Why are Primestar dishes oval?

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laseradam

Thread Starter
SatelliteGuys Pro
May 11, 2006
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Goshen, OH
I as aiming my primestar dish at G10R when a question came to mind. I noticed that up and Down adjustments did not make as much of a change as left to right movements. For example I could move up and down 2 deg without any change in signal. But left to right was very sensitive. Also I was only using the vertical polarity. Do these dishes work better for one polarity than the other?

So I was thinking that maybe the primestar network was only one polarity. But that doesn't make sense because the lnb has both outputs.

I cant figure out why the dishes are oval.

I am getting about 59 quality on 11720.
 
iammike

iammike

SatelliteGuys Pro
Dec 29, 2003
953
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Roanoke,VA
I don't know for sure, but I'd think they were made oval so they could pick up 2 satellite locations better.

When you're adjusting your dish, be sure to adjust the skew also. I've got a P* dish on G10 also, and the skew adjustment made a big difference. I think my quality with a Coolsat is in the 80's on a lot of channels, but was only in the 60's until I fine-tuned the skew.
 
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Mr Tony

SatelliteGuys Pro
Supporting Founder
Nov 17, 2003
299
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Mankato, MN
I think they were originally made to support 2 satellites. An oval dish has a bigger "sweet spot" for the focal point

SC uses basically the same dish now....Its not SC..Its Primestar rising from the ashes :D:D
 
drhydro

drhydro

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Oct 19, 2004
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I think they were originally made to support 2 satellites. An oval dish has a bigger "sweet spot" for the focal point
They do have a wide focal point. I was able to hit both 123 and 91 with my p* (aimed at 123) when i was playing around with a circular lnb earlier this summer.
 
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chadzx11

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Jan 28, 2006
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memphis
I used to work for primestar, and I thought that the oval dish was intended to be their trademark, rather than the same old CM .75 and .90 dishes that services like DTN used. I never heard anything about multiple satellites out of them. They were preparing to go high power (and even had recievers and 18" dishes made). We ended up using the pizza dishes for our DTV installs (they were dark primestar grey, just like the oval dishes). We had to peel the logos off and replace them with directv logos. That's also the only time I ever saw DTV dishes with color logos (they were blue). The 18" dishes were the same fiberglass dish that RCA used, but I don't think it had the wire mesh built in for OTA.

I recently did a E* for a couple that had switched to D* from P*, and said they were still paying the $10 fee (that was P*'s lease fee unless you paid a buy down)!!!!!
 
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Mr Tony

SatelliteGuys Pro
Supporting Founder
Nov 17, 2003
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recently did a E* for a couple that had switched to D* from P*, and said they were still paying the $10 fee (that was P*'s lease fee unless you paid a buy down)!!!!!

We use to "sell" Primestar and it was 199.99 down payment and then the monthly. We sold a bunch because Univision was on 24 hours a day on P* and our cable company only had it on from 6AM to 6PM (PPV the other times)

When the Mexicans came in, I turned on 190 and would sell it on 4 words
“Primestar 24 hour day” :D
 
Optical Serenity

Optical Serenity

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Jun 4, 2006
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Marietta,GA
Iceberg, thats too funny. I've heard that a huge portion of the DBS business is the spanish userbase in north america...
 
iafirebuff

iafirebuff

SatelliteGuys Pro
Feb 10, 2006
4,392
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Waterloo, Iowa
My favorite Mexican grocery store has Dish, and has Univision playing in the store all the time. They also sell Dish Latino there.
 
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Mr Tony

SatelliteGuys Pro
Supporting Founder
Nov 17, 2003
299
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Mankato, MN
Optical Serenity said:
Iceberg, thats too funny. I've heard that a huge portion of the DBS business is the spanish userbase in north america...

That was late 95/early 96…what’s sad is I STILL remember the channel number. :D
The trailer park near the Radio Shack I worked at had nothing but P* dishes.

Primestar was pretty cool. You got the regional sports nets and networks included. I think it was NBC Boston, ABC Miami, CBS Washington DC and Fox Philly. West coast I think was all California. Fox SF, one from Sacramento (I think NBC) and the others from LA

Now the Univision channel for Minneapolis on cable is Equity’s own WUMN :D
 
iafirebuff

iafirebuff

SatelliteGuys Pro
Feb 10, 2006
4,392
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Waterloo, Iowa
I always wondered why Medicom had them, yet they also had cble service. I could see if it were for areas that could not get cable. I saw alot out in the country. Not many in town though.
 
swampman

swampman

SatelliteGuys Pro
Jul 22, 2006
503
3
South Louisiana
chadzx11 said:
I used to work for primestar, and I thought that the oval dish was intended to be their trademark, rather than the same old CM .75 and .90 dishes that services like DTN used. I never heard anything about multiple satellites out of them. They were preparing to go high power (and even had recievers and 18" dishes made). We ended up using the pizza dishes for our DTV installs (they were dark primestar grey, just like the oval dishes). We had to peel the logos off and replace them with directv logos. That's also the only time I ever saw DTV dishes with color logos (they were blue). The 18" dishes were the same fiberglass dish that RCA used, but I don't think it had the wire mesh built in for OTA.

I recently did a E* for a couple that had switched to D* from P*, and said they were still paying the $10 fee (that was P*'s lease fee unless you paid a buy down)!!!!!

Being you worked for P*, did you guys ever handle the 1.2 meter dish? Or was it specifically targeted for certain areas? Sure wish I could get my hands on one down here in Louisiana. I cant remember ever seeing one out here. :hatsoff:
 
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mastermesh

SatelliteGuys Pro
Apr 18, 2006
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I got mine off of freecycle. I can almost guarantee you that there's a freecycle group in your area... whether it's been publicized enough that there are folks on it that have primestars that they want to give you is the question... if so, great. If not, at least there's other good free stuff out there that you can get or give to folks.
 
swampman

swampman

SatelliteGuys Pro
Jul 22, 2006
503
3
South Louisiana
Oh yea, I can get my hands on plenty of primestar dishes...out here they're a dime a dozen. But getting my hands on a 1.2 meter Primestar is a different story.
 
Hermitman

Hermitman

SatelliteGuys Pro
Jul 2, 2006
420
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Limestone, Mi
The oval shape of a primestar dish (as well as others) is based upon the type of feedhorn used for this offset dish. Primestar used a long, tapering cone-shaped feedhorn connected to the LNB. The oval shaped dish was the best shape to get the maximum signal off the dish to the feedhorn without picking up any signals outside the dish surface.

The best example I can think of is a flashlight beam. If you point a flashlight straight at a wall you get a round beam of light. However, if you start angling that flashlight beam up the wall (like the feedhorn being placed low and angled on an offset dish) you'll see that the beam shape becomes an oval just like the shape of the primestar dish.

Later, Primestar added scalar rings or chokes to the feedhorns and that allowed for different shaped dishes. It's important to use the right feedhorn for the matching dish if you want the maximum signal gathering and transfer to the LNB.

As a side note, the offset dish started out as a prime focus dish. Someone got the great idea to take the top one-quarter section of the prime focus dish, point the LNB toward the center of this section and you have an offset dish. That way you can eliminate any support structures from blocking the satellite signals.


Have Fun.
 
swampman

swampman

SatelliteGuys Pro
Jul 22, 2006
503
3
South Louisiana
Hermitman said:
The oval shape of a primestar dish (as well as others) is based upon the type of feedhorn used for this offset dish. Primestar used a long, tapering cone-shaped feedhorn connected to the LNB. The oval shaped dish was the best shape to get the maximum signal off the dish to the feedhorn without picking up any signals outside the dish surface.

As a side note, the offset dish started out as a prime focus dish. Someone got the great idea to take the top one-quarter section of the prime focus dish, point the LNB toward the center of this section and you have an offset dish. That way you can eliminate any support structures from blocking the satellite signals.


Have Fun.

Good info. Were all Primestar dishes offset?
 
Tron

Tron

SatelliteGuys Master
May 6, 2005
6,599
33
Metro New Orleans, LA
I'm pretty sure they were all offset dishes. I can't ever remember seeing one that was a prime focus. It would have to be a rather large dish (6' or more) for the obstruction of the LNB on a prime focus dish not to be a serious issue with signal quality.
 
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