Need assistance with Ka(high) band satellite specifics

Discussion in 'DIRECTV General Discussion' started by Julie, Feb 22, 2019.

  1. P Smith

    P Smith Mr. FixAnything

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    the meter will show only a signal level at certain IF, but to understand what sat/tpn is linked you must get full understanding
    please, don't cut corners - be a professional, at least beginner ;)

    [I'm very skeptical to believe the meter would lock to DTV Ka tpns and does show C/N, BER, etc]

    Edit: watching a presentation... they cannot LOCK to DSS tpns ! That's pretty much conclude - no Ka real "tracking", only signal level is the parameter of tuning (perhaps they have sort of bandpass filtering to _estimate_ CNR, eg present it in some artificial units, I'm very skeptical on this count).
     
    Last edited: Feb 26, 2019
  2. Julie

    Julie Member

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    Sep 28, 2013
    Las Vegas
    P Smith: My experience was that when I entered in various random frequencies it showed me a weak signal bar on some of them, others didn’t display anything. Again, these were just random picks as I didn’t know what I was doing.

    I then searched the web and came up with a couple sites with the necessary transponder info for the 101W satellite. When I punched that data in the meter, it showed me a strong signal strength graph, and also displayed an actual value in dBuV. The Q bar (which the manual said represented the actual quality of the signal) also worked (it was blank without the correct parameters entered into the meter). Also blank, but displayed when the correct parameters were entered, was the signal to noise ratio (in dB), and the Bit Error Rate.

    So all I know is that, without the data that I found on the web for the 101W satellite, and without the data for the 99/103 satellites that slice1900 gave me, the meter didn’t display anything that would be helpful to an installer. However, with the correct data the meter it was displaying these other values that, I could only assume (I didn’t try to climb up on our roof), would fluctuate as the connected dish is repositioned.

    I guess what I’m trying to say is that to an EE like yourself this data might not be usable, but to someone simply trying to install, or align, a dish I think it would be valuable (even if just in a relative sense).

    My friend said he’s willing to take some screen pics. If you still want them, I’ll follow up with him. However, they won’t look too different than the ones in the pic on the website link I posted above.
     
  3. P Smith

    P Smith Mr. FixAnything

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    Yes, please post them here, particular for Ka band eg 99/103
     
  4. Julie

    Julie Member

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    Sep 28, 2013
    Las Vegas
    P Smith: Per your request...
     

    Attached Files:

  5. P Smith

    P Smith Mr. FixAnything

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    Thank you darling :)
     
  6. P Smith

    P Smith Mr. FixAnything

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    Well... definitely the BER is fake, S/N looks like a CNR. For sure there are no lock.
     
  7. Julie

    Julie Member

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    Sep 28, 2013
    Las Vegas
    You're welcome. I don't know what to say because I don't know enough about it. However, he claims the meter is fantastic, and really works well. He says that I can visit him anytime and he'll let me resetup his dish from scratch (his dish is mounted on the side of his house close to ground level). I may just take him up on that so I can learn more about all of this, but he is about 50 mins away from me so I'm not sure when I'll be able to get there.
     
  8. slice1900

    slice1900 Well-Known Member

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    Why do you think the BER is a "fake"? Why would someone design a meter to lie?
     
  9. P Smith

    P Smith Mr. FixAnything

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    Perhaps they must make "good face" when the device cannot lock to certain transponders with unknown/unsupported modulation.
    So, please tell me how such tpn's parameters will display by the device ?! It will drop down all processing related to demodulating and taking measure a spectrum of the tpn in best case scenario. Hence only signal level and possibly CNR will be close to real values.
     
  10. Julie

    Julie Member

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    Sep 28, 2013
    Las Vegas
    A couple quick updates. First is that my dad and I finished the modifications to the B band converter that I described above. The process was much harder than either of us anticipated, and there were a few times where we weren’t certain we were going to be able to (successfully) finish. This was because the internal circuit components are much smaller than the pictures make it appear as the web instructions are substantially magnified (but don’t mention this fact on their webpage). Simple in concept, but difficult to accomplish for novices like my dad and me. Regardless, with some luck, we were able to complete the mods, and then tested the unit with a satellite receiver to verify it was working. It was, yea!!

    Second, yesterday, I had some shopping to do at a store close to my friend on the other side of town so I stopped by to give him the modified converter, and check out his Slimline dish installation (as mentioned above, he has it mounted on the side of his house close to ground level). Hopefully he’ll be able to use the modified BBC to extend the measurement range of his meter to the Ka(low) 99 and 103 satellites. As he promised previously, he then let me use his meter to align his dish.

    He started by explaining the basic concepts of (1) how critical it is to start by making sure the pole is plumb and level (there is even a little bubble gauge installed to aid in this process), and (2) a process called dithering to be certain one has the strongest signal possible. He then loosened every nut and bolt and threw the entire thing out of whack. We used the receiver to verify that it wasn’t able to receive a single satellite, then he turned me lose with his meter, and told me to give it a shot. That meter makes the process so simple it’s absolutely amazing! It was my first time ever attempting to align any dish, let alone a Slimline with an SL5, and I completed the task in about 5 minutes.

    When the meter locks onto a satellite it shows its signal strength, but the important values are the Q bar and the bit error rate. As the Q bar goes up, the bit error rate goes down. I only really focused on these two parameters. It was incredibly sensitive to the Ka satellites, and allowed me to quickly make the necessary (very minor) adjustments to maximize the signal.

    I was completely blown away by how easy the whole process was, and am now confident, I could do it by myself if I ever needed to (with access to his meter). I’m still not certain about what P Smith said above It might not do the things that he mentioned (not sure as I’m not technical enough), but, even if not, it’s still incredibly useful for aligning dishes, and I don’t think that anything else would be needed. I mean, if someone like me could do it so quickly and so easily, I’m not sure what else could be done to improve the process.
     

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