Twinhan 3250 ATSC only one card works at a time

[FM5]

Hello.
I have two Twinhan 3250 ATSC TV tuner PCI cards. 
The drivers show up in Windows 7 32-bit as DVB-TV 878 Digital Capture Driver and DVB-TV 878 Digital Tuner Driver. There's two of each of those drivers. Two cards, four drivers. No yellow exclamation point errors or anything in Windows in Device Manager.

NextPVR only lets me use one card at a time. If I start a recording, it will then say tuner not available etc if I try to start a second recording or watch a live channel.

Swapping cards in the PCI slots doesn't help.
Both cards work at the same time in Windows 7 Media Center.
I'd rather use NextPVR than Media Center.

Right now, with nothing being recorded or being watched, NextPVR "show status" popup window shows both tuner cards and neither is shown to be doing anything. It all looks normal.

The channels and device settings seem fine. The ATSC part of both cards show Present and Enabled in NextPVR.
I am guessing the Twinhan drivers and NextPVR have a conflict of some kind.  Searching the forums, there's a couple threads about other cards working only one at a time but then sub changed something in NextPVR to get both working to compensate for the weird card driver.

I've been using NextPVR this way for months and just now upgraded NextPVR to 4.2.5. It still only uses one card at a time.  I saved the logs about five minutes after trying two channels at a time again.

I'd consider switching to Linux if both cards would work, but these cards are so old (but have strong tuners) I'd be surprised if any drivers would work at all. They don't even work with 64-bit Windows 7, only 32-bit.



  logs-20200722-1532.zip (Size: 321.62 KB / Downloads: 1)

[mvallevand]

It does look like a driver problem.

2020-01-01 17:58:19.611 [DEBUG][11] Failed to start device: 0x8007048f

but if you want any extra support getting this going you should move to v5.

Martin

[FM5]

  logs-20200725-1753.zip (Size: 157.34 KB / Downloads: 2) Thanks. If nothing else, it's at least good to know it's probably not something I can fix.

I now uninstalled v4. Installed v5.  Windows 7 32-bit.
Multiple times, I scanned for channels, rebooted, tried to record two TV shows at the same time, etc. Same result as v4. V5 sees both tuners, the "show status" popup window will show they're not in use, one will show in use when recording.  Trying to watch live TV on the second card, in the TV window it will say it's starting to initialize, but then fails.  OTA EPG works. All channels scan in and work. Just can't use both cards at the same time.

Attaching the log of it.
Earlier in the log, I had two shows recording at the same time, but they were on the same multiplex.

I tried the Linux version too. Both tuners work at the same time in that, but it has other problems.
I'll swap hard drives and post a log of that within an hour. Hopefully at least one of the two versions is an easy fix. Thanks.

[FM5]

haha...I swear I could record two shows at the same time on the linux version, had it all set to go on a different hard drive, but after swapping the drive in I figured why not try to scan for more channels one more time. The scanning itself takes about an hour. That turned into finding fewer or no channels, and multiple times getting a generic Linux popup window for a generic error that only asks if I'd like to report it. So I formatted the entire drive again and reinstalled fresh Linux and NextPVR again.

So, now using Linux instead of Windows in the first post, v5 and Linux Mint Cinnamon 64-bit, I have yet to get any OTA EPG info, (the Update EPG button starts a scanning countdown but then seems to freeze at one second), and now I can't record with both tuners again, but the actual main problem is the tuners can only find half of the channels. Other than one channel, all of the channels the scan doesn't see are in the lower range. It basically doesn't scan any channel below about 20. (actual frequency channels not the display channels.)

So it scans frequency channel 22, 25, 36, etc. But it never sees 12, 15, 19. 
Though now the latest scan sees 22, but not 23.  A prior scan did see 23.

NextPVR v4 and v5 scan all channels fine in Windows.

These Twinhan 3250 cards were popular enough at one time to now be listed on the Linux TV tuner cards page, and it says the drivers were added to the kernel.

Installing v5 on Linux is surprisingly easy, by the way. I basically don't know how to do anything in Linux, but I can do an internet search and copy/paste command lines from the NextPVR wiki into the Terminal.

Anyway, in Windows 7, can only use one tuner at a time.  In Linux, I swear I could use both tuners yesterday, so the main problem is only half the channels show up.  I'm hoping this isn't a lost cause since these PCI tuners are stronger than all the USB ones I've used in the past.
  logs-20200726-1137.zip (Size: 392.33 KB / Downloads: 1)

[mvallevand]

You can save some time if you use us-ATSC-center-frequencies-8VSB-062009 there aren't any OTA channels higher then that anymore. With signal strength issues you will see variations on scan results. Make sure you don't use any splitters for the best test.

Channels aren't frequencies. Often frequencies in the VHF band especially the lowest frequencies will need a different antenna then the UHF antenna most people use.

If you can download and compile dvbtee following the instruction you can quickly see if linux can find EPG data or not. Trying to use that data is such a waste of time that you should just get Schedules Direct.

Martin

[FM5]

I had been wondering about having a dash and numbers after the 8VSB. That's good to know. Yours is the first info I've seen anywhere on the internet about it. Was often scanning with both options (in Linux anyway) trying to get the missing channels.  NextPVR in Windows gives three options. I use the ATSC All (or similar wording) option. The other two options I think limit the scan to 51 but also say something like "except 31."  ATSC ALL option finds all the channels, so I didn't worry about it. 

Even rabbit ears work well enough here for most channels. Though I have a DB4 rectangle antenna and a 7-foot-wingspan arrow V-shaped one.  I swapped them yesterday during testing and will swap them again today while also removing the splitter for the two tuners.  They both work great with NextPVR on Windows. With the drivers for these tuner cards built into the Linux kernel, I had high hopes they'd work well with Linux. It's quite unexpected that the same tuner tunes great with Windows but not with Linux.

[sub]

You could try using w_scan on Linux to see if it finds all your channels. NextPVR uses the same libdvbv5 to identify channel information.

The USA is a bit annoying that different TV stations often come from different transmission towers, so you often end up with drastically different signal strength for different stations.

[sub]

Sorry - not w_scan. It's dvbv5-scan

[sub]

apt install dvb-tools
dvbv5-scan /usr/share/dvb/atsc/us-ATSC-center-frequencies-8VSB-062009

[mvallevand]

Since v5 deb installs dvbv5-scan you also that for testing.

dvbv5-scan /usr/share/dvb/atsc/us-ATSC-center-frequencies-8VSB-062009

Note on linux NextPVR locks the tuner so you will have to stop the service to do this test.

Martin