TROOPER
09-29-2008, 03:13 PM
c/p
There has been much confusion and mis-information about Signal Strength and Signal Quality, and I want to try and dispel these myths and rumors to help testers use these two indications properly and effectively.
Signal Strength (SigS) - is little more than an indication of LNB output power - a good reference that your LNB is turned on and working, and that your STB output power, cabling, switch, and connectors are all OK. The SigS indication is only measuring as far away as your LNB, and That's it.!! Once you see a reasonably good SigS indication, make a mental note that your LNB and antenna system is working fine, and then FORGET ABOUT IT..!! DO NO USE IT FOR ANYTHING ELSE ..!!. Conversely, if you have a low or no SigS, it's time to start looking for a bad LNB, poor or wet/corroded connections, damaged cable, STB output problems, etc. To prove this explanation, humor me and try this..: Connect a spare LNB to your receiver with a short RG6 jumper, turn on your receiver, and note the SigS and SigQ indications.. See how the SigS is relatively high, while the SigQ is low or non-existent.. put the LNB in your pocket and note that you still have the same relative SigS.. definitely *NOT* any indication that you are receiving a sat signal..(unless you have a very unusual pocket.!!)
Signal Quality (SigQ) - *IS* an indication that your dish/LNB setup is receiving a valid satellite signal from somewhere ...although not necessarily the bird you really want...SigQ is actually measuring a signal being received from a satellite 22,300 miles away. The absolute value of SigQ will be directly related to how well you point your dish, and align your LNB. Once you determine that it is, in fact, the correct bird, ONLY then is higher SigQ is always better..Tweak your dish and LN, to max SigQ for highest indication, which will ensure best viewing, and greatest fade-margin against weather and other occurances. Once you have Locked-On to a valid signal and have reasonable SigQ, then it is time to do a quick sat scan to verify what bird you have locked on to, and then move on with your receiver setup, etc...
Both SigS and SigQ are "relative" numbers.. In other words, they are not calibrated or referenced against anything in particular.. So, a 75 on one STB might read 48 on another box connected to the exact same antenna setup. I have personally witnessed this, and learned the hard way, not to trust absolute numbers.
DOs and DON'Ts
NEVER try to scan for channels before achieving a reasonable Signal Quality on your receiver.. It is futile to try and scan a satellite that you have not locked on to yet..It's like trying to start a car before putting gas in the tank.
NEVER use Signal Strength to try and align dish/LNB.. it's futile, since it only means that your LNB is working..
NEVER use Signal Strength and Signal Quality as absolute numbers.. What you are used to on one receiver might be totally unattainable for another user.. and what he is observing might seem low to you, but is totally maxed out on his setup by comparison.
ALWAYS use Signal Quaility to line up your dish and LNBs.. It is *THE* indicator that tells you you're on a valid satellite, and most likely the one you are trying to lock on to.
ALWAYS scan for channels after maxing your Signal Quality indication and verifying that you're locked onto the correct bird.
ALWAYS use the Signal Strength and Signal Quality indications as references for YOUR box
There has been much confusion and mis-information about Signal Strength and Signal Quality, and I want to try and dispel these myths and rumors to help testers use these two indications properly and effectively.
Signal Strength (SigS) - is little more than an indication of LNB output power - a good reference that your LNB is turned on and working, and that your STB output power, cabling, switch, and connectors are all OK. The SigS indication is only measuring as far away as your LNB, and That's it.!! Once you see a reasonably good SigS indication, make a mental note that your LNB and antenna system is working fine, and then FORGET ABOUT IT..!! DO NO USE IT FOR ANYTHING ELSE ..!!. Conversely, if you have a low or no SigS, it's time to start looking for a bad LNB, poor or wet/corroded connections, damaged cable, STB output problems, etc. To prove this explanation, humor me and try this..: Connect a spare LNB to your receiver with a short RG6 jumper, turn on your receiver, and note the SigS and SigQ indications.. See how the SigS is relatively high, while the SigQ is low or non-existent.. put the LNB in your pocket and note that you still have the same relative SigS.. definitely *NOT* any indication that you are receiving a sat signal..(unless you have a very unusual pocket.!!)
Signal Quality (SigQ) - *IS* an indication that your dish/LNB setup is receiving a valid satellite signal from somewhere ...although not necessarily the bird you really want...SigQ is actually measuring a signal being received from a satellite 22,300 miles away. The absolute value of SigQ will be directly related to how well you point your dish, and align your LNB. Once you determine that it is, in fact, the correct bird, ONLY then is higher SigQ is always better..Tweak your dish and LN, to max SigQ for highest indication, which will ensure best viewing, and greatest fade-margin against weather and other occurances. Once you have Locked-On to a valid signal and have reasonable SigQ, then it is time to do a quick sat scan to verify what bird you have locked on to, and then move on with your receiver setup, etc...
Both SigS and SigQ are "relative" numbers.. In other words, they are not calibrated or referenced against anything in particular.. So, a 75 on one STB might read 48 on another box connected to the exact same antenna setup. I have personally witnessed this, and learned the hard way, not to trust absolute numbers.
DOs and DON'Ts
NEVER try to scan for channels before achieving a reasonable Signal Quality on your receiver.. It is futile to try and scan a satellite that you have not locked on to yet..It's like trying to start a car before putting gas in the tank.
NEVER use Signal Strength to try and align dish/LNB.. it's futile, since it only means that your LNB is working..
NEVER use Signal Strength and Signal Quality as absolute numbers.. What you are used to on one receiver might be totally unattainable for another user.. and what he is observing might seem low to you, but is totally maxed out on his setup by comparison.
ALWAYS use Signal Quaility to line up your dish and LNBs.. It is *THE* indicator that tells you you're on a valid satellite, and most likely the one you are trying to lock on to.
ALWAYS scan for channels after maxing your Signal Quality indication and verifying that you're locked onto the correct bird.
ALWAYS use the Signal Strength and Signal Quality indications as references for YOUR box