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Radio in the 1632 Universe

Written by Rick Boatright

Introduction

The military and diplomatic radio situation in Europe at the end of the novel 1633 is a result of a unique combination of the authors' needs in the story line, the limitations imposed by the authors' choice of town to base Grantville on, and other historical accidents which left us with a wealth of some technologies and a dearth of others.

There are four important elements to the radio background of the 163x series: the environment that the planet and solar system provide due to Eric Flint choosing to start the series in the year 1632, the people of Grantville, the physical resources they have available, and the goals of their government.

The Radio Environment

From a political perspective, 1632 occurs during the Thirty Years War. From a social perspective, 1632 occurs during the "Early Modern Era." From a biographical perspective, 1632 features players who are still household names, such as Cardinal Richelieu, Galileo, King Charles the First, Oliver Cromwell, etc. It's a fascinating time and a critical point in the development of western culture. When Eric contacted me and asked that I help brief him on the possibilities for radio in 1632, it became quickly clear that from a radio specialist's perspective, Eric could not have chosen a worse time to drop a town into than 1632. Just at the beginning of the period where there are telescopic observations of the heavens, approximately simultaneous with the trial of Galileo, 1632 drops Grantville into the beginning of a time best known to science as the "Maunder Minimum."

At about the same time as Galileo published his description of his construction of the Dutch invention of the telescope, natural philosophers throughout Europe began noting that the sun had imperfections, "spots" on it. This was far easier to watch with a lens, since you could project an image of the sun onto a white sheet, and observe it without destroying your eyes. The novelty led several natural philosophers to begin a program of noting the sunspots on a regular basis. Therefore, we have an excellent European record of the number of sunspots starting with Galileo's first such observation in 1610.

This notion of the imperfection of the sun would have come as no great surprise to the court astronomers of China and Korea. In the court logs of the observations of those staff astronomers, there are sunspot records made with the naked eye going back another millennium and a half. Using those records, we can trace the sunspot number from about 28 bce, using a reasonable relationship between the capabilities of naked-eye astronomers and those using projections and lenses.

For all of this two thousand year period of recorded observations, the number of sunspots on the surface of the sun has varied in an eleven-year cycle. As of this writing, in 2003, we are near the falling side of the peak of the current cycle with sunspots near the historic high of over 200. This extreme activity has resulted in spectacular auroras being seen as far south as 30 degrees north (Oklahoma City). At the other end of the measure, the lows have had sunspot numbers in the low teens to the mid-20s. The "average" low is between 20 and 30.

For reasons that no one understands, starting in about 1610, the number of sunspots plummeted. By 1632, which should have been a peak year, the sunspots were down to the mid-teens, and by 1640, had dropped to zero. (There is an anomalous high data point in 1639.) The 11-year cycle did continue, with peaks as high as 8 or 9 between 1645 and 1700. Then, again for reasons that no one understands, starting in 1710, the numbers went back up, and have continued quite regularly for the last three hundred years. This is not a "lack of observations" artifact, since the court observations in China and Korea correlate quite well with the western records. This is real.

Recent work by observational astronomers using a combination of new techniques by really really smart people on type G2V stars like our sun have figured out a way to measure the sunspot number of a star even though we cannot "image" the star. This work indicates that G2 stars may typically spend as much as 20% of their time in this "quiescent" mode. It could start again tomorrow. No one has any models for why it happens, or what causes it, or why it stopped. It's all quite confusing.

So what, you say? Well, it turns out that the number of sunspots is very highly correlated with the thickness of the upper layers of the ionosphere. There are several "layers" in the upper atmosphere, which get ionized for different reasons. These are labeled, from the inside out: D, E, F and "topside."

It turns out that the number of sunspots is very highly correlated with ability of the atmosphere to reflect radio waves back to the earth. There are several "layers" in the upper atmosphere, which get ionized for different reasons and have different effects on radio waves.

The layers are caused each day by the action of solar X-rays, ultraviolet light, and charged particles streaming out from the sun on the earth's upper atmosphere. This is the same action that splits O₂ apart and gets the free oxygen that can combine into O₃, to form the "ozone" layer. Ionization increases in the sunlit atmosphere and decreases on the shadowed side. Although the Sun is the largest contributor toward the ionization, cosmic rays make a small contribution. Any atmospheric disturbance effects the distribution of the ionization. These ionization layers form every morning at sunrise, thicken throughout the day, and then begin to fade at sunset. The combination of their chemistry and their electrical properties causes them to absorb and reflect radio waves. The amount of the ionization in each layer controls the absorption and reflection of radio waves. High frequency radio waves are absorbed by the weakly ionized D region.

Further out, the topside and F2 layers are ionized not only by UV light, but also by the action of the solar wind on the outer layers of the earth's atmosphere and its interaction with the earth's magnetic fields. During periods when there are lots of sunspots, the sun puts out a lot of particles, and these ionization layers are quite thick and robust. Without the solar action, during sunspot minima, the F2 layers are thinner and weaker.

The thicker and more robust the outer layers are, the shorter the wavelength they can refract or reflect. During sunspot maxima, the maximum usable frequency (MUF) can get as high as 30 or even 50 MHz (six meters). That is, 30 MHz signals can bounce right off the ionosphere, or be trapped between two upper layers and ducted around the world before breaking out and coming down most anywhere. That's how CB radio "skip" works, when folks listening to the radio in their cars on the highway in Kansas hear the chat between boats working the shrimps in the gulf of Mexico. Normally a CB radio is good for 5 miles, but when the sunspots are high, all bets are off.

During a normal sunspot minimum, when the sunspot count is down around 20 or 30, the MUF stays up around 14 MHz for at least part of the day, and seldom goes below 7 Mhz.

Frequency and wavelength are related. The higher the MUF, the shorter the wavelength and the smaller the antenna that is needed to send and receive radio signals. In general, one wants to use as short a wavelength as possible, because the higher the frequency, the smaller the antenna needed. A 30 MHz transmitter uses a "natural" antenna that is only three meters long. But a 7 MHz transmitter uses a natural antenna that is about twenty meters long.^§ Thus, the higher the MUF, the more convenient it is to build radio installations. Most Hams therefore work the 20-meter bands, and the 40-meter bands are not uncommon. But it's the rare Ham who works 80 or 160 meters, since the natural antenna for 80 meters is 40 meters long, and 80 meters long for the lowest common Ham band of 160 meters.

However, remember the missing sunspots? During the Maunder Minimum, during the period that Eric has set the 1632 series in the middle of, the F2 layers of the ionosphere go away to a great extent. Of course, there is always some solar wind, some extreme UV, and some ionization by solar X-rays and cosmic rays. Thus there will be some ionization and some reflection. But for the purposes of the story, the tech team and the authors have decided that the MUF keeps dropping and dropping toward the lowest usable frequency (LUF) until, by the year 1640, to do long-distance communications without relays you would need to be using 2 MHz for much of the day, and can get up to 4 MHz only late at night.

And remember that the D layer absorbs the radio waves, so the low MUF means that you have little if any ability to do long distance communication during the day at all. The absorption of the layers defines a lowest usable frequency, an LUF. It is possible for the LUF to be higher than the MUF. Then, nothing much reflects.

No one really knows what the effect of the Maunder Minimum was on the radio characteristics of the atmosphere. Some contributors have suggested that the poor ionosphere is balanced by the low amount of interference due to the low number of radios on the air. Nevertheless, based on some reasonable guesses, the tech team and the authors have decided that for the purposes of the 163x stories short wave above 80 meters is pretty much useless from 1630 to 1710.

As a result of the long wavelengths, the radio installations in 1632 universe end up using very large antennas. The most common antenna for a diplomatic mission will be an 80M inverted V two-element beam installed this way:

Take a piece of wire, forty meters long, and cut it in the middle. Put a glass insulator in the center of it, and hook another piece of wire to each of those twenty-meter-long pieces. The "hookup" wires are held apart every few inches by a hunk of glass or plastic or wood, like a little ladder two inches wide. This ladder leads back to the transmitter. Meanwhile, take your center insulator and haul it up to the top of a tower as high as you can get. One hundred and fifty feet is really a good height. Attach the glass insulator to the tower, and then draw a line on the ground, in the direction of the city you want to talk to the most. Stretch each of the twenty-meter-long legs away from the tower at 60 degrees up from vertical, 30 degrees down from horizontal, and perpendicular to the line you drew (crossing it). Then hook the end of each wire to a rope with another glass insulator, and pull the ropes taut so that the wire is as straight as you can get it.

Now, remember how you drew a line towards the radio you want to reach, that you want to "beam" at? Build another tower, 20 feet back away from your destination, on that line. Now, do the exact same thing with another piece of wire on that tower. (You do not need hookup wires on this one.)

So, two 150-foot towers, two 40-meter long hunks of wire, suspended in the air, and lots of rope. If you want to use 1.7 MHz (160 meters) instead of the 3.5 MHz we designed this for, double all the numbers above. (Well, you can keep the tower height the same, but taller is better.)

Repeat this, as often as necessary to build a beam pointing at each city you want to talk to. A big central diplomatic radio installation will have a cluster of these beams pointing in a variety of directions and will require a clear level space a quarter of a mile on a side.

You begin see the problem. . . .

As the characters in the series approach 1640, the electronic situation in the atmosphere worsens. The MUF drops towards 1.7 MHz, and the antennas and such get bigger as above, and harder to build. It's not fun. That's why Gayle and Jeff kept muttering about the bad timing of the radio situation in 1633. From the perspective of a Ham, they were dropped straight into hell.

What can be done about it? Several things:

1) You use a lot of power to overcome the fact that not much bounces.

2) You experiment to find the best frequencies available and use them.

3) You build good antennas.

4) You send your messages at the right time of day (generally a window about four hours long starting at sunset called the "gray line").

5) You set up relays, i.e., you send the message as far as you can, and then relay it. Thus, in 1633 the mission in Amsterdam relays to London and to Scotland.

6) You maximize the use of the power you have, by using CW (Morse code) instead of voice. Voice requires far better signals than CW does.

Very awkward, yes. But that's the situation until the newly emerging society can get satellites back up, which will be a long time yet—in fact, at least as long as the year 1700, which is about the same time that the short-wave bands will reopen.

In short, no matter how you slice it, long-distance radio communications will be a very different thing in the 1632 universe than what we've experienced in our own timeline. And as tube production comes on line, and high power radios go into production around the world, bandwidth for long distance communications will be a precious and rare resource. The pressure to build cables across the ocean will be even higher in the 1632 universe than it is in ours.

The Physical Resources

In addition to the physical world around them, the radio situation in Grantville is shaped by the technological world they brought with them. What radio technology does Grantville posses? What just won't work? Let's examine each of the common up-time radio technologies and consider its place in Grantville after the Ring of Fire. When Eric began writing 1632 he did a very clever thing. He decided that with a few exceptions which he has carefully limited, Grantville is based on the real-world town of Mannington, West Virginia. In general, and with a few specific exceptions (the main one being the power plant), it's safe to assume that if something was in Mannington in late 1999 or early 2000, it's in Grantville; and if something was not in Mannington then, it is not in Grantville. That presumption drives the following discussion.

Stores

There is not a Radio Shack store in town, there is no electronics store, there is no radio dealer of any kind. Some CB radios will be available at a few stores. There is one TV repair shop.

Cell Phones

Sadly, while there was a cell phone antenna and cell in Mannington and thus, in Grantville (an analogue one—no CDMA or TDMA digital cells were operating in Mannington in late '99 or early '00), the cell was not linked to the local phone switch. It was operated by a different company. And while one of the short stories from the Ring of Fire anthology explains that there is an excellent phone tech in town, he's not a cell phone guy. It may be possible eventually to cross connect that cell to the phone system, but in the first two years, no one has had any success at it. The manuals for the cell weren't in town, no one knows the computer passwords, and the cell was not set up for autonomous operation. The cell phones themselves are useless without the cell being attached to a billing and authorization computer system and to a phone switch. For all practical purposes, you may regard cell phones as a source for small high energy density rechargeable batteries and other electronics parts, but not as radios.

Commercial Radios

Pre-Ring of Fire handheld and base station commercial FM radios were used by the coal mine, by the electric company, the police, the school district, the city water department, etc., etc. The presumption of the 1632 authors is that these radios remain dedicated to their pre-RoF use. One radio from each incompatible frequency set was placed in the Grantville emergency Operations Center to provide cross\network links.

CB Radios

CB radios are featured in 1632 because they were owned by Mike Stearns and his friends, as well as many other residents of Grantville. CB radios are common in the U.S., particularly among rural populations prior to the wide spread of cell towers. They provided unlicensed, free, simple radio communications for a variety of purposes. It was automatic that the Stearns administration began to use the CBs to coordinate the new military actions that Grantville found itself engaged in. By the end of 1632, CB radios are primarily used by the military for tactical coordination.

CB radios operate at 21 MHz (11 meters) and are well above the MUF described above. Without relays, they are good for one to five miles on level open ground. The signals are blocked by hills or mountains. CB radios in airplanes, or situated ...