Zero4K Signal Meter Problems

[el bandido]

I bought the VuPlus Zero4K receiver soon after it was first released. The signal meter has always been a bit crazy on it. Some people have graded the performance of this receiver by mostly what the signal meter says. Tonight, I made a comparison of signal strengths between the Zero4K and the Octagon SF8008. I chose the Octagon for no other reason besides it being available.

There is a transponder on 117w that is DVB-S2 8psk with a fec of 8/9. According to the charts, it takes about 10.5 db of signal to lock this transponder. The Octagon SF8008 usually shows around 15 db on this transponder, so I de-tuned the dish by moving it one click at time until I lost signal lock. Then I moved it back two clicks. The results of what the SF8008 and the Zero4k did are shown below.

The signal in db is currently broken on the Zero4K, so I set the SF8008 to read in percent. This was done in attempt to make the signal readings equal. Both receivers are running the same image.

In the de-tuned state, the SF8008 shows 67 percent and the Zero 4K shows 100 percent.
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Next, we can look at the signal strengths in satfinder:
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The dish is moved back two clicks to the point where lock is lost.
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The satfinder shows both receivers bouncing from Lock to No Lock and No Signal in the last screen captures. We would think since the Zero 4K would still be showing an usable signal in the end because it was stronger in the beginning. But that is not the case! In the end, neither receiver can produce anything that is usable.

Sure, some receivers will operate and perform better than others. And some receivers can perform a bit better on certain frequencies than others. I have done many reception tests with different fta satellite receivers, and have yet to find one that performed noticeably better than all of the other receivers on marginal signals. Granted, there are some receivers that perform poorly, but a poor performing receiver is usually consistent and performs poorly in other areas too.

Don't pay much attention to what a fta receiver reads in signal strength. Pay attention to the channels you get or don't get. Find out WHY if you have one receiver that is outperforming another receiver by a wide margin under supposedly identical environments or circumstances. Most of our fta receivers should perform pretty much the same in the signal receiving area, providing all things are equal...

[lme]

Nice test.
Have 2 questions:
1- are both boxes using same image ?
2- why "inversion" and "roll-off" values are not the same ?

[el bandido]

The enigma2 images are the same in both receivers.

The channels in the two receivers are products of blindscan. The two receivers see the inversion and roll-off values differently in blindscan. This is why they are not the same. Both of these receivers can auto-detect some values for the transponder, so it does not matter what values inversion or roll off have.

[el bandido]

I made a few adjustments to the Zero4K db signal scale this evening. A Dutch mixed with English thread on this subject is ongoing at OpenPLi:
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The c band dish is centered on 117w for these demonstrations.

For transponder 3925, The sf8008 shows 14.8db and the Zero4K shows 14.9db
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For transponder 3960, the SF8008 shows 12.0db and the zero4k shows 14.8 db
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Move the dish 10 clicks to the west to de-tune.
The SF8008 shows 9db on the 3960 tp and the zero4k shows 8db.
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As can be seen, the signal meters do not make much sense.