GY/T 170-2001< products based on the number of cable television channel coding and modulation standards ", which meet the DVB standard for digital TV channels TS, QAM modulation and frequency for transmission to change.As a result, business data and other digital audio signals through cable or MMDS network transmission.Product technical specifications, performance is stable and reliable.

First, functional

1. DVB-C standard with ETSI/EN 300 429
2. Constellation 16QAM/32QAM/64QAM/128QAM/256QAM
3. Symbol rate support 1MS/s ~6.999MS/s which can set up in panel,step 1KS/s
4. TS ASI input interfaces, SPI (for a factory setting), adaptive packet format goat
5. Panel set up the output frequency, and the output frequency can be 49-860MHz between 125KHz distance
6. Panel set up to regulate all the buttons, LCD display, intuitive convenience
7. On the embedded converter
8. Chinese and English menu shows

Second, the principle :

QAM part Frame

TS signal input interface into the data buffer.After finishing the data buffer parameters set by synchronous data output signal.On the DVB standard with the base-band formed after Channel I, Q signals.By the square root of roll-off filter for QAM modulation, frequency modulation by the panel set up,and the adjusted QAM signals will be sent to the RF channel after being dealed with the final IF Interface Circuit.

Indicators :

QAM part

35.25 MHz IF frequency

Carrier frequency tolerance ≤ 20 ppm

IF output level of 75 dB ±

IF output impedance 75 Ω neighbor

Output Return Loss ≥18dB

Adaptive Packet Format 188,204 characters

ASI input interfaces, the SPI one election (when it leaves the factory setting)

QAM mode support 16,32,64,128,256

Symbol rate MS/s 1.0～6.952

Roll-off factor α 0.15

Modulation rate of amplitude imbalance ＜0.2dB

T amplitude modulation time gap ＜0.02 (T = symbols cycle)

Orthogonal modulation degree imbalance＜1.0

Phase Noise dB c/Hz -90dB10kHz

30W rated power

The dimension of 250 x 480 x 43.6 mm

About 2.5kg quality

Working environment :Temperature 0-40 °C Relative Humidity ： ≤80%

Pressure : 86～106KPa

Frequency on the part of

1. Phase NoisedBc/Hz <-70dB @1KHz
   <-80dB @10KHz
   <-100dB @100KHz
2. Input frequency 30-80MHz
3. Import level was 80~100dB v
4. 47-750MHz output frequency, the frequency of 125KHz installed step
5. Input return loss ≥12dB
6. The maximum output level 118dB ± 6 v
7. AGC changes +10dB input output characteristic changes ≤±1dB
   
8. KHz frequency accuracy ≤±20
   
9. Noise figure VHF of ≤8dB UHF of 10dB
   
10. Carrier to Noise Ratio VHF of ≥57dB UHF of≥54dB
11. Band control ≥60dB
12. Fluctuation band ≤±2dB

◆Digital front-end equipment

◆Microwave Transmission Equipment

★ Simulation of point-to-point microwave transmission equipment