I want OB van

By Eugene Brudno

Review contents:

I want OB van Mini mobile television stations by “AudioVideo Technologies” Company “Veresk” Mobile television stations by “Figaro” company “Pultex” mobile multi-camera station Mobile multi-camera TV station by “Era” company is a new series of finished decisions Mobile TV stations by A&T Trade company Mobile television stations by Elvia (Czech Republic) Mobile television stations by I.S.P.A.-Engineering Mobile television station of JC-Sport manufacture Proline multi camera mobile station Mobile television station by Protec company Digital mobile TV stations of Qualitron manufacture Mobile television station of Sat-Comm manufacture If you can not afford mobile television station (instead of afterword)

Material, offered in this article, does not pretend to be directivity or an attempt to classify something or to introduce any definitions. We even find it difficult to define genre of the article. Most likely it is a kind of essay. This is a sort of reflection on Mobile Television Stations topic.

Mobile television stations (MTS) take the same place in television as fighters do in air force or motor torpedo boats do in navy. All these are highly mobile means of goal achievement.

Action scene is almost always scope of activity of MTS. There are exclusions when MTS is put for continuous operating, still it is not their main scope of activity and it happens very rarely. Although even in this case, there is main element of use of MTS: operating on unequipped area.

Thus, main cases of use of MTS have two common characteristics: event is not repeated and operating area is not equipped. So full independency is the main feature of MTS.

This is ideal. There is an opinion that the ideal is unreachable, but in our case it is only a matter of investments. As this question is not that simple, one must think over thoroughly his/her variant of ideal in every individual case. In other words, when planning building up of MTS, one should try to define what purpose the desirable machine is intended for. The following material is an attempt to remind the reader about peculiarities of MTS from the point of view of technological means of TV program creation.

The only condition is: no strained circumstances.

So: I want mobile television station!

What do they shoot or transmit with the help of MTS? That is sport competitions, game and politic shows, public actions, production programs of different orientation, ready theatrical plays and concerts. Sport programs stand out of this list and there are several reasons for it. First, many international competitions have quite strict rules as for their TV interpretation. These rules regulate number of cameras, number of long-focal-length lens, number of programs being formatted, number of repetitions and a lot of other requirements. Now MTSs are built specially for broadcasting basketball, skiing competitions, etc. Observance of all these requirements raises the price of the machine. Besides, specific equipment (for instance, mini and micro cameras, cameras with radio lines, lens with stabilizers, etc.) is also required for demonstrating sport programs. All this equipment, though may be used not only for sport programs, will have low use factor all the same. Second, sport competitions take place, as usual, on big areas, which requires employment of long cables and fair quantity of long-focal-length optics.

Thus, there can be defined some generalized image of sport MTS. It is multi camera (12…30 cameras) machine with big inventory of expensive optics, with equipment for repetition, powerful commutation system and lots of additional equipment. It is a quite expensive machine. So expensive that there is no real buyer of the machine in Russia, many people willing to have it. Considering growing interest to sport on the governmental level, one may predict emergence of one or several similar machines already in nearest future.

Shooting or broadcasting of mass shows have some features making them similar to sport shows. These are big areas, essential number of cameras, long-focal-length optics. But for such shooting there are no strict regulations. Although demands of directors of such programs often exceed demands that a really necessary, being rather indication of some status of director in TV community. And this may bring the same worry as the strictest regulations. Fortunately, these are a kind of inner problems that may are easily settled.

Practically all other shootings, except sport programs and extremely big shows, require MTS of so called medium class. It is true that MTS is a machine of high class for sport programs.

Medium class stations contain 6…10 cameras, one “long” objective lens, and considerably smaller number of external communications.

Machines of small class (2…4 cameras), in our opinion, do not relate to MTS. These are mobile reporting television stations (MRTSs). Much of the following below relate to MRTSs also.

It is worth mentioning that with emergence and wide spreading of shooting systems one should realize completely what he/she want, considering that shooting systems do not substitute MTS but allow solving many production tasks. However, they cannot be used instead of MTS, and in some cases cannot replace MTSs at all. Their main advantages are relatively low price in comparison with MTS and high use rate of equipment. But let us come back to our subject.

It may sound strange for article about MTS but we will not pay much attention to their technological stuff. Set of equipment, available at the market, allows supplying the machine with devices of any quality and quantity. We will not give preference to any manufactures because of advertisement ethics.

Mercedes-based OB Van	Two-camera OB Van with automated satellite signal delivery system

Machines of high and medium class differ by their equipment stuff only. Main approaches and principles of their design are identical. What MTS is to be designed: analog or digital? The question is not that simple, as it may seem at first. If you analyze structural schemes of digital machines, you will find out that they employ great part of analog equipment. All additional and control channels are analog. And this is standard. People save money for completely digital machine is much more expensive. But completely composite machine is not popular because of its low quality. Maybe it will be good to work in component or by two-signal system? This variant is an absurd for large machines, but what is the situation with small ones? It is necessary to consider all factors.

What cameras should be used? We think, cameras in ENG embodiment are optimal variant. There are the following cases: shooting from the shoulder, a method that is very popular among operators, is available, inventory of cameras and optical devices on company basis is unified, operating of MTS during unwinding-wining is lightened because small cameras are lighter. Besides, big cameras require heavier, and thus more expensive stands and heads. Qualitative indexes show that there is not much difference between big and small cameras, and additional functions, employed by big cameras, are not used very often.

Optics. Optics is a serious point, especially for MTS. Inventory of objective lens for MTS must include various devices with different focal distance. From the point of view of exploitation, it is necessary to select objective lens with good encapsulation and simple operating gears, reliability of equipment for MTS being primary requirement. Any set of optics for MTS must contain at least one (the more the better) long-focus objective lens. This is the most expensive component in optic inventory. When selecting long-focus objective lens one should not only estimate rationally its maximum focal length, but also consider minimal one. Why? Because even the most long-focus lens takes not only close-ups, and the smaller the minimum focal length, the more acceptable this lens will be.

If you plan shooting something highly artistic with very slow zoom or zoom-out, you should be aware that ENG-lens would not be useful in such case. They have a certain limit of ranging speed. It depends on number of teeth of driving gear per unit length of its outer circle. In case of very small speed, ranging changes in steps (owing to inevitable errors during production of teeth and their deterioration), from teeth to teeth. The gear becomes similar to step motor. The thing to do is application of studio lens having greater diameter of driving gear and, correspondingly, greater number of teeth per circle unit length since extent of error is small as compared to dimension of gearing. Of course, this is subject to equal teeth pitch, which is usually provided. When selecting the optics, one should consult with operators about proper each optic unit and its control system. This type of equipment is expensive but there is a choice set.

Stands. Usually, MTS uses tripods, but not footstall. Also dollies are frequently used (cameras do not often run in shooting area). But what is necessary to use with tripods is medium brace that fixes tripod’s opening. Very often camera seat has great incline or is a stepped area (e. g. gangways or rows in auditoriums, halls, etc.). That is why it is necessary to fix stand’s legs thoroughly, preventing its shutdown. To save money one should not buy all tripod heads of one type. It is worthwhile to purchase one or two powerful heads for big lens, other heads may be lighter and cheaper in accordance with weight of shooting cameras, which includes weight of all necessary devices.

Interior of OB Van

Video path. There is one omnibus approach: the more finished product (both on video tapes or at broadcasting) you want to get from MTS, the more complex and expensive the path should be. Classical structure contains patchboard, mixer, DVE block, decoder, and, sometimes, graphics workstation. Anyway, video path should contain input synchronizers for receiving non-synchronous external programs and one or two output coders since we will not get rid of analog SECAM or PAL signal soon. There is an interesting combination of standard video patchboard and DVE block of Magic Dave type. In such combination DVE with its eight inputs operates as DVE, mixer, and rear projection device, and video patchboard, in addition to its main functions, perform role of mixer’s input commutator. This combination allows refusing from video mixer, which is a quite expensive device.

Patch panel is an indispensable part of video (and sound) path of MTS. Patch panel, which is developed and projected correctly, widens extremely technological possibilities of MTS, allowing flexible changing its scheme, and provides reliability of the system as a whole. Patch panel should not be neglected or saved on.

Display systems (means of visual control). Traditionally these were CRT-based monitors. Now there are, first of all, gas panels, second, LC monitors, and, third, split screen systems. Lets start from the end. What do split screen systems provide? They are used both with CRT monitors of large cornerwise dimension (20") and gas panels (42"). Undoubtedly, this leads to reducing monitors’ quantity, facilitation of layouts, flexibility in use of visual control means. One will easily reconfigure monitoring bay for a specific shooting session or even requirements of concrete director. And, finally, it looks modern and fashionably. But what should one remember when evaluating such system? First of all, it costs quite a penny, and saving on monitors will be insignificant. Secondly, reliability of MTS will go down, for death of one of the monitors or the gas panel containing split screen system will reduce many of your control means. Thirdly, the system control computer requires certain space on control panel. One should consider that each separate split screen entry has fairly much more worse picture quality than full screen control system does. That is why split screen control systems are more appropriate when used as “spy” systems and in cases when it brings real gain in equipment dimension. Now you decide!

LC monitors. That is a good thing! LC monitors are light, flat, and of moderate cost. Still they have small viewing angle and low picture quality as compared with traditional video control devices.

Item repetition. This technique is required in sports. It may be realized by different ways, beginning with online use of several videotape recorders, ending with use of specific Slow motion equipment. Application of inexpensive Profile-type video server with necessary number of input/output ports is also possible.

Video recording is, most often, a final product of MTS. Here a question occurs: what recording format should be used? The answer is simple: the format that is supported by the main company production, for we do not forget that final product of MTS is source material for subsequent production. It would be interesting to discuss possibility of total refusing from means of tape recording and using video servers as registering equipment.

There is a separate question on if MTS must or must not contain editing controller. Controller seems to be quite inexpensive thing that contributes greatly to a list of MTS’s capabilities. Strange it may seem, this matter is not technical, but organizational. MTS’s having editing capabilities will lead to necessity of accurate coordination of its operating time for edits and set-offs not to impede each other. If you are ready to carry editing at nights also, utilization ratio of MTS equipment will rise greatly.

Enough number of outer inputs and outputs of native signal are also important for MTS video path. This is not dear, but important during work with complex technological schemes equipping other hardware systems and various additional means. It is worthwhile to have two or three outputs of video array with remote control panel (for instance, when project cameraman is working indoors or chief lighting engineer is working in shooting area). There must be a developed intercom system capable of accepting personnel, working in shooting area, and receiving signals from outer sources. It is quite good if MTS employs on-air signalization’s output from several inputs of mixer. But all stated above is required only during work with complex, branched schemes. And it costs much!

Audio in MTS is one more separate issue. Till recently it has been paid less attention than video has. Maybe that is because high quality multi-channel sound was recorded in special tone wagons, and MTS used sound only for control. Or maybe that is because audio program is often formed by some other devices, and MTS receives practically finished product, as they say “on a cord”. Now the situation has changed. Modern equipment allows MTS to form and record complex multi-channel programs with all possible processing and special effects in small volumes. But one should decide clearly what type of sound he wants as final product: program’s accompanying sound only or independent result of any creativity. Even the coolest sound does not breach total cost of MTS.

MTS, designed for sport and show programs, should employ remote equipment: several monitors for project cameraman and chief lighting engineer, commentator unit for sport commentator, several acoustic systems for sound amplification of shooting area or issuing director’s commands, remote panel(s) for array control, communication equipment.

Now let us talk about what makes MTS a real mobile studio: body and running gear. Today there are two types of MTS: monoblock and semitrailer. Monoblock is a body set directly onto running gear of a vehicle. Semitrailer, having only rear axles (one or several), is moved by artic. Monoblock is usually set on a long chassis of lorry, still there are good MTSs based on land cruisers’ chassis. Monoblock MTS has smaller dimensions than semitrailer one. That is because dimensions are defined by running gear. By the way, there is no any standard for MTS’ dimensions, but there is practice. Monoblock MTSs employ bodies of maximum 10…12 m length with total 13…15 m length of vehicle. Semitrailer MTSs employ bodies of 13,6 m — a length of standard semitrailer. This length may be more or less, but in the second case there is no much sense to use semitrailer. In the US, for instance, they use bodies of up to 18 m. Height is a strict dimensions. It should not exceed 4 m. Usual height makes 3,8…3,9 m. Width always makes 2,5 m.

What is better: monoblock or semitrailer? You decide, depending on your tasks. We may only compare these two types.

Monoblock MTS employs special elongated vehicle chassis with additional rear axle, principally smaller size that may be expanded by sliding walls and consoles, monitor bays and cable layouts. But this is worth much. Besides, long monoblock stations have large turning radius, i. e. worse mobility, which is important for MTS. And finally, monoblock MTSs are less reliable, product of reliability ratios of MTS’s technological part and reliability of vehicle making reliability of the whole system. Since both indexes are under 1, their product is even smaller. In other words, monoblock MTSs requires good and reliable, hence expensive, vehicle (maybe, of foreign manufacture). Now you count: running costs, service, spares, and service materials. There is one more circumstance: MTS’s running gear and body are connected permanently. I. e. chassis is idle for most part of its operation life. Though running costs are sometimes less.

Semitrailer MTS may employ any artic with engine of 280…320 liters. Body is much more spacious, there is no need in sliding walls. One may rent artic instead of buying. Semitrailer’s mobile rate is higher. There is one little thing: when ordering body one should try to ensure that move angle of vehicle is as big as possible. This enlarges vehicle flotation greatly, which is important for Russian roads.

OB Van with sliding out wall on the base of a trailer

Here you will find several requirements to vehicle that will carry MTS, no matter if it is monoblock or semitrailer. For easy exploitation fuel filters and fuel tank should employ heating system and engine start heating. And one should not forget about driver’s cab for driver spends quite a lot time in his cab. Suspenders for running gear, artic and semitrailer should be pneumohydraulic. It will prolong operation life of equipment. By the way, monoblock MTS should employ towing bridle just in case.

Body. Stated below relates to all bodies (large, middle, and small). Body must be warm, corrosion-resisted, and eligible for repair. Body’s design should provide easy access to back sides of stands and bays, as well as roof. Frame body, covered with “sandwich” panels, is ideal. “Sandwich” panels contain stainless steel and 50…60 mm of polyurethane foam from outside, plastic with decorative coat inside. Access to back sides of stands and bays realized through hatches that should be horizontal and of two halves. Dropped lower half makes a kind of floor, upper half making ceiling. This is handy and easy during exploitation. Hatches’ upper halves are equipped with gas blocks in the way that makes it possible to open the hatches easily. All hatches and doors must employ protected from dirt and identical locks with the same keys. It is worthwhile to set one alarm system onto all hatches and doors.

Any MTS should employ two back or four angle jacks. They stabilize body during stops and allow compensating area slope to some extent. In case jacks employ hydraulic or electric driving gear, it is necessary to provide its hand doubling.

Roof. Why would one get onto roof? First of all, out of curiosity. To be serious, roof may stand and stands as an area for cameras, though it is not of great benefit. That is because vehicle usually stands out of operation place, and you will have to install long-focus objective onto camera, set on vehicle. But even jacked MTS is not absolutely stable, which makes picture received from long-focus objective unstable. Taking into account the fact that according to safety code shooting area must be enclosured and its dimensions should be not less than 2×2 m, this plan does not look successful. Usually, they get onto roof because of different reason: it is a popular place for additional power cable that is set eight-like and fastened with belts. This is cheap and reliable. So, now all on roof!

Good body should employ good ladders. They should be easy in installment and demount. They should be very strong, equipped with nonskid steps and railing. Each door, even reserve one, should employ a ladder. And, of course, all ladders should be alight.

During the last 10-12 years sliding walls have become popular and defensible. When ordering sliding walls, don’t forget about two things. First, upper horizontal part of the wall in risen state must be protected from snow (imagine how you will move the wall when it is covered by frozen snow). Second, reserve hand wall bar assembly should be provided. Everything happens: accumulator may run out or hydraulics may flow, but you have to drive on. Hand drive may be of great help.

Body’s interior is a matter of your taste. Just do not forget about section for sound producer. It requires special sound conditioning. And there is one more thing — chairs. They are quite many, getting underfoot and all over the body during driving. Folding chairs are very handy: they do not occupy much area and can be fixed to the walls with the help of plait.

Now we will talk about body layout. Term “layout” includes such characteristics as number of sections, work places, doors, etc. Usually, MTS’s body is divided into three stand-alone sections: director, sound producer, and engineering section. Such division is logical for each worker is occupied with his business and does not disturb others. We will not describe how equipment is placed in each section. But it is worth talking about organization of members’ workplaces. In the whole, principle of three sections, i. e. production areas, is quite relative. There are single-section bodies and two-section bodies in which director and engineering areas are combined. Kind of work in each section, its matter, number of workers equipped in process, number of talks online, etc differing for director’s group and operating personnel a lot, it is better to separate these two areas. As for sound producer, he is always separated. Thus we will discuss thee-section configuration.

Let us see who work in each section. Director section is a place for director, his assistant, titles editor, one or two repeat system operators — in the whole we have got four or five persons. There are some more participants: producer — quite mysterious but obviously managing person, and other members whom one gets rid of very seldom. Often director section is overcrowded during shooting of considerable programs. Videotape operator is one more person who works closely with director group. And it is more suitable for him and all videotape recorders to be in director section for tapes are to be replaced from time to time. Besides, director section of large MTS must contain area for computer graphics station. This may be standard or detachable equipment. Thus we have eight permanent work places to be available in director section. Reduction is quite possible for we are talking about maximum requirements.

Engineering section contains main equipment and means of objective control. Number of workplaces in this section depends on number of cameras. Practice shows that cameraman, whose responsibility is controlling cameras operating and managing their technical characteristics, may work productively with no more than six cameras. And this is subject to professional skills and reaction of cameramen. This is quite tiresome work — only professionals may operate cameras control panel during 2…3 hours without a break. It is better to reduce number of cameras to four items per a person. It is more expensive for number of oscillographs and monitors grows, but one will receive high quality of picture. This is especially desirable in case MTS is oriented for sport and show programs, since conditions of subject illumination cannot be predicted.

Besides cameramen, engineering section is a working area for video engineer, who is responsible for all technical part of picture formation, and MTS shift engineer. Thus, number of working places in engineering section must be calculated according to the formula 2 + N/4, where N is a number of cameras.

Sound section is usually designed for two persons (in Russia this is a case for almost all MTS): sound producer and sound engineer.

Each section must employ separate exit. Inside door between director and engineering sections is obligatory.

Let us make summarizing. Body layout must provide maximum functional division of inner area into production zones. These zones must be autonomous by habitability conditions, but provide necessary production relations. Arrangement of equipment should allow quick access to unattended parts and sides of stands, racks, and devices. Number of working places should be optimized in accordance with conditions of maximum work comfort and cost.

General engineering support of MTS is a separate point. This includes power supply system, heating and air-conditioning systems. Besides, there are some subsidiary systems: battery charging, hydraulics or electrics of sliding wall and jacks, built-in generator (if available), various sliding towers, antennas, etc. We will examine these systems below.

Power supply system. The main point here is whether built-in generator is necessary or not. Built-in generator provides full autonomy, which is very important. But availability of own generator will cause complication of MTS’s body for there must be provided noise insulation, vibroinsulation, cooling of diesel generator, exhaust outlet, easy access for maintenance, fuel weight for diesel with easy access to refueling tank. Just provide all stated above and enjoy built-in generator!

There is also a variant with trailer-mounted power supply unit. It is often used by low-powered MTSs. But we think that normal mobile electric power station, which may be used for any purposes, is the best variant.

As it is silly to refuse from line supply anyway, power supply system of MTS should include isolating power transformer. This is important from both safety measures and ground decoupling points of view. There is an absolute necessity in system of constant insulance control with alarm notification about insulance derating. Shutdown of equipment in case of insulance derating is also possible. It is up to you. Shutdown of MTS during online broadcasting will not look professionally, no matter what the reason is. It is good when MTS employs two infeeds, but this is in case when there are two quite autonomous power sources (i. e. electricity supply network and diesel power station). It is safer to have two feeding cables.

Having touched on a point of grounding, we would like to discuss it in detail. Qualitative grounding is very important for MTS. Mobile stations often operating with outer sources and signal customers, there is always addle scheme of grounding cables, which leads to backgrounds and crosstalks. The famous grounding stake, an obligatory accessory of any MTS, does not carry out its functions very well. Video and audio galvanic isolations (i. e. isolating transformers, switched into breaks of input and output lines) are more effective. Remember about them during itemizing. It will save you time and nerves.

Let us now get back to power supply system. Modern equipment, afraid of power failure, should employ in MTS continuous power supply blocks for securing servers, moulds and other similar devices. It is unnecessary to remind that all power joints, switchers, and measuring devices must be visible and accessible. Do not forget about heating and conditioning systems — in Russia it is extremely important! Environment ranges from -30°C to +30°C. For workers to feel comfortable MTS should employ heated floors. Aside from warmth it will provide cleanness of station during slushy times. Next, it is necessary to have autonomous section heater (Webasto solar heater is the best variant). It will allow constant above-zero temperature, which is innocuous for equipment. Now there are body-heating systems with heat-transfer liquid. Body is equipped with radiators; its walls are interlaid with pipes. It is good, but what if the pipes begin to flow?

And, at last, let us discuss conditioning system. During designing conditioning system one should consider number of heat-evolution and comfort cooling zones. If MTS is divided into separate sections, it is easier to design conditioning systems for they are split into local systems. In case body has one or two sections, designing, adjustment, and operating of conditioning system become more complicated. The point is that because of big number of heat-evolution zones (warmth is out) and comfort cooling zones (comfort air is in), number of conditioners will be greater than number of sections. Temperature inertia of each zone being small, thermal balance is broken even because of opening the door. If it is an isolated section, restoration of thermal balance is a responsibility of conditioner of this very section. But in case it is one-section body, all conditioners will start restoring status quo, and the system may become unstable soon for the door may be opened any time. People leave the vehicle by various reasons and with different frequency. Thus, body should have localized conditioning zones, for each uncapping the section changes its temperature.

Next we will say several words about cable winding. MTS carries kilometers of cable. And it is no matter where the cable is: in the MTS or in the additional vehicle. Cable is wounded onto reels that may be set in motion both manually or by electric drive. Electric drive is very attractive, still one should realize that it may handy during winding straight cable. But when it is not straight or is mixed with other cables, manual winding is the best way out. One may move the reel anywhere and start winding. Moreover, manual winding is much cheaper than mechanical one!

And now let us say last words about the body, or rather the enable panel (i. e. thermopanel). It is better to put it onto back wall of the body and install retractable shed. Then hatch opening and the shed will protect people operating with thermopanel in the snow and rain. It is good if panel employs oscillograph and monitor for quick controlling picture signals and identification.

There is one trifle: as any transport facility, body has sidelights and stoplights on behind. Body’s aerodynamics being too bad and our roads being too muddy, low lights will certainly get dirty. Just double the lights quite high and you will not face difficulties during transportation.

Equipment in MTS can be divided into two big categories: stationary equipment fixed in body and everything else. “Everything else” includes cameras, objective lens, supports, cable reels, and many other devices that are used during shootings. Where should one carry all those stuff, that is, by the way, quite expensive? And how one should get personnel to shooting area? Existing rules prohibit transporting people in MTS. Additional cargo-and-passenger vehicle is a way out.

As illustration of allocation of MTS’s total cost by its main systems we will provide generalized results of analysis of several MTSs’ projects designed under the same specification by various companies. Cost of body ranges from 16,7 to 24,3%; cost of shooting equipment (i. e. cameras, optics, and supports) makes 27,8…41%, cost of visual control systems makes 3,4…4,5%. Cost of other systems and devices, except maybe a video mixer, makes few percents from total cost of MTS. You decide where you may save money.

In conclusion let us say a few words about people who operate mobile television stations. MTS is not just technological means, but lifestyle of people working with it. All peculiarities of MTS — autonomy and unsettled shooting area — require specific knowledge and skills from its personnel. Being formed during many years, MTS “crews” are of great value. Dear directors and managers! If you decide to get MTS, make sure you recruit good staff and guarantee goof wages. It is hard work, really! And very qualified! Do spare money to install microwave oven, refrigerator, and coffee maker in MTS or additional autobus. A cup of hot coffee with a hot sandwich will regain productive spirit of personnel after any work in the rain or snow!

Attentive and patient readers are sure to have noticed that all these material is just a kind of expression of requirements for designing MTS, but not essay or article. Indeed! Everyone would like to have really good mobile television station.