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A very wise videographer named Jim Billipp recently quipped, "Good is just an intermittent that hasn't happened yet". (Jim, a client of ours since 1995, prompted us to manufacturer the original professional "Warm card" and helped us with our new logo).

There are three states of operation for all video gear; operating properly (good); in some sort of failure mode (bad); and intermittent (ugly). When a unit is functioning properly, all is well. When a unit fails consistently, you just fix it. However, when a unit only fails intermittently, it can be absolutely nerve racking. If the unit is sent in to us functioning properly, it presents a big problem. With most malfunctions having several possible causes, it's impossible to know what component to target for the fix. And it's impractical and too expensive to fix all possible causes.

The stories we could tell of how we tried for days to recreate some problems in the shop. From turning our bathroom into a "tropical room" with heaters and humidifiers, to putting a camera in the refrigerator overnight, to actually driving down the bumpiest road I could find while my tech, Danny, shot video (he still has the bumps on his head). How many times have you brought your car in for service only to find that it's not doing what you said it is doing? You say to yourself, "I just know this thing is gonna stall when I'm in the harbor tunnel during rush hour!" Well video equipment is similar and in some cases even more of a problem than your car.

Many shoots involve great expense and are often non-recoverable events, from space shuttle takeoffs, productions with large crews and talent, and important interviews, to even your own or another's wedding. These are times that you can't afford to experience any problems.

With the size our client base, we see all sorts of problems. Many problems repeat themselves over a product line and become common and easy to fix. The difficulty for all of us is when we can't recreate the problem that occurred in the field. The first thing we try to do is help you diagnose as much of the problem as possible while it is happening, before you send your gear in for service. This can greatly decrease the total costs involved, including down time, shipping and repair costs. We prefer to provide our clients with telephone support to help with this trouble-shooting before sending the unit in for service. Too many times we can not recreate the same problems, which causes frustrations for us as well as clients.

In this series, I will be discussing several problems which you may encounter intermittently. In part one of this series I will discuss one area that we have experience in that can help you get through those tough times with minimum expense and client frustration.

Tape Stock Issues - Head Clogs

With videotape, clogs happen. Hopefully, you will get an RF warning from the recorder and can quickly clean your heads and get up and running again. Depending on the severity of the clog, you may not always get an RF warning, so be sure to check playback as often as possible.

While there is a lot of quality control in the manufacture of tape stock, there can be some bad batches and even recorder or environmental problems which can contribute to head clogs and severe drop-outs. High heat and humidity for example, can reek havoc on perfectly good tape stock

What can you do to minimize problems? First realize that you have been lucky if you have never experienced one. We rarely hear from clients who have never experienced a head clog after years of shooting. When we do, it is the exception not the rule. Tape stock and environment play a large part in the head clog problem. All videotape decks have a number of stationary and rotating heads that record and playback video, audio, time-code, and control track signals. Each of these heads is subject to clogging.

High speed rotating video heads lay down incredible amounts of video, audio, and time code information, the amount depends upon actual tape format of course. At times, spots that have missing RF signal interrupt playback of this recorded signal. This is called a dropout. Small dropouts are common and normal and don't even show up in playback because of playback dropout compensation in the analog world and error correction with digital playbacks. Unfortunately, with high dropout rates or massive head clogs these circuits are of little use.

Being diligent with head cleaning and frequent spot checking of recorded video is the best way to keep ahead of intermittent recording problems, but there are other things that should be considered beyond keeping heads cleaned. Over the last thirty-five years of experience with tape manufacturers, we have come across a number of bad runs of stock. When problems all of a sudden begin to happen and you find yourself having to clean your heads frequently, switch to another batch or tape brand all together, then notify your tape supplier. They will welcome feedback because of the competition for your tape business.

When you have had excellent results with a particular stock or brand, stick with it. Often problems occur after switching to a less expensive product that may not have the quality that you have been accustomed to. With the smaller format, ¼ inch digital decks from DV, DVCAM, to DVCPROHD, it is very important to use the highest quality tape stock that is recommended by the manufacturer as your starting place. Nobody knows better and has as much control of the recording process as a manufacturer that makes the recorders and tape stock.

With that said, there are other tapes stocks that can be as good and in some situations better. Ask others what they recommend and use. Consider that different tape manufacturer's formulations include some with materials that act as lubrication of video heads to extend head life, and some with materials that are abrasive, which in effect clean the heads as they record or play. When a client expresses a desire for reliability, I recommended one popular brand with near problem free recordings because of its inherent self-cleaning action. If long head life is the main concern, I recommend another brand because of its low abrasive nature and resulting long head life. Clients should make up there own mind what is more important, reliability or head life. Over time however, tape manufacturers change formulations so that the past is not always what's happening in the present. This would be a good topic of a video news group. Ask others what their experience has been with different tape stocks, and notify the group when you see bad runs of stock.

Another important tip that can go a long way in saving your relationship with your client is when you suspect you have a tape problem, grab another tape from the suspect batch and make a short recording. This tape can be used as evidence if the tape stock proves to be bad. We have used some of these tapes in the past and have made bad recordings on a number of other decks in the shop. Why should your equipment be blamed when it may be the tape stock your client provided?

In my next article I'll be discussing the effect the video heads have on minimizing tape problems.

Take care,
Roger 
 

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