ka feeds?
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I lucked up with a discarded Directv dish Saturday, supposed to have a ka lnb on it (I think) Do these fta receivers work on KA band? I don't even know what ka is, have to go do some research. If they do, I will put the dish up tomorrow and see if I can find anything.
If you can set the LO Frequency of your receiver to a frequency around 18 - 22 Ghz then you might have a chance.
I am not sure if the FTA receivers around today are capable.
The Ka band operates between 18.3 and 18.8Ghz and between 19.7 and 20.2Ghz.
I will be interested to here your results, hopefully someone will know the exact LO frequency for the DirecTV dishes, or hopefully it is listed on the LNB.
I am not sure if the FTA receivers around today are capable.
The Ka band operates between 18.3 and 18.8Ghz and between 19.7 and 20.2Ghz.
I will be interested to here your results, hopefully someone will know the exact LO frequency for the DirecTV dishes, or hopefully it is listed on the LNB.
it should still downconvert it to L band, so as long as you have the lof/h you can figure it out, if your not to concerned the freq the ird tells you is correct then you can just wing the lof/h and blindscan...
18750 lof/h should do it, all lof/h does is add the lof/h onto the lband freq being tuned to give you a number for you to look at and compare to websites etc. the ird doesnt care what it is. as long as you have blindscan that is
else you need to know what the freq is.
if youve got a spectrum analyzer you can look directly at the lband and figure it out with a calculator.
take the freq youve got, and compare it to lyngsat.com, now subtract lyngsat freq from lband freq and youve got your lof/h
18750 lof/h should do it, all lof/h does is add the lof/h onto the lband freq being tuned to give you a number for you to look at and compare to websites etc. the ird doesnt care what it is. as long as you have blindscan that is
else you need to know what the freq is.if youve got a spectrum analyzer you can look directly at the lband and figure it out with a calculator.
take the freq youve got, and compare it to lyngsat.com, now subtract lyngsat freq from lband freq and youve got your lof/h
What I meant about the LO frequency issue was, are the FTA receivers radio tuning circuitry capable of producing 18 GHZ +, the LO frequency has to be mixed with the Satellite signal in the Ghz range to bring it down into the L-Band.
technology is documented
The local oscillator is inside the LNB, so a Ka band LNB would have an 18+ghz LO, producing the usual range for our existing receivers to deal with.
Just the same way any typical FTA receiver does C-band and Ku-band.
The receivers really receive 950 - 2150mhz , as down-converted by the LNB.
They just do the math if you give them the LO, and tell you they are receiving at 3800 or 12000 mhz
Since they were never meant to receive Ka band, they probably won't do the math at Ka frequencies (try and see if you can put in an 18ghz LO).
So, early experimenters might want to put in more traditional LO frequencies, and use a calculator to figure out where you are actually receiving.
Another point in question, is this: are the Ka band LO below or above the incoming frequency.?
I'd assume below, but if you get it wrong, you'll be tuning backwards across the band.
I remember reading about the LNBs on the DirecTV dish, somewhere.
I think it was in the installation instructions for the AT9 (now discontinued*) dish on the SolidSignal site.
They have a 5 video set you can watch, for alignment instructions.
(look directly under the picture of the dish)
edit: from the video -
DirecTV Ka sats are at 99º & 103º
down link freq range: 18.3 to 20.2ghz
converted freq range going to receiver: 250-750mhz, 950-1450mhz, and 1650-2150mhz
the 250-750 mhz is outside the range of FTA receivers.
the Ka output uses the 250-750mhz and 1650-2150mhz range
sounds a lot like bandstacking to me.
*discontinued means some have shown up at the dump - TurboSat already has his!
The local oscillator is inside the LNB, so a Ka band LNB would have an 18+ghz LO, producing the usual range for our existing receivers to deal with.
Just the same way any typical FTA receiver does C-band and Ku-band.
The receivers really receive 950 - 2150mhz , as down-converted by the LNB.
They just do the math if you give them the LO, and tell you they are receiving at 3800 or 12000 mhz
Since they were never meant to receive Ka band, they probably won't do the math at Ka frequencies (try and see if you can put in an 18ghz LO).
So, early experimenters might want to put in more traditional LO frequencies, and use a calculator to figure out where you are actually receiving.
Another point in question, is this: are the Ka band LO below or above the incoming frequency.?
I'd assume below, but if you get it wrong, you'll be tuning backwards across the band.
I remember reading about the LNBs on the DirecTV dish, somewhere.
I think it was in the installation instructions for the AT9 (now discontinued*) dish on the SolidSignal site.
They have a 5 video set you can watch, for alignment instructions.
(look directly under the picture of the dish)
edit: from the video -
DirecTV Ka sats are at 99º & 103º
down link freq range: 18.3 to 20.2ghz
converted freq range going to receiver: 250-750mhz, 950-1450mhz, and 1650-2150mhz
the 250-750 mhz is outside the range of FTA receivers.
the Ka output uses the 250-750mhz and 1650-2150mhz range
sounds a lot like bandstacking to me.
*discontinued means some have shown up at the dump - TurboSat already has his!
Last edited:
Thanks Anole for clearing up the my local oscillator question, that makes sense how you can have a C-Band LNB and Ku-Band LNB connected to the same receiver.
Aren't all of the DirecTV KA feeds MPEG-4? Even if you changed your LO settings, MPEG-2 FTA receivers still wouldn't be able to "see" these transponders, right?
Not too mention the fact that I believe all of these channels are scrambled...
Not too mention the fact that I believe all of these channels are scrambled...
Chuck is prob right about mpeg4, I have this viewsat ultra, don't think it will do anything on mpeg4. I may still try it, but it will be hard to lock on the sat with only mpeg4 signals. Unless there are some reg mpeg signals for the circ lnbs to see first.
fun with Ka
Well, MPG4 and scrambled would certainly prevent you watching the picture.
But if you'll note, Dish scrambled signals are still something you can tune up with.
The modulation scheme Dish uses for mpeg4 is the problem.
FTA receivers can't lock to that. (has nothing to do with being mpeg4)
Then, there's the way the data is packaged.
Somewhere, many years ago, I think I recall that Direct used a different number of bytes in their data packets.
DVB standard used by Dish and FTA is not compatible.
Whether your stand-alone FTA receiver would register a Direct Ka signal is doubtful.
But, I don't know, so someone will have to fill in that blank.
Advanced users with TSreader and some DVB cards could certainly observe signal strength.
Whether there are any unscrambled barker channels, you'll have to await the tests of those with computer-interfaced receivers.
The purpose of these comments is to encourage experiments with Ka-band LNBs, not see what's on DirecTV.
They are just a Ka signal we know where to find, and might be useful to get aiming experience.
From the alignment video, you gotta know tweaking a Ka dish is going to be a lot of fun!
Well, MPG4 and scrambled would certainly prevent you watching the picture.
But if you'll note, Dish scrambled signals are still something you can tune up with.
The modulation scheme Dish uses for mpeg4 is the problem.
FTA receivers can't lock to that. (has nothing to do with being mpeg4)
Then, there's the way the data is packaged.
Somewhere, many years ago, I think I recall that Direct used a different number of bytes in their data packets.
DVB standard used by Dish and FTA is not compatible.
Whether your stand-alone FTA receiver would register a Direct Ka signal is doubtful.
But, I don't know, so someone will have to fill in that blank.
Advanced users with TSreader and some DVB cards could certainly observe signal strength.
Whether there are any unscrambled barker channels, you'll have to await the tests of those with computer-interfaced receivers.
The purpose of these comments is to encourage experiments with Ka-band LNBs, not see what's on DirecTV.
They are just a Ka signal we know where to find, and might be useful to get aiming experience.
From the alignment video, you gotta know tweaking a Ka dish is going to be a lot of fun!
According to Lyngsat, Directv is using DVB-S2 on Spaceway 1 and 2. So you would need a receiver or card that does DVB-S2. I have a Techotrend TT Connect S2-3600 which receives DVB-S2, but I don't have a KA lnbf, so I can't try it yet.
I was told by the xplornet rep that there is a video feed on one of the anik f2 spot beams, but in my area I dont get that beam so I cant test to be sure. wouldnt hurt to scan 111.1w and see.
I may be wrong about this but I believe the directv Ka dishes are set up so that the Ka LNBs output their signals in B band. They do this so they can stack the signals from all the LNBs (ku and Ka) and send them all down the same cable simultaneously. So, to get this signal back into an L band signal you'll need one of the B band converters they use to do this before the Ka signal goes into the receiver. These can be found on ebay pretty cheap. Just search for "B band converter".
Also if your interested in the Directv Ka signals, my understanding is they use DVB-S2, or at least that's what I've heard. So, you'll need a dvb-s2 receiver if you want to attempt to lock them. I've also heard they're all encrypted. So, you probably don't even need worry about decoding the Mpeg4 video as it'll likely be scrambled anyway.
Stefan , for what its worth, this Directv dish I got hold of last week has a triple-conductor cable (3 rg6 runs). Whether or not there was a switch or something mounted close by the dish , I don't know. Looks like this guy just cut the cable and took the dish/mount off his roof, there's about 15' of this triple cable still connected.
The KA lnbf looks a lot like one of those old dishnetwork twins, about that size.
The KA lnbf looks a lot like one of those old dishnetwork twins, about that size.
Definitely sounds like an AT-9 to me. A friend of mine has one of those on his roof. The elevation adjustments on the dish are really interesting, lots of hardware
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