GOES 16 GRB downlink vs GVAR

Discussion in 'Free To Air (FTA) Discussion' started by GOES 12 GVAR user, Sep 17, 2017.

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  1. N6BY

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    I had mistakenly assumed that KWX was already using the sawbird and added the AM filter.

    I later learned that he doesn't have the sawbird yet.

    But I am now curious to see what, if anything can get through the sawbird (outside of its target frequency range).
     
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  3. GOES 12 GVAR user

    GOES 12 GVAR user Topic Starter SatelliteGuys Pro

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    Brett, Is there a possibility that if there is a problem it could be in crazycat's portion of the software that you are using?
    Not to blame anyone but just asking since several of us have seen this issue.
    I want to take a look at TBS IP Data software and see if it has the lock issues that we are seeing. I know that I can't get any data off it but it should tell me the receiver lock status.
    I was going to try EBS software but there was a major problem with the Windows file to be downloaded. So I went with the former.
     
  4. GOES 12 GVAR user

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    Correction, It does help with higher freqs. but it filters more of the lower freqs. below it's cutoff range.
     
  5. N6BY

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    Its possible, but I think the loss of lock, or difficulty getting a lock is more likely due to signal quality issues.

    To lock a signal using 'streamreader.dll' is simply a call to crazycat's 'SetChannelExEx' function. After that, I just call 'GetSignalExEx' or 'SignalInfo' (if the card supports it) and wait until the card is successful in getting a lock.

    The only change I need to make is automatically resume streaming when signal lock is re-established.
     
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  6. KWX

    KWX SatelliteGuys Family

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    As a little FYI... by LNA/Filter setup is:

    coax - > LNA -> 1690 filter -> LNA -> 1675 Filter -> FM Filter -> LNA -> 1675 Filter -> FM Filter -> AM Filter -> DD or TBS

    I must say that the TBS5925 is running rock solid, so far keeping with the same performance as the DD, I'll give it 24hr to see how it fairs out.
     
  7. GOES 12 GVAR user

    GOES 12 GVAR user Topic Starter SatelliteGuys Pro

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    I can see if your signal is low quality the issue there.
    I know that you talked with crazycat, did he ever mention using his software before we have tried with generic stream?
    Just curious.
     
  8. GOES 12 GVAR user

    GOES 12 GVAR user Topic Starter SatelliteGuys Pro

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    Holy cow!, That's filtered.
     
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  9. N6BY

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    He added the option for generic stream a few years ago I think. There's a 4 year old thread about generic stream and raw BBFrames over at Ricks. Back then they were having problems with missing bytes in the BB Frames. Crazycat thought it was a hardware or PCI bus problem.

    We aren't seeing that problem now though. I know of no other satellite signal where they transmit RHCP and LHCP on the same frequency. I suspect our difficulty is with cross polarization isolation.
    You have found the magic combination of parts-- lock them up and throw away the key. :)
     
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  10. KWX

    KWX SatelliteGuys Family

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    I kept adding LNA/Filter until I saw there was not further improvements. Hopefully the Sawbird will help cut down on the LNA/Filters.
     
  11. GOES 12 GVAR user

    GOES 12 GVAR user Topic Starter SatelliteGuys Pro

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    It could be the issue, good point. I just figured to bring up the question about it.

    KWX, are you really using 2 1675 MHz filers and 2 FM filters? or is that a typo.
     
  12. KWX

    KWX SatelliteGuys Family

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    No typo, I might do without one of the FM filters but left it there since it hasn't hurt any. The real big difference came by using the AM filter.
     
  13. GOES 12 GVAR user

    GOES 12 GVAR user Topic Starter SatelliteGuys Pro

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    What are the 1675 fiters if I may ask?
    and if you are having issues with AM radio station's causing issues on the GRB station..
    Can you see the Xmitter towers from where the dish is?
    and..
    Does it change (I know this may be early to ask) during day and night?
    AM changes the direction of the signal from day to night.
     
  14. KWX

    KWX SatelliteGuys Family

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    They're LORCH filters. There're a couple cell towers to the S but not visible.

    During the late morning into early afternoon is when I would notice a little higher rate of sync errors.
     
  15. GOES 12 GVAR user

    GOES 12 GVAR user Topic Starter SatelliteGuys Pro

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    Thanks, Hmm. Look around your local area an see if there is a cell, or commercial radio setup nearby.
    I know you said that they out out of view but cell sites are disguised very well sometimes. Maybe on top of a tall building or looks like a tree.
    Of most concern would be in the path (ground path not beam path of 2 miles) of the antenna and off to the sides a bit as the side lobes can pick up that kind of unwanted signal.
    If the Xmitter is behind the antenna it would be close enough to see to be that strong. That's what we experienced with that EMWIN setup.
    If one is found close you my have to work with the filters and or put up a fence the blocks the offending Xmitter near your dish. It's a suggestion as every one of these issues are different.
    And it's touch and go as you determine the problem.
    Here's one more to consider, power line noise.
    An AM radio tuned to an unused frequency can help find something like that. I've had that issue here and it can tear up a satellite image.
    So can your SDR as the video shows.
    Here's an excellent exp. of what it does to wanted radio signals. Youtube video.
    power line noise

    So for everyone there are some suggestions to make your satellite reception better.
     
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  16. KWX

    KWX SatelliteGuys Family

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    That would be great if it can automatically resume after detecting a signal lock reestablishment.
     
  17. GOES 12 GVAR user

    GOES 12 GVAR user Topic Starter SatelliteGuys Pro

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    I would hope so too. It seems like A good filter for it's cost.

    Got the Sawbird+ in a temporary box now so
    This is how I shield my RF blocks.
    Amp filter case.jpg
    I make a cardboard box to put the filter/LNA into. This way no shorts can happen as there's no conducting surface on the inside of the box.
    Next like a present I wrap the box in tin foil. Carefully cutting around the connectors and power inlet.
    This way the block can be moved in the circuit's path if needed. Later it'll be in a diecast enclosure.

    Next, I set it where I want it on my feed setup.
    Feed electronics W filter on board.JPG
    This is what I have been using with all the uploads and info I have gotten.
    With the addition of a short jumper coax the filter/LNA is in.
    I left the LNA I have been using there as it may be needed to give the final boost to bring the signal within the receiver's specs.
    Circular polarized feed with filter and amps.jpg
    I didn't have a 5V DC power supply (wall wart) so I used the USB power device that I have for anything that needs 5 volt and is low draw. It has a 1000 mAh so for the test it should be fine. The UTRLA LNA uses 12V DC for power and I have that covered.
    Labels explain the the different parts, and you can see how the wavegide feed set up is all laid out.
    The next part is the test...
     
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  18. KWX

    KWX SatelliteGuys Family

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    Very nice!!!

    I like the cardboard idea. I'll do the same with my SAWBird+ which I got yesterday and use aluminum tape. I did happen to test it out and wow, force is strong with this filter, got ~26dB signal amplification as a max, but still testing various configurations.

    I'm using a solar panel to power my LNA outside, but ordered some parts to test out the SAWBird outside. As you previously mentioned, this one should definitely be a good one at the feed point.
     
  19. N6BY

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    Nice work Tim. I look forward to learning how well it does. I am still sidelined -- I developed pneumonia after the flu. It's not fun, but I will probably survive.

    Be careful not to place your feed in front of a government building. It would easily pass as a 'bomb'. Let's see, do we cut the red wire or the blue wire? :)
     
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  20. GOES 12 GVAR user

    GOES 12 GVAR user Topic Starter SatelliteGuys Pro

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    Some old business:

    Depending on the location and the antenna setup (of the FM station and yours) that could, if strong enough get through the nooelec filter there Brett. It may need a FM filter as well.
    One sure way to see that would be to hook up the SDR in place of the GRB receiver and tune to the FM band, If the FM signal is stronger then the GRB signal then you could have problems. Same for in the cellular bands.

    A reminder that anybody that uses satellite services should know this. That at certain times of the day the satellite gets eclipsed by the sun. Meaning the sun is almost or is in line with the satellite so the result may cause loss of data or even loss of signal lock.
    KWX signal issue most likely is not related to that.
    Though since the filters he may have solved it.

    With that taken care of..
    Thanks for the complements ;)
    Looks is one thing as long as it works well is what will count, looks can be improved later.

    Just make sure the aluminum tape is making contact, I don't know if the adhesive would cause to be that much of a barrier but if it is, then you will have a poor circuit for shielding. Use the OHM meter to determine this.
    I checked mine and (where I didn't tape it) found a low resistance path so it's the way I want it.
    If it shows "open" or very high resistance, you need to redo it.

    A solar panel should be a fine supply but make sure that it don't have any ripple on the DC.
    Most likely there is a battery in line so that "should" take that away. Ripple is an enemy of the feed electronics and can cause all kinds of issues that result in data errors. Same is a bad filtered wall wart.

    Take it easy and watch yourself, this flu has claimed several lives. Stuff is nasty this year. :(

    LOL, :biggrin There is some truth to that comment. :cool:
    It involved the bomb squad and a ham radio balun in Omaha. It would seem that ham radio baluns are considered dangerous when in or on PVC pipe....
    You can probably find the story on the web somewhere.
    I won't put anything on here.

    Got the new (used) computer, Win 7 Pro so as of tonight I got GRBStreamer on it and GRBDump as well along with the TBS5927 driver.
    I see what you said about the streamer there Brett, for configuring it.
    Maybe this weekend I can test it all but it's going to get cold again and windy, with all the snow melt that's happened it's a muddy sloppy mess around the dish now.
     
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  21. N6BY

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    Tim,

    The probes mounted on your cylinder look like they are more than 1/4 of a guide wavelength (37.35 mm) from the back of the can. Are you using 1/2 of a guide wavelength or something else? Just curious.
     



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