singMai DB09 Video Receiver User Manual

: June 13, 2024
: singmai

Table of Contents

Revisions
Introduction
Quick start guide
DB09 Technical Details
Specification
Appendix A: AC-DC adaptor
Documents / Resources
- Read User Manual Online (PDF format)
- Download This Manual (PDF format)

DB09
Video Receiver
User Manual

Revisions

Date	Revisions	Version
27-09-2023	First draft	0.1

Introduction

DB09 is a standard definition (SD) / high definition (HD) video receiver. It accepts analogue video from either twisted pair (differential) or coaxial cable and compensates for long cable runs using an adjustable matching filter. Its 75MHz video bandwidth means it can accept NTSC, PAL, 960H, AHD, HD-CVI and HD-TVI video. The video is DC restored and two buffered and filtered single ended outputs are provided.
DB09 requires 12VDC which is provided via the supplied AC-DC converter.

Quick start guide

Connect the DB09 to the supplied AC/DC adaptor. Fit the appropriate blades to the adaptor for your country. Blades are supplied for North America, Europe, UK, China and Australia. The adaptor accepts AC between 90 and 264VAC – the full specification is provided in Appendix A.
The connections to the DB09 are shown in Figure 1.
Connect the 12VDC jack from the adaptor to the +12VDC ‘Power in’ socket on the DB09. The ‘Power On’ LED should light up blue.
Connect your video input to either the UTP (RJ-45) connector or the coaxial video input (BNC). Switching between the two inputs is by the Coax (switch UP) / UTP (switch DOWN) switch. You can connect both UTP and coaxial inputs at the same time if required.

singMai DB09 Video Receiver - Connections Figure 1 DB09 Connections.

The DB09 provides two independent video outputs. The single ended outputs should be terminated in 75Ω. The outputs are filtered and buffered. The SD/HD switch selects the output filter bandwidth, reducing any out of band noise. The SD selection (switch UP) passes NTSC/PAL or 960H video, the HD selection (switch DOWN) is for analogue HD such as AHD.
Two adjustments are available to compensate for cable loss. The DC Gain control allows an adjustable gain that affects all frequencies equally and is designed to compensate for the DC cable loss. The HF Boost control boosts the high frequencies of the video input using a filter that is the inverse of the cable high frequency loss. The response of this filter is set using the Coax (for coaxial cable) / UTP (for UTP cable) switch. The filter can accurately compensate for up to 300m of UTP cable and 200m of coaxial cable. Longer distances can be compensated for but with less accuracy.

DB09 Technical Details

A simplified block diagram of the DB09 is shown in Figure 2.

singMai DB09 Video Receiver - Block diagram Figure 2 DB09 Block diagram.

The +12VDC from the AC/DC power adaptor is filtered and protected from over- range or reverse polarity inputs. The 12VDC input is then regulated to provide clean ±5VDC for the module.
The coaxial video input is pseudo-differentially received which reduces hum pickup over long cable runs. The video input is terminated by 75Ω and is protected from out-of-range inputs or glitches.
The UTP video input is differentially received, terminated in 100Ω and is protected from out-of-range inputs or glitches. Pin 1 of the RJ-45 input is the positive video input and pin 2 is the negative video input. The other pins are not connected.
The selected video input is then passed through the cable compensating filters. The broadband gain and high frequency boost are user adjustable. Figures 3 and 4 show the expected results for different lengths of coaxial and UTP cable.

singMai DB09 Video Receiver - cable lengths

The output from the compensating filter is then DC restored and filtered and buffered. The output filter helps to reduce noise and can be set to either SD or HD video. The filter responses are shown in Figures 5 and 6. This output filter sets the overall frequency response of the DB09.

singMai DB09 Video Receiver - HD setting

The buffer amplifies the video by a gain x2 (6dB) so that it can drive a series 75Ω resistor. Each output must be terminated in 75Ω for the DB09 to have the correct gain. Because each output is individually buffered either or both outputs maybe be connected – any unused output may be left unconnected.

Specification

Power: +9-14V (+12VDC nominal) @ ~120mA (all outputs driven).
Dimensions: 120mm x 78mm x 27mm.
Video input: NTSC-M / PAL /SECAM, NTSC / PAL 960H, AHD, HD-CVI, HD-TVI.
75Ω input impedance (coaxial).
100Ω input Impedance (UTP).
1V pk-pk nominal input. Maximum input before clipping 1.6V pk-pk.
Luma bandwidth: 9.0MHz ± 0.5dB (SD mode). 50.0MHz ± 0.5dB (HD mode).
Gain controls set to minimum.
Gain: 0dB ± 0.5dB. Gain controls set to minimum.
Differential gain/phase: <1%, <1°. (NTSC/PAL). Gain controls set to minimum.
K-factor: <1%. (NTSC/PAL). Gain controls set to minimum.
Group delay: ±10ns.
Operating temperature: -10 – +40 degC.