Overview:

IFB (Interruptible Fold Back) systems are used for talent cueing and crew communications in broadcast and motion picture production. In addition, the IFB system can be used by both directors and management to monitor program audio during a production. Whether the program material is a local audio source or an IFB feed from the station, it is inserted via the combo XLR/1⁄4in. jack on the rear panel. Connection to the IFB packs or intercom system is made at the female 3-pin XLR on the rear panel.

• Performance: The Production Intercom TT-1 has two applications. It was designed to be a portable master station for a compact IFB sys- tem, but may just as easily be used as a beltpack in an intercom system with the facility to inject program material onto the intercom channel to which it is connected.
• Durability: The TT-1 is built in our familiar extruded aluminum case with CelconM90 end bezels. It is equal in resistance to breakage as our BP-1 beltpack, with one exception. The rotary control for program level does protrude outside the protection of the bezel. With a little caution for this, the TT-1 can be tossed around much like the BP-1. The main PC board is supported by internal slots on the sides and by the rear panel. Every other internal component has been designed and supported for maximum resistance to shock.
• Value: The TT-1 shares not only the case and bezels from the BP-1 but many internal parts, controls and connec- tors. This allows us to manufacture the unit efficiently, in relatively small quantities, and to offer surprisingly modest pricing.
• Compatibility: The TT-1 is compatible with all popular intercom and IFB systems operating on the 200Ω unbal- anced principle, a list which includes Clear-Com.

Panel Features:

• A 4-pin male XLR is provided for connection of a standard intercom headset with a dynamic microphone.
•  A modification to allow use of a headset with an electret microphone is available.
• Control of the level of the program material to be heard in the system is by a rotary control on the front panel.
•  A true VU meter (LED-type) is provided on the front panel to monitor the program input.
• The LEDs are bright and easily visible in daylight.
•  Control of the user's headset volume is by a thumbwheel.
• A green LED confirms that the TT-1 is receiving DC voltage from the intercom or IFB power supply.
• The talk button is momentary in stock form, but can be modified to be latching.
• A separate button allows the user to choose to talk over the program material, or to interrupt the program material while the talk button is pressed.
• Production Intercom users will recognize the sound.
• When used as an intercom beltpack, power will be provided by the intercom system's power supply.
• When used as an IFB mini-master, power will come from the IFB power supply.
• When used as a mini-master in a portable stand-alone IFB system, power will come from an AC adapter through an accessory which regulates and filters the power for ultra quiet operation.

• Power requirement: 24~30 VDC, 10 mA quiescent, 40 mA max. w/VU meter
• Active Headphone output: 8~4K ohm acceptable, 200 ohm ideal
• Microphone input: 200 ~ 600 ohm Dynamic
• Sidetone rejection: >50 dB
• Audio bridging impedance: 200 ohm unbalanced
• Program input: 600 ohm, line level, balanced
• Size: 3.70 x 4.30 x 2.50 in. (93.98 x 109.22 x 63.5 mm)
• Weight: 13.5 oz. (0.385Kg>)