INVACOM QUAD QPH-031 (1 Viewer)

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ishare

Well-Known SatelliteGuys Member
Oct 5, 2006
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Does anyone know if there is a problem using this LNB and "Mpeg4"?
Have 1 meter PS dish w/sg2100 motor, INVACOM QUAD QPH-031, Pansat 9200HD.
When I lock on standard Mpeg 2 Transponders I am fine 90+ quality, but when I go to the exact same TP for mpeg4, (21500 instead of 20000) I lose all signal quality.
Any thoughts or comments??????:D
 
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Tron

SatelliteGuys Master
May 6, 2005
6,599
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Metro New Orleans, LA
Which satellite/channels? The LNBF shouldn't have anything to do with the type of stream being used, but you might want to re-check your cable and fittings...
 

AcWxRadar

SatelliteGuys Pro
Apr 26, 2006
4,575
4
40 miles NW of Omaha. Omaha?
Ishare,

The Invacom QPH-031 works fine with MEPG4 signals, so you are alright there. You may be looking at an encrypted signal, one that has a signal format that is not compatible with a FTA receiver, not even for the signal meter's recognition, such as Turbo 8PSK.

RADAR
 
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Jim S.

When someone asks you if you're a god, you say yes
Lifetime Supporter
Jan 2, 2006
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When I lock on standard Mpeg 2 Transponders I am fine 90+ quality, but when I go to the exact same TP for mpeg4, (21500 instead of 20000) I lose all signal quality.

I don't know what you mean. Are 20000 and 21500 the symbol rates? You can have MPEG2 and MPEG4 channels on a transponder simultaneously, but the transponder can only have one symbol rate at a given time. Symbol rate isn't a parameter of the compression, it's a parameter of the modulation.

The best way to figure this out is to tell us what satellite and transponder you're talking about, and where you're getting the information about it. Maybe you have outdated information.
 

Mr Tony

SatelliteGuys Pro
Supporting Founder
Nov 17, 2003
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21500 is the symbol rate Dish uses on their turbo 8PSK transponders and out recievers can't pick them up so dont bother :)
 

AcWxRadar

SatelliteGuys Pro
Apr 26, 2006
4,575
4
40 miles NW of Omaha. Omaha?
IShare,

I just did some testing regarding what Iceberg and I suspected. The DN signals with 21500 symbol rates are not acknowledged with a FTA receiver. Therefore, they are modulated with Turbo 8PSK and not "normally" detectable. You would require an add on board for this.

Such channels are simply not available to us ITC. You will have to subscribe to DN in order to view them with their equipment. FTA receivers won't even detect their signals so that is why your signal meter drops out.

This is somewhat disappointing as at least with DN signals, even though they were encrypted, you could at least mark the satellite position and use their signal blip to help align your dish and motor (if you were using one or setting one up). This will probably all become a thing of the past in the near future.

RADAR
 
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B.J.

SatelliteGuys Pro
Oct 15, 2008
2,029
1
Western Maine
21500 is the symbol rate Dish uses on their turbo 8PSK transponders and out recievers can't pick them up so dont bother :)

IShare,

I just did some testing regarding what Iceberg and I suspected. The DN signals with 21500 symbol rates are not acknowledged with a FTA receiver. Therefore, they are encrypted with Turbo 8PSK and not detectable.

Such channels are simply not available to us ITC. You will have to subscribe to DN in order to view them with their equipment. FTA receivers won't even detect their signals so that is why your signal meter drops out.

This is somewhat disappointing as at least with DN signals, even though they were encrypted, you could at least mark the satellite position and use their signal blip to help align your dish and motor (if you were using one or setting one up). This will probably all become a thing of the past in the near future.

RADAR

Yes, most of the 21500 SR signals are turbo 8PSK, and you can't lock them on *MOST* FTA receivers, but if you have the right receiver, and/or add on cards, you CAN lock these signals, and there are a few viewable FTA channels that aren't encrypted, although not many at this time.
I use the Genpix Skywalker-1 for the turbo 8PSK channels, which is a USB receiver for a PC. There are also a few STB receivers that have turbo-8PSK add-on cards, but I'm not familiar with those.
There are also a few DN transponders with a 22500 SR. I can't lock these with the Genpix. Or to be more accurate, I can't get a "data lock". I DO get a "signal lock". The way this was explained to me is that a signal lock sort of means that the receiver is demodulating the signal OK, but it doesn't understand the data structure and FEC, so it can't interpret the data. My Broadlogic control app has little boxes that get checked when it gets signal and data lock, which is kind of interesting to see signal lock but no data lock on a strong signal. The Broadlogic shows a signal lock on the 22500 SR DN signals, but won't give a data lock. I have been told that these signals are Turbo QPSK. The Genpix does Turbo QPSK, but apparently doesn't do the FEC that these signals are using.


Also, it isn't quite accurate to say:
"Therefore, they are encrypted with Turbo 8PSK and not detectable."
and
"FTA receivers won't even detect their signals so that is why your signal meter drops out."

The turbo 8PSK is not encryption, it's just a modulation format. And they are "detectable", they will give you a signal strength reading, and even using my analog receiver coupled with a short wave receiver, I can "detect" and measure the SR. It's just that the way they do that turbo FEC thing, regular DVB-S or DVB-S2 receivers won't lock on the signals. Or at least you won't get a data lock.
 

AcWxRadar

SatelliteGuys Pro
Apr 26, 2006
4,575
4
40 miles NW of Omaha. Omaha?
B.J.

Very good follow up information! Thanks for indicating that *MOST* FTA receivers will not detect Turbo 8PSK. A receiver that can at lest detect the carrier could be useful for alignment purposes, at least.

RADAR
 

B.J.

SatelliteGuys Pro
Oct 15, 2008
2,029
1
Western Maine
B.J.

Very good follow up information! Thanks for indicating that *MOST* FTA receivers will not detect Turbo 8PSK. A receiver that can at lest detect the carrier could be useful for alignment purposes, at least.

RADAR

Any FTA receiver should be able to "detect" Turbo 8PSK, it just that it can't lock the signals. You should still see a signal meter indication.
My Broadlogic card is a regular QPSK DVB card, but I can do a slow scan of the band and it will "SEE" the signals, and from the width of the signal, I can estimate the SR. If I feed the baseband from my analog receiver into a shortwave I can measure the exact (within 1 unit) SR value. So basically ANY receiver can "detect" the signals, it's just that only receivers capable of the turbo 8PSK can understand the data format.

I like to be capable of receiving as many different formats as possible, even if there isn't anything unencrypted there to watch. The Genpix thing is neat, because it does Turbo 8PSK, Turbo QPSK (in a couple FEC values), regular DVB-S, DCII (ZK only), and DSS. Only a few FTA channels in the Turbo mode, and only audio in DSS, but there are quite a few DCII channels that the Genpix will pick up. It's a nice little receiver. I wish it did DVB-S2 though.
 

AcWxRadar

SatelliteGuys Pro
Apr 26, 2006
4,575
4
40 miles NW of Omaha. Omaha?
Also, it isn't quite accurate to say:
"Therefore, they are encrypted with Turbo 8PSK and not detectable."
and
"FTA receivers won't even detect their signals so that is why your signal meter drops out."

The turbo 8PSK is not encryption, it's just a modulation format.

Correct. The Turbo 8PSK is a modulation method and the encryption is separate from this. The CS 5K and AZBox will not process or "lock" on this format of "modulation" and these signals are mostly encrypted as well. So it doesn't seem very useful to me in either sense, even if there may be a few ITC channels available. One would need a receiver that is able to process Turbo-8PSK in order to even see the signal properly.

This is the major crux of the whole thing and basically is the answer to Ishare's question... Which is that it is NOT a problem with the LNB that he is using, but that his Pansat 9200 receiver cannot process Turbo 8PSK formatted modulations.

He may be able to "detect" some form of a signal on the meter, but it won't provide a lock, so the signal reading should be in the red. I am assuming that when he said that "I lose all signal quality" that he did not mean that it went to a null indication, but that it just wasn't a valid indication, like looking at a strong noise signal. The receiver knows that there is something there, but since it doesn't know how to process it, it treats it simply as more noise.

Your quote here: "it's just that only receivers capable of the turbo 8PSK can understand the data format." is basically what I was attempting to state, though I may have phrased it poorly.

RADAR
 
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nycrich

SatelliteGuys Pro
Jun 25, 2006
271
9
West Palm Beach, FL
I've use the Invacom QPH-031 on Galaxy 19 (97 West) to lock in FashionTV ( 11929V 22000 3/4) using Mpeg4. I used my Viewsat 9000 HD. This is a good sat with North American coverage to test reception of Mpeg4 equipment on this channel.
 
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