C-band EIRP numbers? (1 Viewer)

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Mr Tony

SatelliteGuys Pro
Supporting Founder
Nov 17, 2003
295
43
Mankato, MN
Just checking some EIRP's on Lyngsat and G11 says I'm between 37 & 38

will I get a decent signal on a 6 footer?
 
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PSB

On vacation
Nov 5, 2003
1
4
I am getting around 55% quality on one feed of interest right now (MN.)


EWTN I am getting around 65%

I am using the DVB World USB Box right now so those signals are going to be low.
 

mikekohl

Prehistoric Satellite Guru
Supporting Founder
Jun 4, 2004
804
187
Montfort, Wisconsin
EIRP numbers are based on a "typical" transponder power level,
(whatever that is). A +37 or 38 will work fine with a six footer;
the two questions that need to be answered include whether or not
there is any interference from 2 degrees away (89 or 93).
And if a transponder is operating at full power, as Pete has noted when comparing active signals on Galaxy 11.

I don't think 89 or 93 will be a problem on most frequencies, because they are not very busy C-band satellites, analog or digital.
 

Krapola

SatelliteGuys Pro
Jan 10, 2006
214
0
Fairfield, Cali
mikekohl said:
EIRP numbers are based on a "typical" transponder power level,
(whatever that is). A +37 or 38 will work fine with a six footer;
the two questions that need to be answered include whether or not
there is any interference from 2 degrees away (89 or 93).
And if a transponder is operating at full power, as Pete has noted when comparing active signals on Galaxy 11.

I don't think 89 or 93 will be a problem on most frequencies, because they are not very busy C-band satellites, analog or digital.

Not quite sir...

EIRP numbers are determined by 2 major factors:
1) Values from IOT( In Orbit Testing ) confirmed by the designated Ground Station preforming IOT measurements and compared with Satellite Manaufacture expected preformances...
2) Link Bugets in relationship to Beam Center, Spot Beam locations and Antenna sizing for Qualified U/L & D/L sites which in many cases are Type accepted...

The main difference between Commercial Traffic birds and DTH birds are the Ant sizing for reception creating an exception...
 

mikekohl

Prehistoric Satellite Guru
Supporting Founder
Jun 4, 2004
804
187
Montfort, Wisconsin
I was trying to put it into layman's terms...as most of the people on this forum do not have the space or $$$ to acquire commercial equipment. Somebody referenced an EIRP number, which is only part of a larger equation to produce
a link budget. The answer was intended to state in general terms whether or
not it would produce acceptable results for consumer/hobbyist use.

Back in the 80s I was getting acceptable results with 12-foot antennas and receive signals under +30 dBw. (Not commercial quality, but sparklie-free analog video). +27 dBw was considered doable in the third world, using threshold extension techniques. Not much harder on the eyes than today's kids looking
at a 2-1/2 inch monitor screen!

The mathematics has not changed, but there are many new dynamics facing those wanting to put up a C-band antenna. 2 degree spacing was not an issue back then. Consumers who are in no position to put up a "real" C-band antenna must make do with what they have.

A +38 or +39 dBw is a screaming powerful signal in comparison to what used to
be common, and if there are no interfering signals from adjacent satellites, it may work acceptably for consumer level reception on a 6 to 8 foot dish. Not a lot of margin, as is mandated in a commercial installation, but often enough signal to
keep those digital pictures from pixelating.

Mike
 

Krapola

SatelliteGuys Pro
Jan 10, 2006
214
0
Fairfield, Cali
.
mikekohl said:
I was trying to put it into layman's terms...as most of the people on this forum do not have the space or $$$ to acquire commercial equipment. Somebody referenced an EIRP number, which is only part of a larger equation to produce
a link budget. The answer was intended to state in general terms whether or
not it would produce acceptable results for consumer/hobbyist use.

No one would need Commercial gear to understand where and how EIRP is calculated which is what I explained in my previous post. The EIRP factors actually come from intense testing held by the Sat Manufacture and Sat Operator.

Back in the 80s I was getting acceptable results with 12-foot antennas and receive signals under +30 dBw. (Not commercial quality, but sparklie-free analog video). +27 dBw was considered doable in the third world, using threshold extension techniques. Not much harder on the eyes than today's kids looking
at a 2-1/2 inch monitor screen!

30dBw was a very good number when dealing with Analogue but as you remember, Satellite Communications in that era was never meant for "back yard" usage..

The mathematics has not changed, but there are many new dynamics facing those wanting to put up a C-band antenna. 2 degree spacing was not an issue back then. Consumers who are in no position to put up a "real" C-band antenna must make do with what they have.

2 degree spacing effected Transmission capabilities more then reception...

A +38 or +39 dBw is a screaming powerful signal in comparison to what used to
be common, and if there are no interfering signals from adjacent satellites, it may work acceptably for consumer level reception on a 6 to 8 foot dish. Not a lot of margin, as is mandated in a commercial installation, but often enough signal to
keep those digital pictures from pixelating.

Mike
 

No Strings

SatelliteGuys Pro
Sep 17, 2005
152
0
Mitchell, South Dakota
I would disagree with that. Both are going to be effected by non-2 degree compliant dishes. The thing is Tx and Rx have different sizes to have 2 degree compliancy, and as such Txmission actually can have a smaller diameter antenna to maintain 2 degree compliancy than Rx.

Iceberg, what you end up with is that your 6 footer is not two degree compliant but you will only (possibly) have issues if there are carriers on the satellites adjacent to G11 at the same frequency. And even if there are they may not affect the signal to where it will cause a problem. The EIRP numbers look good!

Neal
 

Mr Tony

SatelliteGuys Pro
Supporting Founder
Nov 17, 2003
295
43
Mankato, MN
thanks Neal

Thats all I was looking for...a simple answer

yes I know the 6 footer isn't 2 degree compliant but it has worked fine For me currently. I get great reception on G4 Nets and for fun over the weekend I was moving around the top of my arc (87-103) to see what I can get.

I know its harder to get great results on a 6 footer but I am very limited on what I can do at my house. I can’t put the dish on the ground (ass’n rule) so its on the deck
 

No Strings

SatelliteGuys Pro
Sep 17, 2005
152
0
Mitchell, South Dakota
Iceberg said:
thanks Neal

Thats all I was looking for...a simple answer

yes I know the 6 footer isn't 2 degree compliant but it has worked fine For me currently. I get great reception on G4 Nets and for fun over the weekend I was moving around the top of my arc (87-103) to see what I can get.

I know its harder to get great results on a 6 footer but I am very limited on what I can do at my house. I can’t put the dish on the ground (ass’n rule) so its on the deck
Phase array a couple 6 footers. :up

Neal
 
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patbelcher

Well-Known SatelliteGuys Member
May 30, 2006
33
0
West Palm Beach, FL
KTI used to make a dish for C band that was only 5 ft.
I used to have one (about 7 years ago) and it worked fairly well on the strong
birds (back then G5), and I lived in Naples, Florida at the time.
Is it really worth getting back into C band?
I have an old Uniden box (runs C and KU) with a video cypher descrambler.
You could pay a subscription to one of several companies and get a boatload of channels. Does the same apply today? Do videociphers even work today? As you can see, I have been out of the loop
for a while. Almost forgot to mention, back then, I could also use a 4ft dish for C band. It was actually watchable on some satellites/transponders.
Thanks,
Pat
 

No Strings

SatelliteGuys Pro
Sep 17, 2005
152
0
Mitchell, South Dakota
patbelcher said:
KTI used to make a dish for C band that was only 5 ft.
I used to have one (about 7 years ago) and it worked fairly well on the strong
birds (back then G5), and I lived in Naples, Florida at the time.
Is it really worth getting back into C band?
I have an old Uniden box (runs C and KU) with a video cypher descrambler.
You could pay a subscription to one of several companies and get a boatload of channels. Does the same apply today? Do videociphers even work today? As you can see, I have been out of the loop
for a while. Almost forgot to mention, back then, I could also use a 4ft dish for C band. It was actually watchable on some satellites/transponders.
Thanks,
Pat
There is certianly nothing holding one back from using a small antenna on an isolated C-band bird.

Neal
 

Mr Tony

SatelliteGuys Pro
Supporting Founder
Nov 17, 2003
295
43
Mankato, MN
I use mine mainly for G4 and it works GREAT for the Nets

90 quality on my Pansat 1500...combined that with the 36" dish at G10 and pumped that throughout the house on different receivers :)
 

No Strings

SatelliteGuys Pro
Sep 17, 2005
152
0
Mitchell, South Dakota
Iceberg said:
I use mine mainly for G4 and it works GREAT for the Nets

90 quality on my Pansat 1500...combined that with the 36" dish at G10 and pumped that throughout the house on different receivers :)
I didn’t think you would have too much of a problem. We have rigged a C-band feed horn on the 1.8m to do a net return off of a different satellite than what we were on with the 4.6m. It was an analog VCII with a few sparkles (due to < 2 degree compliancy).

Neal
 
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