P4-A WB Transponder Bandplan and Operating Guidelines

P4-A WB Transponder Bandplan and Operating Guidelines

September 17, 2018 Off By Peter Gülzow

The following operating guidelines and bandplan are designed to enable the most efficient use of the 8MHz wide transponder for all users.


Due to the very large number of variations of transmission parameters, it is essential that all users notify their transmission parameters on the co-ordination chat room page that has been established by AMSAT-DL and BATC  at the Qatar-OSCAR 100 Wideband Spectrum Monitor which is hosted at the Goonhilly Earth Station in Corwall, UK.

Transponder Usage

As a general principle, the transponder should be only be used for short-duration tests and contacts.

The only long duration (more than 10 minute) transmissions should be:

  • The TV beacon channel uplinked from Qatar (A71A) or Bochum (DK0SB).
  •  Video of the live proceedings of AMSAT and Amateur TV Lectures and Conferences of wide interest. Examples might include:
    • National AMSAT Conferences
    • National Amateur TV Conventions

The following content is unacceptable:

  •  Recordings of events, or broadcast of events not explicitly concerned with Amateur Satellites or Amateur TV
  • Transmission of any copyright material (such as movies or TV channels)
  • Repeated transmission of test videos unless essential for equipment alignment
  • The relaying of terrestrial Amateur TV Repeaters is discouraged unless the content is of exceptional amateur radio interest.

Transmission Power

All uplink transmissions should use the minimum power possible. QPSK transmissions should have a downlink signal with at least 1 dB lower power density than the Beacon – the web-based spectrum monitor enables users to set their uplink power to achieve this.  Transmissions with symbol rates of less than 333 kS using 8PSK, 16 APSK or 32 APSK should use the minimum power density required to achieve successful reception.

Transmission Modes

Transmissions should use DVB-S2 where possible.  For normal standard definition transmissions, 2 MS is the maximum symbol rate that should routinely be used.

To enable easy decoding the following DVB PIDs are recommended: Video 256, Audio, 257, PMT 32 or 4095, PCR 256 or 258.  Service Name should be set to CallSign.  PMT PIDs 4000 – 4010 should not be used.

On Wednesdays (UTC time), experimenters are encouraged to try other modes – perhaps 6 MS using the whole transponder for brief (less than 10 minute) periods. It is essential that users announce their plans on the chat room page, and always monitor it.

Experiments using unusual modes (for example ranging) should use the lower 1.5 MHz of the “Wide and Narrow DATV” Segment.


Beacon Settings

The beacon transmits continuously (24/7) to provide a test signal and to allow new users to precisely align their antennas.

DATV Beacon DVB-S2 parameters:

  • Center Frequency: 10.4915 MHz
  • DVB-S2
  • QPSK 4/5 FEC
  • 1500 kSymbols
  • RollOff = 0,25
  • Pilots = off
  • min. C/N = 4.6dB
  • Datarate 2.383 MBit

Bandplan  (V2.0 2020)

  1. Narrow DATV transmissions should be confined to the “Narrow DATV” section, but may use the “Wide and Narrow DATV” section if the Narrow DATV section is fully occupied.
  2. A maintenance uplink occupying 10494.0 MHz – 10497.0 MHz will be used very occasionally; users are requested to give it absolute priority when notified.
  3. Recommended spot frequencies for various usages and symbol rates are listed below.
  4. Uplink 2401.0 – 2410.0 MHz RHCP, Downlink 10490.5 – 10499.5 MHz Horizontal.


Mode Symbol Rate Uplink Freq MHz Downlink Freq


Beacon 1500 kS 2402.0 10491.5 Beacon DVB-S2 FEC 4/5
Wide 1 MS 2403.75 10493.25 1.5 MS and 2 MS transmission should use this part of the band
Wide 1 MS 2405.25 10494.75
Wide 1 MS 2406.75 10496.25
Narrow 333 kS 2403.25 10492.75 Use these 14 frequencies for

500 kS, 333 kS and 250 kS


Use frequencies above 10497.0 first

                     Then every 500 kHz until
Narrow 333 kS 2409.75 10499.25
Very Narrow 125 kS 2403.25 10492.75 Use these 27 frequencies for

125 kS, 66 kS and 33 kS


Use frequencies above 10497.0 first

                     Then every 250 kHz until
Very Narrow 125 kS 2409.75 10499.25


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