NEC PCN-1800 User Manual

PCN-1800 Series

VHF TV Transmitter

2nd Edition

The Benchmark in Analog TV Broadcasting

Compact design and innovative technology establish NEC’s new transmitter as the new benchmark in analog TV transmitters.

■ Easy conversion to digital TX

After a period of simultaneous analog-digital broadcasting, analog broadcasts will be discontinued.

Analog TV transmitters will then be converted to digital and utilized as auxiliary transmitters or main

transmitters in order to increase the number of MUXs (multiplexers) and utilize resources more

effectively. With this in mind, NEC has come up with a new digitalized exciter that enables easy

conversion from analog to digital through the replacement of software in our newest transmitter

series.

■ All-band solution

Broadcasters are required to employ broadband-compatible transmitter units in situations that require

channel change for common spare units or digital conversion. NEC’s PCN-1800 series provides an

optimum solution for this requirement. Its exciter features direct modulation and a synthesizer,

enabling the transmitter to be used for any VHF channel, simply by changing the frequency setting,

and eliminating the need for BPF (Band Pass Filter) adjustment at the exciter stage. Its power amplifier

(PA) incorporates a frequency table that automatically adjusts the gain and phase, providing an all-band

solution and streamlining frequency adjustment.

■ Superior maintenance function

The automatic correction function in the exciter’s compensation circuit makes it extremely easy to

perform characteristics adjustment as an automatic compensation, without having to use a

demodulator. The color LCD panel enables easy monitoring of transmitter operation. The warning

indication facilitates optimum troubleshooting before possible transmitter malfunction, enhancing

availability.

■ User-friendly monitoring

The TX control unit features a built-in web server and SNMP. By connecting transmitters to a local area

network, transmitters can be monitored and controlled from a remote PC with a web browser.

Monitoring and control are also possible using the SNMP manager.

■ Sophisticated hybrid liquid cooling

NEC’s extensive liquid cooling experience has enabled us to design a simple but highly efficient

cooling method that incorporates an automatic air-purge function and ensures easy water feeding.

Proven results

NEC transmitters are renowned throughout the broadcast community for their superior reliability and minimal maintenance

requirements. The new PCN series is the outcome of NEC’s vast experience in providing thousands of transmitters around the

world, applying our sophisticated expertise in product design to set a new standard in ultra-compact VHF analog television

transmitters. And now, by employing a new exciter, the PCN-1800 series enables easy conversion to digital TX.

PCN-1800 Series Features

■ DM-3000B Analog Exciter features

The DM-3000B analog exciter is packed with state-of-the-art NEC technology. Integrating a broad

range of functions into a single unit of greatly reduced size, this exciter can be easily upgraded from

analog to digital TX system. A synthesizer tuned to all VHF band signals enables all-band direct

conversion to an RF output. By employing an all-band synthesizer and direct conversion, any channel

can be used simply by setting the compatible frequency. Furthermore, automatic compensation can

be performed at the touch of a button, without having to use a demodulator.

■ Power Amplifier (PA) features

The PCN-1800 series power amplifier is a compact, highly efficient broadband solid-state amplifier

which offers high linearity and incorporates circulators and a self-protection circuit for superior

reliability. The PA features a built-in power supply that can be connected and removed, even during TX

operation, to ensure prevention of leakage of liquids.

The latest digital broadcasting technologies

■ Control and monitoring system

The control and monitoring system is composed of the TX control unit, an RF detector and a color LCD

screen. To enhance transmitter availability, the system is divided into a unit that manages basic control

and protection operations and a monitor. The monitor consists of an easy-to-view color LCD screen

that enables effortless monitoring of transmitter operation and detects any possible malfunction at a

glance.

■ Liquid cooling system

The PCN-1800 series transmitter features an innovative, highly efficient liquid cooling system

employing a hybrid closed circuit method that provides such advantages as automatic air purging, easy

coolant feeding, coolant replacement during operation and lower overall cooling costs.

NEC’s liquid cooling system is based on an original adaptation of common cooling methods. It allows

multiple transmitters within the same building to be handled by a single, common cooling system,

providing an exceptionally cost- and energy-effective cooling solution.

■ Monitoring system with remote control function

The TX control unit incorporates a web server and SNMP agent, enabling the transmitter to be

connected to a local area network for monitoring and control of transmitter operations via a remote PC

with web browser. At the same time, monitoring and control from an SNMP manager are also

possible.

PCN-1800 transmitter

With SNMP AGENT/WEB SERVER

function

Internet Explorer

WEB Browser

• NMS

(SNMP MANAGER)

Network

• WEB CLIENT

SITE-2

SITE-1

Heat Exchanger Passive/Reserve

Fan 1

Fan 2

Fan 3

(Reserve)

Water/ glycol

Passive/Reserve

Pump Rack

Transmitter

FM: Flowmeter LS: Level Switch M: Motor PS: Pressure Switch TS: Thermal Switch

PA/PS

Pump

Water/ Glycol

(Single with Redundancy System)

Configuration of PCN-1800 Series

PCN-1800 Series Lineup

PCN-18 /

1 2

: Output Power

: System Type

Type Number Output Power

01 1kW 02 2kW 05 5kW 10 10kW 15 15kW 20 20kW 30 30kW

SS: Single Transmitter with Single Drive

SSP: Single Transmitter with Dual Drive

and Multiple PAs

SSPE: Single Transmitter with Dual Drive

SSW: Dual Transmitter in Active Reserve

Type

Separate Amplification Common Amplification

SSP

SSW

EX-A

EX-B

BPF

Cooling Equipment (with redundancy)

n-Combiner

n-Divider

TRPA

EX-A

VIA COMB

n-Combiner

n-Divider

V-PA

A-PA

Cooling Equipment (with redundancy)

EX-A

TX-A

TX-B

V-PA

A-PA

(Same as TX-A)

COMB

V/A

Combiner

Cooling Equipment

EX-A

Cooling Equipment

n-Combiner

n-Divider

TRPA

BPF

EX-A

VIA COMB

Cooling Equipment

n-Combiner

n-Divider

V-PA

A-PA

EX-A

TX-A

TX-B

TRPA

(Same as TX-A)

Cooling Equipment

COMB

BPF

System Configuration

: Cooling Type

Q: Liquid Cooling

4 5

: Visual/Aural Power Ratio

1➝10:1

5➝5:1

Nil: Separate Amplifier

C: Common Amplifier

: Amplifier Mode

Configuration of PCN-1800 Series

PCN-1800 Series Specifications

Characteristics

625-line ITU-R Standard-B/G 625-line ITU-R Standard-I 525-line ITU-R Standard-M 625-line ITU-R Standard D/K

Type of Emission

Operating Frequency Range

Carrier Frequency Stability

Load Impedance

Input Level

Sync.

Video

Input Impedance

AM Noise

Periodic Noise (1kHZ LPF)

Unweighted Continuous Random Noise

Weighted Continuous Random Noise

Group Delay

Transmitter without RX precorrection measured with phase linear demodulator

Transient Response

Bar Response

Nonlinear Distortion

Diff. Gain*

Output Power Variation*

Black to White Transition

Linear Distortion

Frequency vs. Amplitude Response

C3F

170MHz ~ 230MHz

50Ω with VSWR ≤1.5

0.3V ± 6dB

0.7V

75Ω, return loss not less than 34dB up to 5MHz

75Ω, return loss not less than 34dB

up to 4.2MHz

75Ω, return loss not less than 34dB

up to 5MHz

-50dB (p-p) or better

-52dB (r.m.s.) or better

-60dB (r.m.s.) or better

•Common Amplification: Up to 4.8MHz: ± 50nS

•Separate Amplification:Up to 4.8MHz: ± 40nS

•Common Amplification: Up to 2MHz: ± 50nS At 3.58MHz: ± 50nS

At 4.18MHz: ± 100nS

•Separate Amplification: Up to 2MHz: ± 50nS At 3.58MHz: ± 40nS At 4.18MHz: ± 80nS

•Common Amplification: Up to 4.8MHz: ± 50nS

•Separate Amplification: Up to 4.8MHz: ± 40nS

Measured with 50Hz and 15kHz square wave, tilt within 2% of the max. amplitude.

•Common Amplification: Within ± 5% at 4.43MHz

•Separate Amplification: Within ± 3% at 4.43MHz

•Common Amplification: Within ± 5% at 3.58MHz

•Separate Amplification:

Within ± 3% at 3.58MHz

•Common Amplification: Within ± 5% at 4.43MHz

•Separate Amplification:

Within ± 3% at 4.43MHz

Within ± 2%

Measured with a 250kHz square

wave (risetime 90 nS):

•Common Amplification:

Measured with a 2T pulse,

within 2%K rating.

•Separate Amplification:

Measured with a 2T pulse,

within 1.5%K rating.

•Common Amplification: Measured with a 2T pulse, within 2%K rating.

•Separate Amplification: Measured with a 2T pulse, within 1.5%K rating.

Blanking Level Stability*

Black to White Transition

Within ± 2.5%

Incidental Phase Modulation

During full sinusoidal modulation of the visual transmitter between 50Hz and 15,000Hz, -46dB or less, relative to ± 50kHz deviation.

•Common Amplification: Phase modulation less than ± 4°.

•Separate Amplification: Phase modulation less than ± 3°.

Visual

Time (µs) Limits (%)

± 0.075 -10 ± 0.1 +11 ± 0.2 ± 7 ± (0.4 ~ 1.0) ± 5

Freq. (MHz) Limits (dB)

-4.43 -30/-

-4.43 ~ -1.25 -20/-

-1.25 ~ -0.75 +0.5/-

-0.75 +0.5/-4

-0.5 +0.5/-1.5 0 ~ +1.5 +0.5/-0.5 +1.5 Ref. +1.5 ~ +4.5 +0.5/-0.5 +5 +0.5/-2.5 +5.5 -26/-

Freq. (MHz) Limits (dB)

-3.58 -42/-

-3.58 ~ -1.25 -20/-

-1.25 ~ -0.75 +0.5/-

-0.75 +0.5/-4

-0.5 +0.5/-1.0 0 ~ +1.5 +0.5/-0.5 +1.5 Ref. +1.5 ~ +3.6 +0.5/-0.5 +4.18 +0.5/-2.5 +4.75 -30/-

Freq. (MHz) Limits (dB)

-4.33 ± 0.1 -30/-

-4.23 ~ -1.25 -20/-

-1.25 ~ -0.75 +0.5/-

-0.75 +0.5/-4

-0.5 +0.5/-1.5 0 ~ +1.5 +0.5/-0.5 +1.5 Ref. +3.0 ~ +4.5 +0.5/-1.0 +6 +0.5/-4 +6.5 -20/-

*2: With automatic correction. *3: For any picture level and variation of ± 6dB in input sync-pulse amplitude.

•Common Amplification:

Up to 2MHz: ± 50nS At 3.58MHz: ± 50nS

At 4.18MHz: ± 100nS