DBu Beltpack Transmitter with Lemo Input

The DBu Beltpack Transmitter is a wideband compact transmitter with switchable 25/50 mW power and 256-bit encryption. It's part of the D Squared digital wireless system.

The DBu is a second generation design with specially developed, high efficiency digital circuitry for extended operating time on two AA batteries. The transmitter can tune in coarse or fine steps across the UHF television band from 470.100 to 607.950 MHz, with a selectable output power of 25 or 50 mW. The pure digital architecture enables AES 256-CTR encryption for high level security applications.

Studio quality audio performance is assured by high quality components in the preamp, wide range input gain adjustment and DSP-controlled limiting. Input connections and settings are included for any lavalier microphone, dynamic microphones and line level inputs. Input gain is adjustable over a 44 dB range in 1 dB steps to allow an exact match to the input signal level, maximizing the dynamic range and signal to noise ratio.

The top panel contains the antenna jack, audio input level LEDs, the programmable function switch and the audio input jack. The LEDs provide red/green indications of the audio level from -20 dB to the onset of limiting to enable accurate input gain adjustment. The programmable switch can be configured as a mute switch, a power on/off switch, or be bypassed.

The housing is constructed of solid machined aluminum for lasting ruggedness. The exterior is finished with an ultra hard, black electroless nickel finish.

The transmitter is supplied with a stainless, spring wire belt clip that is secure, but easily detached and re-attached without tools. A spring-loaded belt clip is available as an option. The battery door is machined aluminum, hinged to the housing to prevent it being lost. The battery door latches securely to prevent being opened inadvertently, and will not pop open even if the unit is dropped.

Firmware updates are made via the USB port on the side panel of the housing. The procedure is very simple using a menu item on the transmitter and a standard micro USB cable.

Setup and adjustment is enabled through a backlit LCD, membrane switches, and an intuitive menu structure. Input gain is adjustable over a wide range in 1 dB steps to optimize modulation and limiting for maximum signal to noise ratio and minimum distortion.