That begs a good question. How many hackers here are also hams? I'm W1OFZ.
I became a Technician when I was in high school because I lived in NYC (went down to Varick street to take the test) but didn't know anyone who could administer the Novice test.
Built a small QRP rig but never made contact with anyone and lost interest.
A few years later I went back to get either my Extra or Advanced...who remembers. I did that more to see if I could copy code at the required rate than for any other reason. Actually I think my last license might be in the safe, I should take a look someday.
I was never that interested in being a ham and talking to other people; SWL was much more fun. I had QSL cards from all over the world.
In practice, especially on bands this low, it's mostly unenforceable. Just don't be a jerk: keep your power low, your bandwidth small, and make sure no one is using the channel before you smear your transmission all over it.
30m rocks for mobile as well.
In classic "CW" (continuous wave, aka. Morse Code), it would be keying the transmitter on and off. When the transmitter is on, it is transmitting a pure sine wave at the Tx frequency (10.140015 MHz). When the transmitter is off, it is transmitting nothing (duh).
Looking at the schematic, the kit in question is transmitting continuously and modulating the carrier to be slightly higher or lower in frequency based on the square wave modulation drive.
For a direct conversion receiver[1], (heterodyne[2] works the same way, but uses intermediate frequencies to improve selectivity) the receiver has an internal oscillator that is tuned to approximately 1000 Hz difference from the transmitter. By mixing the two signals in the receiver, it demodulates the transmitted signal into a 1000 Hz tone when the transmitter is transmitting and nothing when it is not transmitting (CW) or higher and lower pitches with the kit from the article.
The CW on/off modulation is what you hear (simulated) in the WW2 movies with the beeping ("dit" and "daaah") sounds.
[1] http://en.wikipedia.org/wiki/Direct-conversion_receiver
[2] http://en.wikipedia.org/wiki/Heterodyne see also http://en.wikipedia.org/wiki/Superheterodyne_receiver
I am starting to think the square wave is an artefact from the circuit design.
[Edit: to lose that extra zero. Thanks Joe.]
Here is an excerpt from his book:
My ham radio link is working better than expected. Before I started this sail, I spent some time installing and testing ham radios and computers in both the boat and my house in Oregon. I wanted to be able to write a message here, transmit it by radio, and print it on paper in Oregon. At the Oregon end, because a normal person (not a radio nerd) has to be able to use the system, there's a simple "message screen" on display. A person just sits down at the computer and types a message, then presses a key that saves it. The next time I make contact I collect the messages.
http://www.arachnoid.com/sailbook/Chapter_2_--_Oregon_to_Haw...
I might just go into the basement and put together a simple 40 meter receiver tonight just to see if there's any activity there and maybe build a small transmitter later.
ISTR that the FCC went to non-expiring licenses. My last one is from the late 80's/early 90's. Anyone know what the likelihood is that I still have a valid license?
Makes me think about an alternet for when they switch the internet down.
