European (Sky Q) LNB compatible when I move to TheUSofA?


#1

So during my move tidying up of my accountants for my move the Colonies, I realized that my Ku band lnb provided by Sky is and I quote ‘wideband’ with a bandwidth of 5GHz.

Is this even marginally compatible with the future outernet service?

Or shall I just use this as a radio telescope :slight_smile:


#2

Henry,
The DreamCatcher 3.0 kit includes the LNB. There is no dish.

ThereIsNoDish

LNBs are nowadays inexpensive and mass-produced in China. You won’t need to pay for shipping on that dish. If you want to build a radio telescope, there’s plenty of old C-band dishes waiting for you to maintain. It may be easiest to leave your dish for someone else in Europe. If your LNB is really 5GHz wide, by all means take it with you.

LNB Types
There are basically three different LNB types for Ku-band: Standard, Astra and US DBS.

Standard - Linear polarized and uses the DC supply voltage to change from vertical to horizontal polarization.

Astra - These add a Ku low band. The linear polarization is switched with the DC bias on the coax line but also selects between the two bands with a 22KHz tone superimposed on the DC bias.

US DBS - The two DBS broadcast services, Dish Network and DirecTV, use circular polarization instead of linear polarization. The bias voltage switches between right hand polarization and left hand polarization.

But wait, there’s more…
There is one more consideration - PLL vs DRO.

PLL - Phase Locked Loop
DRO - Dielectric Resonator Oscillator

For a narrow-band signal like Outernet, a PLL LNB was chosen because it’s more frequency stable than the older DRO type.

What does Outernet use?
Outernet, according to @Syed will use a Maverick MK1-PLL LNB. It’s “Standard” and PLL frequency stabilized. Just perfect for LoRa from Geosynchronous orbit.

References:

  1. YouTube Movie Clip (1999) Matrix - There is no spoon

  2. Wikipedia article on LNBs.

  3. LNB � types DRO or PLL ?

–Konrad, WA4OSH


#3

Thank you for the very well thought out response.
What I know is Sky uses the Astra 2 fleet for their broadcast downlink so perhaps the source was misinformed (and thus me) about 5Ghz, either way I know that circular polarization is not linear and for those dB losses, it’s staying on my roof!

Thanks for the tip about C band antennas/dishes, I’m new to this rabbit hole of radio. Finding my specialties =]


#4

Lyngsat is a great resource for finding free to air (FTA) satellites. The Astra 2 fleet of satellites is actually on Ku band (10-12 GHz) and linear polarized, not circular polarized.

Here in the US, you can receive all sorts of FTA as well as pay-TV (DBS) programs.

My next house will have an unencumbered view of the southern sky for satellite hunting along the Clarke Belt.

C-Band antennas were very large in the 80’s and 90’s because LNB’s were still very noisy then. Modern C-Band dishes are much smaller.

If you catch the satellite hunting bug, there is a really neat site N2YO that you can’t do without.

Well, I’m looking forward to hunting the first LoRa satellite transmission. I can’t wait to order my DreamCatcher 3.0.

–Konrad, WA4OSH


#5

By the way, here’s an example of what you can get under $10 for a brand new C-Band dish.
C-Band dish in Estate Sale

–Konrad, WA4OSH


#6

I wonder what my wife would say to this turning up in the mail :wink:


#7

So I’ll need a new lnb anyway, because the polarization is incompatible. Good job they’re cheap!

I believe I already have said bug, I went to watch Humanity star fly overhead at 4 am! Billionaires and their toys.

So I think I’ll leave this dish on the roof, a nice gift for the landlord!


#8

I see there is again confusion:

MaxLinear was the first company to develop an integrated circuit that down-converts the incoming satellite RF signal from 10.7 GHz-12.75 GHz into two wideband IF outputs, each supporting the 290 MHz to 2350 MHz extended L-Band (XLB) frequency range. MxL80x devices enable up to 4 GHz of satellite spectrum to be captured and placed onto two coaxial cables connected to a Sky Q video server in the home.