Just a few additions to what Steve said.
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Originally Posted by pdn6420
1. Is there a way to measure the elevation of the dish to check against calculated value? Would this measurement be the difference between calculated value and offset angle? the reason for this is the mount that come with the dish if a U bolt mount with the elevation scale adjustable via two nuts on two arcs. There seems to be enough play in the arc to make a different in the elevation and I just want to be able to verify the elevation. this is the U mount bracket.
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Originally Posted by elgemcdlf
1. Forget about getting all scientific on the dish. Locate peak signal and that is that. Standing there saying "but the settings are exactly what ... says" does not get you signal.
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I agree to an extent. If you check my post where I tried to find a suitable place on those dishes to measure the elevation angle with an inclinometer, I basically came up empty. There isn't any surface on these offset dishes that corresponds to where the dish is actually
aiming, so that setting is unfortunately going to be only a starting point. However, it helps tremendously if you have either the motor angle or this dish elevation (declination) set accurately before starting your search for signals. With a big dish it is best to accurately set the declination, then set the motor elevation via peaking on a signal. Since that isn't possible with these little dishes, it becomes advisable to set the motor angle accurately, THEN, when you peak on your south sat, both will be set properly, and you probably will never have to touch them again.
Now, re getting scientific with the motor elevation, this CAN be done, because it isn't complicated by that offset angle. You can generally find a surface on the motor which is either parallel or perpindicular to the motor's shaft rotation axis, not the bent part, but the part inside the motor. With an inclinometer, you can verify that the motor elevation scale is correct, and, if you use this after the motor is on the pole, it can compensate for a non-plumb pole tilting to or away from the south. ( Tilt to the east or west can be compensated for too, but it's much more complicated.)
Anyway, I agree that you should forget about trying to be accurate with that dish elevation, since there is no easy way to measure it. However I really think that you should do your best to be very accurate with the motor elevation. It will save you a lot of work. I set my motor elevation, then set the dish elevation by peaking on the south sat, and never had to touch either again ie the remaining adjustment was done by rotating the whole assembly on the pole.
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Originally Posted by pdn6420
2. I have a merc II and was wondering what is the signal bar indicated? Is this power from the LNB? or something else. What is the quality% measured? i.e if you have signal should you not get similar quality?
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Originally Posted by elgemcdlf
2. One of the great mysteries of life  |
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I agree with this one completely. No two receivers give the same reading on the same signal, and even the same receiver gives different values when upgraded with different software. Signal, as you say relates to the signal strength (not sure if power or voltage) from the LNB, but it's not in any absolute units. The quality, is a mystery. It seems to relate to some combination of signal/noise and error rates, and the error rates can be corrected or uncorrected. But basically, if you have a bad enough signal that you have a lot of uncorrected errors, you won't get a lock, and if you don't have a lock, you generally have a ZERO quality reading. Once you get that lock and start getting quality, then it seems like different receivers have different ways of calculating quality. I have one receiver where 30% is a good reading, while on another receiver on the same signal I might get 90%.
Basically QUALITY is more important than SIGNAL, because signal includes components of noise, and you'll typically get a signal reading even when pointed at the ground, and I've seen examples where signal gets higher when you move away from the sat you are aiming at, because it also contains components from nearby sats that may be stronger than the one you're aiming for. However QUALITY only occurs when you are locked on the signal, and higher is always better.
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Originally Posted by pdn6420
3. Does distance and impedance on the RG6 cable have affect on quality and signal? what is the distance limit on the RG6 cable from LNB to receiver.?
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Originally Posted by elgemcdlf
3. Yes. The recommended limit is 75' but many of us here are running far longer runs than that. I have one going roughly 90' to a DiSEqC switch and then another 55' or so to the lnbf (circular C Band). There are some here saying they are in the 200' range. Personal experience has shown me that the longer run does mess with the DiSEqC switch a bit.
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I'm one of those in the >200' range. This isn't a problem for the signal. It may be a problem for DC and for DiseqC transmission, but I'm not sure. In theory, impedance shouldn't be a problem for the signal, but the DC resistance can be a problem for the DC power to the LNBs and motor.
Linear Mode
