Receiving free-to-air satellite with USRP?

[ZuluLima]

Not that big of a fan with satellites except for weather imaging. But I have both the Hack RF and USRP B210 that both receive up to 3ghz quite well with the AOR LN4000 preamp. Has know of software decoding for use with GNU radio for free to air on the C and K bands maybe Ku? There are boxes and cards that do it, but these recievers can do everything. Don't have a dish setup yet but do have a couple of homemade QFH and ADS made up. Just wondering if anyone tried free to air on this forum. Had Direct TV a long time ago. That's completely different from free to air. If there was something to decode the signal working with GNU radio it might be possible. I might be barking up the wrong tree here but its worth a shot.

[stj]

Re: Receiving free-to-air satellite with USRP?

i'v done real pro-sat stuff with the correct equipment.

i can tell you that you wont use the same feedhorn or lnb/antenna-element for KU and C/S band.
they need to be a different diameter to act as a reliable waveguide.
you may be able to use the same polariser.
if the signals are circular you will also need a de-polariser - it looks like a short pipe with a bit of teflon plate in it.

finally, you cant use a C or S band mesh dish for KU because it will pass the signal instead of reflecting it.
you really want a solid dish and a good solid mount.
and as you cant build houses properly in the u.s. you need a concrete foundation to mount the dish.

that is unless you want to see how much force the wind can exert on a reasonable dish.
i'v seen my old 1.2m one sheer a 17mm mild-steel bolt that was fitted by mistake instead of a hardened one!

[ZuluLima]

Re: Receiving free-to-air satellite with USRP?

May need a GPSDO reference for this one. Unless I can find a LNB with a reference built in. Then it would have to have Bias-T turned on. I think the boxes and PCi cards Bias-T to the LNB. Don't know.

[ZuluLima]

Re: Receiving free-to-air satellite with USRP?

So C and S require a larger area and a small metal dish won't work? Looks like I'm stuck in the K band. Don't have the room for that size of dish. At that high of a frequency a C band dish is a giant compared to a small DTV dish. I guess once the signal is near ground level, the wavelength won't be caught in a small dish.

[stj]

Re: Receiving free-to-air satellite with USRP?

S & C are old, the birds transmit at much lower power levels - hence needing a 2.5m+ dish usually.

the lnb is multi-mode controlled by the supply voltage (14v / 18v) and also can band shift by overlaying a 22khz squarewave if i remember right.

[ZuluLima]

Re: Receiving free-to-air satellite with USRP?

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