PLL vs DRO LNBs

Discussions techniques et évolutions technologiques de la réception par satellite en bandes Ku et C (initiés)
Répondre
Feedman
Curieux
Curieux
Messages : 46
Enregistré le : jeu. 31 déc. 2015, 18:41

PLL vs DRO LNBs

Message par Feedman »

Anyone made detailed comparison tests between PLL and DRO LNBs? Obviously I know that PLL units are more and more stable than DRO (10 or 25 KHz vs 250 KHz), but what about real noise figures? For example, many DRO LNBs specifications read 0.2 dB in noise figure, but I suspect it's not totally true.... it seems too much. PLL LNBs declares around 0.6-0.7 because they include more "noisy" local oscillators. What about differences in daily reception, particularly looking for SNR parameter? Is there real difference getting very weak signal, obviously with the same dish size? Anyone made real field tests? Thanks.
mattmatt73
Passionné
Passionné
Messages : 2043
Enregistré le : mer. 21 oct. 2009, 01:25

Re: PLL vs DRO LNBs

Message par mattmatt73 »

Feedman a écrit :Anyone made detailed comparison tests between PLL and DRO LNBs? Obviously I know that PLL units are more and more stable than DRO (10 or 25 KHz vs 250 KHz), but what about real noise figures? For example, many DRO LNBs specifications read 0.2 dB in noise figure, but I suspect it's not totally true.... it seems too much. PLL LNBs declares around 0.6-0.7 because they include more "noisy" local oscillators. What about differences in daily reception, particularly looking for SNR parameter? Is there real difference getting very weak signal, obviously with the same dish size? Anyone made real field tests? Thanks.
hi and be the welcome to this board.

The difference between LNB DRO and PLL is only the stability of oscillator , there no link with noise level.
Except with real professional product, the indicated noise level is a pure poetry.
Feedman
Curieux
Curieux
Messages : 46
Enregistré le : jeu. 31 déc. 2015, 18:41

Re: PLL vs DRO LNBs

Message par Feedman »

Thank you very much for your reply. OK, you just confirmed my opinion. I tested two SMW PLL LNBs (25 KHz). Although during first test I suspected noise figure was little high complared to common DRO units, making deeper tests it was good, and this units are very solid and stable. Thank you again.
mattmatt73
Passionné
Passionné
Messages : 2043
Enregistré le : mer. 21 oct. 2009, 01:25

Re: PLL vs DRO LNBs

Message par mattmatt73 »

Feedman a écrit :Thank you very much for your reply. OK, you just confirmed my opinion. I tested two SMW PLL LNBs (25 KHz). Although during first test I suspected noise figure was little high complared to common DRO units, making deeper tests it was good, and this units are very solid and stable. Thank you again.
You've right...
Répondre