TECHNICAL INFORMATION Transmitters & Telecommunication

TECHNICAL INFORMATION

Transmitters & Telecommunication Informations

Dr. Campanella Michele

TELECOMPONENTS SRLS - VIA DEGLI OLIVI 3 - 74020 MONTEMESOLA (TA) - ITALYPh/WhatsApp: +39 3929784631,Email: [email protected], Web: www.telecomponents.com


TELECOMPONENTS SRLS - VIA DEGLI OLIVI 3 - 74020 MONTEMESOLA (TA) - ITALY

Ph/WhatsApp: +39 3929784631,Email: [email protected], Web: www.telecomponents.com



Notes for Switch On Transmitter

Given that these operations must be performed exclusively by technical staff, this short guide provides

some basic information on how to proceed in the activation of a radio transmitter or television.

1) Power Supply:

Before connecting the transmitter (as well as any other device) to the mains make sure that the operating

voltage is the same network. This can be 220 Vac, 110 Vac or 380 Vac.

In addition to the value of the voltage necessary to determine the frequency and phases. For the frequency

it can be 50-60 Hz, while the phases can be 1 or 3 (single-phase or three-phase power).

Once you have verified the above must, for safety reasons, connect the apparatus to the ground (earth).

In addition to preserving the operation in time of the apparatus must be:

- If the transmitter is installed in mountain sites is necessary to protect the power grid separator network

and traps;

- If the transmitter is installed in sites where the mains voltage fluctuates, you must install a stabilizer.

It is very important that the site where you will install the transmitter there is adequate electrical

installation with paintings by sectioning equipped with circuit breakers

2) Site:

The transmitter is usually installed into the transmitter site . To avoid the life of the transmitter is reduced

drastically and to prevent or stop the transmitter is necessary that the site is sufficiently cooled down, this

can be achieved through the installation of air suction bowls that allow the circulation of air in the box

housing the transmitter.

When the natural circulation of air is not sufficient , it is necessary to install the fan suction .

For the installation of the suction necessary to follow the rules that the fresh area has to enter from North

and out hot of the South.

Since the transmitters produce hot air is necessary, if possible that this air produced is fed directly to the

outside and not in the box site .

In particularly hot areas will need to install an air conditioner .

Regarding the water-cooled transmitters must study with mote attention site as the radiator goes on the

outside of the box.



3) Connect the Transmitter:

First of all, you should verify that the transmitter antenna is suitable for the transmitter , is need to check:

- That the antenna is able to work to the output power of the transmitter ( to this purpose it is very

important to check the cable that goes from the transmitter to the antenna that must be able to hold up

the whole power of the transmitter ) ;

- The antenna is able to work with same frequency to the transmitter ( FM, VHF , UHF, etc. . )

- What antenna not has VSWR . The VSWR indicates the percentage of the power delivered to the antenna

back to it. If the antenna has VSWR may happen that the transmitter does not start because his guards,

avoid the damage. If the SWR is particularly high the transmitter can be damaging . VSWR depends on

several factors: the operating frequency of the antenna and different from that of the transmitter, in the

antenna system (partition , connectors , coaxial cables, etc.) entered atmospheric water , etc. ..

Once you have verified that the antenna system is well, before turning on the transmitter , check that all

cables ( power , audio, video , coaxial , etc. ) is connected .

Particular attention in this phase, needs to be done to the connections between the antenna and the

transmitter . Is important to check the tightness of the antenna cable to the transmitter.

TURN ON TRANSMITTER WITHOUT CONNECTING THE ANTENNA MAY DAMAGE TO THE SAME .

When you turn on the transmitter, it is necessary to act on the regulation of power, bringing it to zero.

Subsequently, after a few minutes and gradually proceed to increase the output power until the desired

power. Avoid placing the transmitter output power greater than that recommended by the manufacturer.

In some cases the antenna, while functioning, has a slight VSWR that prevents the transmitter to work at

full power which to protect crashes. In cases faulty adjust the output power to a value suitable for not to

block the transmitter and, as soon as possible, you check the antenna.

**** / ****


MAIN RF CONNECTORS

Sma SMB BNC

‘Siemens’ ‘N’ PL259

7/16’ 7/8 Eia Flange 1+5/8’ Eia Flange



MAIN RF CABLES

Cable attenuation Vs/frequency

‘Celflex’ Cables


TABLES RF CONVERSION

dBm / millivolts / milliWatts conversion table

This conversion table charts the values for dBm against milliwatts and the relevant voltage expressed in

millivolts.

It is applicable to many lower power applications.

DBM MILLIWATTS VOLTAGE

MILLIVOLTS (P-P)

VOLTAGE

MILLIVOLTS (RMS)

-30 0.0010 20 7.1

-28 0.0016 25.2 8.9

-26 0.0025 31.7 11.2

-24 0.0040 40.0 14.2

-22 0.0063 50.2 17.8

-20 0.010 63.2 22.4

-18 0.016 79.6 28.2

-16 0.025 100 35.5

-14 0.040 126 44.7

-12 0.063 159 56.4

-10 0.100 200 71.0

-8 0.16 252 89.4

-6 0.25 317 112

-4 0.40 399 142

-2 0.63 502 178

0 1.00 632 224

2 1.58 796 282

4 2.51 4000 1420



dBm - milliwatts - Volts conversion table:


volts.

It is applicable to many medium power applications.

DBM MILLIWATTS VOLTAGE

VOLTS (P-P)

VOLTAGE

VOLTS (RMS)

0 1.00 0.632 0.224

2 1.58 0.796 282

4 2.51 4.00 1.42

6 3.98 1.26 0.45

8 6.31 1.59 0.56

10 10 2.00 0.71

12 15.8 2.52 0.89

14 25.1 3.17 1.12

16 39.8 3.99 1.41

18 63.1 5.02 1.78

20 100 6.32 2.24

22 158 7.95 2.82

24 25.1 10.0 3.55

26 398 12.6 4.48

28 631 15.9 5.64

30 1000 20.0 7.10

32 1585 25.2 8.94

34 2510 31.7 11.2


dBm - Watts - Volts conversion table


volts.

It is applicable to many high power applications.

DBM WATTS VOLTAGE

MV (P-P)

VOLTAGE

MV (RMS)

30 1.00 20 7.10

32 1.58 25.2 8.94

34 2.51 31.7 11.3

36 3.98 40.0 14.1

38 6.31 50.2 17.8

40 10.0 63.2 22.4

42 15.9 79.6 28.2

44 25.1 100 35.5

46 39.8 126 44.7

48 63.1 159 56.4

50 100 200 71.0

52 159 252 89.4

54 251 317 112

56 398 399 142

58 631 502 178

60 1000 632 224

62 1585 796 282


As a result many power levels are specified in dBm or dBW, and much RF test equipment including power meters,

spectrum analysers, signal generators and the like have calibrations in dBm or dBW. Often RF components such as

mixers, oscillators and the like, as well as the interfaces between modules in RF equipment have their levels specified

in dBm or dBW. Radio transmitters may also have their output levels expressed in this way.

What are dBm and dBW?

In itself a decibel is not an absolute level. It is purely a comparison between two levels, and on its own it cannot be

used to measure an absolute level. As a result of this the quantities of dBm and dBW are used:

• dBm - This is a power expressed in decibels relative to one milliwatt.

• dBW - This is a power expressed in decibels relative to one watt.

From this it can be seen that a level of 10 dBm is ten dB above one milliwatt, i.e. 10 mW. Similarly a power level of 20

dBW is 100 times that of one watt, i.e. 100 watts.

A more extensive conversion table of dBm, dBW and power is given below:

DBM DBW WATTS TERMINOLOGY

+100 +70 10 000 000 10 Megawatts

+90 +60 1 000 000 1 Megawatt

+80 +50 100 000 100 kilowatts

+70 +40 10 000 10 kilowatts

+60 +30 1 000 1 kilowatt

+50 +20 100 100 watts

+40 +10 10 10 watts

+30 0 1 1 watt

+20 -10 0.1 100 milliwatts

+10 -20 0.01 10 milliwatts

0 -30 0.001 1 milliwatt

-10 -40 0.0001 100 microwatts

-20 -50 0.00001 10 microwatts

-30 -60 0.000001 1 microwatt

-40 -70 0.0000001 100 nanowatts

-50 -80 0.00000001 10 nanowatts

-60 -90 0.000000001 1 nanowatt

The use of the values dBm and dBW is widespread. They are found as direct calibration scales on many items of RF

test equipment often being used in preference to the more elementary basic units of watts or milliwatts. Items of RF

test equipment including power meters, signal generators and RF spectrum analyzers in particular use these units.

Accordingly to be able to understand the RF test equipment specifications it is necessary to have an understanding of

dBm and dBW. Also many RF components are also specified in terms of dBm or dBW.


General considerations on the creation of a network and transmit

information by radio or television

Given that the study of a network or television system must be planned in advance by trained personnel,

the following will indicate some general guidelines to follow to build a system or a television or radio

network efficient and functional.

Broadcasting networks

In broadcating networking, the first step is to verify which locations should be covered by the signal the

radio unit - television. In this phase it is necessary to utilize the simulation programs of the territory or,

alternatively, obtain maps and delineate the areas to be served with the signal.

Once you have found the 'area to cover, please also identify the sites of transmission from which the signal

will be radiated. This is one of the most important steps in the whole study of the network.

The identification of the site should be carried out according to the following general rules:

Height of the site:

- The higher the site, potentially the greater the area of service;

- The higher the site, the easier it can be connected via bridges transfer, various sites that make up the

network between them;

- The higher the site, potentially greater, problems relating to the supply of electricity, protection of

equipment (due to weather conditions), the attainment of the site (by street)

Once the site (which is not the same as reside studies issuer) is necessary to design the system formed by

the radio antenna system (antenna), the transmitter and possibly transfer from the bridge.

The radiant system (Antenna Transmitter)


The radiant system (or antenna) is the most important element. Since it depends on the coverage area of

the radio signal and its intensity (the intensity of the signal received by the user affects much more the

antenna and the transmitter).

The antenna can to be omni- directional (typically used for broadcasting FM) or directive (used in FM

broadcasting and television). Omni-

directions (360 °), while those directives

radiation).

It is evident that the design of the antenna shall take into account the areas to be covered in the area and

for this reason the antennas must be properly designed (Telecomponents t

antenna design in the area provides this service).

In some cases it is useless to have transmitters of thousands of watts of power when they are on just a few

watts and an antenna designed and built properly.

For example, the following System:

- Transmitting System 1

- Transmitter by 1000 Watts (60 dBm)

- # 1 x Television Panel Array

Total EIRP is : 60 dBm + 10 = 70

- Transmitting System 2

-Transmitter by 200 Watts (53 d

- # 1 x Television Panel Array (

Total EIRP 53 dBm + 19 = 72

In our simulation we can see that the system 2 while having a less powerful transmitter (200W instead of

1000) produces a stronger signal and a double

The types of antennas used in broadcast systems are different, we can remember:



directional (typically used for broadcasting FM) or directive (used in FM

-directional antennas radiate electromagnetic energy uniformly in all

directions (360 °), while those directives in particular directions and with particular angles (angle of


for this reason the antennas must be properly designed (Telecomponents through simulation software and

antenna design in the area provides this service).


watts and an antenna designed and built properly.

:

1000 Watts (60 dBm)

# 1 x Television Panel Array (10 db gain) (ex 1 panel)

60 dBm + 10 = 70 dbm = 10 kW EIRP

200 Watts (53 dBm)

Television Panel Array (19 db) (ex 8 panel)

Total EIRP 53 dBm + 19 = 72 dbm = ~ 18 kW EIRP


1000) produces a stronger signal and a double coverage area compared to system 1

The types of antennas used in broadcast systems are different, we can remember:



directional (typically used for broadcasting FM) or directive (used in FM

energy uniformly in all

in particular directions and with particular angles (angle of


hrough simulation software and



system 1.


- For the FM band (87-108 MHz) - Dipoles and Yagi (single or collinear configuration) in vertical polarization;

- Television Par band VHF (170-250 Mhz) - Yagi or panels (arrays) in horizontal or vertical polarization;

- For Television UHF band (470-860 MHz) - Panels (arrays) in horizontal or vertical polarization.

Arrays

Transmitter

Another important element of the system is the transmitter. There are many types of transmitters and the

choice will have to be made taking into account the quality of the audio output, reliability and electricity

consumption. Generally the transmitters have efficiencies ranging from 30% to 50%. This means that the

electrical energy consumed in equal RF power is different.

For example:

- 1 kW transmitter with yeld 30% uses about 3 kw;

- 1 kW transmitter with yeld 50% uses about 2 kw;

As can be seen the second transmitter consumes less of the first. Therefore, before the purchase the

transmitter, it is necessary to evaluate these parameters. A transmitter to match power output, may cost

more than another but in a short time the difference in cost would be absorbed by higher electricity

savings.


The new types of transmitters, using organic in the amplifier power transistor new generation, they also

yield higher (around 60-70%).

Links between stations (Network)

Rarely broadcast transmitter is located in the studies, the easier it is localized at the site of transmission

(mountain, hill, etc..). To bring the audio and video signal produced in the studios at the various sites that

make up the network, it must be used to transfer links.

Such transfer link operate on specific frequencies ranging from VHF to microwave. Typically, you use very

high frequencies (from 800 MHz to 22 GHz) that mainly because these frequencies have several

advantages:

- They are less subject to interference;

- The transmitting and receiving antennas used in links are relatively small;

- More higher are the frequency used , more greater is the gain of the transmitting antenna and the

receiver.

Since the powers used in flight transfer are very low from (1 - 5 Watt), antennas used necessarily have high

gains (16 to 43 db).

Typically antennas are used in decks transfer Yagi high gain (8-10 items or more) or of parabolic type.


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TECHNICAL INFORMATION Transmitters & Telecommunication