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Main / SDI audio embedding and deembedding / PEXT-3325-8

PROFLEX™ PEXT-3325 multistandard deembedders accept the SDIembedded input, up to eight audio channels are deembedded along with PAL/SECAM/SDI video.

PEMB-3325-8 module occupies one slot in the PROLFEX 1U/3U racks so that up to four receivers fit into a 1U rack and up to fifteen into a 3U rack.
If paired with PEMB-3305-8, the PEXT-3325-8 deembedder allows for the following modes of operation:

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

• eight analog balanced outputs (24-bits ADC) - the "AA" index, (f.e. PEXT-3325-8AA)
• four analog balanced outputs and two balanced AES/EBU outputs (8 channels totally) - the "AE" index, (f.e. PEXT-3325-8AE)
• four balanced AES/EBU outputs (8 channels) - the "EE" index, (f.e. PEXT-3325-8EE)

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

PEXT-3325-8 features

• multiformat outputs (SDI/PAL/SECAM)
• built-in VITS generator
• high quality PAL/SECAM encoders
• signal loss indicator
• automatic detection and indication of an embedded audio in an input SDI signal
• automatic cable equalizer on SDI input
• built-in 1kHz test generator
• EDH status indicators
• audio group selection for deembedding
• audio remapping (user-configurable assignment of audio groups to the physical output channels)
• bargraph audio level meter (quazi-peak and UV) OSD on PAL monitor output
• an analog, AES/EBU or combination of audio outputs
• 10-bits video DAC
• 24-bits audio DAC
• optional +6dB audio gain on analog audio outputs

• Inputs
  • SDI input
    

    Number of inputs		1
    Input impedance and connector type		75 Ohm, BNC
    Automatic cable equalizer		up to 100 meters of Belden 8281 or similar cable

• Outputs
  • SDI output
    

    Number of outputs, standard compliance	2 reclocked, ITU-R BT.656
    Embedded audio	supported
    Output impedance	75 Ohm, BNC connectors
    Return loss	better than 18dB at Ft
    Amplitude	800mV±10%

  • PAL/SECAM output
    

    Number of outputs				2
    Output impedance				75 Ohm, BNC
    Luminance channel frequency response
    SECAM	1.0MHz	2.0MHz	3.0MHz	4.0MHz	4.286MHz	4.8MHz	5.8MHz
    	±0.1dB	±0.1dB	±0.5dB	-6±2dB	-16±2dB	-3±1dB	-0.5dB
    PAL	0.3dB up to 5.8MHz
    2T pulse K-factor				<0.5%
    Diff phase				<1%
    Diff gain				<1%
    S/N ratio (weighted)				63dB
    Chrominance error			PAL	<2%
    			SECAM	complies with Rec.470 ITU-R and GOST 845-92
    Chroma to luminance delay				<5ns
    Sampling				10 bits

  • PAL monitor output with audio level bargraph meter OSD
    

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

  • Analog audio output
    

    Connector	DHS-26F
    Output impedance	<50 Ohm
    Output type	balanced
    Output headroom	+18dB
    Dynamic range	100dB
    Distortions and noise	less than 0.006%
    DAC	24 bits
    Sampling rate	48kHz, synched to video signal

  • Digital audio output
    

    Output type	transformer balanced
    Connector type	DHS-26F
    Amplitude	3v at 100 Ohm

General description

PEXT-3325-8 simplified schematic diagram

PEXT-3325 accepts the SDIembedded input. SDI input is equalized, decoded into a 10-bits 4:2:2 stream which is processed by a video/audio processor. The video/audio processor deembedds up to eight audio channels. Output audio may be an analog ("AA" model index), digital AES/EBU ("EE" model index) or combination of both formats ("AE" model index). The video signal is made available as analog composite video (PAL/SECAM) or digital (SDI) video.

PEXT-3325-8 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:

• GROUP - an audio group number selection for embedding
• VITS - the test signals insertion ON/OFF (composite output only, TV lines#: 17, 18, 330 and 331)
• VU METR - an audio bar-graph OSD placement and scale controls
• TON - 1kHz test signal ON/OFF
• VIDEO STD - output signal's standard selection (PAL/SECAM/SDI)
• LOSS - an input signal loss indicator
• EDH DET - lit when an input SDI signal contains valid EDH packets
• 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
• AUD DET - lit when an input SDI signal contains valid AUDIO data packets
• EMBEDDED GROUP - each lit LED denotes an audio group number (1, 2, 3 ,4) detected in an input SDI signal

Configuring the PEXT-3325 deembedder

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). The default factory setting is "12" - the first and the second audio groups are deembedded. The audio level of the four channels, deembedded from the group number shown on the leftmost digit in the mail LED display, is presented on the four leftmost OSD bargraphs. The rightmost four OSD bargraphs present the audio level in the channels deembedded from the group number on the rightmost digit on the mail LED display.

The VITS insertion in the TV lines #17, #18, #330 and #331:

Toggling the MODE button select the VITS mode. Press the UP button to enable and the DOWN button to disable the VITS insertion:

• oF - the VBI test signals are OFF
• on - the VBI test signals are inserted into the 17th, 18th, 330th and 331st lines

PLEASE, NOTE!
The VITS insertion is not possible into the SDI output signal, the main display shows the "--" marks.

The 1kHz test tone operation:

• OF - the test signal is OFF in all channels
• On - the test signal is ON in all channels
• 01...08 - the test signal appears in a selected channel

Selecting the VU METR modes:

Toggling the MODE button select the VU METR mode. Pressing the UP and DOWN buttons adjust the 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 output signal format selection:

Toggling the MODE button select the VIDEO STD mode. Pressing the UP and DOWN buttons select the desired output standard:

• Sd - SDI output signal (270Mbps)
• PL - PAL
• SE - SECAM

Both the OUT A and OUT B are affected by this setting. The X5 jumper allows to override this setting for the OUT B output. In the "SDI" position the X5 jumper forces the SDI output format at the OUT B output. Placing the X5 jumper into the "VAR" position restores the software control over the output B standard.
PLEASE, NOTE!
The "CS" on the main display means that the composite signal (PAL or SECAM) is being transmitted in an un-decoded form, the output standard alteration is not possible.

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.