Antenna socket
Antenna sockets , also known as junction boxes, provide the signal transmitted via a coaxial cable network for connecting the end devices, for example television sets. For cable television , they usually have a Belling Lee connection for television as a plug and a Belling Lee socket for connection to VHF radio . Newer versions also have one or more F sockets for connecting satellite television receivers or a cable modem .
For other antenna connector systems, e.g. BNC, F, FME, N, SMA, TNC, TS-9 connectors, see coaxial connectors .
connections
| Connection for | Socket on the antenna socket |
fits on it | Socket on the end device |
fits on it | Connector type |
|---|---|---|---|---|---|
| FM radio (R) | Female | Male connector | male | Connector female | Belling-Lee or IEC-60169-2 connector |
| Television (TV) | male | Connector female | Female | Male connector | Belling-Lee or IEC-60169-2 connector |
| Satellite television (SAT) or cable modem (DATA) | Female | Male connector | Female | Male connector | F connector |
Cable TV and VHF connection cables usually have a female plug on one end and a male plug on the other. This means that the same cables can be used for radio and television (they just have to be turned around). These cables can also be plugged together as an extension. However, this pinning can have a negative impact on signal strength. Connection cables with two F connectors are common for satellite reception.
Types of use of antenna sockets
The following types of antenna sockets are available in stores:
| Art | internal terminating resistor | Connection option for further socket or terminating resistor | comment |
|---|---|---|---|
| Single can | No | No | |
| Through socket | No | Yes | Can be used as an end socket by connecting a separate terminating resistor |
| End can | Yes | No |
Antenna sockets can
- as a junction or through socket with so-called tree cabling with optional terminating resistor or
- as a branch socket decoupled by a branch with a central star cabling or
- as a junction box with a junction box each with a terminating resistor, i.e. terminated
be executed and used accordingly.
With a through socket, a terminating resistor always belongs to the output of the last antenna socket. With the so-called branch or end sockets, the terminating resistor in the antenna socket is always available as standard.
The antenna signals can be decoupled during distribution using splitters, amplifiers with multiple outputs or multi-switches in satellite television .
Attenuation types for antenna sockets
- All antenna sockets have a frequency-specific connection attenuation or so-called subscriber attenuation. This connection attenuation of an antenna socket is used for the individual limiting compensation of the signal strength for the respective connection socket, which is required by different cable lengths or previous branch or through sockets after a central antenna or house connection amplifier in the cable network.
- The decoupling attenuation of an antenna socket is a measure of the suppression of interference signals from a device connected to the antenna socket into the cable network.
- Only the so-called junction or through sockets have an additional system-related attenuation to reduce the level after the antenna socket for the following subscriber through the built-in passive branch distributor.
In very rare cases, the attenuation for shielding against radiation from external sources of interference is also given in the case of expected EMC interference, for example from neighboring DAB or VHF transmission systems with high power.
Antenna sockets should conform to the class A standard against radiation ingress .
Additional functions in antenna sockets
In addition, attenuators and filters can be present in the antenna socket to separate the analog or digital television signal from the VHF radio .
In the case of antenna sockets for satellite reception, so-called DC blockers or 22 kHz filters can also be used for single - cable systems .
Plug-in adapter for Internet access with a cable modem
If a customer decides to use the Internet only after upgrading the cable network, some network operators do without replacing the antenna sockets and provide the customer with an attachable push-on adapter (POA) that generates the Internet signal for the cable modem from the existing frequency spectrum at an additional third connection. However, the POA is often only an emergency solution, as the correct shielding and signal level cannot always be guaranteed.
Aerial sockets for cable television
For cable television in Germany, the antenna connection socket is the end point of network level 4 of the customer's cable network. Because of the different design options, antenna sockets should always be replaced by a technician from the cable television provider.
The antenna sockets for the cable television network usually do not contain an additional capacitive sheath current filter for a network separation between the cable television network and your own devices. This filter can prevent the so-called network interference and a ground loop (" hum loop ").
In return channel-capable cable networks that offer Internet access via a cable modem, only the antenna sockets approved by the cable network provider, also known as multimedia connection sockets (MMD), are to be used when replacing the socket.
Typical features of antenna sockets
There are antenna sockets that are only suitable for cable or satellite television, as well as models that can separate both signal areas or have separate connections for the two signal areas.
| Data | Data | FM radio | Television digital radio ** |
Digital television digital radio |
satellite | DC pass | |
|---|---|---|---|---|---|---|---|
| Frequency range | 5-65 MHz and 118-862 * MHz |
5-1800 MHz | 87.5-108 MHz | 47-68 MHz and 111-862 MHz |
258-1800 MHz | 950-2400 MHz | 14-18 volts |
| Two-hole puncture or pass-through socket | ✗ | ✗ | |||||
| Data two-hole puncture or pass-through socket | ✗ | ✗ | |||||
| Sat three-hole junction or pass-through socket | ✗ | ✗ | ✗ | ✗ | |||
| Data three-hole puncture or pass-through socket | ✗ | ✗ | ✗ | ||||
| Data four-hole stub or pass-through socket | ✗✗ | ✗ | ✗ | ||||
| Sat four-hole junction box | ✗ | ✗ | ✗✗ | ✗✗ | |||
| Data-Sat four-hole tap socket | ✗ | ✗ | ✗ | ✗ | ✗ |
* Upper limit not specified by Euro- Docsis , but through the expansion of the cable network; the cans filter z. B. often up to 1000 MHz.
** Analogue television, digital radio (television / radio) in DVB-C standard, radio if necessary also DAB in VHF band III and DVB-T (rarely)
Some versions are only conditionally suitable for Internet using cable television, as they have a very strong decoupling attenuation for the return channel.
Screws to connect the cover to the antenna socket
Antenna sockets are often used that do not come from the manufacturer of the switch range otherwise used in the building . In order to attach the cover of the existing switch range to the third-party sockets, care must be taken to use the screw that matches the socket.
For example, for cans made by Wisi, screws with an M 4 thread and a total length of around 12.5 mm were used in the past .
In the meantime, screws with an M 3 thread are mainly used. For boxes from AEG-Telefunken , Astro, Bosch, Fuba, Hirschmann , Kathrein , Philips , Solitron and Stolle, screws with a length of 22 mm are usually required. Screws 17 to 20 mm long are used for boxes from Wisi and 12 mm long for boxes from Siemens.
Web links
- Notes on connection attenuation at conrad.de
Individual evidence
- ↑ Connection attenuation ( Memento from April 2, 2015 in the Internet Archive )