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Main / SDI audio embedding and deembedding / PEMB-3305-8

PROFLEX™ PEMB-3305 multistandard embedders accept up to eight audio channels and one PAL/SECAM/SDI video signal to obtain the SDIembedded output.

If paired with the PEXT-3325-8 deembedder, the PEMB-3305-8 allows for the following modes of operation:

The input and output audio signal may be in any standard: an analog, AES or combination of both. These modificatiuons are designated the following model indexes:

• eight analog balanced inputs (24-bits ADC) - the "AA" index, (f.e. PEMB-3305-8AA)
• four analog balanced inputs and two balanced AES/EBU input (8 channels totally) - the "AE" index, (f.e. PEMB-3305-8AE)
• four balanced AES/EBU inputs (8 channels) - the "EE" index, (f.e. PEMB-3305-8EE)

At a deembedding side the audio format must not necessarily coinside with the one at the source (f.e., an analog input signal embedded is deembedded in the AES/EBU).

Both the embedder (PEMB-3305) and the intended deembedder (PEXT-3325) are featuring the PAL-monitor output with the OSD of the bar-graph audio level meters (quasi-peak and VU).

PEMB-3305-8 features

• multiformat inputs (SDI/PAL/SECAM)
• PAL/SECAM may be transmitted either decoded or "as is"
• analog inputs with high CMRR, cable equalization and overvoltage protection
• automatic cable equalizer on SDI input
• built-in 1kHz test generator
• built-in color bar generator
• signal loss indicator
• EDH status indicators
• automatic detection and indication of an embedded audio in an input SDI signal
• audio group selection for embedding;
• ancillary data stripping capability
• cascadability to allow for embedding of more than four audio groups
• high quality PAL/SECAM decoder
• bargraph audio level meter (quazi-peak and UV) OSD on PAL monitor output
• an analog, AES/EBU or combination of audio inputs
• 10-bits video ADC
• 24-bits audio ADC
• audio gain adjustments for each analog stereo pair or AES/EBU channel
• VBI contents pass-through (WST Teletext compatibility)

Technical specifications

• Input
  • PAL/SECAM composite input
    

    Number of inputs, type				two, AC-coupled, balanced, with overvoltage protection
    Input impedance				75 Ohm, BNC
    Cable equalization				0~200m
    ADC, sampling rate				10-bits, 27MHz
    Frequency response ripple (undecoded transmission mode)				less than 0,2dB, up to 5,75MHz
    Luminance channel frequency response (decoded transmission mode, apperture correction OFF)
    SECAM	1.0MHz	2.0MHz	3.0MHz	4.0MHz	4.286MHz	4.8MHz	5.8MHz
    	±0.1dB	±0.2dB	<-2dB	-6±2dB	>-40dB	-3±1dB	±0.5dB
    PAL	<0.5dB up to 5.8MHz
    2T pulse K-factor				<0.5%
    Diff phase				<0.2%
    Diff gain				<0.2%
    S/N ratio (weighted)				>65dB
    Return loss				better than 40dB at 4,43MHz

  • SDI input
    

    Input impedance, connector	75 Ohm, BNC
    Automatic cable equalization	up to 100m (8281or similar)

  • Analog AUDIO input
    

    Connector	DB-15
    Input impedance	10 kOhm
    Input type	balanced
    0 dB FS level	+18dB (+24dB jumper-selectable)
    Dynamic range	better than 100dB
    ADC	24-bits at 48kHz (20 MSB are embedded)
    Harmonic distortions and noise	less than 0,006%

  • AES/EBU input
    

    Input type	transformer balanced
    Connector type	DB-15
    Amplitude	0.2~4.0V
    Input impedance	110 Ohm
    Maximum input cable length	up to 100 m of twisted pair

• Output
  • SDI output
    

    Number of outputs	one
    Compatibility	ITU-R BT.656 (embedded audio)
    Connector type , output impedance	BNC, 75 Ohm
    Return loss	better than 18dB at Ft
    Amplitude	800mV±10%

  • PAL monitor output with OSD
    

    Connector type	BNC
    Amplitude	1000±20mV at 75 Ohm
    DAC	10 bits
    Frequency response	<3dB to 5,5MHz

General description

PEMB-3305-8 simplified schematic diagram

PEMB-3305 accepts either analog composite video (PAL/SECAM) or digital (SDI) input video signals and up to eight analog or AES/EBU audio channels. SDI input is equalized, decoded into a 10-bits 4:2:2 stream which is processed by a video/audio processor. An analog video input is also equalized/normalized (EQ/GAIN) in a cable equalizer, decoded by a PAL/SECAM decoder and digitized into a 10-bits 4:2:2 stream. The PAL/SECAM decoder may be bypassed - in this case a special mark is inserted in the output stream by which a receiver automatically detects the transmission mode and the receiver's output format cannot be changed then.

The video/audio processor embedds the audio data streams. Input audio may be an analog ("AA" model index), digital AES/EBU ("EE" model index) or combination of both formats ("AE" model index). The SDIembedded signal is present at the "SDI" output on a rear panel.

PEMB-3305-8 rear panel view

Controls and indicators

All the controls and indicators are located at the module's frontal board.

The operation mode is selected by toggling the MODE button, the editing is done by pressing the UP and DOWN buttons.

The following modes are available:

• INP - an input signal format selection
• GROUP - an audio group number selection for embedding
• TON - 1kHz test signal ON/OFF
• VU METR - an audio bar-graph OSD placement and scale controls
• ANC STRIP - ancillary data stripping ON/OFF
• GAIN - an audio gain controls for each channel or stereo pair
• EDH MIN/HOUR - lit if two or more EDH errors were detected within one hour/minute interval, both LEDs blink if an SDI input is lost

Configuring the PEMB-3305 embedder

The input signal format selection and the built-in color bar generator ON/OFF:

• Sd - SDI input signal
• CS - composite PAL/SECAM input transmitted WITHOUT decoding
• Cd - composite PAL/SECAM input transmitted being decoded (on a receiving side the output format is SDI/PAL/SECAM selectable)
• br - the built-in color bar generator is ON. An autonomous mode, no video input signal is nesessary, the audio embedding or 1kHz test signal are possible

Built-in color bar generator autoinsertion mode:

• SY - insert color bars, keep audio data intact. To enable: in the INP mode, press and hold the MODE button again, press the DOWN button. Release both buttons.
• nS - insert color bars, erase audio data. To enable: in the INP mode, press and hold the MODE button again, press the UP button. Release both buttons.

The audio group number selection:

Toggling the MODE button select the GROUP mode. Pressing the UP and DOWN buttons select an audio group number (12, 23, 34, 13, 14 and 24 groups are available).ATTENTION! If there is an embedded audio in an input SDI, only the free group numbers will be available to select. For example, if SDIembedded input has the first group audio, only the 2nd, 3rd and 4th could be toggled. It is advisable to select the nearest higher number, i.e. the 2nd group. If we select a currently available group number and later the same group appears at the SDI input - the AUD DET indicator starts blinking notifying about the conflict. The PEMB-3305 stops to embed it's audio and the input SDIembedded audio group is passed through. You should either select any other group or use the ANC STRIP mode to erase the input SDI from any preembedded audio data, the indicator will show the On mode, the conflict will be resolved and there will be no need to change the group number.

The 1kHz test tone operation:

• OF - the test signal is OFF in all channels
• On - the test signal is ON in all channels
• 01...04 - the test signal appears in a selected channel

Selecting the VU METR modes:

Toggling the MODE button select the METR mode. Pressing the UP and DOWN buttons adjust the horizontal position of the VU-meter OSD. Pressing the MODE and DOWN buttons simultaneously switches the OSD off (the indicator shows "On" -> "OF"). Pressing the MODE and UP buttons simultaneously selects the VU-meter scale mode:

• EBU scale, 0dBfs corresponds to +18 dBU (indicator shows "FS")
• quazi-analog scale, 0dBU corresponds to 0,775VRMS (indicator shows "db")

The ancillary data stripping:

In the case of a conflict between a selected audio group number and an input SDIembedded stream one may resolve it by stripping the input SDI signal. Toggling the MODE button select the ANC STRIP mode.Pressing the UP or DOWN buttons enable the stripping mode.

• OF - the ancillary data stripping is OFF
• On - the ancillary data stripping is ON in all four audio groups
• 01...04 - the ancillary data stripping is ON in an audio group number shown

The audio gain presets:

Toggling the MODE button select the GAIN mode. Next depressions of the MODE button scrolls through the channel pair number (12, 34, 56 and 78). Pressing the UP and DOWN buttons select gain for a channel pair. While decreasing the gain (by means of the DOWN button) - the left dot LED in the main display blinks, while increasing the gain (by means of the UP button) - the right dot LED in the main display blinks. The audio gain range: ±6dB in 0.2dB increments. The simultaneous depression of the UP and DOWN buttons resets the gain to 0dB and the dot is LED becomes OFF.

The remote control and monitoring

The “PROFLEX” modular system provides the remote controls and monitoring capability. An optional CPU module installed in a rack connects to an IBM PC via the proprietary protocol and software package.