标签: radio

In certain respects, things were much simpler in the old days. Take synchronizing images and sound, for example. In the case of traditional movie films, the analog soundtrack was included on the film itself, thereby ensuring that the two were fully synchronized. Similarly, in the case of video like VHS, audio tracks were recorded along the top edge of the tape, thereby ensuring synchronization with the images.   Things are more complicated these days, with audio and video being processed by largely separate subsystems, which goes some way to explain why -- when you are watching a modern television program -- people's lips often appear to move completely independently of the words they are saying (much like watching a badly dubbed Godzilla movie from Japan circa 20 years ago).   (Source: pixabay.com)   It seems a tad ironic that we have such amazing home entertainment systems these days -- with high-definition video (which is already moving to 4K x 2K) and surround-sound audio -- yet we appear to be incapable of getting the sound to be synchronized with the images. As a somewhat related problem, if I have the same program playing on multiple televisions in my house -- say the family room and the kitchen -- there's a noticeable delay between the two systems resulting in a very annoying echo-type effect. It makes you want to cry.   I seem to recall that there's a lot of work going on at the moment to sort this problem out by associating time-stamps with both the audio and video and then delaying one or the other to ensure that they are fully synchronized but (a) I forget the details and (b) that's not what I wanted to talk to you about.   The thing is that I was chatting to a friend-of-a-friend the other day, and he posed an interesting problem. It seems that he prefers to watch American football on his television while listening to the commentary on his radio.   I was a bit puzzled as to why he wanted to do this, but he explained that both the game (on the TV) and the commentary (on the radio) are transmitted in real time -- however the commentary continues when the TV breaks for adverts, and he prefers to listen to the ongoing discussions about the plays and suchlike rather than watching adverts for things like hemorrhoid creams (and who amongst our number would argue with this philosophy?).   The problem comes with regard to our definition of "real time" because -- even though the video and audio are going out "live" -- they are traveling and being processed via different systems, which means that there can ensue quite a large miss-sync amounting to multiple seconds in some cases.   So, this friend-of-a-friend was asking as to the best way to address this problem. My knee-jerk suggestion was to forget the football and instead watch Dr. Who, but it seems this is not a satisfactory solution (you just can't please some people).   So, is this guy "one in a million," or is this a common problem to which there's already an existing solution? Alternatively, does any possible solution spring into your mind? If so, please share it with the rest of us in the comments below.

All I can express is that I am flabbergasted. In fact, I would go so far to say that it's rare indeed for my flabber to be quite so gasted. I was sitting here in my office slaving away over a hot keyboard when my chum Charles Fulks unexpectedly breezed in.   Charles (he lets me call him that) leads the FPGA development group for Intuitive Research and Technology just down the road from me. I shared the stage with Charles and RC Cofer at this year's EE Live! Conference and Exhibition.   You can only imagine my surprise to discover that Charles had brought me a little something. There's an old saying that goes something like "Beware of Geeks bearing gifts," but I certainly wasn't going to look this gift horse in the mouth, because this little beauty was a vacuum tube radio from the early 1940s.   Amazingly enough, I have the perfect spot for it. The photo below shows the bay outside my office. The comfy chair and ottoman in the foreground allow one to take a few minutes' break now and then. Standing against the wall is a 100-plus-year-old wooden chest, upon which rests the frame for my ongoing mosaic project -- and now my beautiful vacuum tube radio.     In case you were wondering, this bay is where I seem to end up storing the furniture my wife doesn't want me to keep in the house (LOL). On the left side of the above picture, you can see my office door. (Mine is the one with the dragon on the far wall.)   The radio is a Grundig 5088. (I need to see if I can find the circuit diagrams somewhere.) This is an AM radio with multiple ferrite rods for long-wave, medium-wave, and short-wave reception.     Charles says that, when he acquired this little rascal several years ago, he was told that it did work, though he's never tried it himself. As soon as I get a free moment, I'm going to power it up, but I will have a fire extinguisher standing by, just in case.   I would love to have this radio playing in the background in our bay. Something about the sound that comes out of a vacuum tube radio makes you want to use words like "smooth," "sensuous," "robust," and "rotund."   Of course, chances are that this little scamp won't fire up the first time. It wouldn't surprise me if we needed to replace the paper capacitors and suchlike. The problem will come with the vacuum tubes. I'm reasonably sure I will be able to pick up anything I need at the Huntsville Hamfest in August (subject of a blog post last year). The real trick is to determine which tubes need replacing.   But where can one find someone who knows how to diagnose and debug problems with vacuum tube-based systems these days? Well, you could have knocked me down with a fishwife (much more effective than feathers) when I discovered that my chum Ivan in the next bay is a diva with vacuum tubes.   Actually, this really shouldn't surprise me by now. Ivan is one of the cleverest guys I know. (Yes, I'm buttering him up; I want him to fix my radio.) When I called Ivan over to see my new acquisition, he foolishly informed me that he used to repair radios and suchlike. Upon further questioning, I discovered that Ivan that was in an accredited trade school while in high school (he crammed standard classes and electronics classes in alternating weeks), and that this involved repairing electronic systems. While in the Air Force, he focused on maintaining and repairing electronic systems. After leaving the Air Force, to supplement his income at college, he worked at Magnavox repairing everything that came his way: CB radios, record players, AM/FM radios, TVs, laser disk players, alarm systems, audio amplifiers, PA systems, walkie-talkies -- the list goes on. Do you ever get the impression that some things were just meant to be? I have a vacuum tube radio that needs some love, but I don't have the skill to treat it with the respect it deserves. Ivan has skill oozing out of his fingertips, but no vacuum tube radio to unleash it on. It's like a marriage made in heaven (LOL).

You sure have had your own A-Ha moment. The Merriam-Webster dictionary defines it as "a moment of sudden realisation, inspiration, insight, recognition, or comprehension." But I'm taking it one step further— a-ha! with an exclamation point. This is a more dramatic realisation. It's the moment when you discover a great truth, when something that was complicated or unpredictable suddenly becomes clear. As engineers, I'm sure we've had many. One of my first a-ha!s came in grade school. I was a hobbyist, and I enjoyed creating things from the local Radio Shack, even though I didn't know why they worked. I had hoarded quite the collection of resistors, capacitors, tubes, and speakers. I could read the colour bands on a resistor to get its value, and I had rudimentary soldering skills, but I didn't know how to design anything. One day, my older brother, who had been a Navy technician, explained Ohm's Law to me. A lightning bolt ignited in my head. You mean, there's a relationship between voltage, current, and resistance? That makes a lot of sense. And the world became a little bit more understandable. Building a circuit was a little less about pleasing the electron gods and a little more like engineering. I've had several of these moments since then. Calculus was a key ingredient to many. Though I knew formulas from high school physics, calculus enabled me to derive the formulas. As a ham radio operator, I knew how to calculate the resonate frequency of an LC network.   But I didn't know why that was the resonant frequency. With calculus, I was able to derive it myself, and I discovered why it also explained the resonant frequency of a pendulum or a spring and mass. Calculus explained that the current through a capacitor was proportional to the first derivative of the voltage. Suddenly, first-order differential equations explained time-domain and frequency-domain phenomena. This was another a-ha! moment. I've had many since then. Boolean logic explained digital circuits to me—no longer a mystery. A more recent a-ha! moment came when I learned how WCDMA worked. In retrospect, all these things seem obvious, but I can recall the very day that each of these a-ha! moments came. Science and engineering aren't the only subjects that have created these moments. An Economist article about international trade led the reader through a simplified two-party, two-industry model, where one party had a productivity advantage for both industries, and the other party had inferior productivity for both. Much to my surprise, simple arithmetic in the example showed that both parties produced and acquired more goods than either one could have done by itself if trading could occur between them. Until I had done the math, I had assumed trade was only advantageous if each had an absolute advantage in some industry. This was the principle of comparative advantage—and another a-ha! moment for me. I remember the day I did the surprising arithmetic. What about you? I'd like to hear about your a-ha! moments. Larry Desjardin Consultant  

Several weeks ago, my chum, Rick Curl, sent me an email asking if I was planning on going to the Huntsville Hamfest in Alabama, United States. In case you are unfamiliar with this term, a Hamfest is a convention of amateur radio enthusiasts. It often involves a combination of a tradeshow, a flea market, and a variety of activities of interest to amateur radio operators, a.k.a. "hams." I responded that I hadn't planned on it for a number of reasons, the main one being that I didn't even know that there was a hamfest planned. Of course, there was also the fact that I don't have a great deal of interest in amateur radio. Rick replied that the Huntsville Hamfest was a lot of fun and that it involved a lot of general electronics "stuff" in addition to the radio side of things. Based on what Rick told me, I decided to go down, and I'm so glad I did because I had a blast. I got there early and was one of the first in (I don't like to miss anything). The picture below was taken just a few minutes after the show opened—at that time there were really long lines of people still queuing up outside waiting to buy tickets:     About 30 minutes after the above picture was taken, the show was absolutely jam-packed. As Rick had promised, although many booths were focused on radios, there was much more on offer. One vendor, for example, focused on vacuum tubes. As you can see in the photograph below, this guy's table was laden with boxes of old tubes:   Now, one of my ongoing hobby projects is to build a "Man vs. Woman Display-O-Meter" (don't ask). As part of this, I've been slowly accumulating old analogue meters. I've picked up a couple from eBay, and a few from my local electronics recycling facility, but generally speaking they are horrendously expensive and few and far between. So you can only imagine the squeal of delight that ensued when my gaze fell upon the scene shown below:   Can you see the sign saying "All Meters $2.00 each"? Suffice it to say that my heart was pounding and I could hear a ringing sound in my ears. It was around this time that I began to curse myself for not bringing a backpack. I quickly purchased a substantial number of these little scamps, which are now sitting proudly on the bookshelves in my office. The bottom line is that you couldn't hope to meet a nicer (or stranger) bunch of people. Also, you get to root around through mountains of modern and antique electronic parts and products. What more could one ask from a Saturday morning? I've already marked my calendar for the 2014 Huntsville Hamfest, and I'll be keeping my ears open for any similar events occurring in my area. How about you: Have you ever attended one of these happenings in your own country? Are there any shows like this that you would want to check out? If so, please share your thoughts and experiences with the rest of us.

There is a forthcoming Geek Hat Competition to be held at Design West 2013. With regard to this, emails have been zipping back and forth between me and my engineering chum Rick Curl, who is just the sort of guy you need on a wild and wacky project like this one. For example, originally I had toyed with the idea of making the base of my hat out of pieces of thin brass sheet metal riveted together (I used to be a dab hand at riveting even if I "say so myself as shouldn't" ). However, I'm now pondering the idea of using my little kiln to make a ceramic cap that LOOKS like it's made out of pieces of thin sheet metal riveted together. (I should point out that that Rick is currently a tad dubious about this approach.) For his part, Rick is bombarding me with ideas about spark generators and smoke generators and plasma globes (I'll need a monster backpack just to carry the batteries). Rick also just sent me a link to the Radio Hat page on the Wikipedia with as associated note saying: "FYI Back in the late '50's my Dad used to have one of these. It was not uncommon for cars to stop in the street when he was out front mowing the lawn." I'm sure it wasn't uncommon for people to stop and stare (grin).   According to the Wikipedia: "The Radio Hat was a portable radio built into a pith helmet that would bring in stations within a 20 mile (32 km) radius." (Surely they were "taking the pith" :-) "It was introduced in early 1949 for $7.95 as the 'Man-from-Mars Radio Hat'" Apparently the hat was available in eight colours: Lipstick Red, Tangerine, Flamingo, Canary Yellow, Chartreuse, Blush Pink, Rose Pink, and Tan (what, no "Spanking Pink"? How disappointing). Well, you learn something new every day. I must admit that I would love to add one of these little beauties to my collection, but I just checked on eBay and nothing was to be found. Maybe one day...