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Have problem to point on IS 904

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Ex Member
Ex Member


Dec 2nd, 2008 at 6:26pm  
Its my first C band Dish to point and i have some problems to point on IS 904.

I have a 2.4 meter Prime Focus Antenna and Idirect 5350 modem.
I using a Rover S2 Sattelite Analyzer .

My problem is that i get more sattelites in this direction and i am not able to find Is 904 to bring the modem to lock on the carrier.

I put as settings in the Rover S2 :

Frequenzy: 3933.3 MHz
L.O. : 5150

but from the S.R. setting i am not sure what to put in.

my Provider told me the Symbolrate, ( what i belive is the S.R for his Carrier is 693.382 but at the S.R. settings i can get only until 45.000

My location is the DRC Near to Likasi .

The Is )04 should be at AZ 76.6 and ElV 49.6

maby someone can help me to setup the analyzer correctly and explain me how to use the Spectrum Analyser on the Rover S2

Thanks
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Eric Johnston
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Reply #1 - Dec 2nd, 2008 at 8:08pm  
Centre frequency:

If you have put Frequency: 3933.3 MHz  LNB L.O.: 5150 MHz into the Rover S2 then the Rover S2 may have now tuned itself and be listening at centre frequency of 1216.7 MHz.  This is the L band carrier frequency in the cable from the receive LNB. ( Note cable freq = 5150 - satellite frequency. )   A centre frequency of 1216.7 MHz may be displayed.  Alternatively, it is likely that you could manually set this screen centre frequency yourself on the analyser.

Span:

You need to know the symbol rate for two reasons: It gives you some idea of the bandwidth of the signal you are looking for and it needs to be entered into your modem configuration via your iDirect options file. If you have been told a symbol rate of 693.382 then this will be in units of ksps, not Msps.  The Rover S2, in addition to its role as a spectrum analyser, is also a satellite TV receiver capable of receiving digital TV with symbol rates, probably in the range 2 - 45 Msps.  I am not sure it is designed to receive and demodulate such low bit rate digital TV carriers as 0.7 Msps. It does not matter much, unless it is DVB-S2 satellite TV carrier that you are actually trying to receive.

What does matter is that what you are looking for is a carrier centered on 1216.7 MHz and about 700 kHz wide at the -4 dB points and 890 kHz wide at the -10 dB points. If you use a span of 50 MHz you should see a carrier hump appear in the middle, about 16% of the screen span width.

Find the satellite:

To find the satellite, set the elevation accurately and then swing the beam sideways.  A suitable do-it-yourself inclinometer is at inclinometer. If you have doubts about the elevation check that the feed is on the centreline the dish.  Measure from the bottom and top of the dish to the feed aperture. Take care not to poke a hole in the feed window.

Polarisation:

If you have problems and find different satellites up and down and you are certain that your wanted carrier is not visible, then the problem may be your polarisation. It is quite a job to change the polarisation so get really confident that you really can't find the wanted signal before doing this.  To change the polarisation you need to undo the flange between the OMT and the polariser and reattach after turning one part 90 deg.  The OMT is the part where the TX and RX waveguide join.  The polariser is a long tube with pins or slots along in two lines inside.  The lines of pins/slots must be at + or - 45 deg to the the TX/RX waveguides. One way gives right hand circular the other left hand circular - don't ask me which !  Your service provider should have told you the downlink polarisation.

Best regards, Eric.
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« Last Edit: Dec 2nd, 2008 at 10:45pm by Eric Johnston »  
 
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Reply #2 - Dec 2nd, 2008 at 9:07pm  
thank you for your help.

thats my option file:

[OPTIONS_FILE]
     modem_sn = 46xxx
     modem_type = Remote
     modem_hardware = 5350
     did = 6862229
     generated_by = NMS version $Name: NetModem-8_0_2_5 $
     is_mesh = 0
     disable_options_flash_command = 0

[SECURITY]
     password = $ixxxxxx
     admin_password = $xxxxx

[NMS]
     timeout = 20000
     server_ip = 10.xxxxx
     broadcast_ip = 10.xxxxx
     keep_alive_port_number = 2860
     NRD_server_ip = 10.xxxxxx
     NRD_remote_status_port_number = 2859
     service_monitor_interval = 1000
     download_monitor_group = 239.xxxx
     download_monitor_port = 9000
     download_monitor_credentials = 1
     is_nms_managed = 1
     event_server_ip = 10.xxxxx
     event_server_port = 2860

[VLAN]
     mode = 0
     vid = 1

[ETH0_1]
     address = 10.xxxxx
     netmask = 255.255.255.240
     rip_enabled = 0

[DNS_1]
     dns_enable = 1
     dns_primary_server_name = ns1.xxxxx
     dns_primary_server_addr = 172.xxxx
     dns_secondary_server_name = ns1.xxxx
     dns_secondary_server_addr = 212.xxxxx
     dns_cache_size = 100
     dns_cache_ttl_min = 300
     dns_cache_ttl_max = 86400
     dns_forward_queue_size = 1000
     dns_forward_timeout = 2000

[DHCP_1]
     dhcp_mode = 1
     dhcp_lease_seconds = 43200
     dhcp_lease_range = 10.xxxx-10.xxxx
     dhcp_dns_server_ip = 10.xxxx
     dhcp_dns_server2_ip = 212.xxxx
     dhcp_gateway_ip = 10.xxxx

[ROUTE_1_0]
     interface = sat0
     network = 0.0.0.0
     netmask = 0.0.0.0
     gateway = 0.0.0.0
     metric = 1

[SAT0_1]
     address = 172.xxxx
     netmask = 255.xxxxx
     rip_enabled = 0

[ETH0]
     interface = ixp1
     phy_count = 8

[LAN]
     lan_ip = 10.xxxx
     lan_subnet_ip = 255.255.255.240
     lan_gw_ip = 0.0.0.0

[MODEM_PARAMETERS]
     data_port = 0
     loopback = 0
     interface_type = 0
     rx_freq = 1216672000
     rx_acqrange = 50000
     rx_bitrate = 1100000
     rx_mode = 2
     rx_modtype = 1
     rx_fecrate = 15
     rx_scram = 1
     rx_diff = 0
     rx_specinv = 1
     tx_freq = 1000000000
     tx_bitrate = 512000
     tx_mode = 0
     tx_modtype = 1
     tx_clksource = 0
     tx_fecrate = 20
     tx_scram = 1
     tx_diff = 0
     tx_specinv = 0
     tx_power_in_dbm = 0.000000
     rx_fsd = 241557
     tx_spreading_factor = 1
     rx_spreading_factor = 1
     is_demod2_active = 0

[ACQUISITION_PARAMETERS]
     fsd = 257633

[UCP]
     power_uplink_control_processing = 1
     max_power_level_in_db = 0.000000

[ODU]
     music_present = 0
     odu_rx_dc_power = 1
     odu_rx_10_MHz = 0
     odu_tx_dc_power = 1
     odu_tx_10_MHz = 1
     odu_disable_tx_pwm = 0

[TDMA]
     tx_watchdog_timeout_in_frames = 2

[TIMEPLAN]
     fec_blocks_per_outroute_frame = 185
     unique_word_len_downstream = 32
     symbols_per_inroute_frame = 262368
     outroute_fec_block_len = 512
     outroute_fec_type = 793
     inroute_fec_block_len = 128
     inroute_fec_type = 533
     unique_word_len = 32
     symbols_per_outroute_frame = 378911
     num_acq_slots = 1
     aperture_traffic = 8
     aperture_acq = 824
     num_traffic_slots = 472
     payload = 512
     skip_slots = 3

[LL]
     ll_open_active = 1
     ll_tx_window = 1024
     ll_rx_window_backoff = 1000
     ll_rx_window = 1024
     ll_t1_timeout = 4000
     ll_t2_timeout = 1000
     ll_t3_timeout = 5000
     ll_t4_timeout = 1500
     ll_t1_retry_limit = 5

[SPOOF]
     spoof_debug_level = 0
     spoof_passthru = 0
     spoof_timeout = 100
     spoof_oos_buffer_size = 64240
     spoof_keepalive_timeout_ms = 6000
     spoof_fwd_ack_ms_timeout = 200
     spoof_fade_timeout = 120000
     spoof_reap_timeout = 480000
     spoof_syn_timeout = 120000
     spoof_max_sessions = -1
     spoof_accel_connect = 1
     spoof_accel_port = 80
     spoof_retx_buffer_size = 137968
     spoof_peer_retx_buffer_size = 63276
     spoof_merge_on = 0
     spoof_compression_on = 0

[MODEM_INSTALLATION]
     hub_lat = 4xxx
     hub_long = 9xxx
     remote_lat = 3xxx
     remote_long = 2xxx
     spacecraft_long = 60.000000
     reflector_offset_angle = 0.000000

[FREQ_TRANS]
     down_translation = 5150.000000
     up_translation = 4900.000000

[DEBUG]
     cpu_util_test_enabled = 0

[GUI_SERVER_PROXY]
     port = 14599

[SAR]
     tx_segment_size = 54
     tx_passthru = 0
     rx_passthru = 1

[POWER_MANAGEMENT]
     enable = 0
     sleep_timeout = 0

[QOS]
     filter_id = 3
     default_allow = 1

[UPSTREAM_VR_1]
     did = 5350.4xxx
     virtual_remote_id = 0
     parent_gqos_id = 42
     priority = 2
     cost = 1.000000
     cir_bps = 51000
     max_bps = 512000
     sticky_cir_enabled = 0
     legacy_fairness = 0

[SERVICE_LEVEL_1]
     name = NMS_ICMP
     virtual_remote_id = 0
     type = priority
     priority = 100
     max_depth_packets = 5000
     max_depth_bytes = 14676
     max_depth_ms = 250
     drop_oldest_uis_first = 1
     rt_weight = 0.000000
     trigger_wakeup = 1
     cir_trigger = 1

[SERVICE_LEVEL_1_RULE_1]
     PROTOCOL = EQUAL 1
     DEST_IP_ADDR = EQUAL 1o.xxx

[SERVICE_LEVEL_2]
     name = NMS_UDP
     virtual_remote_id = 0
     type = priority
     priority = 100
     max_depth_packets = 5000
     max_depth_bytes = 14676
     max_depth_ms = 250
     drop_oldest_uis_first = 1
     rt_weight = 0.000000
     trigger_wakeup = 1
     cir_trigger = 1

[SERVICE_LEVEL_2_RULE_1]
     PROTOCOL = EQUAL 17
     DEST_IP_ADDR = EQUAL 10.xxx

[SERVICE_LEVEL_3]
     name = NMS_TCP
     virtual_remote_id = 0
     type = priority
     priority = 100
     max_depth_packets = 5000
     max_depth_bytes = 3004
     max_depth_ms = 20
     drop_oldest_uis_first = 1
     rt_weight = 0.000000
     trigger_wakeup = 1
     cir_trigger = 1

[SERVICE_LEVEL_3_RULE_1]
     PROTOCOL = EQUAL 6
     DEST_IP_ADDR = EQUAL 10.xxx

[SERVICE_LEVEL_4]
     name = VOIP Priorisation
     virtual_remote_id = 0
     type = priority
     priority = 75
     max_depth_packets = 5000
     max_depth_bytes = 14676
     max_depth_ms = 250
     drop_oldest_uis_first = 1
     rt_weight = 1.000000
     trigger_wakeup = 0
     cir_trigger = 1

[SERVICE_LEVEL_4_RULE_1]
     PROTOCOL = EQUAL 17
     DEST_IP_ADDR = EQUAL 172.xxxx 255.255.255.255

[SERVICE_LEVEL_5]
     name = ICMP
     virtual_remote_id = 0
     type = cost_based
     cost = 0.400000
     max_depth_packets = 5000
     max_depth_bytes = 14676
     max_depth_ms = 250
     drop_oldest_uis_first = 1
     rt_weight = 0.000000
     trigger_wakeup = 0
     cir_trigger = 1

[SERVICE_LEVEL_5_RULE_1]
     PROTOCOL = EQUAL 1

[SERVICE_LEVEL_6]
     name = DNS
     virtual_remote_id = 0
     type = cost_based
     cost = 0.100000
     max_depth_packets = 5000
     max_depth_bytes = 3004
     max_depth_ms = 20
     drop_oldest_uis_first = 1
     rt_weight = 0.000000
     trigger_wakeup = 0
     cir_trigger = 1

[SERVICE_LEVEL_6_RULE_1]
     PROTOCOL = EQUAL 17
     SOURCE_PORT = EQUAL 53
     DEST_IP_ADDR = EQUAL 172.xxxx 255.255.255.255

[SERVICE_LEVEL_6_RULE_2]
     PROTOCOL = EQUAL 17
     SOURCE_PORT = EQUAL 53
     DEST_IP_ADDR = EQUAL 213.xxxx 255.255.255.255

[SERVICE_LEVEL_6_RULE_3]
     PROTOCOL = EQUAL 17
     SOURCE_PORT = EQUAL 53
     DEST_IP_ADDR = EQUAL 213.xxxx 255.255.255.255

[SERVICE_LEVEL_7]
     name = UDP
     virtual_remote_id = 0
     type = cost_based
     cost = 2.000000
     max_depth_packets = 5000
     max_depth_bytes = 14676
     max_depth_ms = 250
     drop_oldest_uis_first = 1
     rt_weight = 0.000000
     trigger_wakeup = 0
     cir_trigger = 1

[SERVICE_LEVEL_7_RULE_1]
     PROTOCOL = EQUAL 17

[SERVICE_LEVEL_8]
     name = TCP
     virtual_remote_id = 0
     type = cost_based
     cost = 0.500000
     max_depth_packets = 5000
     max_depth_bytes = 3004
     max_depth_ms = 20
     drop_oldest_uis_first = 1
     rt_weight = 0.000000
     trigger_wakeup = 1
     cir_trigger = 1

[SERVICE_LEVEL_8_RULE_1]
     PROTOCOL = EQUAL 6

[SERVICE_LEVEL_0]
     name = DEFAULT
     virtual_remote_id = 0
     type = cost_based
     cost = 0.500000
     max_depth_packets = 5000
     max_depth_bytes = 14676
     max_depth_ms = 250
     drop_oldest_uis_first = 1
     rt_weight = 0.000000
     trigger_wakeup = 1
     cir_trigger = 1

[ENC]
     enc_layer_enabled = 0
     enc_enabled = 0
     enc_mode = 0
     peer_mode = 1
     auth_level_required = 0

[NET_ENC]
     id = 4
     is_encrypted = 0

[UDP]
     passthru = 0
     force_udp_fullheader = 0
     force_rtp_fullheader = 0
     payload_comp = 1
     max_hdr_comp_packet_size = 180

[COMPRESSION]
     Threshold = 90

[PAD]
     partial_passthru = 0

[OOB]
     mem_low_percent = 75
     mem_high_percent = 90

[SWITCH_PORT_1]
     vid = 0
     autoneg_off = 0
     speed = 0
     duplex = 0

[SWITCH_PORT_2]
     vid = 0
     autoneg_off = 0
     speed = 0
     duplex = 0

[SWITCH_PORT_3]
     vid = 0
     autoneg_off = 0
     speed = 0
     duplex = 0

[SWITCH_PORT_4]
     vid = 0
     autoneg_off = 0
     speed = 0
     duplex = 0

[SWITCH_PORT_5]
     vid = 0
     autoneg_off = 0
     speed = 0
     duplex = 0

[SWITCH_PORT_6]
     vid = 0
     autoneg_off = 0
     speed = 0
     duplex = 0

[SWITCH_PORT_7]
     vid = 0
     autoneg_off = 0
     speed = 0
     duplex = 0

[SWITCH_PORT_8]
     vid = 0
     autoneg_off = 0
     speed = 0
     duplex = 0

[TX]
     device_path = /dev
     device_mode = tdma
     device_name = tx

[RX1]
     device_path = /dev
     device_mode = scpc
     device_name = rx1

[BTP]
     device_path = /dev
     device_mode = tdma
     device_name = btp

[SOF]
     device_path = /dev
     device_mode = tdma
     device_name = sof

[SATELLITE]
     min_look_angle = 0.000000

[SYSTEM_TRAY]
     mode = 1
     server = 10.xxxx
     port = 2859
     interval = 5000
     service_monitor_group = 239.xxx
     service_monitor_port = 9001

what for frequenzy  and symbol rate i have to put now in the rover ?

sorry i am just a newbee
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Eric Johnston
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Reply #3 - Dec 2nd, 2008 at 10:25pm  
You don't need to change anything in the options file. Your service provider has given you a complete options file ready for use.

The rx frequency is shown as
rx_freq = 1216672000
This means 1216.672 MHz, which is the carrier frequency in the cable and the same as what you will see on the analyser.

This line
rx_acqrange = 50000
says that the receiver needs to sweep up to a maximum of 50 kHz to acquire the carrier. So you need a high stability LNB.  What is your LNB type and model number?.  Does it say something like LO=5150 PLL +/- 25kHz on the label?.

Regarding symbol rate you don't need to input symbol rate into the modem. (I was wrong above) The relevent information has already gone in thus:
rx_bitrate = 1100000
rx_mode = 2
rx_modtype = 1
rx_fecrate = 15
The modem uses the bit rate, modulation type and FEC rate to work out the symbol rate for itself. My guess is QPSK=2, FEC=TPCrate0.793, Bit rate=1100000 so symbol rate = 1100000 / ( 2 * 0.793) = 693 ksps approx.
Leave the options file alone.  Looking at it has verified that you will be looking at the correct frequency on the analyser.

You do need to know the symbol rate so that you can look for a carrier that is the correct bandwidth on the analyser, since the -4 dB bandwidth is the same as the symbol rate.  i.e. about 800kHz wide centered at 1216.672 MHz.

If you have your receive cable coupled through to the modem it should indicate RX good when you swing the dish slowly past the satellite.

Best regards, Eric.
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« Last Edit: Dec 3rd, 2008 at 8:48am by Eric Johnston »  
 
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