The following are mini-reviews of books I read in 2009.
Also see the full index of books I've read.

The ARRL Ham Radio Licence Manual: Level 1 Technician

Around 1970, my older brother got interested, deeply interested in ham radio; he eventually went on to get an Amateur Extra-Class license, became an electronics engineer, and now specializes in QRP (low-power) gear and contacts. I always copied everything he did, so I followed in his footsteps with regard to electronics and ham radio. Although I grasped the technical knowledge needed for the novice license (at the time), I never felt comfortable with Morse code, even at 5 words per minute. In late 2008, I started to get interested again in getting a license. I tried a Palm Pilot application that presented you with the ARRL examination questions. I still remembered a good bit of the technical knowledge, but some rules and laws had changed (or new ones had been introduced). So, I began reading the latest License Manual in January 2009.

Unfortunately, I came to a grinding halt on the page that explained amplitude modulation (AM). I was confused. First, the manual shows you the conventional graph of a radio wave whose amplitude varies according to the frequency of the input audio signal. Then, the manual shows the constant carrier wave along with the upper and lower sideband signals—whose frequency varies according to the frequency of the input signal. (I remembered the beat frequency oscillator, BFO, on my brother's equipment, so I guess that generates an artifical carrier wave so your receiver can convert the sidebands to listenable audio.) So, aren't the sidebands frequency modulated (FM)?

I called my brother up long-distance and explained my confusion about how AM radio works. He hemmed and hawwed and then mumbled something about how it depends on whether you look at the signal in the time domain or frequency domain. (Keep in mind that it's probably been decades since he gave any thought to this.) I understood that the domain in which you're looking at the signals could make a difference, but I didn't give it much thought and I put the License Manual aside.

For some strange reason, I didn't have any urge to read more books the rest of the year. I renewed my interest in Forth programming and got deeply into that; see my "FINC Web Server on a Nintendo DS". In the course of doing so, I effectively read a couple of books on Forth and a bunch of papers on the subject.

In January 2010, hearing the call of Rumpole and SWMBO, I began reading books again!