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Laptop Repair Made Easy

Laptop Repair Made Easy

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Autostar Patches Meade is very conscientious about releasing software updates for the Autostar II and Autostar 497 hand controllers. Most of the new software releases, however, are minor updates designed to extinguish bugs, not add new features. Meade isn't the only game in town for Autostar users, however; ETX guru Dick Seymour regularly releases "patches" for the Autostar that add new capabilities and go beyond Meade in squashing minor bugs. Dick's patch "kits" are easy to install and modify the current Autostar software ("patch it"). The Autostar patches, including those for non-ETX telescopes, are available free for download at Weasner's Mighty ETX site (Appendix 2).

Telescope Connector Protectors Meade and Celestron scope bases and control panels are festooned with RJ-type connectors. Some of these, such as the Aux Port on Meades and the PC port on Celestrons, are not used frequently, and when it comes time to use them, sometimes they don't work or work intermittently. That's because these female RJ connectors have gone years being exposed to the oxidizing air and collecting dirt. A simple preventive measure is to plug male RJ plugs (without cables) into them and remove them only when it's time to use the ports. If it's difficult to unplug these RJs, make handles for them. Small thumbscrews or knobs can be glued to the connectors and will make them easier to unplug.

Battery Box A 12-volt garden tractor or motorcycle battery can provide all the power a go-to telescope needs. However, using a bare battery may not be the best idea. A battery sitting under the tripod and connected to the scope and accessories via a pair of alligator clips is just asking to be knocked over in the dark, possibly shorting out the telescope and causing damage. If the battery is a non-sealed type (not recommended), battery acid may spill everywhere. The same may happen when it's being transported in the trunk of the car. The solution is simple. The local auto parts or marine store sells plastic battery boxes (Plate 83). These cost only a few dol-

Plate 83. (Battery Box) A plastic battery box from an automotive discounter provides a secure home for a 12-volt lawn tractor battery used to power a go-to telescope. Credit: Author.

lars and are big enough to accommodate large deep-cycle marine cells. This large size can also work very well for the amateur using a smaller motorcycle battery, as it allows enough room for some wiring if desired.

While at the auto parts house also purchase a female cigarette-style receptacle, one that attaches to a battery via two large alligator clips. Place the battery in the box—there'll sometimes be a strap or bracket to hold it firmly in place. Then just attach the cables to the battery with the alligator clips, hang the cigarette lighter receptacle outside the box, put the box lid on (don't fasten it down tightly enough to pinch the cigarette lighter cable), and the project is done.

This box is a considerable improvement over a bare battery, but it would be nice to eliminate the alligator clips. To make a neater and more permanent battery box, while at the auto parts store pick up two battery cables with terminal connectors appropriate for the battery that is to be used. Get the shortest ones available without regard to whether they are black or red. The ends not connected to the battery will be fastened to a small terminal strip. This terminal is just a small piece of wood. Drill holes in the wood large enough for two ? inch bolts. Insert these bolts through the connectors on the free ends of the battery cables and through the wood, securing them with nuts and washers on the other side of the terminal board. Mark each terminal in some way as + or -. Cut the alligator clips from the ends of the wire going to the cigarette lighter receptacle and strip the insulation off about 1-inch of the ends. Attach the bare wires to the bolts on the terminal strip (observing correct polarity) by wrapping the wires around the nut end of the bolts between nut and washer and tighten the nuts down. Route the cigarette lighter cable out of the box through a small hole or mount the female plug receptacle in a hole drilled in the side of the battery box.

Scope Batteries on the Cheap One big facet of the modern CAT experience is the need for plenty of power to run scopes and computers. The astronomy merchants offer batteries, but as mentioned elsewhere in this book, they are not any better (and are sometimes worse) than what can be found at the local Costco, Walmart, or Asda. Keep a weather eye out for specials on jump start battery packs in these stores. Often battery packs with 25 to 50 percent more power than those sold by scope companies can be found for considerably less money than those with a "Celestron" or "Orion" sticker on them. I'm constantly amazed at how much "astronomy gear" its possible to acquire by watching the ads of discount department and sporting goods stores. Everything from dew heaters (hand warmer packs) to eyepiece cases (pistol cases) can be got there on the cheap.

Maintaining a Scope Battery Inexpensive 12-volt lead acid batteries used in lawn tractors and snowmobiles can work well as telescope and dew heater power sources. So do automotive jumpstartbattery packs, which usually also contain (sealed) lead-acid batteries. Neither battery type will work well for long, however, without occasional TLC. Want to destroy a lead acid battery? Discharge it completely a few times. Or let it sit around for months unused. Or partially discharge it and let it sit. It's easy to keep the battery healthy by avoiding these things and following the instructions below.

After each use, place the battery on charge for 12 hours. If it has not been used over the course of a month, charge it anyway. Just as it's inadvisable to discharge a battery all the way, it's also a bad thing to overcharge one. However, 12 hours on a trickle charger or a computer controlled charger won't hurt it. How do you tell when a battery is sufficiently charged? Modern, inexpensive battery chargers include charge indictors—lights or meters—to tell the tale. These indicators are usually built into jumpstart packs. Unless a battery is very low, a voltmeter across the battery terminals will not give a reliable indication. If the charger doesn't have an indicator, an inexpensive 12-volt battery tester can be bought at an automotive discounter.

Dressing Cables The average go-to scope sports enough cords to make it look like a demented octopus. There are dew heater cords, power cords, hand controller cords, camera cords, computer cords, and more. To impose some order and provide strain relief, visit the local hardware store and look for bundles of Velcro ties. Sold in packages of a dozen, these can help reduce cord tangle, and prevent that bane of go-to fanatics—a suddenly unplugged power cable. Another way to keep telescope cables neat is a thing called a "wire loom." These hollow flexible tubes can be found at home entertainment and electronics discount stores. Run all the cables through one of these tubes and cable mess is a thing of the past.

Snugger Power Cables for NexStars Celestron's NexStar go-to telescopes are reliable and easy to operate. Unfortunately, almost all of them suffer from a minor but aggravating problem: the scope end of the power cord does not plug in firmly and is prone to being accidentally disconnected during observing or becoming so loose that it does not provide sufficient power to run the scope. The Velcro ties in the hack above can help by providing strain relief (Velcro the cable to the tripod at a point near the tripod head), but the ultimate solution is to fix the scope side connector's center pin. This pin is composed of two halves that can be spread apart to provide a better connection. Spread these halves a little bit using a jeweler's screwdriver, and power cord problems will be permanently banished.

Computer Program "Upgrade" of an Older Go-to Scope Some users of older computer telescopes, like the LX200 Classic, constantly dream of upgrading to the latest go-to marvels, moving up to the hundreds of thousands of objects and countless features that the new scopes possess. If the old CAT is functioning properly, however, there's no need for that. The simple addition of a laptop computer will "upgrade" older scopes to match or exceed the latest one.

Controlling a CAT with the freeware program Cartes du Ciel, for example, brings the number of objects available to the telescope into the hundreds of thousands. Most programs also add features older telescope may be missing, such as sync. Some software will even allow GPS to be used with a non-GPS telescope if a handheld GPS receiver is available—all this for just the cost of a cable (assuming a laptop is available). Don't want to tote a laptop PC or Macintosh into the field? Many of the same benefits can be achieved by operating the scope with handheld computers alike the Pocket PC and Palm. A surprising amount of full-featured astronomy software is available for these PDAs.

Powering a Computer in the Field Some laptops are more power-hungry than others, but all need a reliable external power source. In most cases, a computer's built-in battery won't have the oomph to power the computer for more than a few hours—especially if power-sucking USB devices such as CCD cameras are connected to the laptop. There are two ways to supply external power to a computer: with an inverter or with a DC converter. Inverters, which are sold by automotive and garden supply stores, take 12 volts DC and convert it to AC. Hook the inverter to a battery and plug the laptop's AC power cord into the inverter. The power produced by modern inverters is of good quality and is more than sufficient to run computers reliably. The only problem is they are not very efficient. The process of changing DC to AC eats up a lot of energy, and a hefty battery may be required to run inverter and laptop all night long.

A better choice is a DC converter. This is a power supply that takes 12 volts DC and changes it to a DC voltage the computer can use. Converters are usually equipped with cigarette lighter connectors and can be plugged directly into a jumpstart battery pack, which makes for a neat portable set up. Since laptops use various voltages and various size connectors, DC converters are designed for use with specific makes and models of laptop. They are easily available for most brands and cost about $50.

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