Difference with new lnbf and old lnbf

[satellitecrazy]

I am using the original lnbf that came out in 1994. It is like a 62 db lnbf. My question is this. What kind of difference would I have with a new lnbf? With this one and a microhd I am getting high signals on most tps.

If anyone can tell me what I can expect with a newer one I would appreciate it. I just dont want to buy one if it wont make a difference.

 

[migold]

It might help to make a comparison, if you could provide a photo of the label on the original LNBF - to show the specs, and if you can give some Qs for Transponder IDs for the satellites that you are receiving. And are there some TPs that you are not receiving on some common satellites?

 

[satellitecrazy]

Ok on the anik 107.3 mux on 4020 v and 4160 nets as well as the others I am gettibg 75 or so avg quality. On 87 ses sat mux nets i am getting 73 or 74. On g16 mux for net feeds i am getting 85 q.

 

[Lone Gunman]

With a DMX-741s I never get any Q higher than 85% with a Micro HD. I'd guess that the average Q I see is somewhere around 70/75% for Cband.

 

[richyrich]

with a dish; it is size, then aiming; then the lnbf does its stuff. Noise level of the lnbf; gain in amplification; size of aperture or designed freq. range or signal desired might be the "actions" the lnbf can be rated for; all by itself from any "one dish". Right now my 1200 receiver is on MPEG-II; using dmx721; and is working at 52-3 quality; but not when it goes to 46 quality. How well I tune a feedhorn into the dish (and its size) it works on makes the only differences old lnbf or new. AND IF C ONLY LNBF; this does matter is the design! These C/Ku are a cause for both; and each; but not one or the other; so the probes or real antenna become the matter of the design that is focal length required for each to receive the optimum signal for each is a point the new design has under an older one. The Ku in the back of the throat requires that the installation point the feedhorn so that the ku is received without the c band probes getting in the way of the ku satellites aim! And be at the correct position to receive the focused ku signal. This makes the installer adjust for ku using a slight offset of c band focus; rolling the ku band into the feedhorn un-obstructed. The C band remains strong also; because the feedhorn (lnbf) has been optomized at KU (and then C Band is rolled into also); making this new style, or type, work as good as any other. Drift, noise, aperture alignment; all for the dish you need to tune; it is not "easy"; but it is optimal!!! The installer then can do it perfectly; or one or the other will lose a little bit of gain; very important at mpeg-iv; let alone 20 channel wonders.

Have you looked at a Co-rotor II+ lately? It is the opposite in design; in that it focuses ku first; while still not getting in the way of the C...No shadows occured on C because ku was focused before the c was realized; allowing the c band signals to go right by the ku. on a dmx741 the ku is way back in the feedhorn, after the c probe and bar caker! The bar at the opposite polarity is thick, and if you point the c band feedhorn at the middle of the dish like it is supposed to be; perfectly; the ku band probe will be partially blocked; but if you offset from the middle the lnbf pointing; the shadow is removed!

A feed with the c Band probes as more forward (bar and probe); would remove some of the shadow. At Ku frequency (a smaller aperture) is needed, but less shadow means smaller obstructions cause more losses.

 

[richyrich]

Seavey's design had old chaparral corotor old bar before probe in its design; and had obstruction using fin's to bring the c band to its probe; or antenna. Each of these designs worked just fine at both ku and c. Seavey's offset ku utilized a toroidial effect of the dish being used; using the offset at horizontal to accrue its ku signal (like dish and directv do) making the dish move the signal 2-3 degree's to receive the same satellite the c was receiving. If the c band bar and probe was changed to dual polarity with each being static as dual feeds do; then the shadow becomes smaller because the bar is not used, and both probes are the same small shadow both polarities at one pointing, and less material towards the back, and in design would be less shadow to the ku would be what could make its design "better".

 

[richyrich]

Now look at the PLL wonders. This part of lnbf design makes the lnbf perform better because it uses isolation to accrue same volume of bandwidth at a better drift quotient. Temperatures do not effect it as much either (sunlight); because the center freq. is the i in the equation; and the waveguide already is focused to this "type of fact" in lnbf design. A beafier set at the waveguide's ground does this as the isolation is doubled to "tune" i. Drift becomes cut in half; and so is the noise because of it!