AMC 21

[Anole]

spacing between 123 & 125 LNBs

I could not find the focal length for the GeoSatPro 90cm.
I do have it for the Fortec Star 90cm dish.
= 510mm (about 20 inches)
edit: added 1.2m GeoSatPro dish as the request of RedSavina.
= 600mm (about 23.6 inches)
edit: added 1.0m Channel Master dish using measurements from Tron
= 705mm (about 27.75 inches)

Using the math in MJflash's thread, we calculate LNB separation for several cities around the USA.
This is for the 123° and 125° satellites:

[FONT=Fixedsys]  
..
                 focal length: 510         600        705
   city           zip         distance between LNBs for 2[/FONT][FONT=Fixedsys]°[/FONT]
[FONT=Fixedsys] -----------      -----      --90cm FS----120cm GS ---1.0m CM--
Long Beach, CA   90807       32.11 mm    37.83 mm    44.42 mm
Austin, Tx       78705[/FONT][FONT=Fixedsys]       25.07[/FONT][FONT=Fixedsys] mm[/FONT][FONT=Fixedsys]    29.50 mm    34.63 mm[/FONT]
[FONT=Fixedsys]Miami,  Fl       33196[/FONT][FONT=Fixedsys]       20.84 mm    24.53 mm    28.82 mm[/FONT]
[FONT=Fixedsys]Boston           02215[/FONT][FONT=Fixedsys]       19.60 mm    23.06 mm    27.04 mm[/FONT]
[FONT=Fixedsys]Minneapolis      55401[/FONT][FONT=Fixedsys]       21.51 mm    25.27 mm    29.72 mm[/FONT]
[FONT=Fixedsys]Seattle          98101[/FONT][FONT=Fixedsys]       24.02 mm    28.28 mm    33.23 mm[/FONT]
[FONT=Fixedsys]        
Width of common LNBs   (minimum center-to-center spacing)
Sky Mexico Universal       60 mm
105° FSS bandstacked       50 mm (maybe 45mm with crowding)
Eagle Aspen oval B/S       40 mm
[/FONT][FONT=Fixedsys]SatAV GeoSatPro Mini       40 mm

[/FONT][FONT=Fixedsys] A lot of manual calculation was required, with opportunity for error.
If you see a number that seems out of place, I'll double check it.
  [/FONT]

Based on these calculations, neither the Fortec Star 90 nor GeoSatPro 90 (with a shorter focal length) would be good candidates for 2° spacing using any of these LNBs.
Obviously, if you live in the south west, you have a better chance than north west or anywhere to the east.

edit: the 120 cm dish has been added .
The results are in reasonable agreement with the comment posted by wescopc, above.
In fact, the 120 cm dish should probably be satisfactory for 2° spacing from Los Angeles, Long Beach, or San Diego. (or Mexico)

edit: the 1.0 meter Channel Master dish has been added.
The results speak for themselves.

Remember, you have the best chance for very close birds...
- when the satellites are near your true South,
- you are further south on the planet,
- and your focal length is longer.

 

[RedSavina]

Anole,

According to the SatelliteAV site, the GS 1.2 has a focal length of 60 cm. How much does that impact the separation numbers for the zips you provided? I have to stay within 1M, but am curious nonetheless.

Red

PS: Yet another way to get the º symbol is ALT+0186 (using the number keypad).

 

[Anole]

updated table

Red -
I updated the table above for the 600mm focal length of a 120cm (1.2m) dish.

Those 1.0 and 1.2m Channel Master dishes look like the LNB is really out there.
Might be an optical illusion.
If not, someone give me focal length, and we'll see how they stack up.
... I think Linuxman has a 1.0m Channel Master... I'll have to go read his posts to be sure...

Still don't know where you are.
Post a Zip, and we'll talk.

 

[gabshere]

maybe its Rio Grande Valley

 

[Tron]

Anole, my 1 meter Channel Master measures about 27.75 inches from face of the feedhorn to the center of the dish... Just checked it.

 

[Anole]

Tron -
Yea, that sounds good.
Your measurement for 1.0m Channel Master converts to about 705mm, so it's probably spec'd somewhere around there.
Send it over and I'll test it on a couple of 2° birds.
edit: the table above has been updated, based on your 705mm focal length.

edit: the Fortec Star 1.0m dish has a focal length of 600mm
The Fortec Star 1.2m dish has a focal length of 720mm

I have no doubt the 120cm Channel Master would be longer and therefore even better.
But, if I had a 4' CM, I might use if for better things than digging out birds 2° apart! - :up

Would probably be better to dedicate two 90cm dishes to combinations like 123/127 and 125/129..
Both those should be no-brainers.

 

[RedSavina]

We have a winner (on RGV)! Any zip in the series 785xx should work; 78526 in Brownsville, 78578 in Port Isabel, 78597 on South Padre Island, etc.

 

[TRG]

Would probably be better to dedicate two 90cm dishes to combinations like 123/127 and 125/129..
Both those should be no-brainers.

Not much on 127 Ku is there?

 

[cracklincrotch]

Would probably be better to dedicate two 90cm dishes to combinations like 123/127 and 125/129..
Both those should be no-brainers.

That's exactly what I'm doing.

 

[Anole]

Red & 1m dish

Red -

If you were to use a 1m Fortec Star, then the 600mm focal length would be similar to the results above for the 1.2m GS with the same 600mm length
And to avoid all the recalculation, you could use the one set of numbers for Texas as a rough guide.
Doesn't look like a good fit for 2° birds.

If you had the longer focal length 1.0m Channel Master, then again using the Texas numbers above, you'd be close.
I'd certainly give it a try.
Call it a toss-up for 2° birds.


A Little Off Topic:
============
In PM, we discussed Glorystar on your 90cm GeoSatPro.
I still don't have focal length on that dish, so let's use the closest one we have, the Fortec Star.
It's certainly a little longer and will give bigger numbers, so you'll have to shorten 'em up for your GeoSat.

Anyway, the 4° spacing from 97 to 101 is very good to you as they are flying over Texas!
Using one of your nearby zip codes of 78578, and the wrong dish, I get:
distance between LNBs = 79.8mm or about 3.15 inches

Remember, your GeoSat would require slightly smaller numbers.
Looks like a great fit for those two birds, and your bandstacked LNBs should be dandy!
When you build it, start a thread and let us know. - :up

 

[Sadie]

I have a PCI card with no blind scan so I was wondering what transponders others are receiving.
This is what I am getting

12140V 30.00 2 PBS HD channels
12180V 30.00 9 PBS channels

The above 2 transponders have always been strong

12100V 4.34 PBS Montana
12145H 4.34 PBS Montana
12156H 4.444 PBS
12165H 4.425 PBS ?
12171H 4.34 Test Card

I have had trouble on occasion with weak signal and/or lock with the above transponders so maybe the settings are incorrect, although tonight everything is rock solid.

So far a total of 16 channels I'm guessing they are all PBS channels, are my settings correct and are the any more transponders up?
A blind scan receiver is on the wish list.

 

[Mr Tony]

nope thats right...thats all that is up there right now

 

[Fizbi]

nope thats right...thats all that is up there right now

...That we know of.

If they squeeze any more birds up there, the sky is gonna go black.

I finally walked my dish over to 125W and got PBS on AMC-21.
Q is about 70 on my CS5000 with cloudy sky, and snowing.

Thanks for the updates everyone!

 

[Mr Tony]

fizbi
sounds right. On my CS5000 the PBS is between 70-72

 

[Radioguy41]

I'm bouncing right at 79-80Q on my Visionsat here in Eastern Pennsylvania.

 

[guapoharry]

PBS is back! Good thread.

Is this temporary, though? Did I hear correctly that PBS is going all HD or something?

Now where else should I point the 180 CM Fortec that was being assembled to point at weak signal AMC3?

 

[Anole]

Texas @ 2°

Red -

If you were to use a 1m Fortec Star, then the 600mm focal length would be similar to the results above for the 1.2m GS with the same 600mm length
And to avoid all the recalculation, you could use the one set of numbers for Texas as a rough guide.
Doesn't look like a good fit for 2° birds.

After a good look at what wescopc came up with in his 2° thread,
and looking at the required LNB spacing for Austin,
you could follow in his footsteps with a 1m Fortec Star dish.

If you choose to follow his plan, then we can do the calculations for whatever dish you find, and your exact zip code.
So, if you are cool with grinding down a couple of Mini's, this could get fun!

 

[McGuyver]

4° spaced lnbfs

Tron -
Would probably be better to dedicate two 90cm dishes to combinations like 123/127 and 125/129..
Both those should be no-brainers.

Anole, what Ku-Band FTA channels are on 127°W?
According to the list there's only power-vu encrypted channels and I can't decode those. I'm strictly FTA only.

Thanks

 

[Mr Tony]

there is nothing FTA on 127

 

[McGuyver]

Oh well

Oh Well, maybe something in the future

Thanks Iceberg