New Dish, LNB, no signal, lots of strength

[dwboston]

A professional installer just installed a new 2.4 meter Geosatpro c-band dish (fixed dish) for me in a pasture near my home (about 25 feet from the house). After finishing the installation, the installer could not pick up a signal from the AMC-1 free-to-air channel I was trying to receive. Signal quality was about 94, but I cannot get a quality reading (on a Globecast receiver) any higher than 49. I also have a couple of professional Scientific Atlanta PowerVu's that were receiving a fine signal on a different dish for the same satellite several weeks ago, and none of these receivers can pick up a signal on this satellite.

The installer told me that the dish i bought was a piece of crap and was probably the reason I couldn't get a signal. The LNB which was purchased new with the dish was not an expensive unit, but given the ideal setting for this dish - no tree interference, an easily accessible satellite, shouldn't I be receiving some kind of signal. Can a 7 and a half foot dish be built so poorly as to prevent a satellite from being picked up.

Before purchasing a better quality dish, I'd love any suggestions.

New and more expensive LNB?
Re-tuning the dish myself?
(I've already tested the reception by placing the receiver right at the dish location so I know it's not the cable length).
(I've also already tried to make fine adjustments on the LNB which did help me get the quality reading to 49, but still not enough signal to result in any channels when I did a channel search on the IRD.

 

[Lak7]

Which LNB?

 

[Mr Tony]

AMC1 has recently become a bugger for me on the 6 footer. Barely any signal

 

[Corrado]

To test the equipment, try to tune AMC4 right next door. You should be able find find some active TPs there only 2° away.

We really need to know more about the receiver and settings, LNB etc.

Do you have a standard FTA receiver to test with?

 

[voomvoom]

My guess is the Installer didn't know what he was doing, and you're not pointed at AMC1, or any other satellite. Most Professional Installers, do Directv or Dish Network and don't have a clue about C-Band dishes? Some do, but most don't. It would be just like one of them to Blame the dish as Crappy, because they don't want to admit they are clueless... and like Corrado says, more info will help us to help you..!!

 

[Anole]

....hrmmm... yea, that first post is confusing.

Why would anyone spend the money on a new C-band dish, and then use a Globecast receiver?
Does Globecast have subscription services on C-band? I know they do on Ku.
edit: Yes, apparently they do, but it's Digicipher II. What receiver are you using , again???
Can you get your subscription channels on Ku band instead?? (Galaxy 25 @ 97° west)

Okay, I re-read the first post for the 4th time.
If you can borrow a blind scan receiver, and scan to find out where you are actually pointed, I think that would be helpful.

BTW, I've done some research on that dish.
It's not real popular, but those who have it seemed happy.
At one time, I considered getting it.

 

[dwboston]

Thanks to all your responses. I'm using a Globecast FTA box to get my strength and quality readings, but in my former installation (I just moved), I used a $1200 Scientific Atlanta PowerVu to receive Deutsche Welle's free to air service, because I'm their U.S. marketing agent. It's the only channel I really need - which is why this is a fixed C-band dish. The higher end boxes aren't really good at giving you much guidance for tuning a dish, whereas the Globecast box has got some pretty simple tuning mechanisms. I've tried a couple different LNB's including an older Chaparral unit which I pulled from the 6' dish I was using up until last year.

The guys that installed this dish are actually professional c-band installers --- they do a lot of local installations for broadcasters and universities, so while I'm still skeptical that the dish is no good, they have done a lot of big dish experience.

I'm going out this weekend to start tuning around a bit to see if perhaps they are on the wrong satellite. The next step is to upgrade to a higher end new LNB. Then and only then will I consider another dish. I'm limited to something that will sit on a 3.5 " mast. I understand that SAMI is one of the few manufacturers still making mesh dishes that will fit on a 3.5 mast, so I may consider one of their 2.3 meter dishes if other solutions don't fix the problem. Any experience with SAMI dishes?

 

[Anole]

which LNB ?

Which LNB?

Yes, please, WHICH LNB is currently on the dish?
. . . and how are you adjusting skew?


As for the dish, no it's not a commercial dish, so I can see the installers turning up their nose at it.
For the home market, what little I've read about it, seemed positive.

A professional installer just installed a new 2.4 meter Geosatpro c-band dish (fixed dish) for me in a pasture near my home (about 25 feet from the house). After finishing the installation, the installer could not pick up a signal from the AMC-1 free-to-air channel I was trying to receive.

Gives question as to how "professional" the installer and his equipment really is.
Do you think he just didn't have experience with a non-commercial dish??

 

[jsattv]

AMC1 has recently become a bugger for me on the 6 footer. Barely any signal

I thought it was just me, but I have had a lot of trouble with AMC 1 / 103.0W on my 12 Foot Mesh Dish - especially the Pentagon Channel. (I know its weaker in Canada). Other Ku Band Tp's on 103.0W ie the color Bars on MS 90?? were coming in much better but when I used Skew Button I was at least able to get Pentagon Channel with 10 to 25 % Quality, while adjacent C Band Satellite Tp's on 99.0W and Ku Band on 95.0W were at least 3 to 4 times better Signal Quality.

 

[dwboston]

The LNB is an older Chaparral (about 6 years old), but I have also switched it out with the cheapy that came with the dish that doesn't even seem to have a brand. So I think I will be ordering a new LNB. Quick question though --- I'm thinking of buying a Chaparral 17 degree 3G Micropak for about $80. Is this a decent LNB... and which is better lower or higher degree rating? I"ve seen 20 degree LNB's as well.

 

[Lak7]

I thought it was just me, but I have had a lot of trouble with AMC 1 / 103.0W on my 12 Foot Mesh Dish - especially the Pentagon Channel. (I know its weaker in Canada). Other Ku Band Tp's on 103.0W ie the color Bars on MS 90?? were coming in much better but when I used Skew Button I was at least able to get Pentagon Channel with 10 to 25 % Quality, while adjacent C Band Satellite Tp's on 99.0W and Ku Band on 95.0W were at least 3 to 4 times better Signal Quality.

Remember that AMC1's Ku Skew is off about 20deg, C Band is normal.

 

[SatelliteAV]

The GEOSATpro 2.4M may not be a commercial grade dish, but I would suggest that it is not even remotely associated with the post digestive matter suggested by your installer. If properly installed, the GEOSATpro 2.4M dish will provide excellent performance for C and KU-band reception. The dish has been rated in several tests to be exceptional in both price and performance. We stand behind the quality and the performance of the GEOSATpro 2.4M 100%. If you find that the poor performance of the dish is due to design or factory defect, we will be happy to refund your purchase. Several thousand of these dishes have been sold and we have never had this dish returned due quality issues, poor performance, design flaw or factory defect.

The GEOSATpro LNBFs are also great performers. You experience is certainly not typical of the response to our products by dealers and end users! I believe that there may be an assembly or alignment issue.

Was the dish parabolic string tested for correct panel assembly? Has the feedhorn been centered on the reflector with a laser or other device? Is the F/D adjusted for optimal BER?

 

[Anole]

It's been a few days, now...
so, I wonder what has come of this problem?
Has it been resolved?

 

[dwboston]

Here's an update. We switched out the GeoSATpro LNBF with a Chaparral 17 MicroPak LNBF with no positive results. We've also tried retuning the dish's azimuth, elevation, and polarity with no better results. Though we're now quite sure we are tuned to the correct position for AMC-1 since we got the highest quality reading we could with the frequency and symbol rate tuned in. Brian Gohl's questions regarding parabolic string testing, etc. might be good ones, but I'm not willing to have the installers come back at $200/hour for this dish. I don't want to cast any negative aspersions against GEOSATpro; I'm sure under the right conditions that it's a fine dish, but I'm just surprised that this particular company would not have done all the right adjustments on this dish. They have been in business for years and generally do big dish installs at local TV stations and universities all the time -- not just some Dish Network guys that rarely touch big dish systems. One thing they did tell me was that this Dish was not appropriate for fixed dish installations (which is what I have). A quick call to Satellite AV on the day of installation got the response from the person at the other end of the line that the GeoSATpro 2.4 is made for motorized installations; and it lacks some of the mounting hardware for fixed dish installation. The installers had to jury rig a few pieces of steel to make it work as a fixed installation. It would have been handy to have known this when I ordered it on-line; there was no indication of this on the web site.

Meanwhile, If I am going to spend a few hundred more dollars to fix this issue, my impression is I will probably upgrade to a more expensive dish --- perhaps a Patriot 2.4 meter offset system.
We'll see.

ONe final question --- when I ordered the Chaparrel LNBF it came with this small orange-yellow plastic bar about the size of a small bar of soap, with virtually no directions on what it's for. Any clues?

Thanks

 

[phlatwound]

Maybe that plastic bar is a piece of dielectric material to convert your LNB to receive circularly polarized signals?

 

[dwboston]

Quote from Brian at Satellite AV: "Was the dish parabolic string tested for correct panel assembly? Has the feedhorn been centered on the reflector with a laser or other device? Is the F/D adjusted for optimal BER?"

Brian, if you are monitoring this thread --- or if someone out there can help... is there a relatively simple way to conduct a parbolic string test? The one thing my satellite installers mentioned was that they sense the dish had some warp to it.

Thanks

 

[dwboston]

Quick reply to my own question regarding string testing --- much simpler than I thought...

"You need to have a very parabolic dish. Warpage will cause
signal mis-reflection and you won't be getting the best performance
out of your system. To check your dish for warpage, you will need to get
some string and some tape. Take one string and stretch it as tight as you
can and anchor it to the dish edges with the tape. Make this string go
"north" and "south" across the face of your dish. Do the same thing with
the other string, yet go "east" and "west" across the face of the dish.
Make sure both strings are tight. If the strings do not come together in
the center, then your dish is warped and you will need to find some way to
take the warp out for maximum performance. If the strings touch in the
center, your dish looks very good as far as not being warped."

 

[Hermitman]

I just spun my 7.5 foot Echostar mesh with its 35 degree lnb over to amc-1 and did a scan. I picked up DW-TV, and the other channels loud and clear (although my german is a little weak). The picture was steady without pixelating. It has to be something simple. Was the lnb installed 90 degrees out? Is the servo moving or the servo wiring hooked up correctly? Did you happen to measure the focal distance and see if it was close? Is the receiver working properly? Is the L.O. set correctly as well as the other lnb settings? Can you try it on another dish? Have you tried plugging in other freqs and symbol rates for other channels to see if they work? Maybe try the freqs and symbol rates for the satellites on either side of amc-1 just to verify the satellite you're on. Did your installer use a spectrum analyzer to find and verify the satellite you're on or just an in-line buzzer? If you haven't picked up any channels or verified the satellite with an analyzer, its hard to tell where you're pointing.

As for an installer saying that a dish is not suitable for fixed installation --- huh? All my movable dishes are suitable for a fixed installation. I just don't move them.

Good luck. Going back to RetroJams.

 

[SatelliteAV]

Replies to this thread have raised important questions regarding the process used to assemble and aim the dish. As a veteran C-band installer since the 80's with hundreds of Prime Focus panel dish assemblies and aimings under the belt, I can assure you that all panel dishes must be checked and adjusted during assembly to assure a perfect parabola.

It doesn't matter the dish dish brand; 12' Paraclipse, 6' Orbitron or a 7.5' GEOSATpro, every panel dish (irregardless of the purchase price) MUST be checked for convergence as part of the assembly process. If the installers suspected that the reflector parabolic shape is not correct, did they verify and correct by loosening the panel connector hardware and adjusting the panels placement? This is a required process for and panel assembly.

Since this dish is mounted for fixed satellite reception, how did the installers aim the dish? Is the dish mounted facing True South then swung onto the satellite using the polar mount?
or
Is the dish fixed in the alignment with the mount then the entire dish elevation angle adjusted while aimed at the correct azimuth? I would suggest the latter.

How did the installers determine the dish angle? Did they use an elevation finder placed on the vertical plane of the dish edges or were they measuring the angle on the rear mount then adding/subracting the declination angle?

How has the skew been set? By rotating the dish on the Polar Mount or by rotating the skew to the correct angle after the dish was set in a fixed position?

Did the installer use a satellite meter or spectrum analyzer to attempt to locate the signal? If they did not have these tools and are relying on receivers to lock and peak the signal, I would seriously question the description "experienced and professional" in front of the word installer. Several things that you have shared in this thread would indicate that you are not dealing with a competent installation company. Even if you decide to go with another reflector, I would suggest that you consider hiring a different company.

We apologize that you were unaware the difference between AZ/EL and Polar Mount designs when you placed your online order. We do indicate on our website that the GEOSATpro dish is a Polar Mount design.

A Polar Mount design will use a linear jack motor to track the arc of satellites. Often installers will purchase or fabricate a lock bar to use a Polar Mount design for a fixed position. I am not aware of any Polar Mount design distributors that provide a lock bar for fixed mounting with their dish. AZ/EL designs are locked into a fixed position.

Once again I will emphasize that we stand behind the design and performance of our equipment. If the equipment is not performing as described due to design flaw or mechanical damage, please contact us and we will work with you to correct the situation.

 

[dwboston]

This just in. Finally got my hands on a FTA blind search receiver - and get this, the closest satellite to the spot where these guys installed this fixed dish was Galaxy 23 which is 18 degrees and 8 satellite slots off from AMC-1. Galaxy 23 comes in beautifully. Will be retuning this to AMC-1 using a compass and an elevation tool tomorrow. I also did the string test, and while the strings that meet at the center are separated by about 1/3 to 1/2 an inch of space, I don't think that's way outside the tolerances needed for c-band reception. We'll see. Will keep you updated. Thanks for all the info.