FAQ

The three product series differ primarily in terms of their output signals and features.

• QAM Series: Converts satellite signals to DVB-C.
• PCU Series: Output available as either DVB-C or DVB-T.
• PXU Series: Same as the PCU Series, but with an additional integrated input multiplexer.

Both devices offer eight output channels and an output level of up to 90 dBµV. The main difference lies in the satellite feed: While the PCU 8510 requires eight individual satellite feed lines, the PCU 8610 features a built-in 4×8 multiswitch. As a result, only four SAT feed lines are needed, which significantly reduces the installation effort.

The following devices have triple tuners for mixed operation:

• 4 tuners: PCU 4111, 4121, 4131, 4141
• 8 tuners: PCU 8112, 8122, 8130, PXU 848 C/T/IP

The triple tuners allow you to choose between receiving DVB-S/S2, DVB-T/T2, or DVB-C signals.

Yes. Multiple POLYTRON compact headends can be cascaded to form a single system. Thanks to adjacent-channel operation and a shared NIT, the entire range of channels appears as a single, coherent network during a channel scan. This makes it possible to implement even large-scale systems with more than 100 TV channels.

POLYTRON recommends switching to DVB-C. Significantly more channels can be transmitted per output channel. Switching to DVB-T only makes sense if the end devices do not have a DVB-C tuner.

Yes. Depending on the application, Sky programs can be fed into the network either decrypted centrally or in encrypted form.

• Central decryption: With a CI module and a compatible Sky Hospitality subscription.
• Encrypted transmission: The channels are transmitted unchanged to TVs or receivers, where they are decrypted.
• The following compact headends are each equipped with 4 CI slots: PCU 4111/4121/4131/4141; PCU 8112/8122; PXU 848 C/T/IP

The most appropriate distribution method depends primarily on the existing infrastructure and whether the building is an existing structure or a new construction.

Coax (DVB-C) is usually the best solution for existing antenna distribution systems. Televisions can be used without an additional set-top box, and a high channel capacity is available.

IPTV is particularly well-suited for new construction or fully IP-based networks. Here, TV services can be flexibly integrated into existing network infrastructures.

Yes. The devices are shipped with a preconfigured transponder list for Astra 19.2° East and are therefore ready for use right away.
If a different channel configuration is needed, it can be adjusted at any time via the web interface or the free SATC12 software.

POLYTRON compact headends are operated worldwide under a wide variety of climatic conditions. They are designed and manufactured to function reliably even in extreme situations.

POLYTRON compact headends can be operated at ambient temperatures between 0 and 50 °C. POLYTRON sets extremely high standards for the quality of all components used.

The ISO 9001-certified manufacturing process at the production facility in Bad Wildbad helps ensure that POLYTRON compact headends “Made in Germany” demonstrate an exceptionally long service life.

Configuration varies depending on the product series.

• IPTV streamers: Setup via the built-in web interface in a browser.
• DVB-C/DVB-T compact headends: Configuration via the free Windows software SATC12.

To set it up, connect the compact headend directly to the laptop or via the network.

• IPTV streamer: Connect via LAN (RJ45) and a compatible web browser.
• DVB-C/DVB-T headends: Via USB by default; newer models also support connection via LAN.

Configuration is performed using a standard web browser. For optimal display, we recommend using the latest browser version.

Yes, as long as the device is connected to a network and remote access to that network is available. The specific procedure depends on the existing network infrastructure. Please contact your local IT administrator for more information.

An active signal input is not required for device settings alone. To analyze and program reception parameters, the appropriate signal source must be connected.

Yes. Saved configurations allow you to quickly transfer proven settings to other devices or use them in future projects.

To back up and restore settings, go to:
Settings → Save Settings / Load Settings

You can find the latest software versions and version information in the POLYTRON download section at https://www.polytron.de/de/service/download.

• IPTV streamers: The latest software package is available for direct download.
• DVB-C/DVB-T headends: The software versions are included in the SATC12 programming software installation package.

First, check the USB connection and make sure the device is receiving power properly. If necessary, reinstall the latest version of the SATC12 software and the USB driver.

First, check whether your laptop and the compact headend are on the same network.

• Make sure your laptop has an IP address on the same subnet as the headend.
• The factory default network is always 192.168.1.xxx / 255.255.255.0.
• You can find the default IP address for each device in its respective user manual.
• If the compact headend is connected to a local network, please contact the responsible IT administrator.

These messages indicate that the input tuner is not receiving a usable input signal or cannot lock onto the desired transponder. The cause is usually related to the signal feed, the reception settings, or the power supply to the signal source.

For “Tuner unlocked,” check the following:

• Is the correct reception frequency or transponder selected?
• Do the symbol rate and modulation parameters match those of the input signal?
• Is the connected satellite or signal source selected correctly?
• Is the signal level and signal quality at the input sufficient?

If you see “No Signal,” also check the following:

• Is the signal input connected correctly?
• Is there actually an RF signal at the tuner input?
• For satellite reception: Are the LNB power supply and DiSEqC settings correct?
• For multiswitch systems: Are the correct satellite levels connected?
• For DVB-T/T2: Is the antenna power supply or 5-V power supply configured correctly?

Technical Background:

• “Tuner unlocked” means: The tuner detects a signal but cannot establish a stable synchronization with the transport stream.
• “No Signal” means: No usable signal is detected at the input.

A “Tuner locked” message indicates that the input transponder has been successfully received and synchronized. You can then use the Service List context menu to check the received channels.

The Input Service List contains all services received by the tuner. The Output Service List shows the channels that are being processed for output.

If the Output Service List is empty, check the following:

• Are there any channels listed in the Input Service List?
• Have the desired services been selected or applied for output?
• Is the selected output type (DVB-C/DVB-T/IP) sufficiently sized for the desired number of channels?
• For DVB-T output: Is the available output bandwidth sufficient for the selected services?

Note:
For DVB-C output, the Output Service List is typically populated automatically with the available services, since the available bandwidth allows for a wide range of programming. When output capacity is limited—for example, in DVB-T implementations—it may be necessary to select or reduce the number of services.

Simply inserting a CI module is not enough to decrypt programs. First, check the status of the CAM in the diagnostics menu, and then verify the assignment of the services to be decrypted.

In the CAM diagnostics menu, the individual steps are indicated by a green check mark or a red X:

• CAM plugged: The CI module has been detected and is physically plugged in.
• CAM initialized: The CI module has been successfully initialized and is ready for use.
• Descrambling: The program is currently being descrambled by the CAM.

If one of these items is marked with a red X, the cause lies in the corresponding step. In addition, the decryption program must be selected in the Output Service List:

• Check the boxes next to the channels you want to decrypt using the CI module.
• Then check the “Descrambling” status in the diagnostics.

Note:
A CAM that has been detected and initialized does not automatically decrypt all available channels. The desired services must be selected for decryption and assigned to CI processing.

Pixelation in the output signal usually indicates an interruption in the transmitted data stream. With POLYTRON compact headends, there are primarily two causes for this:

1. The available usable bandwidth is fully utilized (overflow)

If the total data rate of the selected services exceeds the available output bandwidth, an overflow may occur. This can result in picture distortion, blockiness, or dropouts in individual programs.

Please check:

• Is the available output bandwidth sufficient for the selected TV channels?
• Have additional HD channels or data-intensive services been added?
• Are too many or too many data-intensive services being assigned to a single channel in the DVB-T output?
• Have unnecessary services been disabled in the output configuration?

2. Interference or frequency conflicts in the distribution network

Incorrect output assignments or interference in the coaxial network can also cause pixelation.

Please check:

• Are there any interfering carriers in the frequency range being used?
• Are the output frequencies of multiple headends or components being reused?
• Are the output channels properly configured and sufficiently separated from one another?
• Are the output levels of the headend and the downstream network components set correctly?

Note:
With digital TV signals, quality issues often manifest as pixelation or brief dropouts. Increasing the output level does not resolve the problem if it is caused by a bandwidth overflow or an interference in the distribution network.

With IPTV programs, pixelation and brief dropouts are often caused by faulty transmission of multicast data streams over the network. In addition to network load, the IGMP configuration plays a particularly important role in this regard.

Please check the following points:

1. IGMP snooping is not enabled correctly on the network

IPTV streams are typically transmitted as multicasts. Without properly configured IGMP snooping, switches cannot forward the data streams to the intended recipients.

Possible consequences:

• Unnecessary strain on the network caused by unnecessary multicast streams
• Packet loss
• Image distortion or dropouts

Please check:

• IGMP Snooping Status: Is this feature enabled globally and for the specific IPTV VLAN on all switches involved in the data path?
• IGMP Querier Configuration: Is at least one switch (or router) in the network configured as an active querier to periodically update the multicast tables?
• Switch Utilization (CPU/RAM): Are the network components showing increased load due to processing uncontrolled data streams?
• Port Statistics: Are packet losses (drops/discards) or CRC errors occurring at the end-user interfaces?
• Multicast Distribution: Are the IPTV streams being incorrectly forwarded to ports where no IPTV receiver (set-top box) is active at all?
• VLAN Configuration: Are the IPTV multicast streams properly separated from the rest of the traffic in their own VLAN?

2. Network components do not support or process multicast correctly

Please check:

• Do the switches in use support IGMP snooping?
• Is IGMP snooping enabled on the relevant ports?
• Is there an IGMP querier on the network, if applicable?
• Are VLANs and network settings being used correctly?

3. Network bandwidth or data rate is insufficient

High network traffic can also cause disruptions.

Please check:

• Is there sufficient bandwidth between the IPTV streamer and the end devices?
• Is there packet loss or high network load?
• Are unnecessary multicast streams being distributed on the network?

Note:
With IPTV, faulty multicast distribution often does not result in a complete outage, but initially leads to pixelation, brief image dropouts, or frozen images.