ZHC518A-3000W/M2 Analog TV Transmitter

Overview:

This Transmitter is a high-standard, broadcast-grade cabinet-type all-solid-state analog TV transmitter with a modular structure, which is very convenient for maintenance. It uses a new software radio technology to achieve the TV modulation function; the use of international high-quality LDMOS high-power field effect tube to achieve RF amplification, the output power can be 3000W.

The TV transmitter is mainly composed of a TV modulation unit and an RF power amplification unit. Among them, the TV modulation unit uses the new FPGA + DDS to realize the software TV modulation function, while obtaining superior technical indicators while ensuring reliability and performance consistency; the RF power amplification unit uses international high-quality LDMOS high-power field effect transistors, Analog/Digital Compatible, stable and reliable.

The whole Transmitter adopts 19 "standard stainless steel case, suitable for all levels of TV stations.

 

Features:

● Analog TV exciter with new digital technology, superior performance, high reliability and good consistency.

 

● The main and backup exciter configurations can be used to reduce the stop rate (spare exciter and automatic switch are optional).

 

● With no video, over standing wave ratio, over power, over voltage, over current, over temperature and other protection functions to reduce equipment damage.

 

● Power control adopts closed-loop automatic gain control to ensure stable output power without drift.

 

● The power amplifier unit is composed of two independent 2000W power amplifiers. Each power amplifier uses three original imported high-quality long-life and large-volume axial fans in parallel, with large redundant air volume and good heat dissipation effect, so that the transmitter is in a low temperature state, which can extend the life of the transmitter.

 

● The 2000W power amplifier is installed in a 3U high 19-inch standard chassis, which is composed of four identical 500W power amplifier modules for low loss, high isolation and in-phase synthesis. The power redundancy design has a large margin and high reliability.

 

● The power amplifier module uses the latest high efficiency and high standing wave ratio LDMOS tube, adopts microstrip impedance conversion technology, simple and efficient, good consistency, easy maintenance and replacement.

 

● Using high-quality switching power supply, with over-voltage, over-current, under-voltage, over-temperature, short circuit, lightning protection and other protection measures, high efficiency, good voltage regulation range, strong ability to adapt to external power changes; and flexible N + 1 heat Plug-in configuration scheme, parallel current sharing centralized power supply. It can also be redundantly configured according to customer requirements.

 

● With intelligent network management and monitoring, with RS232 and TCP / IP communication interface.

 

ZHC518A-3000W/M2 Analog TV Transmitter Diagram

 

Technical Specifications:

 

Overall performances:

1. Operating frequency band:   VHF / UHF

2. Image carrier frequency deviation: ± 300Hz

3. Output power:              3000W

4. Output impedance:          50Ω

5. Inter-modulation distortion: ≤-50dB

6. Useless emission:          ≤-50dB inside adjacent channels;

≤-65dB outside adjacent channels

7. RF output interface:       7/8” Flange or 1-5/8” Flange

8. Power supply:             three phase 380VAC

9. Cooling method:           forced air cooling

10. Working environment temperature: -10~+45℃

11. Dimensions: 570mm(width) x 1360mm(height) x 850mm(depth)

12. Weight:                  180Kg

 

Image performance:

1. Video input level:          1VP-P positive polarity

2. Video input impedance:             75Ω

3. Video in-band reflection loss:        ≥35dB

4. Video input interface:               BNC-K

5. Periodic clutter signal-to-noise ratio: ≥55dB

6. Continuous random wave SNR:      ≥60dB (weighted),

≥55dB (un weighted)

7. Group delay:                       ±30ns

8. 2T square wave distortion:          ≤1%

9. Distortion of brightness waveform:  ≤1.2%

10. Non-linear brightness distortion:   ≤3%

11. Differential gain DG:              ≤±3%

12. Differential phase DP:             ≤±3°

13. Color / bright gain difference:     ≤1%

14. Color / bright delay difference:    ±5ns

15. Modulation degree:               ≤87.5%

 

Sound performance:

1. Sound / image carrier power ratio: -10dB

2. Sound carrier frequency deviation: ±200Hz

3. Audio input level:                 0dBm ± 6dBm

4. Audio input impedance: 600Ω balanced or 10KΩ unbalanced

5. Audio input interface:             XLR-K / BNC-K

6. Sound modulation capability:       >±100KHz

7. FM signal-to-noise ratio:           ≥70dB

8. Amplitude-frequency characteristic: ± 1dB

9. AM noise (no modulation):         ≤-55dB

10. Internal carrier noise (100% modulation): ≤-50dB

11. Harmonic distortion:              ≤0.3%

12. Maximum frequency deviation:    ±50KHz

13. Pre-emphasis time constant:      50us