12 Dec 2016

DVB card comparison - TBS not the winner?

Submitted by drhans

I've decided to test 6 DVB tuners and compare how suitable are those for more demanding users. Now here's what that means:

 

1) the tuner must work with CrazyScan and StreamReaderBDA.dll

2) the tuner must work with EBSPro

3) the tuner must do RF scan and reliable blind scan

4) the tuner must show precise SNR readings

5) the tuner must lock any transponder within tuner's specification

6) and it should do everything very fast

 

On the other hand, what I did not care for was the following:

 

1) price does not matter

2) no extra points for fancy stuff like multistream or DVB-S2X

3) power consumption, working temperature or OS compatibility don't matter

 

I tested on Windows 10, using CrazyScan and EBSPro, running streamreader.dll version 1.2.3.1399 and except TBS 5925, I used manufacturer DVB tuner drivers. For TBS 5925, I used CrazyBDA in order to speed up blind scan and RF scan.

Among the tested tuners: TBS 8922, TBS 5922, TT-budget S2-4100 (TMAX TAS210x), TBS 6522 (Si2183), TBS 5925 (STV090X) and DVBSky S960 (Montage M88DS3103). That's 4 different demodulators and there's PCI, PCI-e as well as USB. The results are not the same for any of the 2 tuners. It seems that USB tuners suffer from longer locking and slower blind scan, just because they're USB. At least this is what TBS 5922 (USB) slowness suggests since the other two cards (TBS 8922 PCI and TT-budget S2-4100 PCI-e) perform much better.

The biggest surpripse seems to be the poor performance of TBS tuners, compared to DVBSky and TT-budget. Only TBS 5925 can compete, the other TBS tuners are quite worthless. Of course, the performance of the most recent (and most expensive) TBS tuners, susch as the TBS 6903, could outperform everything else but I don't have one of those yet for testing. Although it would not be a fair test, comparing a 230 EUR tuner (TBS 6903) to TT-budget S2-4100 which you can get at 25 % of that price, the price shouldn't really matter since we just want to find the best DVB tuner there is.

I was surprised by the outstanding blind scan speed of the two non-TBS tuners in this test. These aren't just some incredible speeds, but the scanning is also very accurate, finding every channel. Unfortunately neither of these tuners got a perfect score since there are some serious drawbacks.

DVBSky S960: amazing RF scan and blindscan speed come with an unpleasant failure to just click into the spectrum and get transponder analyzer running. It's great to get all channels found during the scan but then it's very annoying having to enter the frequency manually in order to see what channels are there. Now, this is just EBSPro that didn't work. Other blindscan programs could behave better but I consider EBSPro very important and that's why I can't just let this one go unnoticed.

TT-budget S2-4100: the best blind scan results I've seen so far - fast and complete. The only problem, and it's quite a serious one, is that the measured SNR values aren't accurate. This is a great tuner for feedhunting and getting quick spectrum reading, but it can't be used to analyze how good or bad the signal really is. In addition to this, a minor problem appears to be in the spectrum graph. Sometimes, during some scans, the spectrum tends to show steep inverted spikes, messing up with the final spectrum view. I don't think this is a software issue since I've never seen this happen with TBS5925 or DVBSky S960. It does indeed happen with TBS 8922, though. One thing that bugged me was the CNN transponder at 4040 H which wasn't found in the blind scan. In the end I decided to overlook this one and give the blindscan full score because it found all close frequencies (3838 H - 3853 H) and the blindscan was so fast. One could also argue that 4040 H is so big that it won't go unnoticed and it's not a big deal to scan this one in manually afterwards.

Of course, not everything about TBS is that bad. The TBS 5925 USB tuner is performing great in terms of SNR accuracy, finding all channels during blind scan and it provides a nice and smooth spectrum scans. The only problem is that it's slow. Scanning and locking takes much longer than desired. But still a perfect, portable, tuner box, which comes with a few pretty bonuses, such as multistream and high SR support (higher than 45000).

The remaining 3 TBS tuners aren't really worth mentioning. I wish I never wasted time and money on those. In the screenshots below, you can see the spectrum from TBS 8922, 6522 and 5922. Not a pretty sight the first two.

Here's how I scored. The total number of found transponders wasn't used in the scoring because I've slightly moved the dish during the tests so not all tests were done with the same signal levels on all transponders.