Satellite Internet

Satellite Internet Forum.

Welcome, Guest.
Welcome to this satellite broadband discussion forum. Wherever you are and whatever your problem we are here to help each other. Connecting to the internet via satellite is not always easy but is critically important to those in remote places or with poor terrestrial infrastructure. Both service providers and customers are encouraged to contribute. Register at the bottom of the forum home page if you wish to contribute or ask question. May 2018: GDPR: Updates to Privacy and Cookies policies: As you may know, a new EU data protection law called GDPR will apply from Friday 25th May 2018. As part of satsig's commitment to protecting the privacy of site visitors and forum members, I have therefore updated the Privacy and Cookie policies. There are now links leading to these policies: Disclaimer, Terms of Use and Privacy, Forum User Agreement, Forum Rules and Cookies at the bottom of the home page and all forum pages. Read the Forum rules.
      Satellite internet forum          
Pages: 1

Re: Help with BW setup on AM22 in Afghanistan

(Read 1551 times)
Eric Johnston
Senior Member
***
Offline


Personal text from Profile,
Options, Top line

Posts: 2108
Jul 31st, 2011 at 2:23pm  
Presumably the 4 satellites you can see are in a gently sloping curved tilted line going down to the right. The highest elevation satellite will be the one on the left, towards due south. The low satellite will be to the right, towards the south east.  The slope of the curved line, in the vicinity of your wanted satellite, will be approx 21 deg. If you aimed due south, you would be looking at the top of the arc and line would be horizontal. Here you can swing the dish sideways and see several satellites, without changing the elevation at all!

Polarisation:  The input waveguide to the LNB is rectangular.  If the broad faces of the rectangle are on either side, like so
...
then you have true Horizontal polarisation.
This is your polarisation starting position (for Horizontal name polarisation). Then apply the +21 deg clockwise adjustment, while facing forwards towards the satellite in the sky.

LNB and the meter
The NJR2837 LNB has a 10 GHz local oscillator and is intended for receiving satellite signals in the range 10.95 - 11.7 GHz. These signals appear in the coax cable in the range 950 - 1700 MHz and it is this range that both your meter and the modem need to be tuned to. Your iDirect options file specifies the wanted receive carrier frequency into the modem.  Your meter may be tuned to the same signal or, more likely, to a convenient large and powerful DVB-S TV carrier, which must be on the same satellite beam, same polarisation and in the same frequency band range ( 10.95 - 11.7 GHz > 950 - 1700 MHz).

HEX file:
The name "HEX file" is normally associated with the Horizon Meter, not the iDirect modem.  Horizon supply HEX files which pre-program the meter to a DVB-S TV carrier in the range 950-1700 MHz and symbol rate.  These HEX files assume some type of LNB, some polarisation, some satellite and beam, some receive location and some carrier freq/symbol rate.  All these must match up if the meter is to say "AM22 satellite found".  Otherwise the meter is just a simple noise power meter, showing the noise power level from each and every satellite as you go past them.

Options file:
This goes to the iDirect Modem to set up its receive carrier tuning etc.

Best regards, Eric.
Back to top
 
 
IP Logged
 
Pages: 1