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4M/bit Uploade /1-2 M/bit Download

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Roesicke
Ex Member


Feb 3rd, 2014 at 4:34pm  
Hello

I have a Tooway system. Sorry, but I do not understand why I have 4M/bit Uploade but only to 1-2 M/bit Download. Does anyone still such a problem? The two question is how high should or must be the cable loss? On my first cable I had 15 dbm now after the exchange I have 0.2-1 dbm.

I hope someone can tell me what to do so.

Have a good evening.

Larsen


Hallo

Ich habe ein Tooway System. Leider verstehe ich aber nicht warum ich 4M/bit Uploade habe jedoch nur auf 1-2 M/bit Downloade. Hat jemand auch noch so ein Problem? Die 2 Frage ist wie hoch darf oder muss die Kabeldämpfung sein? Bei meinem ersten Kabel hatte ich 15 dbm nun nach dem Tausch habe ich 0,2-1 dbm.

Ich hoffe das jemand mir dazu was sagen kann.

Schönen Abend noch.

Larsen
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Admin1
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Reply #1 - Feb 4th, 2014 at 11:32am  
Here some examples from other Tooway sites:

IF power  -29      -33    -32.6    -27.0    dBm
RF power  +29.9    +30    +33.7    +31.0    dBm

Rx power  -35.5   -34.5   -37.0    -33.9   -32.7   dBm
Rx SNR     16.3    13.9    14.1      1.1    15.7   dB

Cable ohms  1.5     0.5     1.5      1.0     1.0   ohms
Cable loss 14.8     6.3     9.0      6.0     5.3   dB


Note:

-30 dBm = 0.000001 watt.  0 dBm = 0.001 watt   +24 dBM=0.25 watt +27dBm = 0.5 watt.
+30 dBm = 1 watt.   + 33 dBm = 2 watt.

RF power is presumably the output power of the BUC transmitter.
IF power may be output of the modem or input power to the BUC ?

RX power is probably input power to the modem, but is it the power of the wanted carrier or the composite aggregate power of all carriers present  ?
Rx power will be lower with longer cable (up to 50m of RG6) but there should be negligible change Rx C/N.

Rx C/N should depend on clear sky, dish pointing and location in the beam.  There is the possibility of the satellite carrier power varying, due to rain in the teleport uplink or the number of carriers active or adjustments in uplink power at the teleport.

Cable ohms (DC resistance) and cable attenuation depend on cable length but also on quality of the workmanship on the connectors.

Typical values for 100 ft RG6 cable:

300 MHz     3.4 dB   RM4100N-010 RX  two cables
-800 MHz    5.8 dB   RM4100N-010 RX  two cables

1000 MHz    6.5 dB   RM4200N-010 RX  single cable
-1500 MHz   8.2 dB   RM4200N-010 RX  single cable

1800 MHz    8.9 dB   RM4100N-010 RM4200N-010 TX
-2300 MHz  10.1 dB   RM4100N-010 RM4200N-010 TX


DC resistance about 3 ohms per 100 ft for centre conductor solid copper 1.13mm dia.
DC resistance about 2.5 ohms per 100 ft for copper braid. Less if copper foil as well.

Most cable problems are due to poor workmanship on the connectors.
The outdoor TRIA is powered by 30V DC supplied up the cable. The slightest moisture or poor connection will allow rapid corrosion and contact oxidation/burning to occur.
The spring contacts inside the TRIA may be permanenty burned.  Cables with aluminium coated plastic film as the RF outer conductor may be spoiled for large distances by moisture.   
Ideally use waterproof axial crimp connectors that match the cable type and a smear of electronic grade silicone contact grease.
Make sure that the braid makes good electrical contact and that the end centre pin is 1.5mm proud of the rim.
When connecting up make sure the pin smoothly goes into the hole and does not push back the cable.
Seal the outer connector extremely well against moisture.
Always power OFF at the mains wall switch before working on the IFL cable(s).
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« Last Edit: Feb 5th, 2014 at 12:03pm by Admin1 »  
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