DVB-S/S2 Reception

The Portsdown will work with the BATC Version 2 MiniTiouner (using the Serit FTS-4334 and FTS-4335 tuners only) to receive DVB-S and DVB-S2 signals over the frequency range 144 MHz to 2450 MHz. The receive symbol rate is limited to the range 66 kS to about 5 MS; reception at below 66 kS is not currently possible.

The receive functionality was recently enhanced in the Portsdown 4. The new capability is described here.

QO-100 or Terrestrial?

The receiver has 2 sets of presets; one for QO-100 and another for terrestrial. Most receiver parameters are also stored separately for each of these bands. You can switch between bands using the top left button on the receiver screen. The Configuration Menu title also shows which band you are setting the parameters for.

Receive Modes

There are now 4 receive modes. Each uses a different Play to UDP Stream or video player.

RECEIVE

The button labelled "RECEIVE" starts the receiver scanning in Cold Start (Zero Offset) mode with a known SR, but an unknown frequency. The receiver will scan for DVB-S and DVB-S2 signals around the set frequency, with the scan limited by a percentage of the set SR. This percentage can be set using the "Tuner Scan Width" button on the Configuration Menu.

For example, if the receiver is set to 437 MHz and SR 250 with the default Scan Width of 50%, it will search from 436.875 MHz to 437.125 MHz.

If a valid DATV signal is found, it will be played on the Portsdown screen using VLC with the ffmpeg option enabled.

RX with OMX Player

The button labelled "RX with OMX Player" uses exactly the same receiver search parameters as "RECEIVE", but uses the OMX Player video player.

OMX Player cannot display H265 signals (or some H264 signals, such as the QO-100 beacon), and has no parameter overlay available. This option is soon to be discontinued as the author of OMX Player is ceasing support for it in favour of VLC.

RX DVB-S2 No Scan

The button labelled "RX DVB-S2 No Scan" starts the receiver scanning in Warm Start (Zero Offset) mode for a DVB-S2 signal with known SR and frequency. In practice, the frequency scan is about 10% of the SR, and the "Tuner Scan Width" setting has no effect. This setting is ideal for the reception of weak DATV signals, especially in the presence of adjacent channel interference.

If a valid DVB-S2 (only) DATV signal is found, it will be played on the Portsdown screen using VLC with the ffmpeg option enabled.

Play to UDP Stream

The button labelled "Play to UDP Stream" uses exactly the same receiver search parameters as "RECEIVE", but sends the received transport stream to the UDP address and port set in the Configuration Menu.

The Portsdown screen displays the received MER in large numbers when this mode is selected.

SCAN TIMEOUT TIME

The length of time that the tuner scans without resetting itself (if no signal is found) can be set using the "Tuner Timeout" button on the Configuration Menu. The default for QO-100 is 5000 mS (5 seconds), but this is doubled at 250 kS and quadrupled at 125 kS to allow for longer lock times.

The default for terrestrial reception is -1, which disables the tuner timeout.