers by playing the (Hammond) organ. Then Bob became a pimp for his high school gym teacher (Sarah can fill you in on the details). Bob had 50+ years of "just OK" life until God sent him a red headed bundle of joy along with her bundle of joy and together they have more fun than a couple of squirrels in a nut forest.

Interview with Bob Heil

W8FG alerted me to this interview with Bob Heil on TWiT. I think you guys will enjoy it (especially all of you rockers out there).

http://www.twit.tv/tri8

WelderSmoke!

FROM STEEL: The Making of a Soulcraft from michael evans on Vimeo.

We need videos like this featuring our kind of smoke!

Beacons from Space! Yuri Gagarin Anniversary

SB SPACE @ ARL $ARLS005
ARLS005 ARISSat-1 On the Air for Gagarin Anniversary

ZCZC AS05
QST de W1AW
Space Bulletin 005 ARLS005
From ARRL Headquarters
Newington, CT April 8, 2011
To all radio amateurs

SB SPACE ARL ARLS005
ARLS005 ARISSat-1 On the Air for Gagarin Anniversary

To celebrate the 50th anniversary of the first human spaceflight by
cosmonaut Yuri Gagarin, the ARISSat-1 satellite aboard the
International Space Station will be on the air using the station's
external antenna. Transmissions will begin on Monday, April 11, at
14:30 UTC and continue until 10:30 UTC on April 13.

To preserve the satellite's battery, transmissions will cycle on and
off. ARISSat-1 will transmit for 40 to 60 seconds, and then remain
silent for 2 minutes.

The FM transmissions on 145.950 MHz will alternate between a voice
ID, telemetry values, SSTV images and audio greetings in 15
different languages. One of the transmissions will contain audio of
a conversation between Gagarin and ground controllers that was
recorded during the historic flight.

A CW beacon will be heard on 145.919 MHz cycling between the
ARISSat-1 call sign, telemetry and call signs of individuals
involved in the ARISS program.

BPSK-1000 telemetry transmissions will also take place on 145.920
MHz SSB using the new 1kBPSK protocol developed by Phil Karn, KA9Q.

AMSAT will issue commemorative certificates to listeners who receive
the ARISSat-1 transmissions. Reports can be e-mailed to
Gagarin@arissat1.org or yuri@arrisat1.org. Include your name, call
sign, a description of what you heard and the UTC time you heard it.
Recording the battery voltage telemetry values and the UTC time you
received them will be especially helpful.

You can determine when the International Space Station will be
passing overhead by using the AMSAT-NA online pass prediction tool
at, http://www.amsat.org/amsat-new/tools/predict/.
NNNN
/EX

Another QRPoet

I'm a big fan of Ade Weiss, and I often find myself reaching to his "History of QRP" for technical or techno-literary inspiration. Most writing about ham radio is (understandably) done in a very straightforward technical way, without a lot of emotion. But Ade's writing style captures both the technical and the emotional aspects of homebrewing and QRP. There is a definite poetic elements to it. This article was sent to us from the Hobbit Hole by the Poet Laureate of QRP (AA1TJ). Just click on on the image to enlarge. From a 1973 issue of The Milliwatt:

How cool: HOWTOONS!

That's the spirit! Maker blog led me to this very nice tech cartoon site aimed at bringing kids into the world of making things:
http://www.howtoons.com/?page_id=2807

PACKET MYSTERY FROM SPAAAAACE!

OK guys, please reach back into your memories, back to the late 80's, back to those sad days before the internet, back to the days of TNCs and packet BBSs and all that. I need some help.

I have my little 2 meter packet station running. I'm sending out beacon packets on 145.825 MHz, the freq of the International Space Station. (Is PC-SAT still on that freq also?)

Every morning I go to the old 1994 Satellite Pro computer (thanks to ZL3KE!) and type in mheard to see the list of stations picked up during the most recent passes of the space station. Every day there are several, each with an asterisk indicating that the packets were digipeated, and on this freq the digipeating is done in space.

Here's my question: Two days ago, MY OWN CALLSIGN showed up in the MHEARD list. (Cue ominous music) BUT WITHOUT THE ASTERISK! If I had seen the asterisk, I would have thought that my own packets were being digipeated by the ISS station and coming back at me. But why no asterisk? Long Delayed Echo? Klingons? My misunderstanding of packet technology?

SolderSmoke Book -- Now on Kindle!

In response to popular demand, "SolderSmoke -- Global Adventures in Wireless Electronics" is now available as an e-book for Amazon's Kindle.

Here's the U.S. site: http://www.amazon.com/dp/B004V9FIVW

And here's the UK site: https://www.amazon.co.uk/dp/B004V9FIVW

Inside the SolderSmoke Microphone

Here's a really excellent description of how an electret microphone works, complete with a dissection of the device.

http://www.openmusiclabs.com/learning/sensors/electret-

Crystal mics are much more interesting, of course, because of the opportunity to chemically tailor the audio response...

The Polyakov QRSS Receiver

Of course, we like it because it is in an Altoid-like box. And because it is Direct Conversion. And because it is used for QRSS, with the output fed to an on-line grabber. But this one is EVEN BETTER because it uses a Polyakov detector!

Check out PA1GSJ's receiver: http://www.qsl.net/dl1gsj/html/qrssrx30.html

View the output (live): http://www.qsl.net/dl1gsj/qrss/

More on Polyakov detectors: http://soldersmoke.blogspot.com/search?q=polyakov

Snort Rosin's Mighty Mite: The Super Duper X Spy Transmitter

Hi Bill,

Attached is a picture of the remains of my transmitter, "The Super Duper X Spy Transmitter". My little rig didn't sit around; it made QSOs the day it was finished, 41 years ago. Since then it has bounced around in various junk boxes and had some parts robbed for other projects but thankfully it's still mostly intact.

I constructed it based upon the original article in Ed Noll's book, "Solid State QRP Projects", pg. 51, Project 17, "10 160 All-Band Two Watter". That transmitter was later to become known as the Michigan Mighty Mite.

My MMM (or SDXST if you will), features a built-in relative power detector, a microswitch key (upper right-hand corner), room for an internal 9 Volt battery and a jack for external power. The jacks are each different; a BNC for the antenna, a 3.5 mm closed-circuit jack for the key, a 2.5 mm for the relative output meter and a phono jack for the external power. My notes say that I added a .1 uF Emitter bypass and that it increased the power output by 50%. I also used a toroid for the output tank instead of the 1-3/4" coil form called for in the article. Use of the "Sucrets" box was not my idea; I got it from one of the ham mag's. of the day, probably 73.

Your coverage of those little rigs has motivated me to restore mine and make some QSOs for old times sake. With, of course, the proper output filter :-). I'll send a picture of the 'guts' when it's finished.

73.......Steve Smith WB6TNL
-------------------------------
Thanks Steve. Great stuff. But... WHERE'S THE OUTPUT FILTER?