Firstly what do DRO and PLL stand for?
Terms perhaps we take for granted without understanding what the real differences are between “DRO” and “PLL” LNBFs.
DRO stands for Dielectric Resonator Oscillator
PLL stands for Phased Locked Loop.
In simple terms, Phase lock loop or “PLL” LNBF’s are more stable than DROs, because they use a more stable internal reference source by utilising crystal oscillators.
Up to now, all domestic LNBFs used for satellite TV reception use dielectric resonator stabilized local oscillators. The DRO resonates reasonably well at the required frequency and is very cheap to produce hence its wide implementation into domestic Satellite TV installations.
However, compared with quartz crystal based LNBFs, a DRO is relatively unstable with temperature, and frequency accuracies of approximately +/- 250 kHz to as much as +/- 2 MHz when used at the higher Ku band frequencies resulting in wide signal fluctuation.
This includes both the initial value, plus variations of temperature over the full extremes of the operating range. This really has not been a problem with most Multiple Channel Per Carrier “MCPC” TV carriers using quite wide bandwidths ( 36 to 18 MHz)
This common use of wide bandwidths has provided a buffer, so even with 2 MHz errors, the indoor receiver will successfully tune the carrier and capture it within the automatic frequency control capture range.
However today we are now seeing the increasing use of Single Channel Per Carrier “SCPC” broadcasts where many narrow carriers are squeezed into a half or full transponder on a satellite.
This requires good phase noise performance for the reception of low bit rate digital carriers and for digital carriers using high spectral efficiency modulation methods like 8-PSK, which reduce the bandwidth required but need more power from the satellite.
If you want an LNB or LNBF for the reception of narrow carriers then the latest generation of “Phase Lock Loop” PLL LNB’s or LNBF’s really is the answer.
PLL LNBs have an internal crystal oscillator or rely on an external 10 MHz reference signal sent up the coaxial cable by the indoor receiver. Because of their stability, they are the choice of commercial installations but their cost has traditionally been prohibitive for the domestic user.
The new Avenger PLL321S-2 now provides the stability that broadcasters have relied upon for stable reception of “Feeds” “back hauls” using as little as 9MHz of bandwidth and symbol rates as low as 2000 M/s but at domestic prices.
Now you can get extremely good stability (300 KHz or better) for your satellite system at about the same price that you would pay for a DRO LNBF. The new Avenger PLL LNBFs are 300 KHz or better for about the same price as a medium priced DRO LNBF
Do not be caught unaware, the digital satellite world is quickly turning to DVB-S2, MPEG4 and High Definition with increasing factors that require much higher stability.
Your solution has arrived, the new Avenger PLL321S-2 has seen the future.