- Apr 18, 2008
low signal that cuts in and out
well since you "randomly" picked two satellites on the western arc for you how about eastern?
try EWTN on G11
This TV or TVU on 87W
you mention NASA is "horrible"...define horrible
-low signal so it cuts in and out?
Heck on my 4 footer I locked NASA at 31 which is just above threshold and it worked fine with no breakups for almost an hour that day I watched it
last pic in thread
the only channel i can get to come in on the h-side of 87 is a channel mvs-better level 69-70 quailty 59-60
il try to get this tv ina minute
EDIT i locked it it level 71 quaility 89-90
i also got the unemployment channel at level 70 quaility 44-48
The lnb is over twenty years old, and is a 25 degree. So im thinking the lnb is not that great with digital reception
Yeah, it's a reflector, but the reflector is still part of the antenna. The OTA antenna you refer to is made up of dozens of elements, including director, and reflector elements, and "driven" elements. With a C-band system, the probe inside the feedhorn would be referred to as the driven element, and the dish itself as the reflector element. It IS proper to refer to a dish as an antenna. I have a book on antenna theory, and there is a whole chapter on parabolic dish antennas......
its the same principle as if i moved an ota antenna and pointed it right at the station, and the picture is bad, its the receiving elements of the antenna
people call that a dish antenna, witch is improper, the dish part is a satellite reflector, the dish itself does not act as an antenna, it just reflects the signal to the lnb, the metal wire inside the lnb, is the antenna
I agree with the other responses, that the lnb is probably not the problem. If you get analog.I could have the best satellite dish in the world, like a birdview, but if the lnb is outdated, it wont work to well with digital reception.
This issue has always confused me.I like my dish, while depeer dishes such as the winegard pinacle, have better control over adjacent satellites, but dont have good gain, the deeper you go, the less gain you have
Oh I have, and have never found anything explaining any relationship between gain or resolution and F/D ratio or FL. Every equation I've ever seen for gain and resolution says that there is no relationship.Google "deep vs shallow dish" you will find the answers.
I like my dish, while depeer dishes such as the winegard pinacle, have better control over adjacent satellites, but dont have good gain, the deeper you go, the less gain you have
This is part of a common misconception. What is critical for receive-only dishes is SNR, not gain. Gain is part of SNR, but so is noise rejection. Radio astronomers employ deep dishes because their noise rejection is higher than with shallow dishes. All things being equal, we should do the same.
However shallow dishes are easier and cheaper to make. A feed designed to match a shallow dish will only illuminate the center portion of a deep dish. Hence the illusion that deep dishes have lower gain. Unfortunately there are very few FTA feeds that perfectly match deep dishes. The scalar ring design is wrong and normally cannot be pulled far enough back. If you look at the theory of feed design, one can achieve almost the same gain out of deep dish as a shallow. Coupled with the better noise rejection, the result can be exceptional.
Would I be correct in assuming that the scalar rings on the C/Ku feedhorns are only effective on C-band?