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Jul 4th, 2013 at 10:23am
TRIA status
The RF output power from your TRIA should be about +30 dBm (1 watt). Your +14.5 dBm (0.03 watt) is abnormally low.
The Tx IF power at -35.5 dBm is just a little low
My ideas: I believe the TRIA should have a gain of about 60 dB. Yours is 50 dB. A faulty TRIA is a possibility but lack of sufficient DC volts and current into the TRIA is more likely. I'm thinking of poor cable connections or steel cored coax with a high DC resistance.
Modem/IFL cable status
The RX power at -71.8 dBm is extremely low. It should be more like -35 dBm. So, either low gain LNB or high loss in IF cable.
The RX SNR at 11.8 is suprisingly good, so the high IF cable loss less likely. Suspect low gain LNB.
My ideas: A faulty LNB is a possibility but lack of sufficient DC volts and current to the TRIA is more likely cause of low gain LNB.
Cable resistance unknown, cable attenuation unknown !. Something serious is wrong !.
Expect cable resistance to be about 1 - 2 ohms. Cable loss about 5 - 9 dB, depending on length.
WARNING: Power off at the AC mains wall plug before any work on the coax cable. Breaking the connection while powered on risks damage to the equipment and electric shock and fall from ladder etc.
My ideas: All cable connectors must be excellent. The outer screen and braid must make perfect electrical contact to the outer of the plug. The centre copper wire must protrude about 1.5mm proud of the rim of the plug. It must not stick out further or be too short. When screwing in, the centre wire should smoothly enter the socket and not push back the cable body within the plug.
The coax cable should have a solid copper centre conductor and sufficient copper wire or foil screen to make a low resistance DC return path. The screen may be solid copper foil (ideal) or, less preferably and cheaper, plastic mylar coated in an aluminium film. The plastic/film will work but will deteriorate to white powder very rapidly with the slightest moisture. Obviously the plactic/film needs to be backed up with plenty of real copper wires in the braid and the braid must make good contact at the plug outers.
Coax cable with a copper plated steel core is NOT suitable.
The ideal plugs to use are the axial crimp type as they contain a rubber 'O' ring that makes a good seal to the outer plastic sheath of the cable. Unfortunately, axial crimp plugs and particualarly the tool to do the axial crimping are not easily available to the self installer. Whatever you do you must seal the outer coax connectors with waterproofing as any moisture getting in will ruin the service within weeks/months. Electronic grade silicone grease may be applied to the cable end and pin prior to connection.
When installing a Tooway make sure your service reseller knows what you are doing and has the correct details of your hardware and has authorised your site to operate with Skylogic.
When pointing the dish remember that getting a good enough signal is not enough, and is not the objective. You must get to the exact centre so that the narrower transmit beam is centered accurately. It is no good if your receive signal looks excellent and the transmit beam is way off.
It would be helpful if more people, with normally operating sites, send in their screen status measurements so we can get a better idea of what is normal.
Best regards, Eric.
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