Advertisment: Broadband via satellite
Advertisment: Planet Earth rotating animation

www.satsig.net

Satellite Internet Forum.

Welcome, Guest. Welcome to anyone who has come from the Space forum. I can cope with one forum, but not two. The Space forum has been deleted       Forum rules.
      Home            Login            Register          
Pages: 1

Cant Find W6 satellite, best signal is 29

(Read 5245 times)
Ex Member
Ex Member


Aug 13th, 2008 at 11:30pm  
I am having a very difficult time finding the W6 sat from Balad, Iraq with a HX50 system.  I have all my stuff set to the exact settings I got from Bentley Walker.  As I move the dish across the azimuth and sweep at different elevations, the most signal I pick up is 29.  

At 33N 44E I am shooting a 214 deg azimuth, 43 deg el, 30.6 polarization.  I have the single notch lined up on the feed horn assembly, with the LNB directly above support bar, lined up with the 5-0-5.  I have the entire dish rotated to the 30 deg polarization.  When it is at this azimuth, the signal stays at 15.  I only get 29 when I move it way away from this setting.  I'm lost and have no idea what to do next - does anyone know someone I have come and help me on Balad Air Base?
Back to top
« Last Edit: Aug 14th, 2008 at 4:28pm by Admin1 »  
 
IP Logged
 
Eric Johnston
Senior Member
★★★
Offline



Posts: 2109
Reply #1 - Aug 14th, 2008 at 9:12am  
If the single tick mark and the 505 are directly away from the feed support arm you have the correct orientation of the feed horn and spacer tube assembly.

If you have the filter/LNB away from the feed arm you are set for nominal horizontal receive polarisation with the feed arm at the bottom (zero adjustment).

You have applied a +30.6 deg clockwise polarisation adjustment, as viewed from behind the dish.

I don't know what nominal polarisation you are supposed to be receiving.

If you are supposed to be receiving horizontal then you have done the right thing.

If you are supposed to be receiving vertical just turn the dish a further 90 deg.  It will go all the way round through 360 deg if you want, while staying pointed at the satellite all of the time.   Nominal horizontal is when the LNB is at the top or bottom.  Nominal vertical is when the LNB is at either side.  An adjustment of +30 deg is 30 deg clockwise, as viewed from behind the dish, from any of these four starting positions.

I hope someone in Iraq or Balad Air Base with an HX dish working to W6 can send a picture to help you.

29 is the maximum reading in the initial power detection mode.   You have found a strong signal, probably a satellite (the sun less likely, but obvious as the shadow of the top of the feed horn will hit the edge of the dish where the feed arm attaches).  The signal does not match the tuning frequency or symbol rate.  Check with BW that you have the correct tuning frequency and symbol rate, which may have changed since your documentation was sent.  

You also need the correct type LNB for the particular satellite downlinik frequency.  The modem tuning frequency is the satellite downlink frequency minus the LNB local oscillator frequency.

For example:
Satellite down  = 11.423 GHz
LNB LO freque   - 10.000 GHz  
Modem tuning  =   1,423 MHz (actually input as 14230, in units of 100kHz )

Example LNBs:
NJR2784   LO = 10 GHz
NJR2744   LO = 10.75 GHz
NJR2754   LO = 11.3 GHz

Read more: NJR LNBs   Invacom LNBs   Ku band TRIA

You may be receiving power from the wrong satellite or wrong polarisation.  Once you modem locks, the display now means signal quality and it jumps into the range 30 - 100.

Best regards, Eric.
Back to top
« Last Edit: Sep 14th, 2009 at 5:11pm by Eric Johnston »  
 
IP Logged
 
A.Walker
Senior Member
★★★
Offline



Posts: 316
Reply #2 - Aug 14th, 2008 at 11:00am  
We have established Nathan does not have the right receive LNB , he needs a lo band NJRC 2784 , does anyone on Balad have one they can loan or sell Nathan so he can get operational  ??

Back to top
 
WWW  
IP Logged
 
Ex Member
Ex Member


Reply #3 - Aug 14th, 2008 at 10:59pm  
Eric- I have also CC'd you on this email back to bentley walker -

I turns out that I did have the wrong LNB.  I had the correct one on hand from an receiver that was not being used. 

I put the NJR 2784H LNB that I had on hand on the dish.  The highest signal I was able to get was 23.  I have sent you some photos in a powerpoint document of how I have the dish set up now.  The changes I made to the dish so far where:

1: Remove LNB that came with system
2: Installed LNB NJR 2784H
3: Polarization set at 30.6, Azimuth at 214.3, elevation at 43.3
4: Feed horn was lined up with single notch to single notch, 5-0-5 and single notch where directly above lower support arm. LNB was directly above the lower support arm.

-Tested and received 15 as highest signal strenght

After reading the link you sent, I though I might have set the polarization wrong.  It said that the receive polarization is set to vertical. After thoroughly reading the article, these are the steps and changes I made (which is what the pictures are of)

1: Using LNB that I had on hand (NJR 2784H)
2: I removed the feed horn from the rest of the assembly and rotated it 90 deg, so that the double notches on the cone where lined up with the single notch on the assembly.
3. I rotated the entire assembly 90 degrees so that the 5-0-5 and single notch was directly above the support arm, and the LNB was off to the side, 90 deg to the support arm (this should mean that it is now set for vertical polarization)
4. Set elevation with inclinometer i made from the satsig website
5. Swept a broad azimuth from 208 to 220 deg

- The highest signal I got on the laptop was 29 at one point, but then it dropped to 23

I think that by switching these settings on the feed horn assembly I have tried both vertical and horizontal polarization.  I am at a loss now, back to square 1- I think the LNB that I had (NJR2784H) may be bad, it was off an old LNB that was not in use.  Other than that I have no idea where to go next.

Thanks for the help,

Nate Ramsey
Back to top
 
 
IP Logged
 
Eric Johnston
Senior Member
★★★
Offline



Posts: 2109
Reply #4 - Aug 15th, 2008 at 8:20am  
With the LNB at the side you are set for nominal vertical receive polarisation when the entire dish is rotated to its start position, with feed arm at the bottom.  You can then apply +30 clockwise polarisation adjustment using the scale behind the dish.   Turn it a further 90 deg and you are now horizontal polarisation with +30 deg polarisation adjustment applied.  So it is easy to test on either polarisation.

Regarding elevation angle.  This can be measured with an inclinometer, using the polarisation scale plate behind the dish.  This plate is at right angles to the beam.

Regarding tuning.  The LNB may be off frequency by up to +/-900 kHz   You could try adjusting the receive tuning by up to +/- 9 units of 100kHz.

29 is the max reading for signal power - so could be wrong satellite, wrong polarisation, wrong tuning, wrong symbol rate.

I can't help further till Monday - over to BW.  Good luck.

Best regards, Eric.
Back to top
« Last Edit: Aug 15th, 2008 at 11:01am by Eric Johnston »  
 
IP Logged
 
Pages: 1