SatSig topic:

HX 50 at Kirkuk, Iraq. Pointing at W6

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Aug 2^nd, 2008 at 6:19pm

I have ordered and received a new HX 50 system, and am working to get it up and running here in Kirkuk, Iraq. I bought the system from Bentley Walker. After 5 days of tweaking various parts of the dish and mount hardware, I am growing frustrated. My main issue is this: I haven’t been able to find the satellite (W6).

My aiming parameters for my location, Kirkuk, Iraq, before hooking up the Horizon meter, are as follows:

System: HX 50
Satellite: W6
Azimuth: 212 degrees (magnetic)
Elevation: 42 degrees
Skew: +29 degrees

Here is the background and detail, along with some specific questions:
(1) Receiver/Transmitter assembly: I was told by Bentley Walker that the polarity of the assembly should be VERTICAL for my dish in Iraq aiming at W6. Looking at the assembly instructions that came with the product, it shows in section 3 that the side port (with the small white box attached to it… what I believe is called the “filter”?) should be oriented exactly AWAY from the feed arm for a vertical polarity set-up. Reading through the posts, here, though, that seems to be misleading… it appears that, for polarization discussions, the following applies:
a. During the initial set-up, most all discussion of polarity refers to RECEIVE polarity, not TRANSMIT polarity.
b. The assembly instructions have therefore labeled the diagrams incorrectly; that is, for vertical polarity, one needs assemble the “505” on the top of the horn assembly directly AWAY from the feed arm, keeping the single score mark also AWAY from the feed arm and rotate the rest of the transmitter/receiver assembly in its yokes to 90 degrees, which makes the side arm stick out to the left or right (depending on whether you rotate the transmitter/receiver assembly POSITIVE 90 degrees or NEGATIVE ninety degrees).

Added by forum admin: Yes, you are correct. The Prodelin assembly manual is ambigious and misleading. The page about polarisation is in terms of the transmit polarisation. I have written to them about this.

(2) Horizon meter: I am connecting it as follows: using the coaxial cable-30 meters- that I bought with the HX 50 system, I connect one end of the marked cable to the female connector coming off of the little white box on the side port (the “filter”?). The other end I connect to the Horizon meter, at the input female connector. Then I check my initial dish alignment using a magnetic compass and a tape measure as a makeshift inclinometer like Eric describes (very helpful). Then I start sky sweeps (most of the time I do this after the sun sets). When I sweep the sky carefully, I get variations in signal strength… (particularly if I am doing the sweeps during daylight hours) which I think is good. In fact, at certain points in the sky, I get strong signal peaks. My received signal as I read on the Horizon meter (I think the units are dB?) stays on 56 as just random background signal, but at certain discreet points, the signal peaks abruptly to as high as 78. I have been able to find about 3 discreet points in the sky where the signal gets strong like that. BUT I NEVER GET A “SATELLITE FOUND” MESSAGE. I talked with Bentley Walker technical support, who emailed me an updated load for the Horizon meter, specifically for the W6 satellite. I loaded it, and now I have about 10 different W6 selections to choose from on the Horizon meter. Bentley Walker tells me I should be using #6.

Questions:
-The Horizon meter instruction manual instructs that I should use a very short length of coaxial cable to connect the Horizon meter to the transmitter/receiver assembly. Bentley Walker told me, however, that that is not important and that I can use the 30 meter cable that was bought with the whole HX 50 package. Is it OK to use the 30 meter cable when using the Horizon meter?

-Are my aiming parameters (azimuth, inclination, skew) correct?
Yes

-Is my understanding of assembly for vertical versus horizontal polarity correct?
Yes

-If I am seeking the W6 satellite, do I need to be set-up for vertical or horizontal polarity?

-If I am correct in the conclusion that for vertical receive polarity, one needs to rotate the transmitter/receiver assembly 90 degrees, then do I rotate NEGATIVE 90 degrees, or POSITIVE ninety degrees? (as read off of the scale on the transmitter/receiver yokes)

Added by forum admin: Nominal vertical polarisation is when the dipole pin inside the LNB waveguide is vertical. The broad faces of the LNB waveguide will be on top and underneath. With the LNB arm sticking out sideways (relative to the ground) you will have a nominal vertical starting position. It does not matter which side. In some cases, applying the adjustment angle will make the LNB hit metal, in which case start on the other side.

-I haven’t even connected or powered up my modem, for fear of messing it up. I think I don’t need to do anything with the modem until I get a nice solid “satellite found” message on the Horizon meter. Is that assumption correct?
Once you connect the low voltage DC multiway cable between power supply module to the modem never disconnect this multiway DC power lead. Always power off at the mains before connecting or disconnecting the coax cables

-Any additional advice for how I can find the W6 satellite?

-Anyone else using HX 50 and W6 satellite in Iraq? Any recent installs of such a set-up that could provide some advice to me?

Many thanks to Eric. Great information here. Eric, I sent you some photos of my set-up.

-Very Very Novice
US Army
Kirkuk, Iraq

Images inserted by admin

View of HX dish. Feed assembly good. Horizontal polarisation. It is not obvious from the camera angle if any polarisation adjustment has yet been applied.

+29 deg clockwise polarisation angle applied.

Correct assembly orientation of the BUC. Horizontal polarisation. Adjustment should NOT be applied here.

Aug 2^nd, 2008 at 11:12pm

The small white module on the side arm is the receive LNB device. The LNB connects to the HX modem satellite receive IN socket. The filter is between the circular waveguide flange and the rectangular LNB waveguide flange.

The transmit cable goes to the IFL connector at the back of the BUC

I don't know the polarisation, frequency or symbol rate of the HX service on W6. The frequency and symbol rate will be on your BW config document. You need to program the frequency and symbol rate information into the modem so it can lock to the outlink carrier.

Regarding safe treatment of the modem and outdoor radio equipment:

Never disconnect the DC cable between the modem and the power supply.

Always power off at the AC mains plug before working on the coax cables.

Regarding the antenna assembly. The Prodelin assembly guide (which comes in the box) is misleading regarding polarisation. The page does not say if it refers to receive or transmit. It refers to transmit which is unusual.

The feed horn and the spacer tube must always be oriented so that the 505 and single tick mark are exactly away from the feed arm. The fat lump on the throat must always be towards the feed support arm. I apologise for being repetitive and pendantic about this but this is critical to acheiving the exceptionally good cross-pol performace of this antenna which beats all other offset antennas on performance, except dual optics antenna systems.

You may attach the filter/radio assembly at the 12 hole flange at any angle.

If you want to receive nominal horizontal receive polarisation then put the filter/LNB at the top. Horizontal receive polarisation is defined by the broad faces of the rectangular LNB input waveguide being on either side. Then apply the polarisation adjustment angle using the giant scale on the back of the dish.

If you want to receive nominal vertical receive polarisation then put the filter/LNB at one site (which side does not matter). Vertical receive polarisation is defined by the broad faces of the rectangular LNB input waveguide being on top and underneath side. Then apply the polarisation adjustment angle using the giant scale on the back of the dish.

A plus + polarisation adjustment means turn clockwise while facing towards the satellite, starting from any 0, 90, 180, 270 deg start position.

Note that if you have set horizontal receive polarisation at the feed then you can acheive ANY polarisation by rotating the entire dish through 360 deg using the polarisation scale. I appreciate it may look unusual to have the feed arm upside down and high up to one side or the other - but it will still work perfectly. Note that while turning the dish with the polarisation scale, the beam will remain pointed at the satellite. The beam is at right angles to the back polarisation plate.

You have found three satellites. Well done. These will be in a sloping line across the sky and it is likely that one of them is your wanted satellite. Whatever the satellite the Horizon meter will help you peak up very accurately - even if there is dispute about its programming and its failure to recognise a carrier on a satellite. It is not easy to get right. To say "satellite found" you must be pointed at the correct satellite and polarisation and the LNB local oscillator must match the programming in the Horizon and the programming must match a known good satellite carrier on that polarisation and in the chosen frequency band.

My personal preference in such confusing circumstances is to use the Horizon just as a sensitive power meter for finding satellites and peaking up and to use the HX modem to recognise the wanted carrier.

I can't retrieve your email pictures now and I can't help further for the next 6 days. Good luck in the meantime.

Best regards, Eric.

Aug 4^th, 2008 at 5:31pm

Thanks to Eric for your advice. Francis, we at Bentley Walker are ready to assist with your setup and also have a Database of installers/personnel in your area who will be able to assist if you have exhausted your options.

My direct contact is james at bentleywalker.com MSN/Yahoo messenger james_bentleywalker at hotmail.com. Please forward your pictures so that we can assist further.

Aug 4^th, 2008 at 11:16pm

EUREKA!

I found W6 about an hour ago. Was a great feeling of satisfaction when my Horizon meter gave me that “FOUND” message.

Prior to tonight’s work to find the satellite, I spent lots of time reading and learning off of the various satsig resources, and some other internet resources. I re-confirmed with Bentley Walker that the receive signal from W6 is polarized vertically.

Here are the pieces that I think were game winners for me:
-I had failed to find the satellite using the tape measure as a makeshift inclinometer, so I went back and made the cardboard inclinometer that Eric describes.
-I confirmed that the “505” on my feed horn was directly away from the large feed arm, and that the fat part of the feed horn throat was directly towards the large feed arm. I re-configured my receiver/transmitter such that the “505” and single score mark and fat portion of the feed throat were oriented properly, and that the transmitter/receiver was rotated in its yokes by 90 degrees, such that the LNB sticks out to the side.
-I set the polarization adjustment (“skew”; for me about 29 degrees) by twisting the DISH, not the transmitter/receiver (which, as noted above, I had set and left at 90 degrees)

At that point I set the elevation to my exact (or as close as possible, using the cardboard inclinometer) setting for the W6 satellite, and then I just started a slow horizontal sweep with the dish. I found the satellite in about 90 seconds. Was fantastic.

An important piece of information for the very very novice (1st time install, very inexperienced) like myself is this: the polarization piece was confusing at first. If you imagine yourself as the electromagnetic wave traveling from the satellite (or perhaps more precisely, the electric vector of that electromagnetic wave) encountering the orifice of the receiver, you see that you are traveling towards the open end of a rectangular box. Inside that box there is a little pin sticking up. That pin (a dipole probe, I believe) juts up from the broad side of the box, into the middle of the box, I think. The issue is this: when speaking of the polarization, think of the orientation of the PIN, and NOT OF THE BOX ITSELF. If, while you are assembling your VSAT set-up, you keep in mind where that pin is and how it should be oriented, things make a lot more sense. Eric does a good job in his diagrams of explaining that.

Vertical =

Horizontal =

Some other points:

I took the advice from satsig.net about setting your elevation first, THEN doing your horizontal sweeps to find your satellite. I tried many other methods, and I can endorse the “get everything all properly arranged, then set elevation, then do horizontal sweeps” technique as the most effective one I tried.

Bentley Walker’s W6 load that they provided for me to load into my Horizon meter has a lot (10 I think) of selections for W6. They explained that selection #006 was the one to use, and they were spot on. That one worked.

I suppose the summary lesson to take away from all of this is:
If you are like me and know nothing about VSAT hardware setup, read and learn as much as you can off of satsig.net, and ask questions about things you are unsure about.

I still feel quite inadequate in my knowledge base and skills here, but at least I have found the satellite. Now on to peaking, commissioning the modem, talking to hub, etc. etc. etc… I am sure there will be many more bumps along the way, and much more to learn.

Many continued thanks to Bentley Walker and Eric.

Aug 5^th, 2008 at 10:22pm

Today I connected everything, called Bentley Walker and things went pretty well I think. I am now online, with functional modem, etc. My transmit strength is at 90 and my receive strength is at 84, all without any adjustments (I used my Horizon meter to peak up last night, and looks like it did a decent job).

Thanks again to Bentley Walker and Eric!

Aug 16^th, 2008 at 7:25am

I believe we have the same system. I am with Wafa though. We just locked in at 91% last night. We ensured that all of our parameters were correct. Our feed assembly is installed such that the single mark and the 5 0 5 are lined up with the LNB, then all of them are pointed opposite of the feed tube. We then pointed the azimuth and elevation (the elevation will be relatively high, if there are other dishes you are comparing it to, be careful because a lot of them are pointing to W3 at 7E and are parallel to the ground). We got about 29 at that point. We made fine tuned ajustments to the left and upwards (there are a lot of satellites in a line). We got a 30 which means we were on the right satellite. We made some more adjustments with elevation and the azimuth. We instantaneously made the most success by changing the polarization by rotating the dish itself on the back with the big scale (it will look like the azimuth changes, but it doesn't because it is an offset dish).

Aug 20^th, 2008 at 11:30am

Below is an example HX dish configuration

In this example it is 34.1 deg beam elevation, nominal Horizontal receive polarisation, polarisation adjustment +45.5 deg

This image above shows a HX terminal as in Iraq, aimed at W3A satellite at 7 East. The entire dish is rotated +45.5 deg clockwise for polarisation, while facing the satellite. 505, single tick mark, filter and LNB directly and exactly away from the feed arm.

If the entire dish polarisation is turned so that the feed arm is at the top or the bottom then it is at a horizontal polarisation starting position.

If the entire dish polarisation is turned so that the feed arm is at a side then it is at a vertical polarisation starting position.

From any of these four starting positions, the amount polarisation adjustment may be applied. Clockwise is positive as viewed towards the satellite.

In all the above, the 505, single tick mark, filter and LNB are directly and exactly away from the feed arm.

The above idea might simplify the installation of HX sites as all sites will have the LNB directly away from the feed arm, regardless of the polarisation in use. The only negative will be the strange appearance of some antenna with the RF assembly up in the air. Note that you can turn the polarisation all the way round and the beam stays pointed at the satellite.

Best regards, Eric.

Aug 31^st, 2008 at 3:23pm

That's cool that you got it going. We just got ours yesterday (here in Kirkuk) and can't get anything above 29! I don't understand ANY of this:

"I confirmed that the “505” on my feed horn was directly away from the large feed arm, and that the fat part of the feed horn throat was directly towards the large feed arm. I re-configured my receiver/transmitter such that the “505” and single score mark and fat portion of the feed throat were oriented properly, and that the transmitter/receiver was rotated in its yokes by 90 degrees, such that the LNB sticks out to the side.
"

Ours is turned 90 deg clockwise, looking at it from the front. But the whole fee horn, fat part, etc is confusing me. Does anybody have a good picture of what it's supposed to look like for vertical receive polarity?

I called BW twice today, the second guy was helpful. But the first guy just told me to look on here and that's IT! Wouldn't help me at all. Didn't even ask for my name!

Sep 1^st, 2008 at 1:04pm

In the image example below the antenna is set for 34.1 deg beam elevation, nominal Horizontal receive polarisation, polarisation adjustment +45.5 deg

Regarding polarisation.

Using the feed assembly as shown (505 and single tick away from arm. LNB away from arm) if you turn dish the dish using the scale behind the dish so that the feed arm is back at the bottom then you have truly Horizontal polarisation. This is a starting position for nominal Horizontal polarisation, prior to the adjustment.
See image below:

You may turn the whole dish 90 deg either way so that the feed arm is at one side. The LNB filter will also now be sideways and the polarisation will be truly Vertical. This is a nominal Vertical polarisation starting position. Then apply the adjustment amount. The actual number on the scale may not apply, but it is the amount and direction of adjustment needed that matters. Use common sense and apply the adjustment amount rather than reading the scale numbers.

If you don't like the appearance of the dish with the feed arm up in the air then you are welcome to start with Vertical polarisation set with the feed arm at the bottom. In this case undo the 12 hole flange between the spacer tube and the filter. Attach so that the LNB filter is at one side and so that the 505 and single tick mark are exactly away from the feed arm. The fat lump on the feed throat must be towards the feed arm.

The 505 and single tick mark must always be exactly away from the feed arm. The fat lump on the feed throat must always be towards the feed arm. This applies regardless of the wanted polarisation or any adjustment applied.

You may alter the 12 hole flange between the spacer and the filter any way you wish. Normally you would choose Horizontal or Vertical with the feed arm at the bottom.

Remember that you can turn the dish all the way round through 360 deg, there are 2 Horizontal positions and 2 Vertical. The beam stays pointed at the satellite all of the time. Start at any one position and then apply the adjustment angle. Adjustment + positive is clockwise, as viewing towards the satellite. The actual number on the scale may not apply, but it is the amount and direction of the adjustment needed that matters. Use common sense and apply the adjustment amount rather than reading the scale numbers.

When you have your dish working OK, please send a picture to help others. If someone else has pictures please send also, to eric@satsig.net - all help welcome !

Best regards, Eric.

Sep 4^th, 2008 at 1:56pm

This is what I get out of this:

Vertical polarization:
1. Feed arm at the bottom (at 6 O’clock).
2. Antenna LNB and filter turned 90 Degrees to either side in its “saddle” (at 3 or 9 O’clock).
3. Undo the 12 hole flange between the spacer tube and the filter.
4. Attach so that the 505 and single tick mark are 90 degrees from the filter (at 12 O’clock).
5. The fat lump on the feed throat must be towards the feed arm.

Horizontal polarization:
1. Feed arm at the bottom (at 6 O’clock).
2. Antenna LNB and filter straight up in its “saddle” (at 12 O’clock).
3. Undo the 12 hole flange between the spacer tube and the filter.
4. Attach so that the 505 and single tick mark are in-line with the filter (at 12 O’clock).
5. The fat lump on the feed throat must be towards the feed arm.

IMPORTANT:
1. The 505 and single tick mark must always be opposite of the feed arm.
2. The fat lump on the feed throat must always be towards the feed arm.
3. This applies regardless polarization.

Edited by admin - hopefully !

Sep 4^th, 2008 at 3:45pm

Horizontal receive polarization:
1. Feed arm at the bottom (at 6 O’clock).
2. LNB and filter arm straight up in its “saddle” (LNB at 12 O’clock).
3. Attach 12 hole flange so that the 505 and single tick mark are in-line with the filter (at 12 O’clock).
4. The fat lump on the feed throat must be towards the feed arm.

Vertical receive polarization:
1. Exactly the same as above, then
2. Turn the entire dish, using the polarisation scale on the back till the feed arm is at one side (3 or 9 O’clock)

Vertical receive polarization (alternative):
1. Feed arm at the bottom (at 6 O’clock).
2. LNB and BUC assembly turned 90 Degrees to either side in its “saddle” (LNB at 3 or 9 O’clock).
3. Undo the 12 hole flange between the spacer tube and the filter.
4. Attach so that the 505 and single tick mark are 90 degrees from the filter (at 12 O’clock).
5. The fat lump on the feed throat must be towards the feed arm.

IMPORTANT:
1. The 505 and single tick mark must always be opposite of (away from) the feed arm.
2. The fat lump on the feed throat must always be towards the feed arm.
3. This applies regardless polarization or polarisation adjustment.

4. Any of the above will achieve a correct nominal starting position for Horizontal or Vertical polarisation.
You then need to apply a polarisation adjustment amount, depending on satellite and site location.
Adjustment + positive is clockwise, as viewed towards the satellite.
Use the big scale on the back to determine the amount of movement.

Best regards, Eric.

Sep 22^nd, 2008 at 2:21pm

Outbreak,

Are you up and running yet? If you have a phone # I can call you and come look at your set-up if you're still having problems...

Sep 25^th, 2008 at 4:52pm

Oh yeah, we're good! I was just trying to make that stuff as simple as possible. it could get pretty confusing! Thanks for the offer though! I appreciate it!

...Out...