Signal quality vs. picture quality

[LordAlex]

I read quite a few posts where people are saying 50-60 is pretty weak and causes the picture or audio to drop out. In my circumstance anything above 40 is perfectly fine...30-40 marginal...25-30 watchable if important....below 25 is not worth watching but I've even seen some 20's that didn't pixelate. I'd like the other 3500sd users to chime in about what low quality signals they can see fine. I'm thinking my meter must just register lower than other brands but the ones that people call strong also register high for me. I'm thinking of putting in an in-line amp right before the receiver. Please make suggestions on ones you have used or heard about.

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[Zero]

Different receivers have different minimum values: on a Coolsat 63 is minimum, where as on a Traxis I get good picture with about 40 quality reading. PAnsat- Sorry no experience

 

[Mr Tony]

Each receiver is different as t how they read signal quality. Here are some examples

-Coolsat 5000…minimum is 63 max is 85 (I haven’t seen higher than 85)
-Pansat 1500….minimum is 32 or so. When you get to 30 you start having issues. Max is 99. Meter is spazmastic 75 to 60 to 72 to 63 etc). Most Pansats the threshold is 30 (I had a 3500 and a 6000 and they did the same)
-KUsat 2600…quality reads 98 pretty much all the time as long as there is signal.
-Satworks 3618 reads low but is rock steady. Very rarely moves.

I just got a Fortec Ultra and on G10 11720 TP reads 77 yet my Pansat 1500 reads 45. Same exact satellite setup. On the other side, 11799 TP reads 77 on the Pansat 1500 and 80 on the Fortec

 

[TiminMb]

I've found in general, that unless the signal quality is in the low 40's, the signal breaks up on a Fortec Ultra. Below 40, I get nothing. Never seen a signal exceed 99. Weak signals will sometimes trick the system and bounce between zero and 99.

 

[Dr_Brian_Oblivion]

Yeah, I usually get the 25%-99% bounce with weak signals also.
I have noticed that since I put the invacom lnb on I can watch stuff at around 40% where it used to need around 45-48% Even high 30's come in but are blocky.

 

[brada]

-Coolsat 5000…minimum is 63 max is 85 (I haven’t seen higher than 85)

My Coolsat 5000 shows 97% quality maximum.
Which makes me think, that even same receivers with the same firmware may show it differently.
Another receiver, I am playing with, Manhattan DSR - 1500, does not show stupid numbers, it has a tricolor scheme: red, orange and yellow. If it's yellow, it can scan and get a channel list.

 

[Eastcoast]

My Coolsat 5000 shows 97% quality maximum.
Which makes me think, that even same receivers with the same firmware may show it differently.
Another receiver, I am playing with, Manhattan DSR - 1500, does not show stupid numbers, it has a tricolor scheme: red, orange and yellow. If it's yellow, it can scan and get a channel list.

Yes My coolsat also bottoms out at 63% but have had Q of up to 98% on a couple of Church channels Dr. Scott was at 91% yesturday.

Dave

 

[Keith Brannen]

I read quite a few posts where people are saying 50-60 is pretty weak and causes the picture or audio to drop out. In my circumstance anything above 40 is perfectly fine...30-40 marginal...25-30 watchable if important....below 25 is not worth watching but I've even seen some 20's that didn't pixelate. I'd like the other 3500sd users to chime in about what low quality signals they can see fine.

Your numbers are fairly similar to my experience with my Pansat 3500SD, though I'd say anything above 30, if a consistent signal, is fine. It is when it is bouncing up and down, that there could be minor problems. An example of two extremes, I have also found that on G10R transponder 11719 that if the signal drops too much below 30 it begins to pixelate and there are sound problems, yet I have a transponder on AMC4 than never rises too far above 30 and is fine, it only begins to break up if it is below 19 SQ (or frequently bouncing below it), and the breakup is nowhere near as bad as the G10R transponder (which would be totally unwatchable at that SQ)!

 

[Remington]

I also have a Pansat 3500 (+Invacom LNB) and same as you it's still watchable between 30-40 many times. I just moved to IA6 again and I now have 99% on the 2 Aztecas! I was surprised...

To compare I hooked my used LIfetime Ultra I just got and it shows 83% for the same 2 channels.

 

[Dr_Brian_Oblivion]

I forgot to include that I get 99% on a few channels with the fortec Ultra;
KUIL, couple on 11799 on G10 also.

 

[LordAlex]

Interesting info......I really want to find someone else in my area who watches FTA so that I can see if my receiver is locking in weak sigals that someone else would have trouble watching. I too have now noticed some consistent thirties qualities the are stable too.

Noone has tried to see if an in-line amp helps pull in the weaker ones?

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[Tron]

As amps amplify both the signal AND the noise, they do not work well on low quality streams.

 

[aegrotatio]

First, "strength" is the power of the received signal as interpreted by the radio part of the receiver. This value is independent of "quality" but it affects "quality" directly.

Second, "quality" refers to how well the receiver is correctly decoding the digital part of the signal. Depending on the broadcaster up to 35% of the signal is redundant data called "forward error-correction." The quality is a numerical representation of both how well the FEC process is correcting for errors and how many errors are being encountered in the stream.

With these facts understood I have to say that lower quality signals can indeed be enhanced by an amplifier. It could be that errors are encountered, thus reducing the quality, because the signal strength is weak and is further attenuated by the cable length and switches, fittings, grounding blocks. The amplifier can help both strength and, indirectly, the quality.

As for interference and noise being amplified: I'm not sure what kinds of interference you would be experiencing in the 11 to 12 GHz range if your dish is aimed properly. There isn't much that can "interfere" except adjacent satellites and that is solved by adjusting your dish, the LNBF skew, or upgrading to a "low noise" LNBF. The amplifier, if introduced directly at the LNBF, would only be amplifying any noise generated by the LNBF itself as it downconverts to the 950-1450 MHz frequency range, and the only way to solve that kind of noise is by getting a better LNBF with a low noise figure.

 

[Eastcoast]

I have tried those in line amplifiers and the do boost the incomming level of both the noise floor and what ever signals are present.The do not change the sig quality to make ot any better or worse then without the amplification.It is meant to compensate for losses due to long cable runs and connector insertion loss etc.
I have also looked at this with a RF spectrum analyzer borrowed from work.

Dave

 

[LordAlex]

As for interference and noise being amplified: I'm not sure what kinds of interference you would be experiencing in the 11 to 12 GHz range if your dish is aimed properly. There isn't much that can "interfere" except adjacent satellites

Good point. I think I'll give an amp a try. But I was wondering about how they will handle passing current.

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[Eastcoast]

Good point. I think I'll give an amp a try. But I was wondering about how they will handle passing current.

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When I tried the in line amp it was between the receiver and the SG2100 motor with no issues and they are usually rated for 500ma.
Meanwhile they should go next to the lnbf.

Dave

 

[digiblur]

Good point. I think I'll give an amp a try. But I was wondering about how they will handle passing current.

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How long is your cable run?

 

[LordAlex]

Ok cool..the amps are usually rated at .5 amps passing current also...I wasn;t sure. I will be placing mine right at the receiver behind a 60 foot cable run.:

 

[ftarock]

FEC can be set up to 50% of the bandwidth of the feed (FEC 1/2). In plain English, it's how the uplinkers assign bits for error correction.
All being equal, the tighter the FEC, the harder to get the signal lock.

First, "strength" is the power of the received signal as interpreted by the radio part of the receiver. This value is independent of "quality" but it affects "quality" directly.

Second, "quality" refers to how well the receiver is correctly decoding the digital part of the signal. Depending on the broadcaster up to 35% of the signal is redundant data called "forward error-correction." The quality is a numerical representation of both how well the FEC process is correcting for errors and how many errors are being encountered in the stream.

With these facts understood I have to say that lower quality signals can indeed be enhanced by an amplifier. It could be that errors are encountered, thus reducing the quality, because the signal strength is weak and is further attenuated by the cable length and switches, fittings, grounding blocks. The amplifier can help both strength and, indirectly, the quality.

As for interference and noise being amplified: I'm not sure what kinds of interference you would be experiencing in the 11 to 12 GHz range if your dish is aimed properly. There isn't much that can "interfere" except adjacent satellites and that is solved by adjusting your dish, the LNBF skew, or upgrading to a "low noise" LNBF. The amplifier, if introduced directly at the LNBF, would only be amplifying any noise generated by the LNBF itself as it downconverts to the 950-1450 MHz frequency range, and the only way to solve that kind of noise is by getting a better LNBF with a low noise figure.