• Description
  • Specifications
  • Ordering info


The DQM-1903ML QAM Modulator offers a combination of features and reliability. It complies with the standard ITU-T(J.83) Annex A, B, C and is applicable for HDTV and SDTV broadcasting.

The DQM-1903 can be used as a DTV broadcast modulator, tester, or a head end of an RF distribution network.

The modulator includes internal high quality up-converter with variable output between 54 and 870 MHz covering full VHF and UHF band.

The DQM-1903ML is very easy to control via front panel. It provides outstanding and reliable output at a reasonable price for customers.


  • ASI input transport stream
  • Excellent RF output
  • Supports QAM modulation
  • Supports PCR re-stamping function
  • User adjustable output level and frequency
  • Front panel control
  • QAM Modulation setting (64, 256QAM)
  • PCR Jitter: ≤ ±200 ns
  • Group Delay as ±20 ns
  • MER After Equalizer: 42dB
  • Phase Noise: VHF -105 dB@20KHz, UHF -103 dB@20KHz
  • Frequency: 54 ~ 870MHz
  • Output Level: 55±5 dBmV
  • Spurious: ≤-63dB


Digital Input

Transport Stream                                           ASI
Connector                                                     BNC (75Ω)
Coding                                                           ITU-T (J.83) Annex A, B and C
Bit Rate                                                         1~52 Mbps
Packet Format                                               188 Byte
Symbol Rate                                                  1~7Mbps
Modulation                                                     64,256 QAM

RF Output

Frequency Range                                        54~870MHz
Impedance                                                   75Ω
Output Level                                                55 ±5 dBmV
Level Control Range                                    0~-15dB
Bandwidth                                                    6MHz : Annex B and C,  8MHz : Annex A
MER After Equalizer                                    42 dB
MER Before Equalizer                                 37 dB
Phase Noise                                                VHF -105 dB@20KHz, UHF -103dB@20KHz
Adjacent Channel Carrier
Attenuation Characteristic                         ≥ 45 dB (Out-of-band)
Spurious                                                     ≤ -63 dB
Return Loss                                               ≥ 15 dB
Group Delay                                               ±20ns
Frequency Response                                ±0.5dB
Frequency Tolerance                                 ±2ppm
PCR Jitter                                                   ≤ ±200 ns


Power Requirements                               AC 90~230V, 50/60Hz
Power Consumption                                13W
Weight                                                      3Kg
Dimensions                                              482 x 44 x 383 mm

Ordering info

DQM-1903ML   – QAM modulator with ASI input, RF output