Technical FAQ

 

Western Europe - CCIR System B/G

Channel

Picture

Sound

Channel

Picture

Sound

E-2

48.25

53.75

E-40

623.25

628.75

E-3

55.25

60.75

E-41

631.25

636.75

E-4

62.25

67.75

E-42

639.25

644.75

E-5

175.25

180.75

E-43

647.25

652.75

E-6

182.25

187.75

E-44

655.25

660.75

E-7

189.25

194.75

E-45

663.25

668.75

E-8

196.25

201.75

E-46

671.25

676.75

E-9

203.25

208.75

E-47

679.25

684.75

E-10

210.25

215.75

E-48

687.25

692.75

E-11

217.25

222.75

E-49

695.25

700.75

E-12

224.25

229.75

E-50

703.25

708.75

E-21

471.25

476.75

E-51

711.25

716.75

E-22

479.25

484.75

E-52

719.25

724.75

E-23

487.25

492.75

E-53

727.25

732.75

E-24

495.25

500.75

E-54

735.25

740.75

E-25

503.25

508.75

E-55

743.25

748.75

E-26

511.25

516.75

E-56

751.25

756.75

E-27

519.25

524.75

E-57

759.25

764.75

E-28

527.25

532.75

E-58

767.25

772.75

E-29

535.25

540.75

E-59

775.25

780.75

E-30

543.25

548.75

E-60

783.25

788.75

E-31

551.25

556.75

E-61

791.25

796.75

E-32

559.25

564.75

E-62

799.25

804.75

E-33

567.25

572.75

E-63

807.25

812.75

E-34

575.25

580.75

E-64

815.25

820.75

E-35

583.25

588.75

E-65

823.25

828.75

E-36

591.25

596.75

E-66

831.25

836.75

E-37

599.25

604.75

E-67

839.25

844.75

E-38

607.25

612.75

E-68

847.25

852.75

E-39

615.25

620.75

E-69

855.25

860.75

 

 

CCIR Television Transmission Characteristics

 

 

 

Field

Line

chan

Video

Vid/Snd

Vest

 

 

 

 

Freq

Freq

Width

B/W

Spacing

SB

Visual

Sound

System

Lines

(Hz)

(Hz)

(MHz)

(MHz)

(MHz)

(MHz)

Mod

Mod

B/G

625

50

15.625

7/8

5

+ 5.5

0.75

neg

FM

C

625

50

15.625

7

5

+ 5.5

0.75

Pos

AM

D/K

625

50

15.625

8

6

+ 6.5

0.75

Neg

FM

H

625

50

15.625

8

5

+ 5.5

1.25

Neg

FM

I

625

50

15.625

8

5.5

+ 6.0

1.25

Neg

FM

K1

625

50

15.625

8

6

+ 6.5

1.25

Neg

FM

L

525

50

15.625

8

6

± 6.5

1.25

Pos

AM

M

525

60

15.734

6

4.2

+ 4.5

0.75

Neg

FM

N

625

50

15.625

6

4.2

+ 4.5

0.75

neg

FM

 

CCIR: Committee Consulatif Internatioonal Radiocommunications NTSC: National Television Systems Committee

 

PAL: Phase Alternation by Line                                                               SECAM: Sequential Color with Memory

 

OIRT: Organisation Internationale Radio diffusion - Télévision 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Optical Fiber Color Code

 

 

Position

   Color

Position

Color

1

Blue

13

Blue w/black tracer

2

Orange

14

Orange w/black tracer

3

Green

15

Green w/black tracer

4

Brown

16

Brown w/black tracer

5

Slate

17

Slate w/black tracer

6

White

18

White w/black tracer

7

Red

19

Red w/black tracer

8

Black

20

Black w/yellow tracer

9

Yellow

21

Yellow w/black tracer

10

Violet

22

Violet w/black tracer

11

Rose

23

Rose w/black tracer

12

Aqua

24

Aqua w/black tracer

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Digital Transmission Standards

 

North American Standard

 

Level

Bit Rate

Notes

DS-0

64 Kbps

Single digital voice circuit, including ISDN

DS-1

1.544 Mbps

24 DS-0s make uo a DS-1. Also called T-1

DS-1C

3.152 Mbps

2 DS-1 plus additional overhead

DS-2

6.312 Mbps

Composite of 4 DS-1s or 96 DS-0s

DS-3

44.736 Mbps

Composite of 28 DS-1s or 672 DS-0s

DS-4

274.176 Mbps

Equal to 6 DS-3s or 4096 DS-0s

European Standard

 

Level

Bit Rate

Notes

E-0

64 Kbps

Equivalent to DS-0

E-1

2.048 Mbps

30 E-0s combined make up an E-1

E-2

8.448 Mbps

Equivalent to 4 DS-1s or 128 DS-0s

E-3

34.368 Mbps

Equivalent to 16 DS-1s or 512 DS-0s

E-4

139.264 Mbps

Equivalent to 64 DS-1s or 2048 DS-0s

SONET/SDH

 

 

Level

Bit Rate

Notes

OC-1

51.840 Mbps

The basic signal is STS-1/OC-1 (672 Voice Channels)

OC-3

155.520 Mbps

Three STS-1s (STS-3)

OC-3C

155.250 Mbps

Three concatenated STS-1s (149 Mbps Payload)

OC-12

622.080 Mbps

Twelve STS-1s (STS-12)

OC-48

2488.320 Mbps

Forty-eight STS-1s (STS-48)

OC-96

4976.640Mbps

Ninety-six STS-1s (STS-96)

OC-192

9953.280 Mbps

One hundred ninety-two STS-1s (STS-192)

 

SONET:

Synchronous Optical Network         OC-* Optical Component -- Level

SDH:

Synchronous Digital Hiérarchie       STS-*   Synchronous Transport

ISDN:

Integrated Service                            Signal - Level

 

 

Digital Network

 

 

 

 

 

Digital Signal Formats and

Occupied Bandwidth 1

 

 

 

Data

Symbol

Occupied

 

 

Rate 2

Rate

BW

Service

Modulation

(Mb/s)

(Ms/s)

(MHz)

Satellite 24 MHz BW

QPSK

39.02

19.51

19.51

Satellite 36 MHz BW

QPSK

58.53

29.27

29.27

OM-1000

QPSK

2.048

1.024

1.200

IRT-1000/2000

64 QAM

30.34

50.57

5.057

IRT-1000/2000

256 QAM

42.88

5.361

5.361

Surfboard, SB7100

64 QAM

30.34

5.057

5.057

Music Choice

QPSK

0.694

0.347

0.347

 

1 Occupied bandwidth at -3 dB points

 

2 Including overhead

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

System Calculation

 

Decibel

 

The decibel is a logarithmic ratio between two power levels:

 

  dB power  = 10 log 10 (P1  / P2)

 

Rule: 3 dB is twice the power, and 10dB is 10 times the power.

 

A voltage ratio for equal impedance is expressed as:

 

  dB voltage = 20 log 10 (E1 / E2 )

 

Rule: 6 dB is twice the voltage, and 20 dB is 10 times the voltage. Increasing the voltage by a factor of 1.4 (3 dB) doubles the power (3 dB)

 

Voltage measurements can be made by using a reference level:

 

0 dBmV = 20 log10 (E / 1mV)

 

Rule: 40 dB (20 + 20) is 100 times the voltage (10 × 10).

 

Signal level measurements is other countries use a 1 microvolt reference:

 

0 dBμV = 20 log10 (E / 1μV)

 

Rule: the difference between dBmV and dBμV is 60 dB (0 dBmV equals 60 dBμV).

 

 

Carrier/Noise Ratio (C/N)

 

C/N at the output of a single amplifier when the noise figure (NF) is known:

 

C / N0 = Output Level- (-59.2 + NF + Gain)

 

To sum identical carrier/noise rations:

 

C/Ns = C/N – 10 log10 N

 

To sum differing carrier/noise rations:

 

C/Ns = 10 log10 ( 10 –C/N 1 / 10 + 10 –C/N 2 / 10  + ….. + 10 –C/N n / 10)

 

Carrier / noise ratio vs bandwidth:

 

Δ C/N = 10 log10 (Bandwidth ref /  Bandwidth new)

 

C/N = carrier to noise expressed as a positive number

N = Number of equal contributors

NF = Noise Figure

G = gain

- 59.2 = thermal noise in 4 MHz bandwidth (dBmV)

 

Rule: Single amplifier C/N Improves by 1 dB with every 1 dB increase in the input signal level.

 

Rule: Total C/N worsens by 3 dB with every double in the number of amplifiers with identical C/N.

 

Cross Modulation Ratio (XM)

 

XM at the out put of a single amplifier operating at a given output level:

 

XM = XM ref – 2 (Output Level – Reference Level)

 

To sum identical cross modulation rations:              

XMs = XM – 20 log10 N

 

 

To sum differing cross modulation rations:              

XMs = 20 log10 ( 10 –XM 1 / 20 + 10 –XM 2 / 20  + ….. + 10 –XM n / 20)

 

Cross modulation vs channel loading:

 

Δ XM = 20 log10 (Channel Load ref –1 /  Channel Load new-1)

 

XM = cross modulation expressed as a positive number.

 

Rule: Single amplifier XM improves by 2 dB with every 1 dB decreases in the output signal level.

 

Rule: Total XM worsens by 6 dB with every double in the number of amplifiers with identical XM.

 

 

Carrier / Composite Triple Beat Ratio (CTB)

 

CTB at the output of a single amplifier operating at a given output level:

 

CTB = CTB ref – 2 (Output Level – Reference Level)

 

To sum identical Composite Triple Beat rations:              

 

CTBs = CTB – 20 log10 N

 

To sum differing composite triple beat rations:              

 

CTBs = 20 log10 (10 –CTB 1 / 20 + 10 –CTB 2 / 20  + ….. + 10 –CTB n / 20)

 

Composite triple peat vs channel loading:

 

Δ CTB = 20 log10 (Number of Beats ref  /  Number of Beats new)

 

See page 69 to obtain the number of beats.

 

CTB = composite triple beat expressed as a positive number.

 

Rule: Single amplifier CTB improves by 2 dB with every 1 dB decrease in the output signal level.

 

Rule: Total CTB worsens by 6 dB with every double in the number of amplifiers with identical CTB.

 

 

 

 

 

 

 

 

Carrier / Single Second Order Ratio (SSO)

 

SSO at the output of a single amplifier operating at a given output level:

 

SSO = SSO ref – (Output Level – Reference Level)

 

To sum identical single second order rations:              

CSOs = CSO – 15 log10 N

 

To sum differing single second order rations:              

 

CSOs = 15 log10 (10 –CSO 1 / 15 + 10 –CSO 2 / 15  + ….. + 10 –CSO n / 15)

 

SSO = single second order expressed as a positive number.

 

Rule: Single amplifier SSO improves by 1 dB with every 1 dB decrease in the output signal level.

 

 

Carrier / Composite Second Order Ratio (CSO)

 

CSO at the output of a single amplifier operating at a given output level:

 

CSO = CSO ref – (Output Level – Reference Level)

 

To sum identical composite second order rations:              

 

CSOs = CSO – 15 log10 N

 

To sum differing composite second order rations:              

 

CSOs = 15 log10 (10 –CSO 1 / 15 + 10 –CSO 2 / 15  + ….. + 10 –CSO n / 15)

 

Composite second order vs channel loading:

 

Δ CSO = 10 log10 (Number of Beats ref  /  Number of Beats new)

 

See page 69 to obtain the number of beats.

 

CSO = composite second order expressed as a positive number.

 

Rule: Single amplifier CSO improves by 1 dB with every 1 dB decrease in the output signal level.

 

 

Carrier / Composite Intermodulation Noise Ratio (CIN)

 

It is assumed that CIN is dominated by 3rd order distortion (CIN3). This is the case in systems with analog television channels to 550 MHz and digital video above 550 MHz.

 

CIN at the output of a single amplifier operating at a given output level:

 

CIN = CIN ref – 2 (Output Level – Reference Level)

 

To sum identical composite intermodulation noise rations:              

CIN s = CIN – 20 log10 N

 

To sum differing composite intermodulation noise rations:              

 

CIN s = 20 log10 (10 – CIN 1 / 20 + 10 – CIN 2 / 20  + ….. + 10 – CIN n / 20)

 

To sum C/N and CIN:

 

C/N s = 10 log10 (10 – C/N / 10 + 10 – CIN / 10)

 

CIN = composite Intermodulation noise expressed as a positive number.

 

Rule: CIN behaves like CTB in a cascade of amplifiers, but it adds to the C/N.

 

Rule: Total CIN worsens by 6 dB, with every double in the number of amplifiers with identical CIN.

 

 

Carrier / Hum Modulation Ratio (C/H)

 

These calculations assume that all system power supplies are connected to the same power line phase.

 

To sum identical carrier / hum rations:

 

C/H = C/H – 20 log10 N

 

To sum differing carrier/hum rations:

 

C/H s = 20 log10 (10 – C/H 1 / 20 + 10 – C/H 2 / 20  + ….. + 10 – C/H n / 20)

 

To convert percent hum to C/H:

 

C/H = 20 log 10 (%Hum/100)

 

To cover C/H to percent Hum:

 

%Hum = 100 (10 – C/H / 20 )

 

C/H = Carrier to hum expressed as a positive Number

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Linear Measure

 

1 mile

=

5280 feet

1 mile

=

1.60935 kilometer

1 kilometer

=

3280.83 feet

1 kilometer

=

0.621 miles

1 kilometer

=

1000 meter

1 meter

=

39.97 inch

1 meter

=

3.281 feet

1 meter

=

100 centimeters

1 centimeter

=

10 millimeters

1 centimeter

=

0.394 inches

1 millimeter

=

1000 microns

1 micron

=

1000 nanometers

1 foot

=

30.48 centimeters

1 inch

=

25.4 millimeters

1 inch

=

1000 mils

1 mil

=

25.4 microns

1 micron

=

0.03937 mils

1 yard

=

36 inch

 

 

 

Volume

 

1 cubic yard

=

27 cubic feet

1 cubic inch

=

16.38716 cubic centimeters

1 cubic meter

=

1.307943 cubic yards

1 US gallon

=

3.7853 liters

1 US gallon

=

128 fluid ounces

1 US gallon

=

0.8327 imperial gallons

1 liter

=

61.025 cubic inches

1 liter

=

1000 cubic centimeters

 

 

Weight

 

1 pound

=

16 ounces

1 pound

=

453.592 grams

1 kilogram

=

2.20462 pounds

1 kilogram

=

1000 grams

1 ton

=

2000 pounds

1 ton

=

907.185 kilograms

1 metric ton

=

2205 pounds

 

Signal Levels

 

0 dBm

=

48.75 dBmV (75 Ohms)

0 dBW

=

78.75 dBmV (75 Ohms)

0 dBmV

=

60 dBμ V

 

 

Miscellaneous

 

1 Watt/hour

=

3.415 Btu

1 horsepower

=

746 Watts

1 atmosphere

=

14.6 pounds/square inch

1 N*m

=

1.3558 ft-lbs

1ft-lb

=

0.7376 N*m

1 psi

=

0.145 kPa

1 kPa

=

6.895 psi

°Fahrenheit

=

(9/5 × °C) + 32

°Celsius

=

5/9 × (°F- 32)

 

Prefixes

 

Milli (m)

=

1/1000

Micro (μ)

=

1/1,000,000

Nano (n)

=

1/1,000,000,000

Pico (p)

=

1/1,000,000,000,000

Kilo (k)

=

1000

Mega (M)

=

1,000,000

Giga (G)

=

1,000,000,000

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Wavelength and antennas

 

Vertical Antenna Separation

 

Antennas for differing frequencies mounted on a common mast should be separated by at least the length of the longest element of the largest antenna.

 

Wavelength

 

Wavelength is inches is given by:

 

λ = 11.811 / f (MHz)

 

Quarter Wave Whip Antenna

 

The approximate length in inches is:

 

λ / 4 = 2.775 / f (MHz)

 

Distance to Horizon

 

Optical: D = 1.23

Radio: D = 1.41

 

D= Distance in miles; H= observation height in feet

 

Velocity of Propagation

 

In free space RF propagates at approximately

186,000 mi/sec or 982 ft/μsec. To find the velocity in cable , use the multiplier given for the cable.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ohms Law

 

Ohms Law for dc Circuits:

 

Known

To Determine Value of:

Value

I

R

E

P

I and R

-

-

I × R

I 2 × R

I and E

-

E / I

-

E × I

I and P

-

P / I 2

P / I

-

R and E

E / R

-

-

E 2 / R

R and P

-

-

E and P

  P / E

E 2 / P

-

-

 

I =current in Amperes                                         E= potential difference in Volts

R =resistance in Ohms                                       P= power in Watts

 

 

Resistors in series: RT = R1 + R2

 

Two resistors in parallel:  RT =

 

More than two resistors in parallel:

 

RT = 1/1/R1 + 1/ R2 +..+1/Rn

 

Power factor: pf= True Power (W) / Apparent (E ×I)

 

 

 

 

 

 

   
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