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Jim Tanenbaum, CAS

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About Jim Tanenbaum, CAS

  • Birthday 01/01/1

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  1. Yes, pverrando, I once was a kid, but that was before the war. I was born before "The Big One". Now I'm a senior citizen, but not an invalid. A couple of months ago I was running around over-the-shoulder with a French documentary crew, and had more stamina than the younger people. (My bag outweighed their camera several times over.)
  2. I remember appearing on a SMPTE.sound panel with Gene some years ago. We dissagreed about some point or other, rather spiritedly as I remember. But several weels later, he recommended me to one of his "regulars" for a show that he was unable to do. However, I don't think Gene will Rest In Peace -- he'll be too busy recording God and the Angels.
  3. I have been fascinated by lightning since I was a little kid, when I used to climb up on the garage roof to watch it. I have studied it extensively and would like to point out two less-obvious points: 1. Although brief, a lightning discharge can produce incredibly large currents: 50,000 amps for the more common negative c-g strokes, and over 100,000 amps for positive ones. In addition to size of these huge currents, their risetime is measured in microseconds. This means that any inductance in the current path (even a heavy straight copper conductor has some) produces a voltage drop in addition to (and often greater than) the resistive (E=IR) component. When lightning strikes a grounded object, the current spreads out from that point and flows radially away through the ground. If the composition of the soil is uniform, the current will spread out uniformly and dissipate fairly rapidly with distance. But (and it's a big but), the soil is rarely homogeneous, and the current tends to flow through a limited area, often for a considerable distance. The electrical gradient may be in excess of 50,000 volts/meter. If you happen to be standing over this area, the low-resistance path through your mostly-water body (up one leg and down the other) will be more attractive than the dirt. (Rubber-soled shoes won't help much.) At the very least, stand wiith your feet together. Crouching down is a good idea too. A nearby strike killed a hundred cows with ground current even though they were not hit directly. If you are inside a metal-framed building, stay at least 10 feet away from the exterior walls and any interior metal support columns. Lightning currents flowing down them can raise their potential to over a million volts, and can cause a side-flash to your body. Avoid (hard-wired) telephones, electrical appliances, and plumbing fixtures for the same reason. In farming/ranching country, stay away from wire fences on wooden poles that can carry lethal currents for many miles. 2. Though not as important as damage to you, your equipment is also at risk. Besides the obvious "lightning rod" aspects of your radio mike antenna and boom poles, long runs of cable (mike or AC power) lying on the ground are a target, for strikes or just ground current. Even if there isn't a direct strike, or close ground currents, an overhead bolt can induce enough voltage in the cables to thoroughly fry your gear. As a precaution, shut everything off and unplug all the cables. A few other comments: if someone is hit, their body doesn't "hold a charge", and resuscitation can begin at once. However, be aware that lightning can, and does, strike twice in the same place. In clear, dry weather (wind makes it worse), static electricity can be a problem, too. If you are set up in the camera truck (and there is no metal ladder attached or lift gate down on the ground), it can become charged to thousands of volts. If you have cables plugged into your equipment and then hand the other ends to someone standing on the ground, they'll get a harmless shock (though they may be startled and drop something) and your gear (especially if it has active inputs instead of transformers) will get a current surge that may seriously damage it. Finally, many years ago I was working on a low-budget, non-union show. We were shooting in the Angeles National Forest when a thunderstorm approached. I announced that I was shutting down until it was safe. The producer was not amused and continued to shoot M.O.S. After unplugging all the cables, I had time to securely tarp my sound cart before the downpour started. The camera department was not so lucky, and when the rain stopped, they found that water had gotten into the cases, and half their lenses were fogged up. I don't know if the producer learned his lesson or not, because he never hired me again. It would have been nice if he had gotten struck by lightning (well, maybe just scared by a nearby bolt), but we weren't in a movie, so he lived to enjoy his ill-gotten gains.
  4. I don't know if anyone reads these older posts now, but here is the explanation for the credits on "Bonfire". I was hired in Los Angles to mix the show, including the NY sequences. Then Warner Bros got cheap and wanted to use a local NY mixer. Brian said. "no, I want my regular mixer (me)." WB found Les, who had worked with Brian before, and insisted Brian use him. Les warned WB that he had a previous commitment, and had to leave at a certain date. One Night, I got a panicked call from NY -- they were way over schedule, and losing Les. I packed up my gear and flew to NY with the gear as baggage (very expensive, overweight baggage). Les did the opening shot (an amazing piece of production sound work), all the courthouse scenes, and the teacher interview. I did pretty much everything else, including the reshoot of the accident scene. We shot most of the show in LA, including the reverses of a driving shot that some locals chased us out of the Bronx in the middle of filming.
  5. Sorry, I've been in China again, and didn't have time to look at the comments for a while. There are no mike-level cables connected to my cart anymore. My boom operators are on Zaxcom Stereoline radio links, so I can get PLs back from them if I need to, in addition to the boom mike. I also have three Comtek xmtrs, so they can each hear only their own boom if necessary. The Stereoline xmtrs are great for plant mikes because I can get two mikes on one radio channel. And for tow car shots, this avoids having to run mike level signals over the hitch next to the HMI light feeders. (Previously, I used a Cooper mike-to-line box in the picture car to boost the signals 60 dB before sending them up front, but I still occasionally had trouble.) I usually give the vid assist a Comtek rcvr with an XLR adapter cable. If I have to hardwire, I always use a condom (line iso xfmr with a ground break). While there are several multi-pair cables that are quite small, for most interconnecting cables I build these days I use mike cable I purchased in bulk from Sennheiser -- it's the stainless-steel cable used on MKE-2s. It comes in black and tan. I hate it for lavs, because it carries mechanical noises like a steel beam, but I haven't had a single cable conductor failure in my jumpers. It's so small that I can put ten of them inside 3/8-inch diameter PVC tubing, but I have taken to leaving them unbound, allowing me to arrange them in a flat row if they have to be threaded through a narrow gap. Hope this is the end of the off-topic thread, although I did mention a "ground break". (Or should that be "ground brake"?).
  6. Are you working with a large, well-established production company that will take care of you if something happens? Consider buying your own emergency medical evacuation insurance policy. Will you have access to safe, competent local medical assistance? Have your US doctor write you a prescription for a dozen disposable syringes and long (IM) and short (SC) needles in case you need injectable medications, and insist that the doctor use a new, unexpired bottle of the drug. Carry a copy of the prescription (or the original marked “filled” by the pharmacist) so you won’t have trouble with immigration or the police. Hepatitis A and B, Typhoid, Meningitis, and Tetanus inoculations are a must, and possibly Malaria prophylaxis if you’re not working exclusively in highland areas. (Addis Ababa at about 2500 m is safe.) Polio and all the “common” shots, too. Pre-exposure Rabies shots if there’s a possibility of being bitten by animals or contacting their body fluids (including bat urine). You will need a few more injections if you are bitten, but less than if you didn’t have the first ones. The various inoculations should be given well in advance of your departure, but now is better than never for any you’ve missed. What countries are you traveling from/through? You may need a Yellow Fever vaccination and official YF Certificate. Be careful of “bottled” water. Check that the cap seal hasn’t been broken and the bottle refilled. Some local brands may be contaminated and unsafe, and bottles of major brands might be counterfeit. Cooked food served directly from a steaming-hot pot is usually safe, if the plate it’s put on has been properly washed. Expensive “tourist” restaurants in major cities are usually safe, but even there, avoid salads and other raw foods. Ditto for iced drinks in glasses. Chilled cans of soda pop are okay, but wipe the top of the can off before you open it. Bottles of soda may have been refilled – inspect the cap carefully. No ice cream or other dairy products, although I’ve never gotten sick from (hard) cheeses. Steaming-hot coffee or tea is safe, but stay away from sugar in a bowl. Carry your own cube or packs if you use it. Ditto for milk/cream in a pitcher – use packaged “creamers”. The concentration of alcohol in beer, wine, or hard liquor is not high enough to have any disinfectant properties at all. Check your room and bed at night for bedbugs, using a flashlight. I recommend spraying everything with Bedlam ™, or Cedarcide ™. Pyrethrin sprays are good for treating clothing to discourage ticks, fleas, mosquitoes, etc. Don’t leave your suitcases or equipment cases on the floor or bed. Put them on a shelf or rack. Use alcohol-based hand sanitizer liberally and often. Buy only name-brand condoms (beware of counterfeits), and check the expiration date. Buy them only at major drug stores that are air-conditioned – heat is the enemy of latex. Have fun and don’t worry (too much). I wish you an absence of bad luck, which is more important than good luck.
  7. Hi Mirror, My cart is a single A&J case, so all the interconnecting cables are on the inside and remain connected. Since I no longer use mike cables, there's not much to see on the back. Empty cable hooks (I sometimes store the AC stinger I use to charge batteries overnight there, or hang a bull horn, etc), a plastic tube that stores my 816s, 5-pin female XLRs that used to feed the boom ops, and some trapdoor holes for the mike cables that used to feed the Cooper mixer. Oh, and some holes where the clamps that held the ATNs and PARs that charged the Nicads in my Nagras used to be. Ah, progress.
  8. Using plastic to support the antennas still presents a problem. The shield of the coax cables attached to the antennas is also a ground, and the cables are usually run along the mast supporting the antennas, so using plastic instead of metal would provide little advantage. The stacked antennas could be supported on a short metal horizontal struts attached at the rear to space them away from the vertical metal mast. The coax cables can be run along the supporting strut to the mast, and then downward.
  9. How old was the program? If the mike looked to be about 1/2-inch in diameter, and 1/4-inch tall, with a metallic grey finish and a pattern of holes on the front like a salt shaker, it may have been an old Electro-Voice CO-85. The capsule has a pin with 2 contacts that plugs into a flat pack behind the fabric. They saved my posterior many years ago when I had to radio mike Jodie Foster and Dennis Hopper who were both wearing aluminized asbestos fire-fighters suits. Fortunately, the suits had a black snap on one side of the collar. I used a black marker on the capsules and now the suits had "snaps" on both sides.
  10. Hi Jeff, I’m using 5, count ‘em, 5 of those SLA batteries to power my cart. There is a 21 A-H version in the same case size as the 18 A-H (and even heavier), which is I what I have. To avoid the pyrotechnics you see in all the action movies (set in a universe where fuses and circuit breakers were never invented), I mount a 20A automotive fuse directly on each battery ahead of the connecting cables. Several points: 1. Where did you measure the 10 volts? There may be a considerable voltage drop in your DC power cables if you measured it under load at the equipment end. 2. The “Amp-Hour” rating of lead-acid batteries is specifically defined, but there are several flavors of it. For automotive batteries, the most commonly-encountered A-H rating is the “5-amp”. A battery rated at 90 A-H is in fact designed to provide 5 amps for 18 hours, to a cutoff voltage of 10.5 volts (when new). For engine starting purposes, the CCA (Cold Cranking Amps) rating is more relevant. Typical values are 650 -1050 amps. Since I have several independent power circuits to avoid ground loops, my individual batteries are loaded from 3 to 10 amps. (I have transfer switches to patch in less-used batteries for heavy demands on the others.) 3. Pulling more amps decreases the available A-H because more of the battery’s chemical energy is converted to heat in its internal resistance (as well as dropping the output voltage -E = I2R). 4. The 6 A-H rating of the Lithium batteries is probably what you should be comparing to the 18 A-H SLA’s. I will definitely be interested in a version of this Lithium battery designed for continuous, low current applications. Thanks for being a pioneer in Lithiania.
  11. Chris, I strongly recommend you eliminate the AC leakage problem at the source. If the bypass capacitor on the hot side of the line shorts out, and you are working in another ungrounded situation (I have gotten stingers from the electric dept with 3-prong connectors on a 2-wire cable), anyone touching your cart or anything connected to it is in danger of being electrocuted if they are standing on damp soil or touching a grounded object. Also, location generator setups are often ungrounded by the third contact, and leakage current from H.M.I. lights set up outside can pass through the earth to provide a return path. To protect against this, I have run my cart solely on batteries for many years now. And I always use isolation transformers on all outgoing and incoming audio (and video) because of AC leakage current from the other departments’ equipment. Even if your equipment is grounded through a proper 3-pin outlet, because of ground loops even this small amount of AC leakage current can flow down your audio cables’ shields to the video assist and cause problems there unless you use isolation xfmrs.
  12. Unlubricated condoms work fine for sweat protection, but not underwater, at least not when using rubber bands to seal the opening around the mike cable. (Silicone sealant might be satisfactory, but would take time to cure, and then be difficult to remove when it was necessary to change batteries.) Here’s a method for waterproofing transmitters that I have used for many years without a single failure, after the initial learning curve. You will need heavy-duty zip-lock bags appropriately sized for your transmitters, and deep enough to contain the antenna. These are not the “heavy-duty” freezer bags sold at supermarkets – you will have to buy them from a commercial bag company. They are marketed as mechanical parts bags, and you should get the thickest gauge available. You will also need 2-inch wide double-sided carpet tape. Look for the most gummy, gooey adhesive you can find. For many years I used Nitto brand (from Japan), but I have not been able to find it recently. Unfortunately, you cannot buy a dozen rolls to stock up, as the adhesive decomposes into a syrupy mess after a few years. Start by cutting off the zipper end of the bag to give a clean opening. Then cut a length of tape that will exactly span the opening. Leave the release-paper backing on and stick it to the inner surface of one side of the bag, across the opening. Be extremely careful to avoid wrinkles in the tape or bag. It is imperative that the adhesive reach all the way to the edges of the bag. Insert the powered-up transmitter, with new, carefully checked out batteries. Remove the release paper and allow the mike cable to stick to the tape. Cut a ½-inch length of tape and place it over the mike cable. Now, carefully lower the free side of the bag onto the tape on the other side, again taking care to avoid wrinkles. To avoid bulges under the wardrobe, do not trap too much air inside the bag. Finally, use a smoothly-rounded object to press the bag against the tape, paying particular attention to the areas at the ends of the tape, along the length of the mike cable, and the ends of the narrow piece of tape covering the mike cable. Air bubbles or gaps will show up as lighter spots compared to places where the tape is properly adhered. You can check the integrity of the arrangement by submerging the bag in fresh water and then squeezing it. I suggest practicing ahead of time with several empty bags. Use a short piece of wire to simulate the mike cable. The Countryman B6 is said to be “resistant to moisture when used with the protective cap”, but the very small opening at the end of the mike or the cap can be blocked by a drop of water held in place by capillary action. The B3 is only twice the diameter of the B6, but has a much larger opening that is not as likely to be occluded by a water droplet. Also, the B3 is described as “water-resistant”. Something that has worked for me as rain protection might work here as well. Saturate a piece of 100% wool felt with WD-40, then wring it out and blot with several paper towels to remove the excess oil. Fasten the felt to the head of the mike with a piece of 28-gauge bare copper wire, wrapping it around the outside of the felt and then twisting the ends of the wire together. The oil will keep the felt from becoming waterlogged. F.Y.I. Equipment that has been exposed to salt water may, I say may, be salvaged if you act quickly. Flush the gear with copious amounts of fresh water. Unplug connectors and open up any compartments the salt water has gotten into. If the supply of fresh water is limited, use a small bucket or pan, swish the gear around, dump the water and repeat the process with a new fill of fresh water. Repeat as many times as you have water, or at least 7-8 times. Then shake off as much water as possible, or better, blow off with compressed air. Next, use several rinses of anhydrous (94-98%) isopropyl alcohol (isopropanol) to remove the remaining water. (The water dissolves in the alcohol, and then runs off with it.) Finally, shake/blow off the remaining alcohol. If you don’t have isopropyl alcohol, use several liberal sprays of WD-40 (until it is dripping off). This will displace most of the water. Shake or blow off the residue. Later, when alcohol is available, you can use it to remove the WD-40. As a last resort, simply allow the fresh water to dry, helping it along with a hair dryer or sunlight. Whatever method you use, moving parts such as potentiometers or motors may still have to be replaced.
  13. 3rd sharkfin swivels independently for aiming at the video assist cart where I have 2 UHF video xmtrs to feed my monitors. A small snake runs up the mast with 3 coaxs and an audio feed to the second Com-Tek xmtr (mounted on the 3rd sharkfin). The 2 monitors are kind'a fragile, so I remove them. Their mounting bracket is secured with a single knob-headed 1/4-20 screw. I just have to unplug one 4-pin XLR for their power and the antenna coax that feeds a 2x splitter. If the file attaches, here's a pix from the days when I still used DAT. Jim T.
  14. Very interesting, Larry. I don't know what differences there are between Lectro and Zaxcom in terms of circuit design, but I used two Zaxcom ENG receivers (true diversity) side by side and set to the same frequency. One had both 1/4-wave whips vertical and the other had them at 45 degrees to the left and right. They were located on the top (metal) shelf of a sound cart, which served as a ground plane. I did not try one antenna vertical and one horizontal. After a number of runs, I changed the vertical antennas to the V configuration and the V antennas to vertical to eliminate any variation in the individual receivers, and made more runs. Transmitter was mounted on subject's body, in the small of the back with the antenna vertical, under a t-shirt, but with 1/4-inch O.D. rubber tubing over antenna (my usual practice). Test was run outdors, walking along a sidewalk in front of buildings, starting at about 300 feet. There were cars parked along the street. When the subject got close to the cart, he turned and walked down an alley at a right angle to the sidewalk, and out of line of sight. Maximum range down alley was about 100 feet. The diversity indicators on the receivers showed a lot of activity. The results were similar with both receivers: the V configuration outperformed the parallel vertical antennas. Fewer (as much as half as many) dropouts at near and middle distances. Toward the far end of the range, results were too erratic to see a clear difference. Jim Tanenbaum
  15. Very interesting, Larry. I don't know what differences there are between Lectro and Zaxcom in terms of circuit design, but I used two Zaxcom ENG receivers (true diversity) side by side and set to the same frequency. One had both 1/4-wave whips vertical and the other had them at 45 degrees to the left and right. They were located on the top (metal) shelf of a sound cart, which served as a ground plane. I did not try one antenna vertical and one horizontal. After a number of runs, I changed the vertical antennas to the V configuration and the V antennas to vertical to eliminate any variation in the individual receivers, and made more runs. Transmitter was mounted on subject's body, in the small of the back with the antenna vertical, under a t-shirt, but with 1/4-inch O.D. rubber tubing over antenna (my usual practice). Test was run outdors, walking along a sidewalk in front of buildings, starting at about 300 feet. There were cars parked along the street. When the subject got close to the cart, he turned and walked down an alley at a right angle to the sidewalk, and out of line of sight. Maximum range down alley was about 100 feet. The diversity indicators on the receivers showed a lot of activity. The results were similar with both receivers: the V configuration outperformed the parallel vertical antennas. Fewer (as much as half as many) dropouts at near and middle distances. Toward the far end of the range, results were too erratic to see a clear difference. Jim Tanenbaum, CAS
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