Tom trolley

The Tom trolley, also known as the Outside broadcast trolley or OB-1, is YSTV's single-unit system for capture and live streaming of shows outside the studio. It is a pre-built system designed to be wheeled to a location and set up within an hour for broadcast to our network.

This article is mostly about how you use the trolley, rather than what goes on inside of it. If you're interested in the tech side instead, have a look at the Tom trolley article in the Technical namespace.

Setting up the trolley requires moderate technical knowledge, though nothing beyond what a competent technical assistant should know already. The most involved part of the setup is likely to be sound, as there is no standard audio configuration (though there are some common ones). In total setup should not take more than around 90 minutes, depending on the size of the event and number of crew.

What to bring

This section is divided into three lists: "Essential", "Useful" and "Optional". Should be fairly obvious what these mean.

Essential

• Cameras: Sony HDV are recommended. Note that the trolley supports widescreen but not HD for capture. You should also bring the requisite accessories, i.e. tripods; batteries and/or power supplies; breakout cables or S-video converters.
• BNC cables: of suitable length to run to the cameras.
• Sound desk: Normally to be found in a white box in the Techie Room. It's a rather sizeable Behringer Eurodesk which is the staple for OBs. Don't forget headphones!
• Microphones: Which ones you need and how many thereof will depend on the event. Don't forget mic stands if you need them.
• XLR cables: Should go without saying really.
• 6-15" TV screen: Optional if you have fewer than four inputs, otherwise needed to see the main output of the vision mixer. Don't forget a BNC and power cable to connect it up with.
• Crew: You'll need a vision mixer, sound op and camera operators. You may also need a VT op. Runners/TAs are also recommended.

Useful

• VT laptop: For playing VTs. You'll also need a stereo 3.5mm mini-jack (from laptop) to 6.35mm jack (to sound desk), and an S-video converter (to the video inputs). See note on using laptop sound.
• Cat5e cable: For running network to the trolley for live streaming. Consult the computing team prior to the event to sort out a network port and setting up the streamers.
• Tape: Of the sticky kind. Gaffer and hazard tape for cable runs, electrical tape for binding up cables afterwards.
• DI boxes: If sound is being done externally (e.g. by Ents), you may need a couple of these to get a sound feed from their equipment. (See Using a DI Box)

Optional

• Plasma screen: Oh, you know you want to. Once again make sure you've got the right cables for video/power.
• Ring comms: If you're worried about your camera ops, comms may be an idea. This will involve more cable runs though, and may substantially increase your setup time.
• Video processor: This is a little black box that can be used to fade video to black. If you're working with a projector in the room, you may want to use this when we don't want to appear on the big screen. It can also adjust the video signal, which can help with more "quirky" projectors.
• PA system: Public address speakers are available on hire from Audio-Visual (£20 plus VAT), or can potentially be blagged off BandSoc for the night. Useful when the event itself has no speakers of its own available to use, and also avoids reliance on the event organisers to engineer the sound (which will usually ends in tears).

The setup

Inputs and outputs

Inputs on the back panel are:

• Video in (4xBNC)
• Network (1xRJ45)

Outputs on the DA are:

• Video Out (Many x BNC)
• Audio Out (Many x Phono)

Sound

Sound is handled with two XLR cables, and 4 compressor cables. The main mix cables are tied to each other, as are the compressor cables.

The XLR cables have adapters on the end because the sound desk does not have XLR output.

When using sound, it seems that the trolley has no head room whatsoever, so you'll want the audio to peak at -2 or so because peaking at 0 distorts slightly.

Tips and tricks

Vision mixing on Max

If you're used to mixing on DaVE then the Panasonic Max might be a bit of a culture shock. Unlike DaVE it is a hardware mixer, which means the T-bar position will change which buttons you need to use. Thankfully this is relatively obvious: use the bottom row when the T-bar is lowered, and the top row when it is raised.

You may well experience a slight jutter when cutting between two inputs on this desk. There is an "auto-take" button located to the right of the T-bar, which will give you a much smoother transition when used. Simply set the duration knob (just above auto-take) all the way to minimum to do a cut, and put it about 1/4 way up for a fade (mix). The duration knob only affects auto-take, it has no effect on the T-bar.

VT laptop sound

Note: This section also applies to any other laptop used, e.g. for music, during the event.

Almost all laptops, when plugged into the mains and wired directly to the sound desk, will suffer from interference. There are a couple of workarounds to solve this:

• Unplugging the power, bit of a no-brainer really. Most VTs are shorter than 10 minutes in length and the laptop's battery will certainly survive long enough for that.
• Using a DI (direct injection) box. DI boxes are specifically designed for the job of putting anything-other-than-mic inputs to the main mix. Simply run the VT laptop output to the DI box first, then out to the sound desk. You'll need extra cables to do this of course. (See Using a DI Box)

Hoping some more sound-engineery types can expand on this section a bit.

Common audio configurations

V/045

For V/045 and other similar lecture theatres (P/X/001, L/N/028 etc.), a cardioid microphone (e.g. SM58, Sennheiser Evo 325) pointed at each table is usually sufficient to pick up everyone sat at that table. You may also want a separate mic for the lectern if that is to be used. Alternatively, you may choose to simply wire everyone up with a separate tie microphone, though this assumes they won't be moving around during the show.

Central Hall

Central Hall has its own sound system installed, however all its equipment is located on the balcony. Liaison with AV will be required beforehand to get sound inputs diverted to somewhere more useful for us, this may also require liaison with the society putting on the event.