Crystal Ham Part 2

It has been a few months since I last visited this topic. Sorry about that. Family matters. However, let us look at how a crystal radio works. For those who’ve been licensed hams for any length of time, this is really simple, but for others, this borders on magic, but we can do this.

Let us start with a basic assumption. Our assumption is that we are surrounded by electromagnetic energy in a wide variety of frequencies and modulations. It doesn’t matter if it is your computer, your mobile device, or something, you are surrounded by RF generating devices, and this makes our basic assumption true. If you want to say that you are miles from civilization and thus it is impossible to be surrounded by RF energy, not only are you wrong, but I’m going to wonder how you can even read this.

This is where it gets interesting, and I will do my best to keep it simple.

A crystal radio, much like any other radio, uses an antenna to pick up an RF signal. That signal is then sent to the antenna coil. The antenna coil converts that energy into a very low level of AC current, which is then fed into either a germanium diode, or cat’s whisker detector (galena or pyrite crystal with a thin wire barely contacting it). This forces the current to flow in only one direction, and rectifies the signal. The rectified signal then either goes to the earphones, creating something you can hear, or into a variable capacitor, and giving you the ability to select what you hear, by varying the amount of energy stored between the detector and the earphone. The earphone transforms that energy into an audio signal, and for the sake of being somewhat technical, it is about 400 to 2000 Ohms.

Realistically, this is an oversimplification of the whole thing. However, for the purposes of this blog, simpler is better. I will be revisiting this topic again as I prepare for the actual build process. Next time, I will build a simple “popsicle stick” antenna for detecting RF energy. Also, I will be using an actual diode for the detector, as a cat’s whisker detector is really awesome, but a royal pain to maintain a signal with.

Road Hog

Our world is awash in technologies that in some way touch upon, or originate with, ham radio. Whether it is wireless internet, or GPS, many of our technologies owe something to ham radio. In fact, when it comes to RF devices, you would be hard pressed to find something that didn’t have its start with amateur radio. However, not all devices are alike, and people have become more dependent upon some than should be the case. GPS is one of them.

GPS is short for Global Positioning System, and has its origin in APRS, or Amateur Packet Reporting System, which borrowed from military doppler shift tracking during the era of Sputnik. Initially, it was intended as a tool to help emergency responders, and also had some use with various radio clubs for Field Day use. However, if there is a technology, it can be commercialized, and APRS was quickly commercialized into GPS, with the first handheld commercial unit being the Magellen NAV 1000.

Now, why would a blog that is, supposedly, dedicated to tube radios talk about GPS? That is a fair question, and worthy of a good answer. The honest answer is that people have become too dependent upon GPS devices, to the point in which they ignore road signs and many don’t even know how to read a proper map any more. It is sad that recent Boy Scout handbooks now address the subject of using a GPS for direction finding, and just barely mention the use of a proper map and compass. However, it gets much worse.

Along the Puyallup River, there is a bridge located at 66th Avenue. It is a small bridge with a single lane in either direction. This bridge was built in 1931, and is still in service today. However, as farm land has given way to warehouse space, there has been a very dangerous trend of truck drivers using this bridge for crossing from Levee Road on the Fife side of the Puyallup River to access River Road (Highway 167) on the Puyallup side of the river. So dangerous is this trend that Pierce County had an ordinance prohibiting any vehicle with a trailer longer than twenty eight feet on the bridge, and there are cameras on the bridge to record offenders.

However, even with signs posted warning of the ordinance, many truck drivers still take the risk of crossing this bridge. Why? Because their GPS device is telling them that the bridge is best route. I have seen, and nearly been part of, many near collision events due to truck drivers taking this bridge. I have also seen many an instance in which drivers get stuck on the bridge, all because their truck was too high, and they were following the advice of the GPS, all the while, ignoring the warning signs.

I won’t lie, I do use the built-in GPS that my Boost Mobile device comes with, but only when I am trying to get someplace that isn’t necessarily on a map, and there are no obvious road signs directing me to the place I am going. Otherwise, I still use paper maps for many places that I want to go, along with road signs. I also use Google Maps to print directions that I can follow. I don’t rely upon the GPS device, especially because you can’t always get it to recalculate your route when roads are closed or traffic is otherwise interrupted.

GPS may be helpful, but when one relies too much upon it, all it is does is become little than an electronic leash, telling you where to go. If you are a truck driver, and mindlessly following the instructions it gives you, it may well be that you are putting others at risk and have now become a Road Hog. Please disconnect from the GPS and double check the map, and read the road signs. Over dependence on GPS is a form of distracted driving, and it puts us all at risk.

Market Ham

Every year I like to attend/work the K7LED Mike and Key Radio Club flea market. I really enjoy seeing what is being sold and catching up with old friends that I don’t see often. This last year, I bought myself a new soldering tool. I also picked up an older solid state two meter transceiver (yes, I know that this blog is dedicated to tube rigs and other such things, but a tube rig would be a bit big for bicycle operations). Currently the radio doesn’t work. However, the is often the case with used gear that is found at a flea market, and that is part of what makes this hobby so wonderful. It is often great fun to repair/restore an older radio to full function. I heartily encourage that if you can attend a flea market, and particularly an amateur radio flea market, that you do so. We ham really can have fun with these. In fact, we often have more fun than a hog in a bog.

Steamed Ham

I have had a fascination with the genre of Steampunk for some time now. However, I was less than impressed with an episode of the competitive series “Steampunk’d”. Grammar issues aside, I didn’t like the episode in which a wardrobe closet was built. In the episode, there was a very painful misrepresentation of radio.

Let me explain. The two teams were required to build a wardrobe. This doesn’t both me. What bothered me was when they reach the part of the episode in which an explanation of the build is given. The team with only three people built a rather awkward room and costume. The costume had a globe valve on the front of it. The explanation given was that it was to tune to other radio channels to call for help. I should mention that the room was themed as “Royal Garrison”. Please excuse my disgust, but a water valve is NOT a VFO, or even a shoddy surrogate for one.

The simple truth of the matter is that radio may have been invented as early as 1895, and is credited to Guglielmo Marconi, the fact is that the distance for a radio signal was exceedingly short, and it was Morse Code only. In fact, the first trans-Atlantic Morse Code transmission would not be until 1901. Additionally, tuning would have been very limited, for though the variable capacitor was invented in 1893 by Dezső Korda, it’s full application wouldn’t be seen for several years after the first trans-Atlantic transmission. Add to that the first voice transmission wouldn’t be until 1906, which would be after the end of the antebellum age, and you find that voice over the radio is almost inappropriate for Steampunk.

Is there room for radio, and voice transmission, in Steampunk? Yes. However, it must be presented as an alt-history scenario, and it must not be misrepresented. When dealing with radio, even in a cosplay, it must be done responsibly. Simply put, if you don’t know and understand radio, don’t talk about it as if you do. The simple truth is, you are very likely to upset somebody who is knowledgeable, and actually has experience doing what you don’t really know or understand.

What does this mean? Realistically, it is just a rant. I really hate seeing radio misrepresented. This is precisely what happened in season 2, episode 4 of “Steampunk’d”. Additionally, not only did they misrepresent radio, they misrepresented the proper use of a globe valve. I will say that had the globe valve been used to “control the flow of plasma” to the costume’s “weapon”, I would not have taken issue with it. However, to say that it was used as a radio to call for help, I have no option but to take issue. However, I will let the reader decide for themselves.

Steampunk’d Season 1 Episode 4. The affront to radio begins at the 26 minute mark.

 

If it was up to me, I’d demand an apology from that particular team for how they misrepresented radio.

Note to critics: I have been a licensed amateur radio operator since 1998, and I have built several radios, both locked frequency and variable frequency. I have also studied the history of radio, and will be quite happy to argue that radio is more product of the diesel era than that of the steam era, as it is the diesel era in which voice transmissions and tuned circuits really belong.

Crystal Ham Part 1

It can often be quite interesting to look back at radio technology, and see where we came from. I am not merely talking about vacuum tubes, which were formerly called “valves”. No, I am looking at something slightly older. Specifically, I am talking about Crystal Radio.

Huh? Crystal Radio? What is that? 

Good question. At its absolute simplest, a crystal radio is a receiver with no actual power supply. Rather, it is the received signal that powers the high impedance ear bug, through which you can hear the incoming audio.

What? No power supply? As in no batteries? Absolutely. Not only that, but this is how many amateur radio operators and electronics technicians got started.

Over the course of the next few months, it is my intent to fully delve into this topic. This post is merely an icebreaker, a teaser if you will. In Part 2, we will go more in depth, discussing materials used, and how it works. In Part 3, we will begin the process of building two radically different radios based upon the same schematic diagram, starting with the coil and antenna. In Part 4, we will continue the build, with one radio having a germanium diode, and the other using an iron pryrite crystal with a “cat-whisker” detector. Part 5 is where we will compare the two radios, and discuss practical applications. 

This is going to get interesting. Please don’t let yourself miss out.

Interesting Interested Ham

Volunteering with the local club at the county fair can be an interesting experience. This has been the case for me over the last few years while helping at the Puyallup fair. Anyone that knows me knows well that I am not too fond of the Puyallup fair these days. Why? I simply feel that it has become way too commercialized. Think of it as being like the Dayton Hamfest, with a roller coaster, but not a radio in sight. I cringe at that thought.

As myself and another ham operator sat in the booth for the local club, I noticed something that seemed rather odd to me. I have long held that amateur radio is for anyone, and everyone. However, it is always very interesting to see who is willing to come up and ask about it.

I have noticed that the greatest amount of interest in amateur radio comes from males. Of that group, married males of retirement age are more likely to look into amateur radio than married males who are still raising children. Likewise, single males are more likely than married males to ask about amateur radio. Of the women, older women are more likely than young women to ask about radio. Women who grew up around amateur radio, regardless of age, are more likely to ask than those who have never been exposed to it. Teenagers tend to be the less likely than pre-teens to ask about radio.

I can’t really say why this trend, which is what I call it after years of observation, exists. I do have a thought about why teens are less likely than pre-teens to ask about radio. It is quite simple. Today’s teens are spoiled. They have mobile devices that tend to be reliable, are capable of nearly instant access to all forms of media, and there is no test to take, just pay your money and run.

However, don’t tell them that their devices aren’t reliable in a disaster. Depending upon where you live, you might encounter any manner of hostility. I happen to live along the Cascadian Subduction Zone. If you have read the September edition of QST magazine, you know full well that FEMA recently conducted an earthquake drill in the Pacific Northwest based upon the likely event of a rupture of this particular fault line, a rupture that is already better than 50 years overdue.

I find that very few people can acknowledge that mobile devices will fail during a disaster, and fewer still that are willing to discuss it and how to maintain communications during such disasters. Part of the problem is that, at least where I live, too many people have a mindset of “it will never happen here”, and have been lulled into a false sense of security. The sad fact is that for many in my region, disasters are something that happens somewhere else, all we get is that occasion snowstorm (which can also be a disaster, but denial is full effect there too).

Unfortunately, even discussing the potential for disasters can be a turn off for those who might otherwise be interested in ham radio. I suppose that when it comes down to it, knowing whom you are discussing amateur radio with helps, but it is not a reliable factor in determining interest. In fact, better than half the people we spoke with, regardless of age or gender, only wanted to know where the restrooms were, or where the giant pumpkins were. No interest at all.

I don’t know that there is any real way to spur more interest in amateur radio. The advent of mobile media devices, with their near instant connection to everything, has spoiled many. Even knowing the vulnerabilities of these devices, or how amateur radio played a part in their development doesn’t seem to help. Perhaps all we can do is wait, wait until an earthquake or volcanic eruption hits before people will be interested, and by then, it will already be too late.

Alien Ham

Exoplanets are trending currently. Why? Recently NASA discovered an exoplanet orbiting a star in the Proxima Centauri system. This planet orbits within the “habitable zone”, and is named (by us) as Proxima B. However, because of its rapid rotation around its star, roughly twelve days to complete an orbit, and the fact that while it is withing the “habitable zone”, it is believed to receive 400 times the X-ray energy from its “sun” than we receive from ours. To that end, it is likely that it is comparable to either Mercury or Venus, both of which are barren and devoid of life.

Why do I bring this up? Humanity has been looking for extraterrestrial life for decades. One would think that it is only a matter of time until we find something, right? Maybe not.

2016 marked the 100th anniversary of the W7DK/W7OS Radio Club of Tacoma. This is the single oldest, continuous, ARRL affiliated radio club in the whole of the United States. This is a big deal when you consider that  on 23 December 1900, Reginald A. Fessenden became the first person to send an audio single via wireless transmission , and that  he made the first commercial broadcast on Christmas Eve of 1906. This means that radio has been a known medium of communications for 116 years, and that there are some earlier experiments that predate these two events.

What does this have to do with aliens? Plenty, if you don’t mind some pretty extreme mathematics. It really has to do with how far radio waves really carry, and they really do carry quite some distance.

I’m going to go ahead and be generous. That is to say that I’m going to ignore the first 16 years of radio transmissions, at least for the moment. Those first sixteen years really are important, but I want to make things easy, at least to start with.

A radio wave travels at the speed of light, which is roughly 186,200 miles per second. This works out to 11,172,000 miles per minute. That, in turn, works out to 670,320,000 miles per hour. In the course of twenty four hours, a radio signal will travel 16,087,680,000 miles. This is nearly four times the distance between the Earth and Pluto. In a month, that signal will have traveled over 482,630,400,000 miles. That means a radio signal will travel, in one year, a distance of 5,876,025,120,000 miles. In a century, that distance is clearly seen as being 500,876,025,120,000 miles. This doesn’t account for those first sixteen years, which adds another 94,016,401,920,000 miles to the overall total.

All that looks impressive, but meaningless, until you start to look at a list of all the potential exoplanets that are thought to exist in the habitable zone. About a quarter of those planets are less than fifty light years from Earth, and some are even closer than that. To date, we have not received an authenticated signal back from any of these supposedly closer exoplanets. Let that sink in for a second.

Over the years, we’ve seen numerous UFO sightings, some going back as far as 1697, though the first fully credited sighting was in 1947 near Mount Rainier, in Washington state. Yet, despite these supposed sightings, we have no hard evidence that extraterrestrials exist, aside from various conspiracy theorist drivel, much of which is easily debunked. Even the “WOW signal” from 1977 has now been attributed to a passing comet, a theory that may very well be tested soon, which only further depletes the potential pool of evidence for extraterrestrial life, and only leaves the flimsiest of evidence, and that being the previously mentioned stuff that is easily debunked.

What does this mean? Ultimately, it means that in all of decades of searching for extraterrestrials, we have found nothing. Furthermore, with at least six exoplanets existing within 56 light years of earth, if they had a level of technological development equal or greater than that of our own (most people seem to seek extraterrestrials with a greater level of technological development for some reason), then we should have already heard something from them, something that would have already put our world into technological overdrive, as we rapidly built a deployed our first hyper-light drive systems. However, no such signal has been shown to exist, and most claimed signals have either been debunked, or have been relegated to suspected pranks by unscrupulous individuals with questionable motives.

Radio has been around for over a century. If there were an extraterrestrial race with a level of technology equal to or greater than our own, we would likely have heard back from them, and it would have been impossible for any government to block such a communication. I know some will believe that I am wrong, and I accept that, but I am firmly convinced that radio, and the lack of an authentic signal from an extraterrestrial race that off of the Earth has heard, is sufficient evidence to suggest we are alone in the universe. This is observational science, and radio is all about what we can observe. If I can be proven wrong, by a personal radio greeting by an extraterrestrial, and they can prove it, I will admit to it, before committing suicide.