How to Connect a Philips TV to Digital Television
To connect the TV to a cable network or digital television antenna, you need to purchase a special television cable and put on F-plugs at its ends.
With an illiterate solution to this problem, the TV when receiving an analog signal may work unstably or with noise, and digital. the image and sound may disappear due to signal loss in the cable and its connection.
The advantage of digital television is the absence of interference in the picture and sound. But if the signal with large noise, then the picture and sound on the TV will periodically disappear, and if the signal is weak, then completely absent.
TV cable selection
Even an excellent TV and correctly plugged on the ends of the cable F-plug will not be able to provide high quality images on the screen when using low-quality television cable. And the question arises, what antenna cable is better for connecting a TV and by what criteria should I choose it?
TV cable device
Consider how a modern television coaxial cable is arranged using the CAT-703 cable as an example.
In the center of the entire length of the coaxial cable passes copper, or steel, coated with a copper layer wire core. This core is coated with a dielectric insulation layer. A copper shielding or aluminum braid made of aluminum foil is worn on the insulation, which serves as the second conductor. To protect against mechanical and climatic influences, the cable is covered with a sealed protective sheath.
In inexpensive cables, only aluminum braid is used, in budget ones. copper, and in expensive aluminum and copper at the same time, as shown in the photograph.
How current flows through the antenna cable
To consciously choose a good antenna cable, you need to imagine how the high-frequency current flows. Current in the electric network flows throughout the cross section of the conductors.
The high-frequency current of a television signal flows according to another law. Everyone knows how laundry is squeezed out in the centrifuge of the washing machine: the higher the speed, the stronger the centrifugal force acts on the water, and it is better removed from the laundry, the laundry becomes drier. On their own bodies, many in their childhood experienced, riding on a carousel, the action of centrifugal force.
Similarly, the high-frequency current of the television signal flows in the antenna cable. The higher the frequency, the closer to the surface of the conductor it flows. The skin effect appears. If we take, for example, a copper wire with a diameter of 10 mm and a tube of the same diameter made of copper with a wall thickness of 1 mm, then a current with a frequency of 1000 MHz will flow through them with the same losses!
Therefore, in antenna cables used for military and space equipment, in order to reduce signal loss (attenuation), the central core and the cable sheath are often covered with a thin layer of silver and even gold. This is a very expensive pleasure, and such cables are not used in everyday life.
Due to the small size of the television signal in the antenna cable and its high frequency, it is not possible to determine its presence in the cable and even more so to carry out measurements at home without specialized expensive devices. Only connecting the antenna cable to the TV will determine the presence and quality of the television signal.
TV cable marking
The most widespread on the market are antenna coaxial cables from different manufacturers with wave impedances of 75 Ohms of the brands RG 6U, SAT 50, SAT 703B and DG 113, which can be successfully used to receive analog and digital television signals up to transmitting it from a satellite dish with a frequency of up to 2, 15 GHz. The brands are given in order of increasing quality of the antenna cable. reducing signal loss (attenuation) during transmission. Marking (designation) is mandatory applied to the sheath of the antenna cable along its entire length every meter with a digital meter mark.
This antenna cable marking indicates the following:
- CABLETECH is a manufacturing company of CABLETECH (China).
- RG 6U / 48. brand of cable.
- HIGH QUALITY COAXIAL CABLE. high-quality coaxial cable.
- 75 OHM. 75 Ohm impedance.
- 055M. meter mark, with each meter the mark changes to 1.
How to choose an antenna television cable
On the jacket of the antenna cable must be marked, as shown above. The antenna cable should have a wave impedance of 75 Ohms (all TVs and switching devices — amplifiers, splitters, consoles for receiving digital DVB-T2 channels — are designed for such resistance). The outer diameter of the antenna cable sheath must be at least 6 mm. Central core and shielding braid of electrical copper. Antenna cables of the SAT 703B and DG 113 brands meet these requirements. In the RG 6U cable, the central core is steel, galvanized with copper, a screen made of aluminum foil and a braid of copper alloy is a budget option.
It is impossible to describe all the television cables available on the market, but the information presented is quite sufficient for the right choice.
How to install the antenna plug on the cable
There is no need to invite specialists in order to connect the TV to the antenna cable. This work can be done by each homemaster on their own using an improvised tool if they follow the instructions below.
The voltage of an analog or digital television signal in an antenna cable is millionths of a volt, so an antenna cable connected to a cable network or other television is not dangerous to humans. You can safely cut the cable without disconnecting the other end of the cable from the splitter or TV. When cutting the cable, there is no danger of accidental short circuit between the center conductor and the shielding braid.
How to install the F-plug on the antenna cable
The plugs are sold in three sizes for antenna cables of different diameters. When purchasing, pay attention that the F-plug is suitable for your antenna television cable. This type of plug is suitable for analogue, digital television signal and signal coming from a satellite dish.
You can screw the F-plug onto the cable by cutting it in two ways, with a twist of the shielding braid, on the diagram on the left side, and without wrapping it, on the diagram on the right, in accordance with the layout diagram below.
reliably the F-plug will hold in the case of a twist of the shielding braid, but if it is not possible to wind it, then you can use the second method.
To cut the television cable, by slightly pressing the knife, so as not to damage the shielding braid of the antenna cable, its outer sheath is cut along several centimeters.
After an incision of the sheath, it bends to the side and is cut off at the beginning of the incision.
Aluminum foil and copper braid are turned off. The screen in the antenna cables comes in three versions: one copper braid, aluminum foil and a copper braid on top of it (as in my case), only aluminum foil.
Many do not know that to give mechanical strength the foil is coated on the inside with polyethylene. It is impossible to clean the plastic. If you screw the plug onto the inside of the foil of the antenna cable, then there will be no contact, or it will be very bad. To prevent this from happening, you need to bend the half of the turned-off foil back, then the conductive side will be outside.
There are situations when the diameter of the hole of the internal thread F of the plug is larger than the diameter of the antenna cable. In this case, before wrapping the foil, it is necessary to wind several layers of insulating tape on the antenna cable in order to adjust the cable size. Then do everything as described. The insulation is removed from the central core according to the technology described in the article “Preparing the wires for installation”.
F plug “cable wrap” is screwed onto the foil.
The central core of the antenna cable bites off so that about 2-3 mm remains to protrude.
The second half of the plug is screwed up to the stop, and the F-plug is ready for operation.
There are cases when after inserting the antenna plug into the TV socket, the cable has to be bent at right angles or it is impossible to install the TV close to the wall due to an interfering antenna cable. In this case, you can use the F-socket. a plug of an angular design.
The difference between the two described plugs is only in their form. The technology for installing straight and angled plugs on a television cable is the same.
How to install an old-style plug on the antenna cable
Before the appearance of the antenna F-plugs, plugs of a different design were used, which also did not require soldering, but were connected to the antenna cable by their technology.
Before starting to install the plug on the antenna cable, you need to hold it by the metal part and unscrew the plastic case by turning it counterclockwise. Then put the case on the cable so as not to forget.
The next step is preparing the antenna cable for installation. To do this, with a knife blade you need to lightly cut through its outer shell to a length of about a centimeter. Next, remove the shell and cut the shielding braid by 5 mm. Remove five millimeters of core core insulation. The antenna cable is now ready for plugging into the plug.
When filling the cable into the plug, it is necessary to exclude the contact of the braiding conductors of the fasteners of the central core. The pliers of the antenna plug are crimped with pliers around the shielding winding. Great effort should not be made. The main thing is to have reliable contact.
Then, the screw for fixing the central core of the antenna cable is screwed to the stop.
The last step is to screw the plastic onto the metal part of the plug and insert the plug into the TV socket.
Where to insert the antenna cable in the TV
Once the connector is installed on the cable, you can connect it to the TV. The socket for connecting the TV to the antenna or cable network is usually located on its back wall and is marked next to it in the form of the abbreviated inscription “ANT”.
In the photo on its right side you can see the socket for connecting the antenna. The socket is special, standard and differs from all other connectors and sockets available on the switching panel. Therefore, it is physically impossible to insert an antenna plug into another socket. Any of the connectors, the installation of which is discussed in the article above, is well inserted into the television jack.
In modern televisions, two connectors for connecting the antenna are installed for receiving a television signal :. cable (digital) television and satellite dishes.
One, which is designated RF (ANT 1 IN), is designed to connect a digital television antenna or cable network, this is installed on all TV models, both old and modern. The second began to be installed recently, LNB (ANT 2 IN with external thread) is designed to connect a satellite dish.
If the TV supports the DVB-S2 standard, then the satellite dish can be connected without a receiver, directly to the LNB connector. To receive digital television channels from a television tower to an individual antenna, the TV must support the DVB-T2 standard. Therefore, when buying a TV, you need to pay special attention to the list of broadcast standards that it supports.
To receive a signal from a given connector by a TV in its menu, select the signal source Antenna or Satellite TV and perform automatic or manual channel tuning.
How to connect an antenna cable to a TV without a plug
In life, there are situations that you urgently need to connect an antenna cable to the TV, but there is no plug at hand. You can temporarily connect the antenna cable without a plug. To do this, you must first remove the upper sheath to a length of 5 cm, develop and unscrew the shielding braid, remove the insulation from the central core of the cable and bend the core itself into a loop. The width of the loop should be slightly larger than the hole in the center socket of the connector.
If the connector in the TV is as in the photo, then on the central contact you need to put on an insulating tube. Next, a loop is inserted into the central contact, and the shielding braid is tucked into the connector with a screwdriver blade. The main thing is to prevent the shielding wires from touching the central core cable.
If the braid is aluminum, then you can insert it into the television connector and in a free place fill thin copper wires taken from any stranded copper wire. To prevent the wire from falling out of the TV connector, you can fix it with a few toothpicks or matches. Such an impromptu connector will serve quite reliably.
How to connect an antenna cable to a crab without a plug
The preparation of the cable occurs in the same way as for putting on the F-plug, the central core is inserted into the F-connector of the crab, and the screen is put on the protruding part of the crab connector and fixed with any wire or clamp. In extreme cases, you can fix the cable by tightly wrapping several layers of electrical tape. It will work no worse than with the F-connection.
If you use a clamp with a screw crimping device, then the quality and reliability of the connection will be no worse than with the F-connector.
Which antenna plug is better
The answer is unequivocal: the best of the three considered plugs for a television coaxial cable is the F-plug. This is easy to notice in the photographs above, without even having special knowledge.
As you can see, the antenna plug of the old design and the Soviet antenna plug have a small section of the central core of the cable that is not covered by a shielding braid. This violates the uniformity of the wave resistance, which leads to insignificant losses of the television signal.
The F-plug does not have an open section of the central core of the antenna cable. Another advantage of the antenna F-plug is the ease of installation. Having a minimal set of standard tools, without skills, almost anyone can correctly attach the F-antenna plug to the cable.
How to connect multiple TVs
to cable network or antenna
Connecting several televisions to a cable network or antenna transmitting an analog or digital television signal is not more difficult than one, unless you have to put on the cable not one F-plug, but several. To do this, there are splitters of the television signal, popularly referred to as “crab”, they are also called “splitter”, “splitter” or “divider”.
The crab has one connector for connecting the signal from the antenna or splitter in the entrance, marked IN (input), and several connectors for connecting TVs, marked OUT (output). If there is no marking, then usually the entrance is at the crab on one side of the hull, and the exits are in a row on the opposite. All outputs for proper crab operation must be connected to televisions.
If there are two outputs, then to two televisions, if there are three outputs, then to three, and so on. There should not be any loose slots on the crab. If there is an unconnected output, then it must be loaded on a resistor with a resistance of 75 ohms. Or as they say, put a stub. But at the same time, part of the useful signal will be lost, it is better to use a crab, in which the number of taps is equal to the number of connected TVs.
The splitter design is a thin-walled case made of silumin or brass, in which at the same time connectors for connecting F-plugs are made. The divider circuit is usually transformer, one coil of enameled wire with a diameter of 0.2-0.4 mm, threaded through ferrite rings or tubes. Installation of transformers is carried out by a hinged method. The case is hermetically closed with a metal cover and sealed or fixed with glue.
For fixing the crab on the wall, eyelets are provided. In the case there is also a thread with a screw for grounding, although where to get the earth wire in the vast majority of apartments is not clear. Usually they do not ground, therefore, on some channels, pickups from wires of electrical wiring, the Internet, and a telephone passing near a television cable are possible. Whenever possible, this proximity should be avoided when laying the cable. For a more detailed acquaintance with the design and electrical diagram of the crab, you can visit the page “How to connect an antenna television amplifier to the power supply”.
If there is a desire, then a crab that is not inferior in technical parameters to expensive samples of well-known companies, you can do it yourself.
When you connect TVs through the crab, the level of the television signal reaching each TV connected to it, regardless of whether the TV is working or not, will decrease due to losses in the crab and the extra cable length. If you connect two TVs. by 30%, three. by 60%, four. by 90%, and if the analog or digital television signal coming to the crab is already weak, then the image quality on all connected TVs can significantly decrease. Typically, the signal in cable television is quite powerful, and its level is enough for the normal operation of all televisions connected to the crab.
How to connect an antenna cable
to the television signal line in the entrance of the house
Typically, a television cable is laid on the roof of the house and then, after amplification by a main amplifier, forks along the porches of the house. Since there are different packages of television programs, at the entrance to the entrance the cable is branched with the help of a filter crab, which is a crab with two outputs. From one output, the signal leaves unchanged, and from the second output it is cut off by a filter at a high frequency. Thus, the ability to watch all television channels for those who buy cheaper social packages is limited. Therefore, two cables pass down the porches.
If you look at the walls in your staircase, you will surely find on each floor a metal box from which television antenna cables go to the apartments. In modern houses, the boxes are no longer installed, but they are all placed in wall cabinets, in which case you will see a metal door with a lock. In these boxes subscriber taps of a television signal are placed. If you remove the lid from the box or open the cabinet door, you will see something like this. In the photo on the left, a coupler for subscribers of a full package of television programs, and on the right for subscribers of a social package.
According to the rules, the couplers must be fixed and grounded, but cable men do not do this to simplify the work. Perhaps this is better, since if the grounding is poor, then such a grounding can create interference.
The couplers installed in the junction boxes do not fundamentally differ from the crabs for connecting several TVs, but they work in a slightly different way. One F connector is used to connect the cable coming from the IN line (Input). The second OUT (Output) is designed to transmit a signal to the next coupler installed floor below. The remaining F TAP connectors (TAP), they can be from one to five, are designed to connect subscribers, that is, to connect television cables to the apartments.
Not connected subscriber connectors should not be. In case of disconnection of one subscriber, for example, for non-payment, it is allowed to install an F-connector with a load resistance of 75 Ohms instead of a cable. If you want to connect a new subscriber to a cable television network, the splitter for two subscribers, as in this example, is replaced by a three-port one.
Thus, to connect the TV to the cable network, a sufficient length of the television cable of the required length with the antenna F-connectors installed at the ends is enough. One F-connector of the antenna cable is connected to the subscriber coupler in the entrance, and the second to the TV.
What is the difference between a crab and a coupler
In a crab, the power of the incoming television signal is usually divided into equal parts between all connected TVs. Unlike a crab, only a small part of the signal power input to the input, about 6 dB, is allocated to subscribers.
To ensure a sufficient level of the television signal supplied to the subscribers, the signal to the input of the coupler is supplied from the main power amplifier, depending on the number of connected subscribers. In aggregate, all the taps installed in the same staircase are a crab with numerous branches.
TV amplifier
If after installing the crab the image became unsatisfactory, then you will have to put an additional television amplifier in front of it. The amplifier is arranged in the same way as the crab, but additional active elements (transistors or a microcircuit) that enhance the signal are additionally installed in its casing. For a television amplifier, an additional supply voltage is required, and this must be taken into account when choosing the installation location.
The television amplifier should be installed as close to the source of the television signal as the amplifier amplifies the noise along with the useful television signal. The photo shows the TERRA HA123 television amplifier, designed to work in a home television network with one output, with the ability to adjust the gain from 8 to 28 dB. If possible, then the ideal option is to place the amplifier directly in the box of the main signal splitter in apartments.
If the TVs are located not far from the television amplifier, then it is more expedient to install instead of the television amplifier and crab only one television signal amplifier with several outputs. For example, a television amplifier-splitter model Televes 5523 (Spain), which has a gain of 16 dB and five outputs, which makes it possible to connect up to 5 TVs to it.
If the signal is taken from an individual antenna, then there are amplifiers that are designed to be installed directly on the antenna instead of a matching loop. Antenna amplifiers provide high-quality reception at a distance from the transmitting antenna up to 100 km.
In the photo, the antenna amplifier of the television signal SWA-555 / LUX, which is available with different gain, from 10 to 15 dB in the meter range and from 34 to 43 dB in the decimeter range. You can find out how to connect the power supply unit to the television cable to supply voltage to the antenna television amplifier on the website page “How to connect the antenna television amplifier to the power supply”.
The antenna amplifier, depending on the signal level at the antenna installation point, needs to be selected according to the gain for each specific case. The supply voltage for such amplifiers is supplied through a coaxial cable.
Interference Control
installation of a ferrite ring on the antenna cable
Sometimes, after connecting several cable televisions to a cable television or antenna using a crab, interference may appear on some channels in the form of randomly appearing white or black dots, traveling waves or a grid across the screen. When receiving digital television, the image and sound may periodically disappear or be completely absent.
This may occur due to a high-frequency interference signal from the local oscillator, parallel-connected televisions, or other sources of interference entering the television’s antenna input. It is possible that interference from TVs connected in neighboring apartments is also possible.
The level of this kind of interference can be significantly reduced or even completely eliminated by installing a ferrite ring on the cable.
The effectiveness of noise suppression with a ferrite filter depends on the cross-sectional area of the ring: the larger its area, the greater the inductance of the inductor made. A ferrite ring worn on the antenna cable forms a choke and, together with the linear capacity of the antenna cable, forms a U-shaped high-pass filter. Maximum interference suppression will be achieved when two rings are installed on the antenna cable at its ends.
Surely you have a dusty old kinescope monitor or there are unnecessary interface cables. It is enough to cut the plastic with a knife, remove the ferrite ring and install it on the antenna cable. After installing the ferrite ring, interference on the TV screen will no longer interfere with viewing TV programs.
