300KHz stability on Ku LNBF..

[Cham]

One manufacturer has started selling a Ku lnbf with 300KHz stability. Wonder how these actually work compared to the standard 1MHz stability most of the LNBF units? There are a few Ku S-2 feeds such as PBS at 125w but these channels work fine using a run-of-the-mill LNBF. Maybe would give an extra 2-5%Q?
I might be more interested in a C-band LNBF with, lets say 100-250KHz stability, if close to the existing products price range. Are any of the forum sponsors looking into this? Just curious.

I have set up both C2 and ESX-241 LNBF units and both work very well as-is.

-C.

 

[SatelliteAV]

We have no plans on distributing a PLL KU-Band LNBF at this time. We have extensively tested many PLL LNBFs from multiple manufacturers and found that they did not provide reception or performance gains over a quality build DRO types. Even though the frequency is stabilized with a phase lock loop electronics, the current PLL LNBF designs do not offer a complete performance package.

KU-Band PLL LNBFs are currently only produced in Universal type with dual LO 9750/10600MHz. Universal LNBFs have traditionally been poor sellers in North America and are outsold by Standard types by over a 200:1 ratio.

PLL LNBFs also have significantly higher noise ratios, lower gains and do not have the even response and gains of traditional DRO types. The PLL amplification gain is typically only 50dB with NR ranges from 0.8 to 1.2dB NR. The polarity isolation is very similar to DRO types. The 300MHz stability is reached after the operation temperature has stabilized and will remain at +/- 300KHz when optimum operating temperature is maintained, but this is quite typical of a DRO LNBF at operating temperature.

We are very familiar with the factory that is producing this LNBF and I can assure you with 100% certainty that this distributors product specifications are pure marketing hype (misrepresentation). The 0.1dB NR is nowhere possible on this LNBF..... PERIOD! So tired of the marketing BS bunk!!! Yes, factories do charge about 50 to 75 cents more for this design, but in my opinion the current PLL LNBF builds are not well designed and do not provide any performance gains or advantages. I believe that a distributor could develop a high performance Standard type LO, PLL LNBF, but this design is just an off-the-shelf design with average performance. The hype is just that...... Typical of this distributor...BTW

Please test and post your PLL LNBF performance results to this thread. You may view the test results from a previous post @ http://www.satelliteguys.us/free-air-fta-discussion/256614-ku-band-lnbf-testing-results.html
Note: At the time on the test, I was incorrectly informed by the manufacturer that the PLL LNBF performance better than subsequent testing indicated....

 

[Pixl]

Brian,

I just came to the same conclusion. I just took delivery of two NJR2842H lnbs, now these are not lnbf, but instead use the original feed horn of my Channel Master dish and a orthomode feed from a Prodlin Tx/Rx dish. They are PLL 100khz design, but perform only slightly better than the Invacom it replaced. An expensive slight improvement, $200 ea, takes two. I'll be doing more testing over several sats. As of now they are only 2 points higher on S and Q than the Invacom. Both are universal and can get the lower band channels from the Eastern sats.

 

[Cham]

Maybe some of the gains we see using higher stability LNBs is more due to feedhorn design and/or type of probe in the feed horn rather than the actual LNB circuitry.
Also the receiver's AFC might compensate for LNB (LNBF) local oscillator drift, 1MHz at Ku is only a few KHz at the receiver's input frequency.
The Invacom LNBFs are well built units both in circuitry and physical design, tough to beat. The ESX-521 is very close in performance to the SNH-031 from what I can tell from using both on the same dish.
-C.