LNB Offset Testing (sorry, no more free LNBs)

I second that.

For fun, I’ve been reverse engineering the firmware for a commercial automatic antenna and there’s really not a lot different. It has a magnetometer and accelerometers so it knows which way is north and how the base is tilted… after that, it does the same thing that we all do: wave the antenna around the sky and look for the strongest signal.

It doesn’t even have a GPS so it can’t even roughly point the antenna. At least we can use a web service to ballpark our aim. .oO(“according to google maps, point the antenna at about 2 fists above that tree over there…”)

I like that ‘rule of thumb’… stretch your arm out and a fist is about ten degrees, so
each finger is about two degrees.

After the new lnb lost its signal and lock after the first time I aimed it now that it’s lost it I am unable to find the signal again when I tried to reaim the lnb this past weekend I have to try to aim it again one of these days but if that failes I’ll have to try the old lnb I have a bad feeling that the new lnb has failed.

Tyler, I’m now on the old Maverick LNB on my offset 80 cm dish. It works fine. As you know, the new LNB had lower SNR readings, and since I don’t need the new LNB to close a link, I went back to the Maverick.

I am wondering what’s going to happen in Europe when @Syed Syed gets a new ku provider up. Will I need the new crystal controlled LNB for the new satellite, or will the old Maverick PLL work.

I’m leaving in 2 weeks for Northern Italy, and would like to take the right gear with me. Ken

@kenbarbi i think i tracked down the issue due to a corrupted sd card ive been running the same sd card since i got it but i didnt think it would of killed it so im wipping it and going to surface test the sd card and then put the os back again…

If you have another SD card, you might want to try that too. Ken

Yep replaced the SD card and it has been going strong I wonder what to the other sd card @kenbarbi

A mystery for sure. I have heard others had this problem, and the cause was usually stated that “the card wore out”, but that makes no sense :unamused: I’ve not had such a problem yet with any of my SD cards in the Dreamcatcher, my computers or cameras.

Possibly you can “recover” the card if you do a complete cleaning with a program like Aomei Partition Assistant or Rufus to satisfy everyone’s curiosity. Ken

When I ran a surface test on my PC on the card it didn’t find any bad sectors.

Just for kicks, reburn the SD card with Skylark 5.5 and see if it works. If so, it’s a keeper - - if not RECYCLE :smile: Ken

Not relevant to your problems, but with the next version of the product, we will be including pre-flashed microSD cards.

2 Likes

good idea , and with the over-the-air update feature that was proven last fall, this will make it more turn-key user friendly.

1 Like

It would be useful, at least to me, to have even a short list of approved/tested LNBs for my own experimentation as well as a spares or local replacement buys considering mine might end up out in blistering heat.

Any standard FTA/universal LNB can work, but the frequency offset needs to be measured. LNBs usually support offset/stability of 1 MHz, which is larger than our carrier bandwidth. Unfortunately, I don’t know of a good way to measure the offset without specialized equipment.

First you need to power the LNB. And then you need to generate a 12 GHz signal (strong harmonics of a lower frequency also work). I guess an RTL-SDR could be used to measure this.

Well, so far any pll LNB worked just fine.
If it can 4K UHD it mostly has a decent enough PLL inside in my experience.

I’m overthinking this. If you don’t mind trial-and-error, then it’s possible to do a manual search by changing the frequency by +/-200 kHz increments.

But @Tysonpower is correct: Most of the newer LNBs should work fine.

I think it is important to note that in version skylark 5.5 in the tuner setup, there are two
options for predefined lnbf
the Maverick1 with a 10.750 GHz LO offset
the Othernet dual band with a two alternative local oscillator frequencies, 9.75 GHz and 10.6 GHz
(note that a the 22khz tone on the feedline to shift to the higher LO)
(thus I think ??? when selecting Othernet dual band it is running at the 10.6 GHz L.O.)

what gets confusing is to try and use custom frequencies or as syed says manual search
if we are given a satellite frequency… what do you enter in the custom frequency setting.

It is not the satellites frequency, but is adjusted for the L.O. differences from the ‘pre-defined lnbf’

what confounds me is how both
Americas 11.90240 - offset 10.600 = 1,302.4 MHz into the dreamcatcher
Europe 11.681242 - offset 10.600 = 1,081.242 MHz into the dreamcatcher

or using the maverick that also works for both
Americas 11.90240 - offset 10.750 = 1,152.4 MHz into the dreamcatcher
Europe 11.681242 - offset 10.750 = 931.242 MHz into the dreamcatcher

You’v stumbled upon a sort of a “easter egg” in Skylark: if you enter a custom freq much below Ku-band, skylark assumes you’v given it the IF output from the LNB. Thats how entering 1.3024 etc works the same as entering 11.90240.

You can enter 11.90240 as well in the custom frequency, in which case Skylark knows this is too high to be IF and adjusts it by the correct LO of the LNB.

Either way is fine. I’d recommend sticking with the Ku-band frequencies, as that means you are not relying on undocumented behaviour. The one scenario where entering the IF is more convenient is if you are using an LNB with a different LO than the official ones.

I think you all are overthinking it. Just use a decent LNB and you will not need any offsets. just enter the frequency of the sat and you are done.

I tested 5 or 6 LNBs and they where all fine. Just get one with PLL / Stable frequency.

@Tysonpower Are you able to use a standard LNB on QO-100?