Valid

GY/T 210-2005Technical specifications for open monitoring of MW and SW AM broadcasting quality (English PDF)

Preview PDF

This is a limited preview

Buy now to download the full PDF (13 pages)

Need quotation for your management?

Get a formal quotation for GY/T 210-2005 in 30 minutes.

Issued by

State Administration of Radio and Television

Level / Type

National · Recommended

Issue date

September 30, 2005

Implementation date

November 1, 2005

Scope

GY/T 210-2005 (Technical specifications for open monitoring of MW and SW AM broadcasting quality) is available as an English-translated PDF.

GY/T 210-2005 — Monitoring of broadcast sound quality includes monitoring of noise, distortion, and amplitude-frequency characteristics. For distortion, amplitude frequency characteristics, Monitoring of technical indicators such as noise, crosstalk, and alternating sound.

This standard mainly refers to GY/T 179-2001 "Operation and Maintenance Regulations for Radio and Television Transmitters." Appendix F of Cheng "carries out subjective evaluation.

Found what you need?

Document preview — GY/T 210-2005

National Standard of the People's Republic of China

ICS: 33.160
Classification: M 60

Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Acronyms
5 Medium and short-wave broadcasting band range
6 Broadcast Quality Open Circuit Monitoring Project
7 Technical indicators for open quality monitoring of broadcast quality
8 Open Quality Monitoring Method of Broadcasting
Appendix A (informative) Medium and short-wave broadcasting band range

Foreword

In order to standardize the open-circuit monitoring of medium and short wave AM broadcasting quality, and to promote the improvement and effective coverage of medium and short wave AM broadcasting quality, this standard is specially formulated.

Open-circuit monitoring of medium and short wave AM broadcast quality refers to the use of dedicated reception in a specific frequency broadcast service area or a specific reception location.

The device receives airwave signals, performs objective measurement and subjective evaluation of a certain broadcast frequency in real time, and accurately reflects the signal quality, Radio characteristics and transmitter operating conditions. There are three main types of broadcast quality monitoring projects.

1 Monitoring the quality of broadcast sound

Monitoring of broadcast sound quality includes monitoring of noise, distortion, and amplitude-frequency characteristics. For distortion, amplitude frequency characteristics, Monitoring of technical indicators such as noise, crosstalk, and alternating sound. This standard mainly refers to GY/T 179-2001 "Operation and Maintenance Regulations for Radio and Television Transmitters." Appendix F of Cheng "carries out subjective evaluation.

2 Monitoring of broadcast transmission characteristics

The monitoring of broadcast transmission characteristics includes the monitoring of frequency deviation, amplitude modulation, carrier level, and technical specifications of transmission bandwidth.

Refer to GB/T 12572-1990 "Transmitter Frequency Tolerance" and GB/T 12046-1989 "Identification of Radio Transmission and Determination of Necessary Bandwidth" to monitor.

3 Monitoring of the operating status of broadcast transmitters

The monitoring of the operating status of broadcast transmitters includes monitoring of technical indicators such as out-of-broadcasting (including miscasting, aerial broadcasting, less broadcasting, late broadcasting, and multicasting) and poor broadcasting for testing, this standard mainly refers to Appendix A of GY/T 179-2001 "Operation and Maintenance Regulations for Radio and Television Transmission Stations" for monitoring.

Appendix A of this standard is an informative appendix.

This standard is under the jurisdiction of the National Radio and Television Standardization Technical Committee.

This standard was drafted. Radio and Television Monitoring Center of the State Administration of Radio, Film and Television.

3.6 Frequency deflection

The center frequency of the band occupied by the transmitter deviates from the assigned frequency, or the characteristic frequency of the transmission deviates from the reference frequency, expressed in hertz (Hz) Show.

Amplitude modulation ratio Modulated carrier wave with a single frequency audio signal, the difference between the maximum or minimum instantaneous amplitude and the carrier amplitude during amplitude modulation the value, expressed as a percentage, to the carrier amplitude during AM.

Transmitted bandwidth the frequency band occupied by the medium and short wave AM broadcast transmission signals in the broadcast band.

Carrier level

In the absence of modulation, the arithmetic mean value of the power supplied by the transmitter to the antenna during a radio frequency period, compared to the standard power reference value.

3.10

Stop dead radio

No carrier is transmitted due to various factors within the specified time of the broadcast operation chart; although there is a carrier but no modulation; the broadcast program is late or less Broadcast, program misplay or its effect is equivalent to program interruption. Including wrong broadcast, air broadcast, late broadcast, less broadcast.

3.10.1

Nomodulated radio

During the specified broadcast time, due to the failure of broadcasting technology equipment or improper human operation, no modulation signal appears, but the carrier wave is normal.

Anomalies, also known as carrier without modulation.

3.10.2

Wrong radio

During the transmission and broadcast of the broadcast program, the broadcast program was not broadcasted in accordance with the regulations of the broadcast station.

3.10.3

Delayed radio

Due to the failure of the broadcasting technology equipment or improper human operation, the broadcasting program was broadcast later than the time specified in the broadcasting operation chart.

3.10.4

Not enough of radio

Due to the failure of the broadcasting technology equipment or improper human operation, the broadcasting program was stopped in advance within the time specified in the broadcast operation chart.

Out.

3.11

Bad broadcasting accident any failure of the broadcasting technology equipment or improper human operation and use causes the listening quality to decline, but it has not reached the limit of stopping broadcasting.

3.12

Multicastexcessive radio it means that the actual broadcast time of the transmitter exceeds the program time specified in the operation chart.

3.13

Amplitude-frequency characteristic when the transmitter is modulated with an audio signal of constant amplitude, its modulation amplitude varies with different frequencies.

3.14

Harmonic distortion

The transmitter's single-tone AM envelope signal is distorted.

3.15

Cross-talk

In the normal broadcast program, due to equipment reasons or human operation improper use, other signals are inserted.

3.16

Broadcasting operation situation Radio program production, broadcasting, transmission and transmission The entire system is implemented in accordance with the specified radio program operation map and related technical standards result.

3.17

Overall rating

Comprehensively consider factors such as signal strength, interference, and noise to be received, and subjectively evaluate the listening effect and quality. Generally expressed in five points.

4 Acronyms

The following abbreviations apply to this standard.

A/D (Analog to Digital) conversion from analog to digital AM (Amplitude Modulation) CW (Carrier Wave) FAX (Fastness Avigation) FFT (Fast Fourier Transform) FM (Frequency Modulation) FSK (Frequency-Shift Keying) ISB (Independent Side Band) LSB (Low Side Band) MW (Medium Wave) RTTY (Radio Teletype) SW (Short Wave) USB (Up Side Band)

5 Medium and short-wave broadcasting frequency range

The range of the medium and short-wave broadcasting bands is based on the and the "National Radio Frequency Allocation Regulations".

See Appendix A for the medium and short-wave broadcasting frequency range.

5.1 Medium wave broadcast frequency range

Refer to Appendix A.1 for the range of medium wave broadcasting bands.

5.2 Short-wave broadcasting frequency range

See Appendix A.2.

6 Broadcast Quality Open Road Monitoring Project

6.1 Monitoring of broadcast sound quality

Including the monitoring of technical indicators such as noise, distortion and amplitude frequency characteristics.

6.2 Monitoring of broadcast transmission characteristics

Including the monitoring of frequency deviation, amplitude modulation, carrier level, transmission bandwidth and other technical indicators.

6.3 Monitoring of the operating status of broadcast transmitters

Including monitoring of technical indicators such as stop broadcasting (including miscast, air broadcast, less broadcast, late broadcast), and poor broadcast.

7 Technical indicators for open quality monitoring of broadcasting quality

7.1 Subjective evaluation level of sound quality of broadcasting

The subjective evaluation level of the sound quality of the broadcast is shown in Table 1.

Table 1 Subjective evaluation levels of broadcast sound quality monitoring

No. level sound quality 1 5 points (Excellent) Excellent quality, very satisfied 2 4 points (good) Good quality, almost no noise or distortion can be detected 3 3 points (medium) Average quality with obvious noise or distortion 4 2 points (poor) Poor quality, serious noise or distortion 5 1 point (poor) Poor quality with severe noise or distortion

7.2 Monitoring indicators for broadcast emission characteristics

See Table 2 for the requirements of the monitoring indicators for broadcast emission characteristics.

Table 2 Requirements for monitoring indicators of broadcast emission characteristics

Item Technical Index Measurement Error Language programs have a duration of more than 6s (including 6s) in the 1min measurement time >=70% 1 amplitude Music programs have a duration of >=30% for more than 6s (including 6s) in the 1min measurement time ± 5% Medium wave synchronization Medium wave <=10Hz Short wave ( > 10kW) <=10Hz Carrier frequency fc is 2.3MHz ~ 4.0MHz fc × 20 × 10-6Hz Carrier frequency fc is 4.0MHz ~ 5.95MHz fc × 15 × 10-6Hz frequency deviation Short wave (<=10kW) Carrier frequency fc is 5.95MHz ~ 26.1MHz fc × 10 × 10-6Hz ± 1Hz Carrier Level medium wave and short wave (under normal modulation amplitude) >=50%-MF 9kHz emission Bandwidth short wave 9kHz ± 5%

7.3 Boundary of Broadcast Transmitter Operation

See Table 3 for the limits of the broadcasting transmitter's operating status.

Table 3 Boundary of broadcasting transmitter operation status

Serial number of items stopped broadcasting

1 The modulation amplitude is normal, and the carrier level is less than 25% of the specified value. 25% ~ 50% Within 1min of automatic measurement, the carrier level is normal, the maximum adjustment is Compared with the normal value, the amplitude is more than 6s (including 6s).

< 50% 50% ~ 70%

8 Broadcast quality open circuit monitoring method

8.1 Method for monitoring sound quality of broadcasting

The sound quality monitoring method is to use a special receiver for medium and short wave broadcasting to receive a subjective evaluation of the sound quality of the broadcast.

8.1.1 Noise Identification

In open-circuit monitoring, the noise of short-wave broadcasting mainly monitors the noise caused by the transmitter, which includes the additional noise and AC sound of the transmitter.

The noise sounds a smoother "snoring" sound, which is monitored in the gap between radio programs.

The sound of communication sounded "humming". Pay attention to distinguish the beating sound caused by co-channel interference, you can use methods such as changing the antenna direction Make a difference.

8.1.2 Identification of Pros and Cons of Amplitude Frequency Characteristics

The pros and cons of the amplitude frequency characteristics are. when the amplitude frequency characteristics are good, the sound of listening to a language program is clear, and the sound of listening to a music program is wide Thick, round, bright and plump. When the bass is too high, the sound is stuffy; when the treble is too high, the sound is sharp; when the middle is too low, the sound Sound clarity is reduced.

8.1.3 Distortion discrimination

A random program signal passing through a non-linear device will generate harmonic distortion of each audio and intermodulation distortion between each audio, making the program sound Blurred, ragged, or spiked.

8.2 Monitoring method for broadcast emission characteristics

The monitoring of technical indicators such as carrier level, amplitude modulation, frequency deviation, and transmission bandwidth of the transmission characteristics of medium and short-wave broadcasting is Objective measurements are made.

8.2.1 Carrier level method

The measurement of the carrier level of a broadcast transmission is to measure the field strength of its transmission frequency. Measure emissions when test environmental conditions are not available the level value of the carrier frequency. When measuring the carrier level, there should be no obvious co- and adjacent-frequency interference. The field strength measurement method should comply with GY/T 82-1989 Relevant provisions.

8.2.1.1 Block diagram of automatic carrier level measurement

The measuring equipment consists of a dedicated receiver (dedicated receiver) for medium and short wave broadcast quality monitoring or a medium and short wave field strength meter with automatic measurement capabilities.

(Field strength meter), field strength measurement antenna, and related software and hardware with control, data processing and analysis functions, can also use dedicated receivers or Field strength meters and antennas are used for manual measurements. The block diagram of automatic measurement is shown in Figure 1.

Receiver for printer (field strength meter) Computer

Figure 1 Block diagram of automatic measurement of field strength (level)

8.2.1.2 Technical requirements for monitoring equipment

8.2.1.2.1 Technical requirements for dedicated receivers for medium and shortwave broadcast quality monitoring See Table 4 for the technical requirements of special receivers for medium and short wave broadcast quality monitoring.

Table 4 Technical requirements for MW receivers

Technical index

Item

A type B type

1 Tuning resolution 1Hz, 10Hz, 100Hz, 1000Hz 10Hz, 100Hz, 1000Hz

2 Frequency stability 5 × 10-7/h 2 × 10-6/h

3 External standard frequency 1MHz, 5MHz, 10MHz None 4 (antenna) input impedance (nominal value) 50ohm 50ohm

5 Demodulation method AM, USB, LSB, CW, FAX ISB, FSK, FM (narrowband), RTTY AM, USB, LSB, CW, RTTY FAX, FM (narrowband)

6 IF bandwidth 0.1kHz ~ 10kHz adjustable 1kHz, 2kHz, 6kHz, 8kHz Sensitivity (S/N = 10dB, narrow band, modulation frequency 400Hz, modulation degree 30%) 6µV (0.5MHz ~ 1.6MHz) 2µV (1.6MHz ~ 30MHz) 10µV (0.5MHz ~ 1.6MHz) 5µV (1.6MHz ~ 30MHz)

8 IF rejection 90dB 70dB

9 Image rejection 90dB 70dB

10 Remote control interface

RS-232, IEEE488, RS-485, Ethernet interface RS-232

11 IF output variable 455kHz, 525kHz

12 Digital Signal Processing (DSP)

13 Operating temperature range -10oC ~ 55oC 5oC ~ 45oC

8.2.1.2.2 Technical requirements for medium and short wave field strength meters the technical requirements of the medium and short wave field strength meters are shown in Table 5.

Table 5 Technical requirements for medium and short wave field strength meters

Project technical indicators

1 Field strength meter calibration error <=1dB

2 Field strength measurement error <= 2dB

3 IF passband width (-6dB bandwidth) 9kHz ± 1kHz or 10kHz 4 detection method average detection

5 Remote control interface RS-232, or IEEE488, or RS-485, Ethernet interface

8.2.1.2.3 Technical requirements for measuring antennas There are two types of measuring antennas. standard loop antenna and rod antenna.

The loop antenna measures the horizontal component of the magnetic field strength. During the measurement, the loop antenna should be turned to maximize the measured value.

Rod antennas are generally short vertical antennas with a length of about 1 m, measuring the vertical component of the electric field. Precisely opening the carrier field strength of a broadcast transmission when measuring roads, loop antennas should be used.

For inaccurate measurements such as relative field strength measurement and automatic spectrum scanning, a rod antenna can be used.

The technical requirements of the measuring antenna are shown in Table 6.

Table 6 Technical requirements for measuring antennas

Technical index

Item

Loop antenna rod antenna

1 Frequency range 10KHz ~ 30MHz 10kHz ~ 30MHz 2 impedance 50ohm 50ohm

3 Voltage standing wave ratio (VSWR) <=2 <=2

4 Antenna correction factor

8.2.1.3 Measurement procedure

a) Connect the antenna, field strength meter or special receiver, computer and printer according to Figure 1, and power on the equipment;

b) Start the measurement software and set the field strength meter demodulation mode to AM and the detection mode to average detection and IF bandwidth through the computer interface.

3kHz or 9kHz, and the receiving frequency of a field strength meter or a dedicated receiver;

c) Select the standard antenna type through the computer interface, set the attenuation (or dynamic range) of the field strength meter or special receiver to make the receiving the frequency signal strength is appropriate;

d) calibrate the field strength meter through the computer interface;

e) Operate the computer for measurement, the measurement data is automatically stored in the database, and the measurement results are displayed;

f) When needed, start the printer to print the measurement results.

8.2.2 Amplitude measurement method

8.2.2.1 Basic requirements for monitored signals

a) The received signal is relatively strong and stable;

b) No obvious co- and adjacent-frequency interference.

8.2.2.2 Automatic measurement block diagram of amplitude modulation the measuring equipment is composed of A/D acquisition card, antenna and related software and hardware with control, data processing and analysis functions.

Adjust the acquisition card and antenna and other equipment for manual measurement. The block diagram of automatic measurement is shown in Figure 2.

Computer dedicated receiver A/D acquisition card IF Amplitude measuring instrument printer

Figure 2 Block diagram of amplitude modulation measurement

8.2.2.3 Technical requirements for monitoring equipment

8.2.2.3.1 Technical requirements for dedicated receivers for medium and shortwave broadcasting See 8.2.1.2.1.

8.2.2.3.2 A/D acquisition card technical requirements the IF signal output from the receiver is sent to the A/D acquisition card. After filtering, amplification and detection, the carrier signal and audio signal are obtained.

The two signals are sampled at the same time, the sampling frequency must be at least two times higher than the highest frequency of the collected signal, the ratio of the instantaneous values of the two signals, Get the instantaneous modulation amplitude; the actual modulation amplitude value takes the maximum modulation amplitude value of the lowest frequency of the sampled audio signal in a period.

The technical requirements of the A/D acquisition card are shown in Table 7.

Table 7 Technical requirements of A/D acquisition card

Project technical indicators 1 input carrier frequency receiver intermediate frequency output frequency

2 Input the adjusted voltage level 10mV ~.200mV

3 Sampling frequency

4 Measurements per second >=50

5 Measurement error ± 5%

8.2.2.3.3 Receiving antenna technical requirements Use directional receiving antenna. When there is no directional antenna, a high-gain omni-directional antenna can be used to improve the signal-to-noise ratio of the received signal.

To improve the measurement accuracy, see Table 8 for the technical requirements of the receiving antenna. Other antennas are available for mobile or remote monitoring.

Table 8 Technical requirements for receiving antennas

Technical index

Short-wave antenna medium wave antenna serial number project Directional omnidirectional

1 Frequency range 3.2MHz ~ 26.1MHz 3.2MHz ~ 26.1MHz 0.5265MHz ~ 1.6065MHz

2 Antenna gain >=8dB >=5dB 0dB ~ 3dB

3 Voltage standing wave ratio (VSWR) <=3 <=3 <=2

4 Output impedance (unbalanced) 50ohm 50ohm 50ohm

5 Polarization method Horizontal polarization Horizontal polarization Vertical polarization

6 Horizontal half power lobe width 60o ~ 80o 360o 360o

8.2.2.4 Measurement procedure

a) Connect the receiving antenna, the dedicated receiver, the dedicated A/D acquisition card, the computer and the printer as shown in Figure 2 and power on the equipment;

b) Start the measurement software, set the measurement frequency and measurement time through the computer interface, and set the dedicated receiver to AM demodulation mode, 9kHz Bandwidth and proper RF attenuation, set the type and orientation of the receiving antenna and attenuation;

c) Operate the measurement through the computer interface, the measurement data is automatically stored and the measurement results are displayed;

d) If necessary, print the measurement results.

8.2.3 Frequency deviation measurement method

8.2.3.1 Basic requirements for monitored signals

a) the audibility of the received signal is not less than 2 points;

b) No obvious co- and adjacent-frequency interference.

8.2.3.2 Block diagram of frequency deviation measurement

8.2.3.2.1 Li Shayu Graphic Comparison Method the block diagram of measuring frequency deviation by Li Shayu's graphic comparison method is shown in Figure 3.

High-frequency standard frequency source Coupler Oscilloscope XY Dedicated connection Close Low frequency oscillator = f deltaf f2-f3 = f-1kHz fohm = 1kHz deltaf f1. the transmitter transmits the assigned frequency;

f2. transmitter transmitting frequency;

f3. The output frequency of the high-frequency standard frequency source is (f1-1kHz);

f4. f2 and f3 pass through the receiver mixing detection frequency (deltaf 1kHz);

fohm. the output frequency of the low-frequency oscillator;

deltaf. frequency deviation.

Figure 3 Block diagram of measuring frequency deviation by Li Shayu's graphic comparison method

8.2.3.2.2 FFT (Fast Fourier Transform) Automatic Spectrum Analysis Method the block diagram for measuring the frequency deviation of the FFT spectrum automatic analysis method is shown in Figure 4.

Printer A/D capture card computer High-frequency standard frequency source Dedicated receiver

Figure 4 Block diagram of measuring frequency deviation by FFT spectrum automatic analysis method

8.2.3.3 Technical requirements for monitoring equipment

8.2.3.3.1 Technical requirements for dedicated receive...

......
This preview omits tables, figures, formulas and parts of the technical clauses. The complete document — 13 pages — is available in the English PDF.

How to Download GY/T 210-2005

1
Add to cart
Click "Download PDF" on this page and choose "Buy this standard". You can add more standards before checkout.
2
Checkout
Enter your email and billing details. Payment is processed securely by Stripe (cards or bank transfer). Prefer bank details? Request a quotation (min. order $300).
3
Instant delivery (0–9 sec)
Delivery is automatic: within seconds of payment you'll receive an email with a secure download link. The link stays valid for 72 hours.
4
Invoice included
A tax invoice is attached to the confirmation email. Need a custom invoice? Contact us.