VSAT Update

I have been putting this one off, waiting for that exciting moment when I will post via my own working VSAT connection. Unfortunately this has not yet happened. Sadly, but not surprisingly I have been hitting quite a few hurdles. The problem boils down to the fact that I can't make my VSAT antenna lock onto a signal - and I have no idea why.

So allow me to introduce the players.


First off is the dish. Grant Smith, a friend of mine, is letting me borrow a 1.2m Patriot dish that his company uses for a moderately expensive VSAT solution. The dish is was damaged on route from South Africa, but the dents are pretty small. I don't think they are significant enough to mess up my signal - but I am not certain. Notice that the dish includes a reflector and a nosecone.

RFU In Pieces.jpg

The next player is the LNB/RFU. I am not sure what these acronymns stand for, not which parts each acronym refers to - but I have been thinking of the sum total as the antenna lately. This is the hardware that captures the radio signal as wel as sends it. This equipment was sent to me by Jeff, and Grant figured out how to mount onto the dish.


Finally we have the modem. The modem is a DirecWay6000, or DW6000 as it is often referred to. This was also sent by Jeff. It connects to the antenna via two coax cables - one for sending and one for receiving. It sets itself up as a DHCP server on and you can telnet into it on port 1953. Setting it up requires a bunch of parameters which have been supplied to my via SatDSL, a company in Czech who will eventually be my ISP if I can ever get this thing working. You also put in your Latitude and Longitude, then the DW6000 tells you which direction to orient your dish, what angle to set it at, as well as a polarization number which requires you to rotate the antenna.

At this point it is just a matter of actually doing the pointing and then trying to maximize the Signal Quality Factor (SQF). And here is where I have been utterly stuck for weeks now. No matter what I do, the SQF is always stuck at 29. No matter where I point the dish it always says 29. The only way I can get the number to change is by unplugging the coax from the antenna, at which point my SQF hovers between 6 and 10. Every day for at least two weeks I would have a new idea, or receive a suggestion from Czech or Grant and I would hook up the whole setup, make my tweak to the hardware or software, then take my laptop outside only to find that I am still stuck at 29. 29! 29 is the bane of my existence.

So what does 29 mean? Well, thanks to Petr Neuman at SatDSL, who has been helping me by sending documentation and patiently answering my questions, it seems that 30 is the magic "locked on" number. Once you reach 30 then you have locked onto a signal and it is just a matter of fine tuning to increase that signal. 29 seems to mean that I am getting signals, but the wrong ones. And since I can point the dish anywhere and still get 29, there seem to be plenty of wrong signals about. And that is pretty much my understanding of unlucky 29.

Last week, Petr sent me an interesting document which has unearthed a new possible problem. Basically there is a piece on the antenna called a waveguide. The waveguide determines whether the hardware is configured to be a vertical receiver and horizontal transmitter or vice versa. The satellite over the US (W1 is its name) uses one configuration, and the satellite over Africa uses the other. Switching configurations requires switching waveguides from the X version to the I version. Here are the two waveguides - I have the one on the left but need the one on the right.


I have also tried running it without the waveguide, as the resulting holes match up into a configuration similar to what happens with the "I" waveguide - but you guessed it - SQF 29.

So I am totally stuck. I am considering trying to machine a new waveguide. Grant offered to let me try an undented dish. SatDSL has offered working hardware at a good price, but it is in Czech and includes a 1.2m dish. Still if I could find a cheap ticket to Europe I could go and pick it up.

I have also asked for help here, but no one has responded despite it being a very active forum. What I need is a Hughes engineer (Hughes makes all of the equipment including the satellite 26,000 miles up) - surely one of you, my millions of readers, is a Hughes Engineer? Or maybe your uncle is, or neighbor. Malawi needs help!

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