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Greetings from Roger Macie,

As many of you probably know, I have been writing "Maintenance Tips" for Prosource’s "PROfiles" newsletter. These have included such topics as "Avoiding Head Clogs", "The Ultimate Standard", and "The Next Step". All of these have been geared to the broadcast professional who makes his or her living off their Betacamcorders. Prosource is a national video production equipment dealer based in Connecticut. Please review these articles, especially those that refer to The Macie Uniform Standard. Its conception was discussed in "The Call for Uniformity" and is written about in two successive articles.

The "The Next Step" discusses specialty set ups that are currently available for Sony and Ikegami digital cameras. The "Macie Uniform Standard", also known as "The Dateline Look", has been used and recommended by some of the top network magazine shows. It has had an absolute success. When you look good, we look good.

If you have not visited us lately, you may be surprised to find how comprehensive our Freelance Listing Guide is. Over 40 countries and all 50 states are listed. We recently got feedback from a freelancer in Oklahoma who got hired for a CBS morning show by the booking guy who uses only broadcastvideo.com's "Freelance Listing Guide" because of the great crews he gets. Check it out.

Now for maintenance tips

The best way to deal with audio problems is to be on the look out for them. There are literally hundreds of things that can fail, from microphone, cables, batteries, audio head clogs from bad tape, to PC board level component failures. Audio should be monitored through the camcorder monitor system because that is the end link in the audio path. EE is best used to judge the audio quality. Usually cable and mike problems are caught because of the higher quality monitor circuits. This EE audio is processed and passed to the linear audio record heads, and/or to the AFM (CH3 &4) audio tracks which are recorded along with the video signal.

On the BVW, HL-V Betacam camcorders and the dockable BVV-5s, there is a separate audio playback head and circuits, which are used to play the audio. Thus the audio being recorded is what you hear in the EE mode, and the confidence playback is what you hear while recording in the PB mode. That is why when you listen to the audio, you hear an echo which is due to the time delay it takes for the recorded audio to reach the playback heads. You will also note the poor sound quality audio playback. In order to keep these decks small, compromises had to be made somewhere.

You judge the quality in the EE mode and use the PB or confidence mode just to see if the audio made it to tape. That’s why it is important to record zero level tone while in EE mode, then either check the PB (confidence mode) while recording, or just rewind tape and playback the tape. By the way, in the "PB" mode it is actually in the EE mode until you hit record at which time it switches to the confidence playback heads.

The playback level on the meter should be within 2 DB of the EE or record level. A drop of 3 db or more usually means that there is a partial or complete head clog. This is a material build up on either the record or playback heads. Because of the two heads used, either the recording is OK and the playback is bad, or the recording is bad and the playback is OK. In a pinch, you can playback a known good tape and see if the playback is good. If it is bad, then the recording you made is probably OK.

Of course if you have access to a playback deck or a VA-500 playback checker, that will verify the audio recording is OK. The playback checker takes the audio signal from the record head, not the playback head. That's why the quality is so much better.

To clean the heads, it's a simple matter of removing the VTR door and wet cleaning the heads. A lint free cloth, or chamois (shammy) tip swab and 99 % isopropyl alcohol is usually the best way to clean the head surface. Note that the recording surface of the head is at the extreme ends, or top and bottom of heads surface. The audio record head stack also records the time code signal. (Our Camcorder Survival Kit has everything you need to maintain your camcorders. It also includes a training video showing the proper way to clean the deck.) If cleaning doesn't seem to work, try another tape. If the tape you're using has edge damage, you could have poor head to tape contact and have what looks like a head clog.

Don't bother with a cleaning tape. This tape was designed to clean primarily the video head tips not the stationary audio heads. What often works in a pinch is to take a tape and fast forward it to the end then rewind it. This has helped me in the field when I didn’t' have any cleaning materials with me. Running thousands of feet of tape across the heads has a tendency to remove any head clog.

I will be picking up from this point on the next newsletter. Good luck and happy shooting.

Take care,
Roger 
 

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