Adjusting A Clock's Pendulum

Back in the mists of time, before people became obsessed with digital watches, clocks had things called “hands” which pointed at “numbers” on a “face” or “dial.” With these arcane devices, primitive man (say, anyone living prior to 1970) could tell what time it was with a reasonable degree of accuracy.

Later versions of these clocks ran on electricity, but earlier versions ran through mechanical power supplied by either a spring (which had to be wound regularly), or a set of weights (which had to be raised regularly). As these springs or weights released their energy, the clock would run; the rate at which the energy was released was determined by a pendulum.

The pendulum was generally a fairly substantial weight located on the end of a stick, which swung back and forth below the clock mechanism. The slower or faster the pendulum swung, the slower or faster the clock ran. Pendulum speed was determined by the distance of the weight below the mechanism - shorten the distance (raise the weight), and the pendulum would swing faster; increase the distance (lower the weight), and the pendulum would slow down.

Making the actual adjustment was generally a hit-or-miss proposition, unless you were schooled in physics and wanted to pull out your slide rule and balance. You would adjust the pendulum to something that seemed reasonable, and then check it against some other timepiece (or dial POPCORN on your rotary phone) an hour later to see how much drift had occurred. Raise or lower the weight as appropriate to speed up or slow down the pendulum, reset the hands to the current time, and check again in another hour. A good adjuster could have the clock keeping reasonable time (no more than 2 minutes' drift per hour) after three adjustments.

An important part of the process is to level the clock. An out-of-level pendulum clock with sound “tick-TOCK” of “TICK-tock,” with unequal intervals between sounds. When leveled, the sounds (which are made by the escapement) are equal and regularly spaced.

Adjusting A Clock's Pendulum

Adjusting A Televisions Color And Hue Adjustments

Field: Home Entertainment
Went Obsolete: Mid 1980s
Made Obsolete By: Improved circuit stability and systems such as VIR (Vertical Interval Reference)
Knowledge Assumed: TV menu navigation
When useful: Visiting your grandparents

The brightness and contrast controls are used on almost all monitors and they are not obsolete. They must be properly adjusted before the color adjustments are made. The brightness should be adjusted until the blackest parts of the picture are dark but still show some detail. Then adjust the contrast until the whitest parts of the picture are as bright as you like, but they too should show some detail and not change color as the contrast is raised Most people tend to set the contrast too high. LCD monitors usually have a backlight level control. Leave it low for viewing in a dark room; raise it for a bright room. Plasma monitors similarly have a power saving feature which should be on for a dark room and off for a bright room.

Modern displays usually offer a color temperature adjustment as well. It can be set warmer or cooler as the user desires.

Now for the “obsolete” part. The color and hue controls are used on a TV with analog broadcast or other composite input.

The color control adjusts saturation or the vividness of colors other than black, white and gray. The hue control ensures that the colors are properly decoded (E.G. red is red and not greenish or blueish) First adjust the hue until the flesh tones look natural- neither too red nor too green. Then adjust the color saturation control until the people are not too pale and not too cartoonish. Try several different channels and readjust as necessary.

Adjusting A Televisions Color And Hue A…

Adjusting drum brakes on a car or truck

Field: Automotive maintenance
Went Obsolete: 1970s
Made Obsolete By: Self-adjusting drum brakes, disc brakes
Knowledge Assumed: Basic mechanical skills
When useful: Working on older cars with stock drum brake systems, performing brake jobs on some newer cars with rear drum brakes

Drum brakes were standard on most cars until the late 1960s and early 1970s when disc brakes became more popular because of their increased stopping power. Drum brakes function by a hydraulic wheel cylinder pushing an abrasive drum shoe outward into contact with a brake drum, causing friction and deceleration. After a few thousand miles the shoes will begin to wear and require adjustment so they make full contact with the brake drum and produce maximum stopping power.

The standard method of adjusting drum brakes requires raising the front or rear tires off the ground (whichever end or side is to be adjusted). A brake drum adjusting tool or a long screwdriver are also required. With the selected wheel in the air, locate the adjusting access hole in the rear of the backing plate (often covered by a rubber plug). Inside is a “star” adjuster that can be turned clockwise or counter-clockwise with your adjusting tool in order to move the brake shoe closer or further away from the brake drum. Proper adjustments vary but a good rule of thumb is to adjust the shoe until it drags ever-so-slightly. It is important to adjust both sides of the car equally so the brakes don't pull to one side.

Many cars and trucks are still equipped with self-adjusting rear brake drums which are often never replaced. However, sometimes a mechanic will need to adjust the rear brake drums “all the way in” in order to remove the drum. After replacing the shoes and hardware, the mechanic only needs to adjust the brakes close and the self-adjusters will do the rest.

Adjusting drum brakes on a car or truck

Adjusting The Dwell Angle On The Spark Distributor Of An Engine

Field: Automotive Repair and Service
Went Obsolete: Depends on your point of view… 1987 Hyundai Pony still had breaker points… Some folks like old cars that still use breaker points (but many at least upgrade to an electronic distributor)
Made Obsolete By Advancements in Electronic Engine Controls and advanced ignition systems
Knowledge Assumed: Ability to read a dwell meter, to use hand tools, an understanding of the system at hand
When useful: Replacing points, troubleshooting a poorly-running engine, when performing a tune-up, when stuck at the side of the road because the points had burned and the engine will no longer run…

Adjusting dwell allowed the breaker points of an ignition distributor to remain closed long enough to permit the ignition coil to fully saturate (i.e. allow the current through the coil to reach its maximum) to create the longest spark.

This required patience, skill, determination and the ability to read a dwell meter or the ability to set the point gap with feeler gage. (An excellent write-up is here: http://home.earthlink.net/~goodspeeds/POINTS.HTM(approve sites). Dwell varied according to the number of engine cylinders and is related to breaker point gap.

Dwell and point gap changed as the friction components of the distributor (the rubbing block of the points and the point cams) would wear.

Dwell and point gap would change as the engine ran, so periodic adjustment would be required even between point replacement.

Adjusting The Dwell Angle On The Spark …
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