Description
BCD TEST GENERATOR - Digital audio - Humbug
Complimentary to BCD's 'Jitterbug' signal analyser, the Humbug is a stand-alone AES-3 digital audio generator, producing fixed frequency tones. When used in conjunction with software and a computer it has greater capabilities, including the generation of sweeps, test sequences and channel status information. Useful in lab, service or operational environments, it is built in a rugged extruded case and powered by an external DC power source. It may be used free-standing or rack-mounted using optional panels.
The front panel has an LCD display which shows the output settings in use and buttons to set them. One pair change level up and down in 1dB steps. A second pair changes the output frequency up and down and offer a 'quick' spot tone of 1kHz, 48kHz sampling when both are pressed together. A single button gives a shift function to access alternative functions of the other buttons. 'Left' and 'Right' mute the channel concerned. In 'shift' mode the 'Left' button toggles the output between sine and clipped sine while the 'Right' button toggles the Validity flag on and off, the frequency switches select 48kHz or 96kHz internal reference, the 'Level' switches select external wordclock or AES reference. The device scales the frequencies automatically with sample-rate.
The rear panel has an transformer-balanced, earth-free, XLR-3M, AES-3 output, a 2.5mm coaxial input for the external DC supply, RCA (phono) socket for an external Wordclock input, and 9-pin D-Sub connector for connection to the PC. When the unit is using its internal reference, the phono socket supplies a TTL Wordclock output to synchronise other equipment. An AES reference signal may be applied to the D-sub connector.
Humbug Software
Software is available for Windows 98 and XP by download from the BCD website. The PC communicates with the Humbug using RS-232 protocol through any available Com port. The GUI replicates the functions of the physical controls and LCD screen on the Humbug front panel and offers various refinements in addition. A gain slider alters level, and levels may be entered directly in 0.1dB steps. Seven preset level buttons are provided. A slider alters frequency and frequencies may be entered directly; the nearest available value is chosen automatically. Seven preset frequency buttons are provided. An extra function is the ability to switch between normal tone mode and DC bit mode, where any 24-bit data sample can be transmitted.
A separate window deals with sweep modes, where any available start and stop frequency and level may be set, as well as the number of sequence steps and sequence speed. The sweep is controlled using 'Sweep', 'Pause' and a sweep 'fader' and may be set to repeat if required. 'Pulse' mode uses a preset signal level and frequency, and a programmable on and off time. Single or repeated pulses can be triggered. A final window displays the channel status frame being sent currently by the Humbug. Normal Consumer or Professional modes can be set and specific data can also be entered, allowing any data to be transmitted.
Output level: 0dbFS to -99dBFS, 1dB (or 0.1dB under software control) steps. Output frequency: 2Hz to 20kHz. AES-3 output: Impedance 110 ohms, 3V peak to peak loaded. Power source: 8 - 30V DC, recommended 12-24V, 120mA at 12V. Dimensions: 94 x 52 x 108 (w x h x d) mm. Weight: 250g.
Included accessories: Instructions.
Optional accessories: Plug-in power supply 23-954 and 23-931 (UK), or 23-954 and 23-932 (Euro). See 'BCD Extruded Box Rack Mounting Panels' for details of rack mounting-options and 'Extruded Boxes Mounting Kit' for fixing to flat surfaces.