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Forever Young
as published in ProSource's Profiles Newsletter
By Roger Macie
Almost every man-made product we know of has a set
life span before requiring replacement. For example, the average auto is
junked after 15 years of service. Video equipment faces a similar fate.
Aging and wear on components have associated maintenance costs which can
be reduced with a little common sense. By being aware of the life cycle
of the components that make up cameras and decks, there are steps you
can take to extend their life and increase your return on investment.
Most camcorders and VTRs have a timing device which displays important
information that can actually be used to determine component wear.
"Operating Hours" is the time the unit has been powered up; "Drum Hours"
is the time the video head drum has been spinning and wearing and "Tape
Hours" refers to the amount of tape that has passed through the
transport.
The most expensive component to replace within any
deck is the video head drum and associated parts such as drum bearings.
This is where the "Drum Hours" reading comes in handy. A typical OEM
camcorder drum lasts about 600 hours on a BetacamSP camcorder and its
motor bearings last an average of 2,000 hours. Let's use Fred Freelancer
as our example on how you can extend head and drum life. His 2 year-old
camcorder has the following timer readings: Operate -1000; Drum -500;
Tape -300 hours. The numbers we'll look at here are the "Drum" and
"Tape" readings. In two years, Fred has passed only 300 hours of tape
through his deck but the video head drum and bearings have been spinning
for 500 hours. The 200 hour difference is wasted drum time, which is
what will bring Fred closer to video head replacement time. By leaving
the deck in "Save" mode - where the heads stop when not recording or
playing - Fred, and you, can save on major wear and tear over the long
haul. The only down side is that you will lose your back space edit
reliability and will have to allow for lock-up time in post, but the
money saved will more than make up for those small inconveniences.
Head cleaning methods will also contribute to video
head wear. A cleaning tape is an abrasive tape which shaves off deposits
from the video head tips. Different tape stocks have different abrasive
characteristics which can also affect head wear. Usually the tape stock
recommended by the manufacturer has the lowest wear characteristic. The
trade-off is that low wear tapes tend to have more frequent head clogs
and dropouts because they lack the self-head cleaning characteristics of
a more abrasive tape stock. I agree with Sony's recommendation of only
using head cleaning tapes in camcorders for five-second intervals every
40 to 50 tape hours. This is a preventive maintenance cleaning that will
keep ahead of glazing deposits that only affect Betacam camcorders. Over
and above the use of cleaning tapes, the preferable way to clean all
video heads is to wet clean them frequently with proper cleaning fluid
such as Isopropyl Alcohol 99% and lint-free cleaning cloths. Although it
takes a bit more time and effort, this procedure is totally non-abrasive
and should be the method of choice to clean your heads.
Proper all-around deck maintenance is another way to
save on video head replacement costs. The tape tension alignment is
critical to head wear. Many decks use a simple felt-on-brass band to
regulate tape tension across the head drum. Often as these bands wear,
tension continues toincrease which in turn increases head wear. When
heads do need replacing, there are now options in after-market upper
drum replacements which have been shown to have better wear
characteristics.
As you can see from the above examples, component
wear of transport parts is predictable. What you may not realize is that
component aging of electronic parts such as electrolytic capacitors- the
next big maintenance cost- is also predictable. These tiny capacitors
are filled with a corrosive liquid which is very similar to automotive
and flashlight batteries. When the capacitors fail, they can affect the
circuit they are in, leak, and damage the circuit board enough to
require replacement of the entire board. As part of your preventive
maintenance procedure, you should constantly look for leaky capacitors.
By replacing them early on, you can prevent non-repairable board damage
and minimize electrical failures which can affect video or audio
quality.
This brings up yet another point: the life of the
electrolytic capacitors is rated by hours and temperature. Lower
temperatures extend hours of life and, conversely, higher temperatures
shorten life. Therefore, we have noticed that video gear used in
southern (warmer) areas fails much faster than gear used in the northern
(cooler) areas. Remember Fred Freelancer? He has only recorded 300 hours
of tape while his actual operating time is 1,000 hours. Since his video
equipment generates heat when it is on that reduces the life of these
capacitor components, the capacitorshave used up 700 more life-hours
than the amount of tape he has recorded. The lesson here? Keep your
equipment turned off whenever possible and store it in a cool,
air-conditioned environment- especially in a warm climate.
I believe that good service should go well beyond the
repair and must include educational tools which can be used in the field
and edit suite that will not only minimize operating cost but also help
provide a higher quality end product.
Take care,
Roger
P.S. I briefly touched base on the subject of
electrolytic capacitors in this newsletter. In my next newsletter
entitled "Attack of the Killer Capacitors", I'll be devoting the entire
newsletter to this very important maintenance issue, including pictures
of circuit boards with leaking caps and corroded boards. |
