Lnb Quattro Vs Quad
Jul 14, 2011 A quad LNB is ideal where a maximum of four satellite feeds is required and there is not much possibility of expansion. Quad LNB is also ideal for TBS 6894 satellite quad tuner card building. The quattro LNB provides four outputs, each with a single band/polarization specific to that output. The band/polarization available at each. I was told some time ago that the Q wide-band LNB was supposedly quite different in that the vertical and horizontal signals where kept completely separate, but i am not convinced as i bought a new motorized dish and LNB which is just a std type and it receives all the free to air UHD broadcasts with no problem, also if the Q LNB was so different why can i receive normal free-sat on all of.
One new development has materialized however, the massification of PLL (Phase Locked Loop) oscillator technology. Before we go further let me quickly explain about this oscillator stuff.LNB's are electronic devices whose purpose is to amplify and convert the extremely weak and extremely high frequency satellite signals into stronger and lower frequency signals capable of being carried over a coaxial cable to the satellite receiver inside your home.
To convert a frequency to another frequency an oscillator circuit is required.Most lnb's use what is called DRO (Dielectric Resonator Oscillator) oscillator technology. And PLL oscillators in lnb's are nothing new, but until about five years ago use of PLL controlled oscillators was restricted to professional use (and expensive) LNB's.
This has changed, and now PLL technology can be found on many low cost mass market lnb's. But is it worthwhile? Let's compare both technologies. Conventional LNB's use dielectric resonator oscillators (DRO) to generate the local oscillator frequencies necessary to down-convert the satellite signal (Ku, Ka or C band) to the IF band used by satellite receivers.
These DRO's use pill-like ceramic components glued to the lnb board as part of the oscillator circuit. If the lnb is dual band it will have two DRO's, one for each band. The DRO oscillators are tuned when the lnb is assembled but they are affected by temperature and can drift in frequency. In a mass market lnb, this frequency drift (up or down) can be as high as 3Mhz.
Unlike conventional DRO lnb's, PLL lnb's use a digital (PLL) circuit to generate the local oscillator frequencies needed to down-convert the satellite signal (Ku, Ka or C band) to the IF band. An lnb down-converter PLL circuit is comprised of a chip (IC) and a crystal oscillator. The IC generates the oscillator frequencies from the crystal and then mixes, down-converts and amplifies the resulting IF signal. Commercial mass market PLL lnb's have local oscillator frequency drift from 300Khz to 500Khz. It can be, but not always.
Lnb Quattro Vs Quad Cities
A PLL lnb is not necessarily better than a DRO Lnb. There are excellent DRO lnb's. You must be aware that other factors besides oscillator stability affect signal quality.
For example, it can happen that you install a more stable PLL lnb but its frequency response is not as good as the previous DRO lnb. If you are having trouble receiving low bitrate transponders (like SCPC) then, a PLL lnb could indeed improve reception. However, if all the channels you are interested in are being broadcast in wide bandwidth transponders with high symbol rates (for example 15Mbits or more), then likely little improvement would be gained with a switch to a PLL lnb.If you would like to share your experience with PLL lnb's please leave a comment!