C-band Sats – Part 3: 100.5E AsiaSat 5, 105.5E AsiaSat 7, 113E Palapa D

Continuing on my quest to hunt all the C-band satellites in sight, this post continues the series up from the western horizon to visit AsiaSat 5, AsiaSat 7 and Palapa D.

100.5°E AsiaSat 5

AsiaSat 5 serves direct to home customers and is a fairly well known satellite.

A scan of the whole band shows it uses the standard C-band layout with fairly well-defined transponders. The radar interference is visible especially on the vertical polarity. The BLscan report shows a decent number of lockable active DVB-S/S2 transponders:

TP N: 1
Frequency: 3660.871 Mhz
Symbol rate: 27499 KS
Polarization: Vertical
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -42 dBm
Signal/Noise: 10.4 dB
Carrier width: 37.124 Mhz
BitRate: 38.014 Mbit/s
----------------------------------------
TP N: 2
Frequency: 3679.185 Mhz
Symbol rate: 3599 KS
Polarization: Horizontal
Spectrum: Inverted
Standard/Modulation: DVB-S2/QPSK
FEC: 2/3
RollOff: 0.25
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -46 dBm
Signal/Noise: 10.2 dB
Carrier width: 4.499 Mhz
BitRate: 4.761 Mbit/s
----------------------------------------
TP N: 3
Frequency: 3700.827 Mhz
Symbol rate: 29999 KS
Polarization: Vertical
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 3/4
RollOff: 0.35
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -40 dBm
Signal/Noise: 8.4 dB
Carrier width: 40.499 Mhz
BitRate: 66.868 Mbit/s
----------------------------------------
TP N: 4
Frequency: 3726.920 Mhz
Symbol rate: 6666 KS
Polarization: Vertical
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 3/4
RollOff: 0.20
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -44 dBm
Signal/Noise: 8.2 dB
Carrier width: 7.999 Mhz
BitRate: 14.859 Mbit/s
----------------------------------------
TP N: 5
Frequency: 3760.908 Mhz
Symbol rate: 27499 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -41 dBm
Signal/Noise: 9.1 dB
Carrier width: 37.124 Mhz
BitRate: 38.014 Mbit/s
----------------------------------------
TP N: 6
Frequency: 3785.169 Mhz
Symbol rate: 3254 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -45 dBm
Signal/Noise: 6.3 dB
Carrier width: 4.394 Mhz
BitRate: 4.500 Mbit/s
----------------------------------------
TP N: 7
Frequency: 3820.806 Mhz
Symbol rate: 27497 KS
Polarization: Vertical
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -40 dBm
Signal/Noise: 8.7 dB
Carrier width: 37.121 Mhz
BitRate: 38.011 Mbit/s
----------------------------------------
TP N: 8
Frequency: 3840.906 Mhz
Symbol rate: 29719 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 5/6
RollOff: 0.20
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -40 dBm
Signal/Noise: 9.2 dB
Carrier width: 35.663 Mhz
BitRate: 73.673 Mbit/s
----------------------------------------
TP N: 9
Frequency: 4000.930 Mhz
Symbol rate: 28125 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -30 dBm
Signal/Noise: 8.1 dB
Carrier width: 37.968 Mhz
BitRate: 38.879 Mbit/s
----------------------------------------
TP N: 10
Frequency: 4020.914 Mhz
Symbol rate: 28095 KS
Polarization: Vertical
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 3/4
RollOff: 0.35
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -31 dBm
Signal/Noise: 7.6 dB
Carrier width: 37.929 Mhz
BitRate: 62.624 Mbit/s
----------------------------------------
TP N: 11
Frequency: 4040.865 Mhz
Symbol rate: 29719 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 5/6
RollOff: 0.35
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -31 dBm
Signal/Noise: 9.0 dB
Carrier width: 40.121 Mhz
BitRate: 73.673 Mbit/s
----------------------------------------
TP N: 12
Frequency: 4114.449 Mhz
Symbol rate: 18399 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 2/3
RollOff: 0.25
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -40 dBm
Signal/Noise: 8.3 dB
Carrier width: 22.999 Mhz
BitRate: 36.448 Mbit/s
----------------------------------------
TP N: 13
Frequency: 4132.493 Mhz
Symbol rate: 10587 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/QPSK
FEC: 2/3
RollOff: 0.20
Pilot: off
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -41 dBm
Signal/Noise: 9.2 dB
Carrier width: 12.705 Mhz
BitRate: 14.007 Mbit/s
----------------------------------------
Total Scan Time = 1707.445s

As usual, I try to tune into each of them and all the other known frequencies from the online listings. Because I got a bit lazy, for whole families of encrypted services, I started using * to denote “and others with the same prefix”.

Of the FTA services available, there’s not that many interesting ones, but at least there’s BBC World. Despite being within the coverage area, some of the transponders were visible but unlockable. This is probably due to the uplink itself, as where a transponder (e.g. commonly of 27Mhz, 36Mhz, 54Mhz, 72Mhz width) is shared with a number of carriers, the powers allowed from each of the carriers are controlled carefully to avoid the transponder from saturating, intermodulating or potentially getting damaged. Some uplink stations don’t have enough power or gain to fully saturate even a transponder that’s not fully used (e.g. satellite feed uplink trucks, VSAT terminals) which results in a reduced SNR. So while other carriers on the satellite may lock fine, that is no guarantee that the carrier you are interested in will lock fine as well.

Interesting Signals

A full swept spectrum of horizontal (top) and vertical (bottom) polarities. Nothing particularly special in terms of signals was identified, although some of the services seem to have taken transponder bandwidth use quite to the limit.

Beacons

At the high end of the C-band spectrum, three beacons were identified that were of horizontal polarity (upper), mostly disappearing in the vertical (lower). Frequencies are approximately:

  • 4197.451913Mhz (H, modulated, single subcarrier)
  • 4198.951163Mhz (H, modulated, dual subcarrier)
  • 4199.950913Mhz (H, modulated, dual subcarrier)

The spacing of the first two is about 1.5Mhz, and the last two is about 1Mhz, which seems quite deliberate.

The beacon at 4197.45Mhz seems to have a single narrow subcarrier at 48khz (PSK? narrow FSK?).

The beacon at 4198.95Mhz seems to have two wide PSK/FSK subcarriers, one at about 48khz, and the other at around 72khz.

The beacon at 4199.95Mhz has two subcarriers as well, it seems. The inner one is a narrow one at 16khz, with the outer being a wider FSK/PSK at 48khz. I wonder if the inner one is actually intended, or a byproduct of the LNB/analyzer/receiver/transmitter in use.

A few more beacons were found towards the lower end of the band, but their nature is so different that I’m not sure that they are beacons. I’ve tried to receive them as best as I can, but some of them are so weak that they could be products of mixing or neighboring satellites (possibly).

This was received at 3635.930376Mhz on the vertical polarity. The carrier seems to be phase modulated in some way, as are the subcarriers at around 28khz and 48khz. The subcarriers appear narrow, could be PSK or even FM of sorts. But there is a decent amount of intermodulation (it seems).

This one is another mystery. The carrier frequency is a bit weak in amplitude, at a frequency of 3747.452544Mhz on the vertical polarity. The subcarrier is at 48khz, but it’s extremely narrow – maybe it’s not even modulated.

This one was at 3754.921913Mhz on the vertical polarity. The subcarriers are very narrow at 32khz and 64khz, which implies the upper one may be a harmonic product.

This was received at 3755.91886Mhz in the vertical polarity, and seems to be a CW tone at first, but there are noise sidebands on both sides which suggest maybe the uplinking device has some residual noise that’s been repeated through, or maybe it’s actually modulated as some crazy modes designed to evade bandwidth limitations in the past have relied on hiding data in weaker sidebands.

This is pretty weak too, but it seems there’s at least one modulated beacon to the right. The one in the middle could be an unmodulated CW beacon … but it’s a bit hard to tell since the noise is pretty high compared to the signal.

Zooming up in detail, it’s at 3754.957189Mhz in the Horizontal, appears to have a narrow subcarrier at 32khz.

105.5°E AsiaSat 7

AsiaSat 7 is also another very well-known satellite that provides direct-to-home broadcasting and is the next one up the belt that serves Sydney, Australia.

According to the CrazyScan output, the radar interference has reduced as the elevation angle increases, further confirming the terrestrial nature of the interference. Some new interference at the high end has been spotted, but otherwise the result is a clean spectrum with many wide carriers. BLScan produced a very meaty report as a result.

TP N: 1
Frequency: 3645.463 Mhz
Symbol rate: 7119 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 3/4
RollOff: 0.20
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -45 dBm
Signal/Noise: 7.2 dB
Carrier width: 8.543 Mhz
BitRate: 15.868 Mbit/s
----------------------------------------
TP N: 2
Frequency: 3652.981 Mhz
Symbol rate: 14099 KS
Polarization: Vertical
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -45 dBm
Signal/Noise: 9.9 dB
Carrier width: 19.034 Mhz
BitRate: 19.491 Mbit/s
----------------------------------------
TP N: 3
Frequency: 3664.955 Mhz
Symbol rate: 2814 KS
Polarization: Vertical
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -46 dBm
Signal/Noise: 7.7 dB
Carrier width: 3.800 Mhz
BitRate: 3.891 Mbit/s
----------------------------------------
TP N: 4
Frequency: 3689.910 Mhz
Symbol rate: 14999 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 5/6
RollOff: 0.20
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -42 dBm
Signal/Noise: 11.4 dB
Carrier width: 17.999 Mhz
BitRate: 37.183 Mbit/s
----------------------------------------
TP N: 5
Frequency: 3690.364 Mhz
Symbol rate: 11393 KS
Polarization: Vertical
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -46 dBm
Signal/Noise: 6.7 dB
Carrier width: 15.381 Mhz
BitRate: 15.750 Mbit/s
----------------------------------------
TP N: 6
Frequency: 3706.579 Mhz
Symbol rate: 5999 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -44 dBm
Signal/Noise: 10.1 dB
Carrier width: 8.099 Mhz
BitRate: 8.294 Mbit/s
----------------------------------------
TP N: 7
Frequency: 3715.817 Mhz
Symbol rate: 8166 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -43 dBm
Signal/Noise: 8.3 dB
Carrier width: 11.025 Mhz
BitRate: 11.290 Mbit/s
----------------------------------------
TP N: 8
Frequency: 3725.909 Mhz
Symbol rate: 8165 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 2/3
RollOff: 0.20
Pilot: off
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -43 dBm
Signal/Noise: 10.2 dB
Carrier width: 9.799 Mhz
BitRate: 16.175 Mbit/s
----------------------------------------
TP N: 9
Frequency: 3734.871 Mhz
Symbol rate: 6499 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/QPSK
FEC: 2/3
RollOff: 0.20
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -43 dBm
Signal/Noise: 9.2 dB
Carrier width: 7.799 Mhz
BitRate: 8.598 Mbit/s
----------------------------------------
TP N: 10
Frequency: 3760.966 Mhz
Symbol rate: 25999 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 7/8
RollOff: 0.35
RF-Level: -39 dBm
Signal/Noise: 12.0 dB
Carrier width: 35.099 Mhz
BitRate: 41.931 Mbit/s
----------------------------------------
TP N: 11
Frequency: 3800.909 Mhz
Symbol rate: 28095 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 3/4
RollOff: 0.20
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -38 dBm
Signal/Noise: 11.9 dB
Carrier width: 33.714 Mhz
BitRate: 62.624 Mbit/s
----------------------------------------
TP N: 12
Frequency: 3820.892 Mhz
Symbol rate: 27499 KS
Polarization: Vertical
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 3/4
RollOff: 0.20
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -41 dBm
Signal/Noise: 8.7 dB
Carrier width: 32.999 Mhz
BitRate: 61.295 Mbit/s
----------------------------------------
TP N: 13
Frequency: 3840.973 Mhz
Symbol rate: 29719 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 5/6
RollOff: 0.20
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -37 dBm
Signal/Noise: 11.2 dB
Carrier width: 35.663 Mhz
BitRate: 73.673 Mbit/s
----------------------------------------
TP N: 14
Frequency: 3860.899 Mhz
Symbol rate: 28099 KS
Polarization: Vertical
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 3/4
RollOff: 0.25
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -39 dBm
Signal/Noise: 9.2 dB
Carrier width: 35.124 Mhz
BitRate: 62.633 Mbit/s
----------------------------------------
TP N: 15
Frequency: 3880.878 Mhz
Symbol rate: 27499 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -37 dBm
Signal/Noise: 11.9 dB
Carrier width: 37.124 Mhz
BitRate: 38.014 Mbit/s
----------------------------------------
TP N: 16
Frequency: 3890.476 Mhz
Symbol rate: 11839 KS
Polarization: Vertical
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 3/4
RollOff: 0.25
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -42 dBm
Signal/Noise: 8.1 dB
Carrier width: 14.799 Mhz
BitRate: 26.389 Mbit/s
----------------------------------------
TP N: 17
Frequency: 3899.460 Mhz
Symbol rate: 2240 KS
Polarization: Vertical
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 3/5
RollOff: 0.25
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -43 dBm
Signal/Noise: 7.5 dB
Carrier width: 2.800 Mhz
BitRate: 3.987 Mbit/s
----------------------------------------
TP N: 18
Frequency: 3906.967 Mhz
Symbol rate: 2814 KS
Polarization: Vertical
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -42 dBm
Signal/Noise: 10.9 dB
Carrier width: 3.800 Mhz
BitRate: 3.891 Mbit/s
----------------------------------------
TP N: 19
Frequency: 3914.051 Mhz
Symbol rate: 7258 KS
Polarization: Vertical
Spectrum: Inverted
Standard/Modulation: DVB-S/QPSK
FEC: 5/6
RollOff: 0.35
RF-Level: -41 dBm
Signal/Noise: 7.8 dB
Carrier width: 9.799 Mhz
BitRate: 11.149 Mbit/s
----------------------------------------
TP N: 20
Frequency: 3920.948 Mhz
Symbol rate: 29719 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 5/6
RollOff: 0.20
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -35 dBm
Signal/Noise: 11.6 dB
Carrier width: 35.663 Mhz
BitRate: 73.673 Mbit/s
----------------------------------------
TP N: 21
Frequency: 3940.945 Mhz
Symbol rate: 28099 KS
Polarization: Vertical
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 3/4
RollOff: 0.25
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -36 dBm
Signal/Noise: 6.4 dB
Carrier width: 35.124 Mhz
BitRate: 62.633 Mbit/s
----------------------------------------
TP N: 22
Frequency: 3960.920 Mhz
Symbol rate: 27499 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -32 dBm
Signal/Noise: 12.1 dB
Carrier width: 37.124 Mhz
BitRate: 38.014 Mbit/s
----------------------------------------
TP N: 23
Frequency: 3980.971 Mhz
Symbol rate: 28099 KS
Polarization: Vertical
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -33 dBm
Signal/Noise: 10.3 dB
Carrier width: 37.934 Mhz
BitRate: 38.844 Mbit/s
----------------------------------------
TP N: 24
Frequency: 4000.911 Mhz
Symbol rate: 29719 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 5/6
RollOff: 0.20
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -29 dBm
Signal/Noise: 11.3 dB
Carrier width: 35.663 Mhz
BitRate: 73.673 Mbit/s
----------------------------------------
TP N: 25
Frequency: 4020.947 Mhz
Symbol rate: 28095 KS
Polarization: Vertical
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 3/4
RollOff: 0.25
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -35 dBm
Signal/Noise: 8.5 dB
Carrier width: 35.119 Mhz
BitRate: 62.624 Mbit/s
----------------------------------------
TP N: 26
Frequency: 4040.966 Mhz
Symbol rate: 26499 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 1/2
RollOff: 0.35
RF-Level: -29 dBm
Signal/Noise: 10.5 dB
Carrier width: 35.774 Mhz
BitRate: 24.421 Mbit/s
----------------------------------------
TP N: 27
Frequency: 4060.951 Mhz
Symbol rate: 26666 KS
Polarization: Vertical
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -38 dBm
Signal/Noise: 6.7 dB
Carrier width: 36.000 Mhz
BitRate: 36.863 Mbit/s
----------------------------------------
TP N: 28
Frequency: 4065.930 Mhz
Symbol rate: 4295 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 3/5
RollOff: 0.20
Pilot: off
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -38 dBm
Signal/Noise: 10.2 dB
Carrier width: 5.155 Mhz
BitRate: 7.645 Mbit/s
----------------------------------------
TP N: 29
Frequency: 4070.957 Mhz
Symbol rate: 2962 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/QPSK
FEC: 5/6
RollOff: 0.35
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -36 dBm
Signal/Noise: 10.8 dB
Carrier width: 4.000 Mhz
BitRate: 4.902 Mbit/s
----------------------------------------
TP N: 30
Frequency: 4076.855 Mhz
Symbol rate: 6499 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 2/3
RollOff: 0.20
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -36 dBm
Signal/Noise: 9.9 dB
Carrier width: 7.799 Mhz
BitRate: 12.875 Mbit/s
----------------------------------------
TP N: 31
Frequency: 4083.117 Mhz
Symbol rate: 3184 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 5/6
RollOff: 0.35
RF-Level: -38 dBm
Signal/Noise: 9.1 dB
Carrier width: 4.299 Mhz
BitRate: 4.892 Mbit/s
----------------------------------------
TP N: 32
Frequency: 4087.700 Mhz
Symbol rate: 3180 KS
Polarization: Horizontal
Spectrum: Inverted
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -40 dBm
Signal/Noise: 8.8 dB
Carrier width: 4.293 Mhz
BitRate: 4.396 Mbit/s
----------------------------------------
TP N: 33
Frequency: 4100.945 Mhz
Symbol rate: 29719 KS
Polarization: Vertical
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 5/6
RollOff: 0.35
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -41 dBm
Signal/Noise: 8.6 dB
Carrier width: 40.121 Mhz
BitRate: 73.673 Mbit/s
----------------------------------------
TP N: 34
Frequency: 4120.877 Mhz
Symbol rate: 27499 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 7/8
RollOff: 0.35
RF-Level: -37 dBm
Signal/Noise: 11.2 dB
Carrier width: 37.124 Mhz
BitRate: 44.350 Mbit/s
----------------------------------------
TP N: 35
Frequency: 4140.921 Mhz
Symbol rate: 27499 KS
Polarization: Vertical
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -41 dBm
Signal/Noise: 8.1 dB
Carrier width: 37.124 Mhz
BitRate: 38.014 Mbit/s
----------------------------------------
TP N: 36
Frequency: 4146.553 Mhz
Symbol rate: 5316 KS
Polarization: Horizontal
Spectrum: Inverted
Standard/Modulation: DVB-S/QPSK
FEC: 5/6
RollOff: 0.35
RF-Level: -43 dBm
Signal/Noise: 9.5 dB
Carrier width: 7.177 Mhz
BitRate: 8.166 Mbit/s
----------------------------------------
TP N: 37
Frequency: 4165.929 Mhz
Symbol rate: 5039 KS
Polarization: Horizontal
Spectrum: Inverted
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -44 dBm
Signal/Noise: 10.7 dB
Carrier width: 6.803 Mhz
BitRate: 6.967 Mbit/s
----------------------------------------
TP N: 38
Frequency: 4173.003 Mhz
Symbol rate: 2481 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -44 dBm
Signal/Noise: 9.6 dB
Carrier width: 3.349 Mhz
BitRate: 3.430 Mbit/s
----------------------------------------
TP N: 39
Frequency: 4176.887 Mhz
Symbol rate: 2814 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -45 dBm
Signal/Noise: 10.8 dB
Carrier width: 3.800 Mhz
BitRate: 3.891 Mbit/s
----------------------------------------
Total Scan Time = 939.785s

The summary of the services that I found is as follows:

The first one is a feed, likely from a truck. Good to see C-band feeds still alive, but it seems they are not that common anymore since the trucks and dishes are physically bigger. Interesting services include Channel NewsAsia, Al Jazeera English, DW English, NHK World TV and Pheonix Infonews. I might park the dish here in the future given the variety of content still available, but it’s sad to see a lot is encrypted nowadays.

Going to the other extreme compared to examples shown in the previous part, this very fuzzy signal was locked and held.

Interesting Signals

Here’s the full swept spectrum in horizontal (above) and vertical (below) polarities, as usual.

Beacons

Looking around proved to be an interesting exercise. I didn’t record which polarity, but the beacon on the right was seen around 3635.439542Mhz, with the CW beacon 1Mhz below.

Zooming right in, it seems there is a main subcarrier at 32khz which seems to be a narrow FSK/PSK. I suspect the outer subcarrier at 64khz may be intended, this seem quite similar to the beacon spotted weakly on AsiaSat 5 but at a different frequency. Curious.

The upper frequency beacons were only seen in the horizontal polarization and were all very strong, making it easy to eliminate the weaker spikes (which may be spurious, or from adjacent satellites). Beacon frequencies were approximately:

  • 4192.943123Mhz (H, modulated, ~7.25Mhz space)
  • 4200.185623Mhz (H, modulated, 0.6Mhz space)
  • 4200.785623Mhz (H, modulated, 0.6Mhz space)

The weakest one at 4192.94Mhz proved interesting with a narrow subcarrier at 32khz which seemed to be unmodulated, and an outer FSK carrier that hopped between about 161.75khz and 166khz (~4.5khz shift).

The one at 4200.19Mhz has an inner subcarrier at 16khz and an outer at 48khz with a shift of about 10khz.

The highest frequency beacon at 4200.79Mhz has three (?) subcarriers, an inner narrow type at 24khz, a middle at 48khz and an outer at 72khz, the latter two being wide FSK/PSK type.

113°E Palapa D

Palapa D is an Indonesian satellite operated by Indosat Ooredoo Singapore which provides broadcast services to Indonesia and surrounding areas. It operates in the extended C-band, but only the global beam reaches Australia.

From the CrazyScan output, it doesn’t seem any of the extended C-band transponders make it to where I am in Sydney. The only transmissions heard are in the horizontal polarity, so if you try lining up the dish with the LNB powered in the vertical polarity, you’re not going to have much luck. In fact, a regular needle sat-finder with this LNB might well be more influenced by the “loud” LTE interference than the satellite signals! Anyhow, the BLScan output gave a few transponders to follow-up on.

TP N: 1
Frequency: 3746.111 Mhz
Symbol rate: 4399 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 3/5
RollOff: 0.20
Pilot: off
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -43 dBm
Signal/Noise: 11.4 dB
Carrier width: 5.279 Mhz
BitRate: 7.830 Mbit/s
----------------------------------------
TP N: 2
Frequency: 3752.009 Mhz
Symbol rate: 4699 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -43 dBm
Signal/Noise: 10.6 dB
Carrier width: 6.344 Mhz
BitRate: 6.497 Mbit/s
----------------------------------------
TP N: 3
Frequency: 3763.309 Mhz
Symbol rate: 3499 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -44 dBm
Signal/Noise: 10.5 dB
Carrier width: 4.724 Mhz
BitRate: 4.838 Mbit/s
----------------------------------------
TP N: 4
Frequency: 3767.700 Mhz
Symbol rate: 3999 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/QPSK
FEC: 4/5
RollOff: 0.20
Pilot: off
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -43 dBm
Signal/Noise: 9.1 dB
Carrier width: 4.799 Mhz
BitRate: 6.350 Mbit/s
----------------------------------------
TP N: 5
Frequency: 3774.512 Mhz
Symbol rate: 6499 KS
Polarization: Horizontal
Spectrum: Inverted
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -42 dBm
Signal/Noise: 10.4 dB
Carrier width: 8.774 Mhz
BitRate: 8.985 Mbit/s
----------------------------------------
TP N: 6
Frequency: 3787.089 Mhz
Symbol rate: 5631 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -43 dBm
Signal/Noise: 13.1 dB
Carrier width: 7.603 Mhz
BitRate: 7.785 Mbit/s
----------------------------------------
TP N: 7
Frequency: 3911.194 Mhz
Symbol rate: 1499 KS
Polarization: Horizontal
Spectrum: Inverted
Standard/Modulation: DVB-S2/QPSK
FEC: 2/3
RollOff: 0.20
Pilot: on
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -41 dBm
Signal/Noise: 12.5 dB
Carrier width: 1.799 Mhz
BitRate: 1.983 Mbit/s
----------------------------------------
TP N: 8
Frequency: 3926.123 Mhz
Symbol rate: 2589 KS
Polarization: Horizontal
Spectrum: Inverted
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -41 dBm
Signal/Noise: 10.9 dB
Carrier width: 3.496 Mhz
BitRate: 3.580 Mbit/s
----------------------------------------
TP N: 9
Frequency: 3934.186 Mhz
Symbol rate: 7199 KS
Polarization: Horizontal
Spectrum: Inverted
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -38 dBm
Signal/Noise: 12.2 dB
Carrier width: 9.719 Mhz
BitRate: 9.953 Mbit/s
----------------------------------------
TP N: 10
Frequency: 3988.696 Mhz
Symbol rate: 2500 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 5/6
RollOff: 0.35
RF-Level: -36 dBm
Signal/Noise: 12.3 dB
Carrier width: 3.375 Mhz
BitRate: 3.840 Mbit/s
----------------------------------------
TP N: 11
Frequency: 4015.166 Mhz
Symbol rate: 7199 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 5/6
RollOff: 0.35
RF-Level: -33 dBm
Signal/Noise: 14.4 dB
Carrier width: 9.719 Mhz
BitRate: 11.059 Mbit/s
----------------------------------------
TP N: 12
Frequency: 4081.188 Mhz
Symbol rate: 28124 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -34 dBm
Signal/Noise: 12.3 dB
Carrier width: 37.967 Mhz
BitRate: 38.877 Mbit/s
----------------------------------------
TP N: 13
Frequency: 4110.703 Mhz
Symbol rate: 11668 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 3/4
RollOff: 0.20
Pilot: off
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -40 dBm
Signal/Noise: 9.9 dB
Carrier width: 14.002 Mhz
BitRate: 26.008 Mbit/s
----------------------------------------
TP N: 14
Frequency: 4132.164 Mhz
Symbol rate: 12249 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/8PSK
FEC: 2/3
RollOff: 0.20
Pilot: off
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -40 dBm
Signal/Noise: 10.9 dB
Carrier width: 14.699 Mhz
BitRate: 24.265 Mbit/s
----------------------------------------
TP N: 15
Frequency: 4159.896 Mhz
Symbol rate: 13999 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/QPSK
FEC: 1/2
RollOff: 0.35
Pilot: off
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -45 dBm
Signal/Noise: -10.0 dB
Carrier width: 18.899 Mhz
BitRate: 13.845 Mbit/s
----------------------------------------
Total Scan Time = 1443.723s

The services I could lock included the following:

Interesting Signals

The spectrum scan in horizontal (above) and vertical (below) shows that virtually no services were resolved in the vertical polarity. A bit of unevenness is expected due to cable losses, impedance mismatches and LNB performance variations.

Some very weak and narrow data services seem to be running through the satellite on a near continuous transmission cycle.

Whereas some others seem to be using a longer TDMA system.

The most exciting ones are the short slot TDMA ones where transmissions are brief and light up the slots making pretty bands which remind me of DNA.

Beacons

At the low end of the band, it seems that a beacon might have been found in the vertical polarity, but it is very weak. Maybe it’s emitted out of the beam not intended for reception in Australia. The approximate frequency is 3702.101462Mhz, and it has a sideband at about 64khz.

At the high end of the band, it seems like there are two beacons (left pair) that are on the horizontal polarity, with the right-most beacon being circular polarity. The one in the middle appears to be vertical. There was also another beacon just out of shot. The frequencies are approximately:

  • 4184.098059Mhz (V, modulated)
  • 4188.643085Mhz (CP, modulated)
  • 4195.130585Mhz (V, modulated)
  • 4199.247244Mhz (H, modulated, ~0.5Mhz space based on later screenshot)
  • 4199.744615Mhz (H, modulated, ~0.5Mhz space based on later screenshot)

The beacon at 4184Mhz can be seen to be quite weak but has two subcarriers – a narrow one at 28khz and a wider one at 64khz.

The beacon at 4188.64Mhz appears to have narrow subcarriers at 32khz and 128khz but no modulation.

The paired beacons at 4199.24Mhz and 4199.74Mhz seem to be identical “twins”. They transmit the same data, with a wider FSK/PSK subcarrier at 65khz and a narrow subcarrier at 132khz which appears unmodulated.

Conclusion

Well, so far the hunt is going well, and it seems AsiaSat 7 might be a slot where I might park my dish. I’m pretty fond of NHK World, especially when it’s in HD, but it was dropped by Globecast off Optus D2 a while back to my dismay. Channel NewsAsia can also be worth watching for short periods.

Anyway, the more signals from satellites I see, the more similarities there seem to be. Beacons like to be towards the edges of the passband, tend to be AM modulated with subcarriers of either narrow or wider PSK/FSK types. Data services come in many varieties, which makes for some interesting spectrums.

The next post (when time permits) will continue along the hunt … there’s quite a few satellites in the C-band to visit!

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C-band Sats – Part 2: 83E G-Sat 10(?), 87.5E ChinaSat 12, 91.5E Measat 3/3a

I decided to start my scan from the western horizon upward. The first challenge was attempting to receive the satellite that is the lowest possible elevation to the west, then tracking the belt upwards to reach the other satellites. At least, this way, I will be able to say that I didn’t miss anything.

83°E G-Sat 10/12/Insat 4A

At the 83 degrees east slot, there are four co-located satellites, of which three are C-band capable – G-Sat 10, G-Sat 12 and Insat 4A. All are built to serve India to my knowledge, so reception in Sydney seems extremely unlikely. Satbeams seems to think there are no channels, but LyngSat seems to claim some on both G-Sat 10 and Insat 4A. From my location, the elevation comes in at 9.7 degrees which is quite low but might be just enough to clear distant trees and fence.

To try for this satellite sounds stupid given the circumstances. Instead, I ended up locked on 87.5 degrees east on ChinaSat 12 and decided to lower the dish slightly to see whether I could hear anything. I wasn’t expecting to hear anything and that would give a baseline as to what to expect.

A CrazyScan trace from the Prof 8000 shows what appears to be mostly quietness. Some very strong spikes from 3400Mhz and 3525Mhz are so strong that they’re probably terrestrial interference. The interference near 3930Mhz is a bit weaker, so its origin is unknown. There’s a few small bumps near 4150Mhz too.

If you blindly ask the card to lock the interference, you get a nice “ring” which isn’t quite perfectly circular on the I-Q constellation diagram, but it’s definitely not a DVB-S/S2 signal.

Interference Analysis

The bumps near 3400Mhz and 3525Mhz were quite easily spotted on the spectrum analyzer as LTE-style signals. Square edges, wide bandwidth, blocks in the frequency domain turning on and off. The reason for their appearance is mainly due to their high strength and vulnerability of the LNB itself. Half those frequencies corresponds to 1700Mhz and 1762Mhz, which are roughly the same frequencies used for 1800Mhz LTE in the phone-to-base direction. Another possibility would be 3500Mhz LTE which is operated on a trial basis.

The other interference near 3930Mhz is a bit of a challenge. At a wider RBW, it seems to consist of a signal which is spread across about 3Mhz of bandwidth. I would assume given the swept nature of the signal, it is a radar or ranging signal of sorts. The signal strength makes it possible that it is a signal emanated from a spacecraft.

At a narrower RBW, it seems it could be a coded FHSS style transmission of sorts to protect against jamming. I suspect this could be a terrestrial radar (e.g. weather radar, as we have a C-band radar in Wagga Wagga which might have been scattered by cloud), but I couldn’t confirm the frequency on the ACMA Radcomms page. It seems this frequency band is used for licensed point-to-point microwave links, but the expected modulation width is 40Mhz.

Not being satisfied with a could be, I decided to take a closer look at the satellite itself. Unusually, G-Sat 10 carries a navigation payload called GAGAN, designed as an SBAS for the Indian market. According to some presentation slides, it uses a CDMA Ranging at 6712Mhz uplink and 3412Mhz downlink with a bandwidth of 24Mhz. While this would put the signal output in the middle of the LTE interference mess and it doesn’t explain this particular signal, I think it deserves mention nonetheless.

Beacons

So far, nothing in the spectrum seems to suggest I am receiving anything from a satellite. I looked around a little further and to my surprise, I saw something that appeared to be satellite beacons.

In the horizontal polarity, there are quite a few carriers (at least five well defined ones) with modulation visible around 4192.5 +/- 10Mhz (RF) at the upper end of C-band. Now that I look at it, I can’t be entirely sure that all of these are actual signals as some could be intermodulation products within the LNB or analyzer.

Switching to vertical polarity did not affect the signal strength, so it appears the beacons are likely circularly polarized.

A closer look at the left triple seems to suggest the frequencies are spaced unevenly with one about 865khz above, and the other about 900khz below. The three beacons RF frequencies are (ignoring measurement error and error in the L.O.):

  • 4194.958758Mhz
  • 4195.822361Mhz
  • 4196.724379Mhz

They appear to be continuously modulated, but sadly, I didn’t take a closer look at each of their modulations and subcarrier spacing.

The right pair of beacons exhibits some interesting properties. We can see from the DPX waterfall that the modulated sidebands disappear at times in synchronism. Thus suggests this pair of beacons belongs to the same satellite – the frequencies seem to be spaced about 1.3Mhz, with the two beacons around 4188.583Mhz and 4187.283Mhz (RF).

The beacon has a modulated data phase lasting about 10 seconds. The slight “lean” of the signal gives us a good hint that the signal is going through the LNB and is suffering from the DRO drift instability – it’s likely space borne but not guaranteed.

The modulated periods are separated by about 9.5 seconds of idle time. This is not like any terrestrial signal that I’ve seen – it appears to be an FSK subcarrier on an AM modulated transmission. The mean subcarrier frequency is ~29khz, with a total shift of ~4khz.

So it seems quite likely I was hearing beacons from a satellite, but the identity of the satellite remains somewhat mysterious. The Indian satellites at 83 degrees east seem the most likely candidates, but I can’t be entirely sure. Maybe it’s an entirely different satellite, being received through a side-lobe?

87.5°E ChinaSat 12

It was nice to start off with a little mystery, but it’s always more comfortable to positively be able to identify the satellite. Moving a little further up to 13.4 degrees of elevation, we hit ChinaSat 12. Unfortunately for me, this is another satellite where I am outside of the intended coverage footprint of the C-band beam and only have “weak” Ku beam coverage. But there are no Ku services that are known. So how do I know I’m on a satellite? Well, for one, I saw some movement on the spectrum analyzer. For another, I managed to lock a carrier (barely).

CrazyScan on the Prof 8000 shows how dire the signal is. While we can see the general outline of the transponders, it seems to be afflicted by fading or modulation especially in the Vertical polarziation. The interference near 3930Mhz is strong compared to the intended signal – this being present again suggests it is terrestrial in nature.

TP N: 1
Frequency: 3775.463 Mhz
Symbol rate: 1799 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S2/QPSK
FEC: 3/4
RollOff: 0.35
Pilot: off
Coding mode: CCM
Long frame
Transport stream
Single input stream
RF-Level: -46 dBm
Signal/Noise: 8.4 dB
Carrier width: 2.429 Mhz
BitRate: 2.677 Mbit/s
----------------------------------------
Total Scan Time = 2575.529s

The BLScan reports just one lockable transponder, with one video program – YNIC with H.264 standard definition video and multiple MPEG-2 AAC audio streams although with a lot of errors. Locking even just one service is enough for me to confirm that the dish is aimed at a known satellite.

A full swept spectrum (including extended C-band areas the satellite is known not to be broadcasting in) in the horizontal polarity (above) and vertical polarity (below) gives more detail than the signal-strength based graph that CrazyScan is able to.

Interesting Signals

A walk through the spectrum on the horizontal polarity reminds us that satellites are much more than just satellite TV. The use of VSAT terminals to access data services in remote areas or as back-up in case of terrestrial infrastructure failure is important for many industries and utility services. These signals often use narrow bandwidths to reduce costs, and require absolute stability in frequency to avoid treading over each other. In a span of 40Mhz, we can see countless services only about 250khz wide that have been through a number of frequency conversion steps. Amazing. These seem to transmit almost continuously.

There are also some other services nearby which are a little wider – it’s amazing to think they’re all co-ordinated so as to avoid interference by having guard bands and limiting transmit powers. Narrow <1000kS/s DVB-S/S2 carriers are hard to lock partly for this reason – specifying frequency to the Mhz is not accurate enough, and neither is the stability of regular DRO LNBs to ensure the right frequency is chosen each time.

The interference is here too … as expected.

Beacons

Four beacon candidates towards the lower end of the RF spectrum were found on the vertical polarity (below), three of them disappearing in the horizontal (above). Their strength was somewhat weak though. The frequencies are approximately:

  • 3693.980052Mhz (CP unmodulated?)
  • 3696.671444Mhz (V unmodulated?)
  • 3700.43094Mhz (V unmodulated?)
  • 3702.454599Mhz (V modulated)

The modulated beacon was very unusual. It does not appear to be quite the same as those I’ve seen before with a solid AM carrier – this looks like AM where the carrier frequency is somewhat frequency/phase modulated? Very odd. Could it be interference causing intermodulation in the LNB?

Even those that I thought were unmodulated look like they’re being swept when looking close enough. One appears to have hints of a subcarrier sideband. Might this be a sign that these emanate from a nearby neighbour being received weakly? Or maybe it’s not a satellite beacon at all, but instead transmissions used by VSAT terminals as their frequency reference?

Towards the upper side of the RF spectrum, there is one beacon of a traditional sort in the horizontal polarity (top) that disappears in the vertical (bottom). The RF frequency is 4200.231281Mhz.

This looks like another AM type modulation with FSK/PSK subcarrier. The subcarrier is at about 65khz, but there is an outer line at about 131.5khz (maybe it’s a mixing product).

At longer time-scales, we can distinguish what seems to be patterns in the FSK.

91.5°E Measat 3/3a

The next one up is the 91.5 degrees east slot at 16.7 degrees elevation, where three Measat satellites presently reside, of which Measat 3 and 3a provide C-band service. The footprint of these services cover Australia, although Sydney is slightly disadvantageous in terms of signal strength. There’s quite a few services according to Lyngsat on both 3 and 3a with 3 responsible for extended C-band and the vertical polarity on normal C-band, and 3a providing horizontal services in normal C-band. This allows both satellites to share the same slot and provide service without interfering with each other.

The CrazyScan output gives us hope as we see the outline of the transponders, but it seems some of the extended C-band transponders are wiped out thanks to the local LTE uplink interference. I suppose this is why you have to plan your frequencies carefully for such “unintended” consequences. Using a full BLscan, we got only three lockable transponders.

TP N: 1
Frequency: 3705.842 Mhz
Symbol rate: 4289 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -46 dBm
Signal/Noise: 7.6 dB
Carrier width: 5.791 Mhz
BitRate: 5.930 Mbit/s
----------------------------------------
TP N: 2
Frequency: 3710.834 Mhz
Symbol rate: 2858 KS
Polarization: Horizontal
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 3/4
RollOff: 0.35
RF-Level: -45 dBm
Signal/Noise: 8.6 dB
Carrier width: 3.859 Mhz
BitRate: 3.952 Mbit/s
----------------------------------------
TP N: 3
Frequency: 3721.138 Mhz
Symbol rate: 2170 KS
Polarization: Vertical
Spectrum: Normal
Standard/Modulation: DVB-S/QPSK
FEC: 7/8
RollOff: 0.35
RF-Level: -45 dBm
Signal/Noise: 6.8 dB
Carrier width: 2.929 Mhz
BitRate: 3.500 Mbit/s
----------------------------------------
Total Scan Time = 2480.786s

Note that blind-scanned symbol rates are always out by a small margin – often by one or two kilo-symbols/second on this card. By using the known list of transponders, we can try them out as well – blind scan tends to work poorly for weaker signals and certain carriers just don’t seem to work with it, but can be locked in manually. Actually locking and analyzing the transport streams revealed nothing particularly new, but at least I managed to see these services on the air – FTA for free, ENC for encrypted.

It also gave me a chance to see how well the card’s blindscan could work –

This one didn’t return the modulation mode, but being -0.4dB SNR means that the card did believe it found something that’s DVB-S/S2 type.

No lock but reporting a healthy but noisy I-Q constellation plot – likely a poor signal or a mixture of ACM/VCM that this particular demodulator cannot handle.

With very high likelihood this is an ACM/VCM stream with some 16APSK component to it – it is plotted but not locked.

This also appears likely to be a QPSK and 8PSK mixed ACM/VCM stream.

Interesting Signals

A fully scanned spectrum of the satellite in horzontal (top) and vertical (bottom).

As usual, there are data carriers – the one on the left has a striated appearance on the spectrum which suggests there is a particular “idle pattern” which is interrupted by data (darkish bands). But more interesting is the two strong CW lines to the left, which I suppose is the reference frequency beacon for this system, sent through the satellite, to allow end-user terminals to use this as a frequency reference to keep their oscillators in check.

On the vertical polarity, there is another wide system with a different striated pattern, next to what appears to a TDMA or FHSS system.

On the horizontal polarity, there’s a mixture of reference pilot tones, narrow/medium/wide data carriers and slotted TDMA style systems.

Beacons

When it comes to Measat 3/3a beacons, it seems that we have a mixture of H and V beacons in the upper part of the C-band. This is not unexpected – we do have two satellites co-located in the slot, so we can expect twice as many beacons. The upper-end beacons appear to be at approximately:

  • 4178.688Mhz (H, unmodulated)
  • 4178.958Mhz (H, unmodulated)
  • 4186.018Mhz (H, modulated – 10Mhz spacing)
  • 4196.028Mhz (H, modulated – 10Mhz spacing)
  • 4191.418Mhz (V, modulated)
  • 4199.028Mhz (V, modulated – 1Mhz spacing)
  • 4200.028Mhz (V, modulated – 1Mhz spacing)

The above is 4186H, and it seems that it is an AM modulated beacon with two FSK/PSK subcarriers.

The one at 4196H follows much the same scheme, but with one FSK subcarrier.

4200V appears to have a subcarrier but it seems to be a single carrier of narrower form compared to the other FSK/PSK carriers but that could be a bit deceptive due to the weak signal nature.

4199V appears to be much the same as the above – a bit more narrow with a single subcarrier.

4191.4V has a wider subcarrier that appears like the other FSK/PSK type of wider sort.

While looking around, it seems there is a lower-end beacon as well at about 3449.349Mhz which seems to be circular polarized with one FSK/PSK subcarrier.

Conclusion

Communications satellites carry more than just TV and without something more sophisticated than a DVB-S/S2 tuner card, you might miss it. It’s probably no big problem, but it’s good to know that while the direct-to-home popularity seems to be waning, the bandwidth is actively being used by other satellite modems and VSAT terminals for data connectivity. The signals are, even looking visually at the analyzer output, rather interesting to see for the first time.

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C-band Sats – Part 1: Introduction to Satellite Hunting

It was a little more than a month ago in March, during some wet weather and a lull in my job-hunting schedule, that I thought I’d embark on a C-band satellite hunt. No, I’m not shooting down satellites … it’s just my term for scanning the skies. After all, I had moved back to the house where I had installed a 2.3m mesh C-band dish seven years ago and finally got myself unpacked to the stage of being functional again.

For the most part, in the intervening years, this dish pointed at ChinaSat 6B with only one phase of scanning the skies around 2013 (that I didn’t report on). Back then, I had a limited set of equipment, relying on my TBS 6925 and Crazyscan to lock onto DVB-S/S2 signals. As a result, I missed quite a few satellites as I just couldn’t find them in the sky. Getting an accurate aim with a relatively primitive “beeper” style satellite finder on those lesser-used satellites can be absolutely impossible for a beginner.

Now that I was equipped with a Tektronix RSA306 spectrum analyzer and a lot more experience it would be good to do it again. In-between, I was playing with Ku equipment since it’s more manageable in a small backyard at the other house, so satellite hunting has become something I’ve become experienced at, but using an RTL-SDR is hardly optimal. Even more unfortunate was the declining health of my favourite TBS 6925 satellite tuners, leaving me without any reliable way of detecting, locking and analyzing 16APSK/32APSK transmissions, or even those using Adaptive Coding and Modulation / Variable Coding and Modulation (ACM/VCM) or Multiple Input Stream (MIS) / Generic Stream formats.

But I don’t let a few minor challenges stop me from a satellite hunt. After all, direct-to-home satellite seems to be a shrinking market in Australia and the cheap mesh dish probably doesn’t have much life left. Unfortunately, this also means getting a new dish isn’t easy or cheap either, so I might as well make the most of what’s left as my Dad no longer watches satellite – complaining of the low quality of satellite and the improved convenience of video-on-demand through the internet.

C-Band Satellite Basics

C-band satellite involves microwave signals beamed down to receivers in the 3400-4200Mhz band (downlink). This band has been used for this purpose since the early days of satellite television, originally termed Television Receive-Only (TVRO) when such C-band transmissions were used (primarily) to network studios and transmission facilities. Originally, transmissions were analogue and in-the-clear which limited the amount of programming on each satellite. Schemes to reduce analog bandwidth use and introduce conditional access scrambling were employed, such as D2-MAC.  This was later followed by digital broadcasting in the late 90’s (DVB-S) allowing multiple-channel-per-carrier operation (MCPC) and digital conditional access (DVB-CSA). At the present time, DVB-S2 has gained significant popularity as a more-efficient mode compared to DVB-S, and DVB-S2X has also been proposed for professional uses. It’s not uncommon to find satellites carrying hundreds of television programs.

C-band’s strength is in its use for wide-area coverage. Many C-band satellites have transmission footprints that cover wide areas as opposed to the narrow “focused” beams that most Ku-band satellites have. Another big advantage, especially in tropical areas, is that the lower frequency is less affected by rain fade, improving communication reliability. However, as with all microwave-based communications with geostationary satellites, sun-outages will be a problem.

Because of the lower frequency of C-band (as compared to Ku-band which operates at 10700 – 12750Mhz), larger dishes are required to receive the signal and achieve similar signal gain. On the upside, the dishes do not have to be as dimensionally perfect and can be made of mesh to economize on weight and reduce wind loading. Commonly, mesh dishes of 2m to 3.7m are used for digital direct-to-home reception, making it more laborious to install compared to Ku-band systems. This is where the “Big Ugly Dish” (BUD) nickname comes from. Where modern apartment-style housing is concerned, there may not be enough space or sky-access for C-band satellite reception – I’ve seen some resort to receiving only some strong carriers with a 1.5m solid-panel “mini BUD” dish or converted Ku-band dish using a conical scalar ring.

Unlike Ku-band dishes, most C-band dishes are prime focus type. The signal from the satellite is reflected by the dish to a focal point, where an low-noise block downconverter (LNB) receives the signal and converts it down to an Intermediate Frequency (IF) for transmission down a coaxial cable to a receiver.

A traditional “wideband” C-band LNB has a single local oscillator (L.O.) of 5150Mhz which is multiplied with the received signal of the satellite and filtered to produce the downconverted signal between 950Mhz and 1750Mhz. Because the L.O. is above the input frequency, an inversion occurs in the spectrum – so a signal appearing at 4200Mhz input is translated down to 950Mhz, and one that arrives at 3400Mhz is translated down to 1750Mhz.

Further to this, satellites also employ frequency re-use through using two different transmission polarities. For linearized transponders, the two polarities are Horizontal and Vertical. The signal can be thought of as being emitted in these two different directions, being picked up by matching antenna probes in the LNB which are sensitive to just a single polarity. This allows the same frequency to be used twice – one signal on the horizontal and one on the vertical should not severely interfere with each other (in ideal circumstances). In practice, this depends on a few factors – cross-polar rejection of the LNB design, the atmospheric conditions (as it can cause depolarization) and the skew adjustment accuracy. Skew is adjusted by rotating the LNB in the holder, and is necessary for linear transmission due to the relative orientation of the satellite versus the dish.

For circularly polarized transponders, the corresponding polarities are left-hand circularly polarized (LHCP) and right-hand circularly polarized (RHCP). Using a regular linear-type LNB, a dielectric plate or block which looks like a thick fibreglass PCB substrate needs to be inserted into the slots in the front of the LNB feed to convert the circular polarized signals to linear polarity. This comes at a cost of signal strength, but has the advantage that skew adjustment is unnecessary.

When it comes to receiving geostationary satellites, they all reside in (or close to, in the case of inclined satellites) the Clarke belt. Following the belt across the sky allows you to “hunt” satellites. In the case of more sophisticated set-ups using polar-tracking mounts, this could be as simple as swinging the dish using a linear actuator from the comfort of your armchair (assuming it’s been installed correctly and working). In my case, it means manually going outside with a wrench, undoing a few bolts and swinging the dish around while adjusting the skew.

While satellite hunting, there’s a few things to be mindful of. Towards the horizon, satellites at low elevation are especially problematic due to atmospheric effects, terrestrial radio interference and physical shadowing by objects such as buildings or trees. While actually aligned to a satellite, the signals received could be interfered with by terrestrial radio waves but also satellites in adjacent slots as the beamwidth of most dishes is about 2-3 degrees (at half-power), so it’s likely that you could see some interference where satellites are closely spaced. In some orbital slots, the space is shared by two satellites which transmit in separate part of the bands.

Originally, when I configured the dish, I used the most popular type of C-band LNB at the time, known as a One-Cable Solution (OCS) or Band-Stack LNB. This type of LNB (illustrated bottom) has two local oscillators – 5150Mhz and 5750Mhz, allowing both horizontal and vertical polarity to be simultaneously received and piped down the same cable. This has an advantage that simple splitters and power injectors can be used to distribute the signal to multiple satellite receivers to allow them to watch different programs simultaneously from a single LNB output. The downside of OCS LNBs is that they only receive from 3700-4200Mhz. Signals outside this range in the extended C-band cannot be received!

For proper satellite hunting, a “regular” wideband LNB is recommended – this uses only a single 5150Mhz L.O. and instead relies on the traditional 13/18V switching to receive each polarity in sequence (illustrated middle). This is particularly important if we want to look at satellite beacons and slightly out-of-band transmissions. Unfortunately, while these were the “normal” type, locally it seems to be quite rare to find. The downside of the wideband LNB is that they are sensitive to interference. Previously, one major offender was the Unwired Navini WiMAX system.

Ideally, if you have access to a more sophisticated phase-locked loop (PLL) LNB, this could be an advantage as the frequency stability will be better than a traditional dielectric resonator-oscillator (DRO) LNB which drifts wildly with changes in temperature. This is especially advantageous for narrow carriers to ensure receivers can lock and track the carriers accurately. Sadly, I don’t have one of these (they’re not exactly cheap either).

Aims

So why would I go satellite hunting anyway? Well, there’s a few reasons:

  • Curiosity – I’ve never been able to hit every satellite I know of from online listings such as Lyngsat or Satbeams. Even though a lot of satellites won’t have footprints covering Sydney, Australia, I can’t say I’ve received all of those which claim to. Not knowing why I missed them in the past is a point of frustration I hope to resolve with better gear and technique.
  • Contributing – Online listings such as Lyngsat and Satbeams tend to concern themselves with TV service listings, but often rely on voluntary contributions to keep them up to date. Without people actively checking out what’s on the air, those listings can get “stale” and miss new services coming online and old services dropping off.
  • Completeness – The online listings are almost all focused on TV services, but satellites carry a lot more than just DVB. What about the services that can’t be locked by DVB cards? Is anyone still running analogue? Are there any satellites we don’t know about?
  • Entertainment – If you have a dish, you’d hope that there’s something to watch. So by sampling the satellites, I’ll have a better idea of what is available and might catch a few feeds or sample transmissions.
  • Identification – While satellites have footprints that are concerned with their broadcasts, they also transmit different types of beacons used to identify the satellite, control uplink powers and relay telemetry/health data. The data about these beacons seems to be rarely shared (maybe with the exception of Optus). What do the C-band satellite beacons look like? What are their frequencies/spacings? Are the beacons receivable outside of the broadcast footprint for recovery purposes (e.g. omni antenna)?
  • Testing – If you have the equipment, I think it’s a good excuse to try it out and sharpen your skills.

One side effect of actually writing posts about the data I collect is that it forces me to look at the data and analyze it, rather than leaving it to sit around. It also means that I end up tabulating it in a way which makes it somewhat more useful when I come back to revisit it.

Equipment Configuration

The equipment used for my satellite hunting was a bit of a disappointment in a few ways. I had to make do with what worked and what I had left:

  • Dish – Space 2.3m Heavy Duty Mesh Dish (7 years old, some dents, lots of rust, a bit small for some of the satellites I’m looking at so I don’t expect good SNR)
  • LNB – Strong SRT L926 DRO Wideband C-band 5150Mhz LNB (drifts a bit, susceptible to interference)
  • Cable – about 20m mixture of RG-6 dual-shield and quad-shield plus flat window cable (unbranded, lossy, impedance nightmare)
  • Switch – Gecen 4-port GD-41C DiSEqC switch (to allow for later Ku-band experiments without unscrewing anything)
  • DVB-S Card – Prof Revolution S2 8000 PCI-E (as my pair of TBS 6925 are retired, but it seems the 8000 isn’t so healthy either)
  • Spectrum Analyzer – Tektronix RSA306 (probably the least disappointing part of the set-up)

Knowing this, I don’t expect to find great SNR to the point of locking 16/32APSK signals which isn’t that big of an issue since the Prof can’t do them anyway. But I’m already quite marginal especially on some of the satellites near the horizon, so we’ll see how far I can get. The DRO LNB won’t help, as it means determining exact beacon frequencies is impossible – but the spacing between beacons should be relatively accurate. Maybe we can compensate for this by finding the offset between known carrier frequencies and actual received frequency (assuming the LNB temperature didn’t change much).

Dish alignment was tweaked with occasional reference to Dishpointer, although it was often easier to get onto just one satellite on the belt, change the elevation until it fades out, then swing the dish slightly to hit its neighbour satellite, then readjust to peak to “walk” along the belt. To do this, I used the Tektronix RSA306 on one machine, and accessed the screen via VNC on a smartphone from the backyard next to the dish to see a real-time read-out of the spectrum.

Conclusion

In this post, I covered some of the basics about C-band satellites and satellite hunting. I also went through some of my motivations for doing this, what I used and how I’m going about it. It’s a bit of a shame that it seems that satellite direct-to-home seems to be declining in popularity, so I fear that being able to obtain and use satellite equipment is going to be more costly and difficult in the future (as it already is). It seems IPTV and VoD over the internet is just too convenient by comparison and the satellite “squeeze” to shove more variety into a limited bandwidth has destroyed quality in a similar way it affected terrestrial DVB broadcasts.

In the following series of posts, I’ll report on the large amount of results obtained in a “group” of satellites at a time.

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