Friday, March 27, 2009

Plastic Crystal Polishing


Plastic crystals scratch easily. Luckily, they also polish easily--if you have the supplies handy, it takes about 5 minutes to restore most scratched plastic crystals to nearly new condition. This is a crystal that I deliberatly scuffed up to illustrate.





With a few minues work, you can turn it into this. Yes, this is the same crystal, and taken after the first picture.


You will need wet sandpaper in 600 grit, plus 400 and 320 or so for severely scuffed watches. Metal polish of some sort, (I use Wrights silver polish or Brasso) and an applicator of some sort. I use an old fuzzy mouse pad, both to cushion the sandpaper and to apply the metal polish. I've also used the back of a chunk of vinyl cloth--you want something just slightly absorbent, not too coarse, but stiff enough so it doesn't bunch up when you polish with it.




Put the sandpaper on the table, ideally on a slightly padded surface. Sand by moving the watch across the sandpaper. First sand across the direction of the worst scratches. with the coarsest sandpaper you will use. For most crystals, you will need to tip the watch case to get to the outside of the crystal. Pay close attention that you don't sand the case itself. A few drops of water will make the sandpaper last longer without getting clogged with plastic, but don't go overboard, especially if the watch isn't water resistant. Periodically stop and dry the crystal off to inspect. When you almost have the worst scratches sanded out, or sanded as much as you think appropriate (if you have one extremely deep scratch you may consider leaving it partially visible rather than thinning the entire crystal that much), switch to the next finer grade, and sand in a different direction. Once the scratches from the original sandpaper are sanded out, switch to the next finer grade and again sand across the direction of the previous sandpaper. Repeat until you get to the finest paper you will use--I recommend at least 600 grit. 400 will work as the final, but often leaves wavy areas.

You will wind up with an evenly frosted crystal.












The final step is polish. Put a little polish on your polishing pad if it hasn't been used before, and possibly a drop or two of water. Run the watch in circles across the polish, again rocking to get the edges, and periodically drying and checking the condition. Avoid polishing the case, especially if goldtone.

You will probably wind up with a nice looking crystal, and a bunch of polish stuck in the cracks. A damp toothbrush works well to remove the excess polish. It works better if the bristles are cut to about half length.

I save the pad, and I don't need to put more polish on it most times.

Wednesday, March 25, 2009

Automatic Winding

The first effective automatic wind system was the one used in the Rolex Oyster Perpetual. The Oyster Perpetual was revolutionary--One of the first, if not the first practical water resistant case, combined with the first practical automatic winding system. The original intent of the automatic wind wasn't primarily convenience but rather to maintain water-tightness--By eliminating the need for daily winding the screw-down crown would last longer, and there would be less chance of forgetting to tighten it. This also has the advantage of keeping the watch at a constant state of wind, reducing the potential for isochronal error. (Sorry, I don't own a Rolex to take pictures of, but there is an interesting and not very complimentary illustrated review here)

The Rolex patent covered a 360 degree rotating rotor. Watch companies that wanted automatic winding had to bypass this patent, and so they came up with the bumper wind automatic. The rotor (at the bottom of the movement, marked "seventeen jewels ERNEST BOREL) was set to be free to move in the most common positions, with a simple ratchet turning the center gear which runs through reduction gears to wind the mainspring. Bumpers (shown here in the upper left) restrained it from making a full revolution. Not tremendously different in basic concept, but less efficient than a rotor that can rotate 360 degrees. It does have the advantage of being a bit flatter than a 360 degree rotor. (Click pictures to enlarge) This particular movement was made between 1935 and 1945. Bumper winds continued for some time after the Rolex patents expired, with some models still produced in the 1950's.




Like the bumper wind automatic, the Rolex only wound the watch when the rotor was turning in one direction. In the opposite direction, the system allows the rotor to spin freely. In 1942, the Bidynator was introduced, the first automatic that wound the watch with either direction of the rotor. The bidirectional design means it can stay wound with less arm movement. Note that this watch clearly uses a jewel for the rotor bearing, but remains marked "17 jewels". This means at least one of the standard jewels in the timekeeping section is missing.








Both the Rolex and the Bidynator used a simple post arrangement for the rotor. Rolex still uses a somewhat fragile jeweled post, one of the weaknesses of their design. Eterna was responsible for the next major innovation, a ball bearing rotor in 1948, on the Eternamatic. The Eterna version used 5 ball bearings, and Eterna took this as their trademark. This was another increase in efficiency and durability, and eventually became the standard on most automatics. Shown is an AS 1996, made long after the Eterna patents expired.









In the early 50's, Timex designed a low-cost automatic based on their existing pinlever movement. It used an eccentric cam on the rotor that moved a lever arm back and forth. (Right hand picture is of the same movement, with the rotor removed) The lever had fingers on the other end that engaged a ratchet on each direction, turning an axle which turns a planetary reduction gear, in turn winding the mainspring. Note that this particular movement is the jeweled version, with the unusal D-shaped jewel pins visible in the hole about 1/3 from the top, and 2/3 to the right.




In the late 50's, Seiko introduced their magic lever automatic system--Similar in concept to the Timex system, but greatly simplified. The 4 piece finger system is reduced to a single flexible arm. The diameter of the ratchet wheel is increased, with a simple pinion rather than the planetary reduction of the Timex. The original versions used an eccentric cam on the rotor similar to the Timex. On the 7000 series movements (a 1970 7005 shown), the eccentric is moved off the rotor to a separate gear. Although this appears to increase complexity, it allowed Seiko to eliminate a separate bridge for the automatic wind system, making the movement thinner without affecting durability. Another simplification on most Seiko automatics is the lack of a hand-wind capability, with these parts often modified to adjust the calendar instead.

A teardown of a 7005 movement, with better pictures describing the magic fingers is here.

A teardown of a Swatch automatic, using the same system as most modern Swiss automatics is here.

Sunday, March 22, 2009

Cord Control

We rearranged Wife's desk today. Our desks are homemade, with a fixed monitor shelf and an adjustable main shelf for the keyboard and such. Hers has standard outlet boxes wired in. The desks were built to fit a different area with a little more space, so we shortened her main shelf by 3 inches to fit the new room a bit better. While we had everything out, we decided to rearrange cords. Velcro cable ties are wonderful. These are strips of velcro with hook on one side, loop on the other. I've seen them in the garden department, at Harbor Freight, and at geek supply places. We stuck a bunch of big cup hooks under the desk for cable management, and occasionally a velcro tie to bundle the wires together. Wrap and unwrap as needed. When we were done, she said we still need to do something about the power brick for her speakers--It is large, and falls out of the plug fairly often, especially when the dogs lie under her desk. Velcro ties to the rescue! Poke a hole in the tie, run the screw for the cover plate through, and reattach the cover plate. Wrap the ends of the velcro around the heavy brick, and the dogs can't knock it loose anymore. I did mine, too.

Friday, March 20, 2009

Watch Photography

The key to good photography is lighting. Most often you want diffused, even light rather than point sources. My wife bought a "portable studio" that included a light tent, a background cloth, a tabletop tripod and 2 small daylight filtered halogen lights. This was an improvement, but it was also a pain to set up--In our house it is hard to find a big flat area other than the floor that isn't already occupied. I'm too old to lie on the floor. I made my own version of the studio suited for my work area. My watch workbench has track lighting, giving me 6 movable halogen spotlights. This wasn't meant for photography--it was a cheap way of getting lots of light to the small area where I fix watches. By themselves, the lights are lousy for watch photography--lots of reflections, hard to see detail. However, they did make a good base for lighting a light tent. I took a square wire grid from shelving, draped sheer white fabric over it, and attached a magnet. The magnet sticks the grid to a shelf bracket mounted in my work area, and the sheer fabric diffuses the lights. Sometimes the windows will add undesired reflections. When that happens I clothes pin a dark cloth with a hole for the lens. The hole is cut off center, so I can get various heights depending on how I clip it. The camera's white balance is set for incandescent--otherwise chrome cases are likely to look gold. The kit my wife got included a background cloth, I use it. This setup isn't perfect, but I'm looking for decent results with little effort--it succeeds at that. It is far easier to get good pictures with this setup than with others I have tried, and it sets up and stores quickly. The next addition is probably going to be an adjustable light that I can set up in different positions For a point and shoot without good native macro ability, I velcro a jeweler's loupe to the front of the lens. Focus is essentially done by moving the camera--you have to use the LCD screen. I'm using jeweler's loupes, available from Harbor Freight. a 2 or 3x is about right for a wristwatch, the 10x for individual parts. . In this case, I cut the front half of the loupe off, to avoid shadows on the pictures. My current Kodak has a bigger, better lens than most point and shoot cameras, but that gives its own problems--The lens is too big to attach a loupe, and when holding one in place, the depth of field is about 1mm--If I'm focused on the top of a part, the bottom is out of focus. You can see here that one arm of the balance is almost in focus, the spring below blurry, as is the pivot above. This can be controlled by manually selecting a higher F-stop number, giving a greater depth of field. Cameras with smaller lenses typically have a wider depth of field, so this isn't as much of a problem. A tripod makes all of this much easier, and is essential when the shutter speed gets low, as often happens when I change the f-stop. You don't need a fancy tripod, a tabletop model will work OK, although a floor model gives more flexibility. My floor tripod has a rack to carefully adjust the height, which makes focusing by distance easier. A quick and dirty alternative to the light tent is a flash diffuser. I used to use watch paper held in front of the flash. (watch paper is similar to wrapping tissue) Anything sufficiently translucent will help, even just plain white paper. This eliminates white balance problems, cuts the flash power down so it doesn't overexpose, and softens up the shadows compared to raw flash. The tripod is less necessary to prevent blur from camera shake, but may be useful to assist in holding the position for proper focus.

Ubuntu vs Windows install

I just finished working on a temporary project helping a relatively new company split their computers off their former owner's network. Although this effort was poorly organized and used brute force rather than the available Windows technology, that's not what this post is about. The manual Windows install process is horrible. The install process for most Windows software is horrible, and the horror is magnified when you are doing this over and over. The problem isn't the technology, it is the implementation. The Ubuntu Linux process is far more user-friendly. When installing XP, there are too many places where it halts progress and demands your attention. Worse, these halts aren't grouped together, so you have to keep paying attention to the screen. It might be 30 seconds to the next pause, it might be 15 minutes. The progress meter is nearly useless--It has a very inaccurate guess at the total remaining time, but gives you no clue how long before it needs your attention next. Installing software is just as bad. The typical install would involve clicking on the setup program to launch it. Then there's a sort of welcome page, to tell you that it is about to do what you just asked it to do. Next is a license page that you have to agree to, then a "start installing" button. At the end, there's a "finished" button to click. before moving to the next software. Some stuff needs to be installed as the user. Some needs to be installed as admin. Some stuff needs admin privileges to install, but has to be installed as the user. There is no sudo command, and "run as" isn't a good substitute. User files are scattered all over. I realize the license page is unavoidable with some commercial software, but it should be combined--Running the install program should give a single page with as many options as will comfortably fit--one of them should be "do you agree to the license", another should be "quit when successfully installed". The only way you should have more than one page is if there are too many options to fit, or if certain options depend on others. Adobe was a particularly bad setup--In addition to installing the software, we had the same "welcome, license, install, quit" process for each of 5 additional font packages for different languages. Ubuntu has several versions of their install disks. The standard is a live CD that launches a fairly complete desktop as soon as you boot up with it, with one of the options "install". While installing with this CD, you can actually use the computer for other things. A few older computers that can run the installed version of Linux can't run the live CD--for them is the alternate, which is similar to a Windows install. Tonight I just installed Ubuntu on an older PC, using the "alternate", because it was handy. It asked a handful of questions in the first 5 or 10 minutes, then it started installing. When I came back, the install was done, and it was asking to install updates. Even better, the system is fairly complete at this point--It has the basic set of software that most people need. Adding software is also simple--Find the software in Synaptic, click the box next to it. You might get another box to click to resolve dependencies. After you have chosen every program you want to install, click the "apply" button. Synaptic will install all the programs you selected without any more bother. If you are reinstalling Linux, the user's home folder has the software configuration files for that user--When you restore the home folder, you are restoring all their settings. I've been spoiled by the way EDS and GM had their systems set up--Almost all their computers are less than 3 years old, with carefully managed software and competent admins. I was thinking that Linux was close, but not quite up to Windows in ease of maintenance. I was wrong--In a less carefully controlled environment, Ubuntu is not only equal to Windows, it is considerably superior. I'm pretty sure that if Ubuntu were in a similarly controlled environment, it would be similarly successful.

Thursday, March 19, 2009

PInlever or jeweled lever

The escapement is the part of a mechanical timepiece that sets the rate. It is the most crucial part to accuracy. The escapement on a watch is made up of the balance, hairspring, fork and escape wheel. (Click the picture to enlarge enough to read the labels. Picture is a 17 jewel Chinese skeleton watch. The part marked "fork" is the lever) The balance wheel and hairspring combine run at a particular rate, generally between 3 to 8 ticks per second. This is based on the elasticity of the hairspring and the mass and weight distribution of the balance. Adding weight or increasing the effective diameter of the balance will slow the rate down. Increasing the length or decreasing the springiness of the hairspring will also slow the rate down. Older watches were "tuned" roughly by adding or removing tiny screws and washers to change the weight of the rim. Ideally these would be added in pairs, so as not to change the poise (see below). Watchmakers would have packages of washers, each adding a certain number of seconds. Fine adjustment would be made with the regulator, a movable slot that slides along the hairspring, changing the effective length. The mainspring attempts to turn the gears in the watch. The gears transmit this power to the escape wheel. When it rotates, it pushes on one arm of the lever, which in turn "kicks" the balance and causes it to rotate. The other arm of the lever blocks the escape wheel from turning more than 1/2 tooth. When the balance turns, it winds the hairspring until the hairspring is tight enough to make the balance go the opposite direction. The balance will then begin to move the lever--When the lever is released the arm blocking movement of the escape wheel releases it, gets another kick, and the first arm moves to block the escape wheel. This process repeats 3-8 times per second, depending on the watch. Consistency is the key to a well-running watch. Temperature, position, how far the watch is wound, magnetism and friction all have an affect on the rate. Much of the cost of a fine movement is in counteracting these errors. If the balance wheel is not perfectly poised (balanced), it will change how it rotates depending on the orientation of the watch-it may run differently when stem up than when stem down. This is known as positional error. On screwed balances this is adjusted by moving individual washers or screws from one screw position to another--This would keep the overall mass (and therefore the overall rate) the same, but change the poise. On smooth balances this is done by removing material from the proper spot on the balance rim. Traditional steel hairsprings change their elasticity or "springiness" at different temperatures. Old high-grade watches would counter this by having split bimetalic balances with screws. The rim of the balance was made of a sandwich of different metals, with different expansion properties, similar to a metal thermometer. Each half of the rim is attached at one end only, the other is free to move based on the temperature. Adding weight to the free end will increase the amount of temperature compensation. Adding weight to the rim near the spokes has little to no effect on temperature compensation. By moving pairs of washers to matching positions on their respective halves of the balance, temperature compensation could be adjusted without affecting poise or average rate. In the 20's, a new class of spring materials were invented that have little temperature sensitivity at normal temperatures. This allowed a smooth solid balance to equal the temperature performance of a bimetalic balance. While the rest of the movement can cause timekeeping errors, the escapement is key. Rough parts will not be as consistent as smooth, and will wear faster. Jewels in a mechanical watch are used to reduce wear and friction in critical areas. In modern watches these are synthetic sapphire or ruby. In watches before about 1902, these were actual mined gemstones--Sapphire or ruby for good watches, garnet for less expensive ones, and occasionally diamond for super grade watches. The typical jeweled wristwatch uses an anchor escapement, named after the shape of the lever. It will be at the same level as the escape wheel, and uses angled jewels glued in place where it contacts the escape wheel teeth. This gives the most consistent operation, and the best resistance to wear, but requires extreme precision in both manufacture and assembly. Jeweled lever watches would typically come in either 7 jewel models, or odd numbers between 15 and 23. 7 is enough to properly jewel the entire escapement. 17 adds jewels to all the train pivots. Jewels above 17 are of marginal value, and jewels above 23 are essentially useless. (This is only counting the jewels in the basic timekeeping section, not in additions like automatic wind modules) Watches with a single jewel are not considered jeweled. The picture to the left is of 3 watch levers--The one above the date is a jeweled lever, the clear red blocks are jewels. A pinlever is more forgiving. giving up precision in operation and long-term durability for ease of manufacture and in some cases impact resistance. The pinlever is simpler, usually stamped sheetmetal rather than the more complicated assembly of a jeweled lever. It sits below the level of the escape wheel, with round pins extending up to engage the escape wheel teeth. The shape of the pins requires a different shape of escape wheel teeth, and the interaction of these parts is compromised. Friction is higher, and is generally compensated by using a stronger mainspring, which also adds wear. These may use a layout similar to the anchor, or have a different angle between the pins and the tail. Both levers behind Lincoln's head are pinlevers. Pinlever watches are most often either unjeweled (the traditional mechanical Timex) or have a single jewel (most Swiss and Hong Kong pinlevers). There were some pinlever watches with jeweled pivots--many of these would get extra useless jewels so they could claim "17 jewels" or more. These were a bit better than their unjeweled cousins, but not as good as a seven jewel with a fully jeweled escapement. Timex had a wierd hybrid--a 21 jewel version of their basic unjeweled pinlever, with shaped, jeweled pins.

Saturday, March 14, 2009

Racism

Someone just replied to a months-old post , where I was poking fun at the now-defunct "Gold Fo Ya Mouth". They accused me of being racist. I live in an Ohio town of around 25,000, with a relatively small minority population. I saw little racism. What showed was from people who I considered ignorant, even before I witnessed their racism. I joined the Air force, and was further insulated from racism. I was in my late 20's before I finally realized that there are some otherwise normal but racist people who use the N word and mean it. It was as shocking as discovering that there were relatively intelligent people who don't read for fun, at about the same age. I don't think there are practical differences between races, and any average differences are massively overwhelmed by individual and environmental differences. I am very prejudiced against thugs and thug cultures. What I know of hiphop culture qualifies as thug--glorifying violence, misogyny and crime. It isn't a race thing--I've got the same prejudice against outlaw biker culture and white supremacist culture for the same reasons. My tastes run to practical and functional--I don't like excessive and useless decoration, whether it is grills, gigantic cowboy belt buckles, riced out cars, gigantic monster trucks, or overdone, tacky BBQ guns.

Promotional watch

This is most likely from the 60's or early 70's. It has an aluminum case, although at least this one has a stainless steel back. Inside is a cheap pinlever movement. The dial is printed paper. More than likely this watch was given away as a prize rather than sold.

Aluminum cases were not successful in their original versions--The aluminum was soft, and the protective coating would scratch easily. This would let the aluminum pit badly, even worse than plated brass.

This particular watch is an interesting variation on the "mystery dial" watch. Mystery dial watches use disks with pointers instead of hands, giving the illusion that the pointers are floating. The most common type has conventional hour and minute hands, and uses a disk for seconds, often with an animal or vehicle "running" around the perimeter of the dial.

This watch also uses a disk, but for a different purpose--It retains the seconds hand, and the disk is polarized. There is another polarized disk covering the dial. When the disks are oriented so the polarization crosses, the dial appears black, as this .

When the polarized disks align, the logo under the bottom disk appears:


So using 60's or earlier technology, they were able to make a watch with a disappearing and reappearing face, cheap enough to be a givaway.

Friday, March 06, 2009

Good Watch

Dad has a Seiko Automatic from 1971 that Mom bought him new. He wore it daily for many years, and still wears it occasionally. He worked construction during the summers while in college, and often his watch was the only one on the crew that wasn't fogged up to unreadability. It is probably seeing him with this watch (and its nearly identical quartz replacement) that shaped my view of an elegant everyday watch--Silver-white dial, simple stick markers, stainless steel case. Around 1992, Mom and Dad bought me my own quartz version, pictured here. It was basically abused for 13 years or so--I rarely took it off even to shower or swim.

When Mom bought Dad's first Seiko, the brand was fairly new to the US market, although they had made either movements or entire watches for US brands--The top of the line Timex in the late 50's used a Seiko movement. Seiko was brought to the attention of Americans via servicemen returning from Vietnam, and wasn't imported in large numbers until the early 70's. It wasn't a horribly expensive watch, but it certainly qualifies as a good one--I'm not sure there was anything close available in the US at anywhere near the price.

Before quartz, good watches were significantly better in almost every way than cheap watches. The movements would keep better time and last longer, the cases would resist water and wear better and they wouldn't have to be serviced as often. If you wanted something accurate and durable, you had to pay.

That changed with the perfection of quartz. For all practical purposes, a dime-store watch keeps perfect time--within a few minutes per year, and will usualy withstand more abuse. The dime store watch may not last as long overall, but it will generally last as long as the maintenance interval on a mechanical, and replacement will cost less than a single servicing of a mechanical.

Besides looks, what makes a good practical watch today?

Most movements are pretty good. Swiss or Japanese are probably the best, followed by other Asian movements made by Japanese companies. As long as you keep them dry, even the Chinese quartz movements will keep time with good accuracy and last years. These are movements in watches that retail for a few dollars.

The case has become the most important difference. Ideally, the case will be all stainless, NOT "stainless back, base metal bezel. It should be water resistant, with a rated depth or ATM rating. (1ATM is equal to 10 meters) Technically you aren't supposed to shower or swim in a watch with no depth rating. Unless you are diving, an extreme rating doesn't gain much--generally seals either work or they don't.

"Base metal bezel" indicates a brass case, plated with chrome or yellow stuff. Goldtone watches are an exception--it is difficult to plate stainless, so gold-colored watches will be "base metal" to a higher price point. Gold plating or goldtone isn't as durable as chrome, and nowhere near as durable as solid metal.

Band material is personal preference. Leather bands don't last forever, but they are easy to replace. I can't wear ordinary leather bands long in the summer before they start to smell funny. Luckily I bought 45 pounds of watch bands from Ebay, and I've still got a few left... Some really nice leather bands have a "deployant" clasp--Instead of a standard buckle, there is a folding clasp like a metal band. Some people say metal bands pull the hairs on their wrists. This depends on the design of the band--Expansion bands are notorious for pulling hair. Most well-designed metal rarely if ever pull hair. Look at the sides--Cheap bands will be obviously folded metal. Better ones will still be folded, but the finish will be smoother--there will be a finishing operation after the links are folded. The best watches use solid links, and solid end pieces. The clasp on a better metal band will have some sort of extra lock--Buttons on the side, or a flip-lock.

Notice that in addition to the standard lugs, this watch has 2 extra bits attached to the case, to match the style of the band. That is known as an integrated band, and it means you pretty much can't change bands, or switch from metal to leather.

Most mid-grade watches have either flat mineral-glass crystals, or domed plastic. Mineral glass is less likely to scratch, but plastic can be buffed out with trivial effort. Better watches with flat or slightly domed crystals will have sapphire rather than mineral glass. These are very difficult to scratch.

There are some features that can be a problem. Many of the "never needs a battery" --Solar (Ecodrive) or rotor-generator (Kinetic, Auto-quartz) add needless complexity, with little benefit on a standard watch. Modern batteries can last 10 years or more, some of the energy cells in the rechargeable watches don't last much longer and are far more expensive to replace. Casio makes a line of "atomic" watches that set themselves via radio. The ones with both analog and digital display can get out of sync--save the instructions.

The less expensive Seikos and Citizens are really good values. Pulsar is a cheaper brand of the Seiko company, using the same movements. Most Pulsars are base metal, but there are some with stainless cases--These are essentially a Seiko. Casio G-Shocks are among the most durable in withstanding abuse, although their newer models don't have quite the reputation of the early ones.

Gruen, Waltham (in North America) and Elgin used to be high quality watches, but are now basic cheap base metal watches, all owned by the same company that does Sharp, Watch-it and Dickies watches. Bulova hasn't slipped quite as far, but it is nowhere near the quality it used to be, and some of their least expensive watches aren't much better than you would find at Walmart. (Bulova has recently been purchased by Citizen, who used to make watches for Bulova's budget Caravelle line)

Fossil and Diesel (same company) have neat looking features, but their cases are rarely above average--In fact, some of their cases with snap-on backs are a significant problem, fitting so tight as to be nearly impossible to replace without damaging the watch.

Tuesday, March 03, 2009

Ringtone rant

I had to buy a ringtone for my new phone, and I object. Under normal circumstances I'm a cheapskate, and since I've got about 2 1/2 months to find a job before I go on unemployment, I'm even more frugal at the moment.

I hardly talk on the phone, so I've got Virgin Mobile's cheapest--pink, because the black phone was an extra $5. The tones on it are mostly hip and cool, but they are apparently designed for younger ears than mine. There's a muffled sounding video game theme, someone sort of panting over music, a male voice mumbling about music over music, a female voice mumbling and giggling over music, and one actual phone sound which would have been OK, except it is the one my wife uses.

None of the included musical ones are easy to distinguish over background noise.

I wound up with the intro to Baba O'Riley:


I'm a fan of The Who, but the primary consideration was that it is something I can actually hear. This isn't my favorite song (although it is better than average) but it is the best bit of a song I could think of for use as a ringtone.

It seems wrong to pay more for a fraction of a song than the whole song would cost on iTunes. On the other hand, it is astounding that even after buying the ringtone, the total is still under $20 for a phone that doesn't have the rest of the price buried in a multi-year contract.