Quick - Help me think this through! Geosat Pro C/Ku

[linuxman]

Got my Geosat Pro C/Ku LNBF today and got it installed.

I am getting perfect analog signal on G1 C-Band, but now have the Traxis controlling polarity and voltage.

With the Traxis on a V TP on G1, I get the Horizontal Transponders booming in.

With the Traxis on a H TP on G1, I get the Vertical Transponders booming in.

I get a pretty decent digital signal on 1 V TP that has been scanned into the Traxis, but no H previously scanned in.

Haven't gotten any Ku digital signal as of yet, but get vertical analog tps on G17 if the Traxis is on a H TP.

I have the arrow on the LNBF pointed straight at 12:00.

The Polarity seems to be reversed. No directions came with the LNBF.

Should I point the arrow at 6:00? 10:30? 9:00?

Please help me think this through to straighten it out. The C-Band analog is outstanding.

If the digital comes in as good, I'll be a happy camper.

 

[linuxman]

Polarity is indeed reversed.

I manually changed the previously scanned in ONN on G17 to a V tp and am getting it just 5% short of where it was on the Co-Rotor. I think that is because I moved the LNBF to a .36 because I was confused in the beginning.

I think if I move that back out to the .38 where it was originally, ONN will be better than the co-rotor was.

Still don't know if it should be a complete turn upside down to change polarity or what?

Thanks for any help,
Fred

 

[qwert1515]

These images I posted a while back might be helpful: My setup

 

[linuxman]

Hi Qwert,

So you are pointed at 103 and setting at about 10:30 with the arrow.

Do both polarities come in for you correctly with the arrow pointed in that direction?

Thanks!

 

[Mr Tony]

Linux
If the GeoSat is like my 621-2 polarity seems to start at 9:00/3:00 instead of 12:00

I've had 3 LNB's (421,621-2 and GeoSat C-Band dual) and all started at 9:00/3:00 for 0 skew

 

[linuxman]

Hi Iceberg,

I thought that might be the case!

Stands to reason that if it is at 12:00 and polarity is reversed, you only need to move half way around the circle to reverse the polarity.

I'll give that a shot!

Thanks a bunch!
Fred

 

[qwert1515]

For the GeoSat the zero polarity mark should point towards 9:00, I can get both polarities on other satellites, 103 one polarity is a little too weak on my 1.2 Meter dish

 

[linuxman]

That did the trick!

Setting the arrow at 9:00 reversed the polarity completely.

Now just have to fine tune the skew a little, and maybe the in/out and I am off to the races.

Thanks,
Fred

 

[gabshere]

sounds like you have it now
this is where i made my box to find the best signal and then ku
good luck

 

[Comptech]

Thanks for this post guys! I blamed my poor reception on my mini bud [4 footer]. Just put my bcs621 back on and set the arrow at 9 instead of 12 and what a difference! Now maybe I can map my dsr 920, Thanks again.

 

[linuxman]

Hey George,

I haven't got it yet, but it is close.

After moving to 9:00 position, I found that the polarity was correct, and could get the verticals good, but the horizontals weren't that great.

I moved it to the 10:30 position which may have been the wrong way to go but I had to do something. That pretty much killed the verticals. I moved it little by little back towards the 9:00 position and am almost back and can get the strong horizontals pretty well and the verticals are better, but I think I am going to be back at 9:00 again and still not have the weak horizontals better.

I think this thing has the potential of working out great, but is a bear to dial in. There seems to be a very delicate line on the skew for both horizontal and vertical to work great on Ku.

The analog is working good except I still can't get either the digital or analog test card on AMC2/16 yet.

Should I have moved towards the 7:30 position to try and improve the horizontals?

If I can get at least as good as the co-rotor SQ across the arc I will be very happy. I was so skeptical after everyone has reported problems with the voltage controlled LNBFs that it took a lot of courage to even buy one.

If it works out and the new Fortec I ordered turns out to be pretty good, I think I will have some major switching around of receivers.

I have just the place for this LNBF. It is called the Birdview. That is where all the multi-LNBFs are hooked up now. I will have to wait and see if the Fortec will handle more than 4 LNBs in the setup menu.

I can them move the Traxis to the motorized Primestar, and the Pansat to the Unimesh and share it with the analog, and I can sell my Coolsat 5000.

Thanks for your help guys!

Please let me know if you think I should have moved it the other way.

Fred

 

[Mr Tony]

the AMC2 digital card is not up right now

 

[gabshere]

after reading your post i will have to check my bsc621 out i think i have it set for 12:00 and get some good readings but not acoss the arc on ku and some ku satellite signals are low. c-band has good readings across the arc

 

[linuxman]

the AMC2 digital card is not up right now

That certainly explains why I couldn't get it. DOH!!

i will have to check my bsc621

Please do and let us know.

I've still got a little ways to go on this one, but I am confident that I will find the right spot.

 

[gabshere]

Please do and let us know.

I've still got a little ways to go on this one, but I am confident that I will find the right spot.

well i checked and found that i do have it set at 9 / 3 but not on my TS satellite thats on my 123 G10 which i origally set it up at. when i move it to my TS sat 97W it is almost at 6pm so i will have to re adjust it and see if it helps ( it will be a monday job) but thanks for the thread looks like i will get most of my missing ku sats worked out.

 

[linuxman]

when i move it to my TS sat 97W it is almost at 6pm so i will have to re adjust it and see if it helps

Hey George,

Isn't your TSS the same as mine 91W? I think you might have mis-typed.

But if you started out at 6:00, that means maybe I should have moved towards 6:00 to correct mine.

Ah the life of experimentation.

Fred

 

[gabshere]

yes , lol i even climbed the ladder in the dark with a flash light to check the direction while at 97W lol with my longatude being 92.141 w i usually use 93W for my TS sat . but goofed up on that last night lol lol but i do plan on rechecking it and re-tuning it. i suspect my current setting to be actually closer to 5:30 and should need to be closer to 7:30 for best ku reception. for c-band it made little or no difference when i installed.

 

[stogie5150]

Hey George,

I haven't got it yet, but it is close.

After moving to 9:00 position, I found that the polarity was correct, and could get the verticals good, but the horizontals weren't that great.

I moved it to the 10:30 position which may have been the wrong way to go but I had to do something. That pretty much killed the verticals. I moved it little by little back towards the 9:00 position and am almost back and can get the strong horizontals pretty well and the verticals are better, but I think I am going to be back at 9:00 again and still not have the weak horizontals better.

I think this thing has the potential of working out great, but is a bear to dial in. There seems to be a very delicate line on the skew for both horizontal and vertical to work great on Ku.

The analog is working good except I still can't get either the digital or analog test card on AMC2/16 yet.

Should I have moved towards the 7:30 position to try and improve the horizontals?

If I can get at least as good as the co-rotor SQ across the arc I will be very happy. I was so skeptical after everyone has reported problems with the voltage controlled LNBFs that it took a lot of courage to even buy one.

If it works out and the new Fortec I ordered turns out to be pretty good, I think I will have some major switching around of receivers.

I have just the place for this LNBF. It is called the Birdview. That is where all the multi-LNBFs are hooked up now. I will have to wait and see if the Fortec will handle more than 4 LNBs in the setup menu.

I can them move the Traxis to the motorized Primestar, and the Pansat to the Unimesh and share it with the analog, and I can sell my Coolsat 5000.

Thanks for your help guys!

Please let me know if you think I should have moved it the other way.

Fred

If you remember Fred I had the exact same problem when you helped me dial mine in. For some reason the voltage controlled LNB's are terribly hard to get exactly right. I still don't think mine is as good as it can be, I am just loathe to fool around with it right now. The skew is indeed about 10:30 on mine too. The difference is that my analog is shot to hell PQ wise the farther east and west I get from due south. Near the center of the arc ( where I installed it originally) analog is fine.

Just like Brian said on the website, these LNB's are ADVANCED HOBBIEST ITEMS.

That would be us, wouldn't it? :up

EDIT: Here's my dish set on AMC 6 Where it is right now the NASA TP's are in the 90's on my Coolsat 5000.

 

[linuxman]

Thanks Stogie,

I am almost there.

I moved back to the 9:00 position and am just a hair above that towards the 10:00 and have the best so far.

I moved the wave-guide out 1/4 inch and improved the signal all around quite a bit even on C-Band, so the Focal Length might be a little different on this than the C-rotor. I am going to move it out another 1/4" now and see what happens.

That would be us, wouldn't it?

Affirmative!!!

Fred

 

[linuxman]

Well here is the latest installment of this saga.

It seems everything I do with a dish turns into a saga.

As I posted before, I moved the Focal Length out another 1/4" from where I was before, and it seemed to help the signal some, but I found a dilemma I couldn't figure out.

On the ends of the arc the H and V were pretty much on the money when the positioner stopped, but on AMC3 which is near the top of my arc, the H and the V were at least 3 or 4 clicks apart. I couldn't figure that out. I kept thinking to myself that this was very strange.

Then I remembered Harold's (caddata) story about the onion. I thought, Okay, I've moved it to the point where the signal is starting to diverge. (Harold says that the signal hits a point where best signal is attained for about an inch or so, then it starts to break back up. That inch is referred to as the onion.)

So I moved it back in and tried the skew some more all without getting the Ku with anything comparable to the co-rotor. The c-band is great and has remained that way through all this even analog, crystal clear.

So after several unfruitful tries, I decided to go for broke. The factory specs on this dish has the F/D ratio at .40 and the Focal Length at 48". I had the co-rotor set at .38 and 47-5/8". That is where I always got my best signal. Believe me I tried it at the .40 and .42 and had it at the Factory specs at least once, maybe more.

So I set the F/d ratio at about where the co-rotor would be at .42. The wave-guide mouth is even with the scalar rings at that setting. There are no marks on the geosat LNBF. I did not move the scalar rings during this process because I have them where I want them for the co-rotor. the .42 had the focal length at 48-1/4". That's 48" to the mouth of the wave-guide and figuring 1/4" inside for total length.

That is where I have my best signal so far, and the H and V tps on AMC moved back together, so I know I am in the middle of the onion.

Here is how it stacks up against the co-rotor. The 1st reading is the co-rotor, 2nd is the Geosat:
G15 - 133W 3745 H C-Band digital 72% SQ 68%SQ
G27 - 129W 11964 H Ku digital 72% SQ 68% SQ
G10 - 123W 11718 V Ku digital 75% SQ 73% SQ
G11 - 91W 3720 H C-Band digital 78% SQ 78% SQ
G11 - 91W 12062 V Ku digital 60 - 65% SQ 58 - 61 SQ
AMC3 - 87W 12144 H Ku digital 70% SQ 15% SQ the vertical PBSs are at 70% and the horizontals are at 75%, so maybe there was a problem with Montana PBS today. Couldn't figure that one out either.
AMC2/16 - 85W 12195 H digital Ku test card 80% SQ 70% SQ
AMC2/16 - 85W TP 24 analog had an almost sparkle free picture. Clear with co-rotor.
G17 - 74W 11734 H digital Ku 80% SQ 75% SQ
AMC6 - 72W 12053 V digital Ku 72% SQ 72% SQ
AMC6 - 72W 4043 V digital C-Band 77% Sq 75% SQ
IS9 - 58W 4040 H digital C-Band 75% SQ 81% SQ

I am quitting for now. I wanted to make sure that it was at least somewhat comparable to the co-rotor, and it turns out to be very close. It will work even better on the Birdview and fit better too. The scalar ring was milled out to .005 clearance for the co-rotor to fit on the Birdview. So the Geosat LNBF will fit much tighter in there. It fits like socks on a rooster using the co-rotor scalar.

I have made at least 40 trips up and down two ladders yesterday and today because I didn't want to un-hook and carry the analog, Traxis, the mini-dvd player all to the roof again, so I opted yesterday to just go up and down. I think maybe I should have gone to the extra effort.

The final pointing of the arrow is just a hair towards the 9:30 point on the dish.

Thanks for all your help!

Fred