PDA

View Full Version : PLL vs DRO LNB?



funtime26
24-09-2020, 09:44 PM
Been a long time since we had proper discussions about LNB's. But after a tip off elsewhere it seems there are some new budget kids on the Low Noise Block.

Time for some plagiarism:

"Do I really need to buy a PLL?

PLL (Phase Locked Loop) oscillators, simply put, use a more accurate reference clock than DRO (Dielectric Resonator Oscillator) on most budget LNB's.

If you are a typical SAT hobbyist, you will benefit from a PLL. You will get higher signal strengths (quality) on most signals, higher rain fade resistance, higher stability. You will almost certainly be able to bring in more channels and stabilize weaker and borderline feeds. PLL will help stabilize troublesome DVB-S2 signals. If you feed hunt you should lock more wildfeeds and bring in many of the weaker ones"

More info here: hxxps://allseeingtech.com/2019/08/20/pll-vs-dro-lnb-which-is-better/

I have just bought INVERTO PREMIUM PLL LNB IDLB-SNL410-PREMU-OPN for less than a tenner including postage!

When I eventually get off my backside and install my new Gibertini OP 125L I will test this out alongside an old C120 inverto black pro (with new Gibertini feedhorn) and my good old faithful inverto black ultra I've used for years.

Gotta love this hobby! Will get there but don't expect this to happen quickly! :D

69185 69186

ouagadougou
25-09-2020, 03:05 AM
One other benefit is improved performance with low symbol rate signals because the LNB Local Oscillator isnt wandering around all over the place like it does with a DRO so its easier in general for the receiver to "Lock" to the carrier from the satelitte and maintain "Lock". There is also a lot of information in the Amatuer Radio community and on Y*****e related to QO-100 at 26E on Es'Hail 2 where they are receiving SSB voice bandwidth signals of 2.4KHz with excellent stability using PLL LNB's that can also be modified and locked to a GPS for even better performance. They are also receiving DVB-S2 TV with very low Symbol Rates and bandwidths, 333Ks/s is quite common and lower is possible but not all receivers can handle these low Symbol Rates. You can also see the Es'Hail promo on 10492H (outside normal band) SR1500 4/5 QPSK DVB-S2.

Barney
25-09-2020, 08:29 AM
@ funtime26 has exceeded their stored private messages quota
please clear your inbox ...
cheers !

3tv
25-09-2020, 10:37 AM
i bought a pll lnb last year, forgot which brand. it performed worse than my old black ultra. I would love a better lnb, any thing that will give me and increase in signal. What ive spent on various so called amazing lnb's, better gain/signal etc has ended up just being snake oil. I should have just put the money aside any used it to buy a bigger dish.

Barney
25-09-2020, 10:50 AM
At the moment i'm using Golden Media Twin LNB on my 1.2M Channel master dish , and Inverto Black Pro C120 Quad LNB on my 2 meter Prime Focus dish . i was hoping to hear that the INVERTO PREMIUM PLL LNB was somewhat better for offset dish i guess i'll be sticking with my Golden media twin LNB then ? :banghead:

funtime26
25-09-2020, 07:15 PM
... ended up just being snake oil. I should have just put the money aside any used it to buy a bigger dish.

This hobby is snake oil :D ... just came across that PLL v DRO article and seeing as I have just bought the biggest dish I'm going to ever buy (which in turn has the best gain for a dish of it's size Gibi) I thought seeing as I'm (initially) ground mounting my OP 125L (it may get promoted skyward depending on my neighbour's 6 metre tree (dishpointer reckons it shouldn't block my view until it's 6.5m tall) ....I may as well test a new PLL LNB as only £8.99 :respect-050:

ouagadougou
26-09-2020, 07:29 AM
I couldnt agree more about the snake oil :-) all these claims about 0.1dB NF LNBs is absolute marketing rubbish! I have an Octagon PLL LNB which I tried this morning just to see how it compared to a cheap Elsat LNB which are widely used in Southern Africa on a 30cm Elsat offset dish. The PLL is more stable in frequency and there is a lot of information about the Octagon LNB on the internet.

Overall the Octagon gave similar Signal Strength and Quality numbers on a Spiderbox 6000. I will try and find some low Symbol Rate signals on 19.2E (fixed dish only at the moment) later. I cant compare the frequency stability unless I hook up an SDR dongle but I do know the Octagon is quite stable and has been measured by numerous people. The Octagon has a long neck and was sensitive to the postion in the LNB holder and mid way along the neck was the best postion on this small 30cm dish.

Pictures below show before and after the change. I tried 3 frequencies Low/Mid/High just to see how things looked across the band.

69187
69188
69189
69190
69191
69192
69193