Another Afghanistan Thread

[ralphmagno]

hello AFN installers,
i have been reading some of these postes.
ok first alignment.
look at other working dishes in your area and see the general direction they are pointing.
this will give you a general idea where it has to point.
next lnb your scew may be off i don't know what 4 o'clock might mean id the lnb is different.
on the top of the lnb there ate hash marks,small ones and one large one.
the large one should be center of the lnb holder and in most of the lnb i have seen this would put the bottom of the lnb where the coax cable is connected to the 6 oclock possion.
last lo of the box should be lo 2.
this generares 22 khz for the upper band of the lnb.
they will never use lower band on this satellite. there is no transponders in the lower band at all running on this bird.
now if your lnb is scew ed correctl and you are in the general direction as the other afn dishes it makes it easier.
send up a picture of the lnb on the top markings and dish set up.
ralph

 

[BM300]

2 points.

1st.
If your LNB is OK.
As ralphmango mentioned, see how other dishes are installed.
If you can copythe reading from the intalled dishes (azimuth and elevation).
I hope that you have a spectrum analyzer, it makes life so much eazier.
Hook it it up to one of the working dishes and see the pattern od the transponders.
Try repeatung this on your dish.

2nd.
Fixing dishes in the inverted mode is common in some areas for the following reasons:
1- Reduce the ground noise on the very low satellite.
2- Solve the problem of the dish mount not going below a certain point (wrong dish mount for the Geographical location).
3- Attempt at hiding the dish in areas that dishes are not allowed.
4- Some installers seen others doing it, so they copied them.

 

[rolfw]

If the system was working a few days ago, there's been no high winds and nobody fiddling with the dish, the dish is unlikely to have moved, it will probably be one of three problems.

Faulty LNB, faulty or damaged cable/connections, or the receiver itself.

The LNB appears to be responding, as you get a signal increase when covered with your hands, but may have switching problems, so as suggested earlier, if you have a spare, swap it out.

 

[jncsk8r]

All connections have been checked and rechecked for connectivity, integrity, and corrosion. Also today we had to do an escort to a base about 45 minutes away. EVERY AFN DISH was mounted upside down. I took pictures of the Az, Elv, and LNB settings hopefully this will help my endeavour. However, I am still open to suggestions.

 

[ralphmagno]

hello,

ok is you can post some pictures of your lnb and dish we can look as well.
i would like to see the lnb marking on the top of the lnb the long mark should be center of the holder.
send us some pictures
ralph

 

[jncsk8r]

Ok so, after taking pictures of a working system about 1-2 miles away from our location, I reset the Az, Elv, and LNB to mirror as close as possible the working systems I studied at the other base. I checked all the connections, REMOVED a splitter that was in the line allowing the dish to be shared to two decoders, and rechecked the integrity of the RG-6 cable from dish back to decoder. I have again checked all the settings in the decoder to match what AFN says is correct for my decoder. Everything seems to be in working order, just low signal, no quality, and no lock. I did however manage to get the signal from 43-44 to 48-49. It seems that removing the splitter is what did that, naturally. The signal I'm getting appears to just be noise and nothing of quality for the decoder to lock on to. Here are some photos of my set-up, to include LNB and decoder settings.

 

[sonnetpete]

Having looked through your photos, there are two things I've noticed. I think the LNB on the dish is 180° out of skew. Regardless of which way up the dish is, the cable and connector should be pointing roughly at six o'clock. On your second receiver set up page (photo2) it says AFTRS Hotbird Europe, I believed AFN was now only on 9°E. Is there an option to change this on the screen?

I'm certain someone with AFN setup experience will comment in due course, but if you want confirmation of the LNB setting I'd look at the AFN video on the first page of posts.

 

[jncsk8r]

As for the LNB I spent about an hour today slow turning the LNB with a partner watching the signal strength with little to no change. As for the decoder set-up screen the "AFRTS Hot Bird" text is just a lable for preset "1" in the LNB settings menu. I can change it but it wont change LNB settings.

 

[sonnetpete]

Turning the LNB will not make any difference to your strength readings, in fact you'd be advised to disregard those and concentrate on getting a quality reading. Move the LNB to where I suggested and then try small adjustments of the dish, left and right, up and down. Can I stress small as well, as much as a centimetre out in any direction may result in no signal.

 

[ralphmagno]

hello,i just got on line and looked at your pictures it is perfect.
do not tuch anything on the lnb.
if you notice the 0 mark on the lnb holder is aligned with the long mark on the lnb.
it is not 180 out since the dish is upside down and the lnb is fine.
the lnb can be mounted 2 ways and its still correct as far as phase relationship is concerned.
if the lnb was straght down to the ground or up like you have it it is correct.
now we have the alignment part. if you are sure the dish base is correct and your elevation is on as well then you must have someone watch the display and move the dish right or left depending on anyother dish you can see that is on the AFN platform.
as you do this the signal will go up and finaly you will get a sig lock.
you can after that put a signal splitter and run 2 afn decoders.
but remember they both have to be set up the same.
if one box had vert and the other has horz they both won't becsue of conflict of polarization.

let us know.
ralph retired USAF

 

[ralphmagno]

PS.
you will never get no signal moving the dish.unless the cable falls off of the lnb or have a short.
the level will be 45 because of the lnb ol generates noise.
as you find the satellite it will go up probably to 57 or 60 and then you get a sig lock and a quality of 4 or higher.
7 or better is the goal if possible.
ralph

 

[jncsk8r]

UPDATE: Ok so this morning I took the decoder and a TV to the dish. Using a 2 meter piece of RG6 cable, good connections on both ends, a very simple set-up I was able to get the signal to 63-64. Still no lock, and no quality. I know I’m focusing too much on the "signal" but it’s the only thing I have to go by. After double checking the Az and Elv I have made the smallest of small adjustments left and right, up and down, with no results. I have even used slight pressure to torque the dish in different directions, paying attention to the effect it has on signal. I just don’t know where to go from here. I’m going to attempt another call to AFN tech support. Wish me luck…

Fishing for suggestions...

 

[sonnetpete]

@ Ralph : Thanks for the clarification, I was hoping you'd come online and offer suggestions.

Other than that, I'm at a slight loss to help further though I have a feeling you are pointing at a different sat (perhaps 10°?)

 

[jncsk8r]

Eureka! So, after speaking to AFU Europe they directed me to AFN Afghanistan who sent me an aiming document that had everything exactly the way I had it, to the T. However, some where during all the up down, left right confusion I missed matching proper LNB skew with proper Az and Elv. After receiving the document i immediately went to my dish, rotated the LNB to the 4 o’clock position and EUREKA! NASCAR comes on behind me. Signal lock, but no quality. Then it started raining so I had to pull down all my equipment and didn’t get to fine tune. Anyway, the hardest part is behind me I’m happy to report. Below is the documentation sent to me from AFN Afghanistan:

Eurobird Sighting Instructions

The Azimuth is 252 and the elevation is 43 if the dish is inverted (if not inverted it is 13). When you are standing in front of the dish looking directly at it, make sure the connecter where you plug into the lnb is at the 4 o'clock position. If you can bring the decoder and small tv out right next to the dish and connect it directly to the dish while you are aligning it, this will help. Go to the menu and then preset lnb and this will allow you to look at the signal levels and whether you get a lock while aligning the dish. Once you get to 252 and 43 put a small tick mark on the dish as a reference point, barely go to the left and then up and down slowly on the elevation arm, go to the left and up and down on the elevation arm, etc....until you get about an inch from the original spot. If you do not get a lock, go back to 252 and 43 and repeat to the right. This should help you to get a lock.


If you have a spectrum analyzer the settings are: Freq 1741.0 MHz, LNB Voltage 13V+22kHz, Units dBmV, LNB OSC 10600.0 MHz. We use a 500MHz span and with these settings you should be able to see 6 camel humps in the middle of the screen. The center of the third hump is at 1741MHz and the center of the 6th hump is at 1818MHz. Hopefully this will help you sight in the dish.

Decoder settings are:

Scientific Atlantic Cisco

Modulation Type is DVB-S
Downlink Freq is 12.34125 Downlink Freq is 12.34125
Symbol Rate is 27.5 Symbol Rate is 27.5
FEC is Auto Net ID is 10
Polar is Vert LO Select is Auto
Net ID is 10 LO Freq 1 is 9.75
LNB Power is 13 LO Freq 2 is 10.6
LO Freq 1 is 9.75 Crossover is 11.7
LO Freq 2 is 10.6 LNB Power is 13V (FOR 1 BOX ONLY)
Crossover is 11.7 Diseqc is Disable
LO Select is LO2 Diseqc Switch is OFF

 

[ralphmagno]

ok good,
now when it is not raining if you can set it up again,since you are in the ball park thats good.
if you get a sig lock now make small adjustments on skew of the lnb and dish.
small flexing of the dish the strenth may go to 65 ot 67 still keeping a signal locked.
now a small wrist of the lnb will give you quality .
make a few degrees conter clock and then try clock wise.
when you get a quality of 4 to 7 stop its maxed out.
send us an update
ralph

 

[jncsk8r]

All done! The rain was short lived and afterwards I took my equipment back out to the dish site and continued fine tuning. I now have AFN back up and running on our two TVs. The solution was right in from of my face the whole time. For anyone who comes across this thread: Start with a solid/level base and a plumb vertical. Using settings to your preferred SAT from _http://www.dishpointer.com/, set your MAG Az with a compass (try to be as exact as possible) adjust your ELV (again, try to be as exact as possible) configure your LNB (for me this was the most crucial part). When you make adjustments, MOVE IN VERY SMALL INCREMENTS, I can not stress that enough. One thing that I noticed, if I ever lost lock and couldn't get it back I would revert back to my initial settings, back out of the dish set-up screen, go back in and start again. It seems my decoder would get hung on no lock. Good luck, give yourself plenty of time and if possible have a small TV and your decoder with you at the dish site. I know it may be a pain to tote all these items to your dish location but after about an hour of adjustments it's not half as annoying as yelling to or talking on a phone or radio to another person who's relaying the signal/quality readings. Thanks to all involved in my resolution! Cheers!

SFC Carlson