MythTV, Tuner locks signal, but can't get channels

[Das Hammer]

Hey, fellas. I originally posted this issue in another forum which is specific to the distribution I'm using for my MythTV setup (KnoppMyth), but the guys there don't seem to be real keen on the dvb-s stuff. You can link to the post HERE, but I think you have to be registered to see it. Alternatively, I've just copied it below.

-----Original posts------

I'm trying to add some DVB-S channels using a Twinhan 1025 PCI card. I'm able to get a signal lock when scanning for channels in the myth setup (backend setup), but it will not pull in any channels. I know everything (dish, motor, lnbs, switch, etc) are working because I can plug the same cable from the mythtv box into an STB and it works fine.

Actually, I was able to pull in some channels once. During the scan, the signal lock went to no lock and none of the scanned in channels would work. I can't figure out why that was, so I deleted the channels out of that source and tried again. Now I can get lock, but no channels to come in. I've tried various sats and tp's.

So, before I try to muddle my way through the dvb-utils and create a manual channels.conf file, did I miss something? Looks like I have the dvb tuning timeout set at the maximum level. Can I extend that somehow to see if that would help? We have LOCK, after all.

Next thing to try is a scan from an existing transport rather than a full scan. I just thought of this while typing. I've only been doing the full scan. Of course, I have to wait for the wife to quit watching Lifetime Movie Network first. Could be a while.


I added a new transport (freq 3824000 and symbolrate 3617000). When I went to scan for channels, I told it to scan an existing transport and selected the newly created transport. Still the same results. Locks, but then times out.

I stopped the backend, but could not get the card to tune using:

root@mythtv:/usr/bin# dvbtune -f 3824000 -p H -s 3617000 -c 0 -tone 0 
Using DVB card "DST DVB-S" 
tuning DVB-S to L-Band:0, Pol:H Srate=-677967296, 22kHz=off 
polling.... 
Getting frontend event 
FE_STATUS: 
polling.... 
polling.... 
polling....

I'm not sure why the L band freq is 0 and the Srate is the way it is.

The switching, motor moving, and signal locking are all working in the backend setup, but why am I not getting any channels to show up? We're locked, I know they are there, everything appears to be working, ah, so frustrating.

----------End original posts--------------------------------------

And emphasis on that last paragraph! The card is sending out the diseqc command to the motor (vboxII positioner) and it DOES move to the correct position number. IT WILL LOCK on a signal, but won't pull any channels now. Sig quality is 23%-24% which seems low. I could try slaving the Twinhan from the Traxis to see if maybe the card just isn't putting out the juice.
I'm using a Twinhan 1025. That's the only card I have right now. I WISH I hadn't got rid of my 102g long ago because that worked well in MythTV. Anyone have a 102g???????

Twinhan 1025 to VboxII to BSC621 (using one coax and the built-in 22KHz switch)
Asus M2NPV-VM with nvidia 6150 video
Athlon 64 X2 dual core 1.9GHz
HDHomerun dual ATSC tuner
PVR150

 

[Das Hammer]

Ok, just tried pulling it out of the MythTV box and using it in Windows. It does the SAME thing. Locks, but when it comes time to get channels, it does not find any.
For what it's worth, I used the BDA driver and Media Portal 0.2 (stable version).

I'm leaning towards a bum card. What do you think?

 

[TheKrell]

I have no clue about whether it's the card or not. Did you try the manufacturer's own client app, DigitalTV 3.3?

 

[Das Hammer]

No I haven't tried that application. I was going to try a couple others this evening (DVB Dream, maybe Prog) and see what happens there. I've also tried bypassing the VboxII, but it doesn't make a difference.

 

[oncewaslost]

I can't help, but let us know if you get it working so l can start another thread to ask you some questions about myth. I pulled my skystar2 from my dvbdream setup two hours before some recordings were to start last weekend, to install it in another box with knoppmyth. Needless to say I didn't have it working in two hours

 

[Das Hammer]

I tried ProgDVB and the card worked. I suppose that the problem can be isolated to MythTV then. It obviously knows the card is there, but seems to have some communication problem with the card. Got a 1020A on the way, hopefully that straightens things out.

------

@oncewaslost - Knoppmyth R5F1 doesn't sound like it plays very nice with the Skystar2. From what I've read on the wiki, you have to scan channels via the command line and export them to a channels.conf. From there, import the channels.conf into your input connections on the backend setup (this is where you would normally just scan for channels).

 

[oncewaslost]

@oncewaslost - Knoppmyth R5F1 doesn't sound like it plays very nice with the Skystar2. From what I've read on the wiki, you have to scan channels via the command line and export them to a channels.conf. From there, import the channels.conf into your input connections on the backend setup (this is where you would normally just scan for channels).

I have been thinking of picking up a cheap twinhan anyway. Maybe I'll wait & see how yours works out

 

[oncewaslost]

By the way, I'm not saying twinhans are cheap, I'm saying I am!

 

[TheKrell]

I'm not saying twinhans are cheap, I'm saying I am!

Well, I just bought an OEM 1025 for $45 shipped from JustFTA.com (via Ebay). Not much considering it is even supposed to do HD! But I haven't plugged mine in yet. I was first going to get it to do something with DigitalTV 3.3 before I try 3rd party apps such as tsreader/audiorip. (I bought it for the music on 119.)

 

[TheKrell]

I just bought an OEM 1025...

I can't find a 1025-specific manual on the Twinhan website. This thing has both in and out F jacks. Are we supposed to terminate one of them?

 

[Anole]

Well, I'm cheap, and Twinhan cards are low-priced.
I think we're both a good value for the money.

I had a 1025 for a few weeks.
No termination required.
I sent it back because it was delivered without a remote.
Replaced it with a 102g... which I haven't done much with these last few months.

Also the happy owner of a StarBox USB.
Even posted some fixes for it in this forum department.

 

[Das Hammer]

Mmmmmmm 102g...:

No termination required as Anole said.

Played around some more with a couple different setups and MythTV. Seems my channel scanning problem might have been limited to the TVU/Spirit Mux on AMC3. It says "Finished scanning NET services" followed by finished scanning 3824000 no tables. It can't find the channels. I suppose I could work around this somehow and put the channels into the database manually, but anyway....

However, I scanned in the Equity mux on G3C and also the ION mux on AMC1. Those channels scanned in fine.

The problem now is that when I select a channel from within MythTV, there is 0% signal and obviously no lock. For example, the dish is pointing at AMC1, I'll be watching some ATSC, go to the guide, select ION East (which is on AMC1), MythTV switches inputs over to the DVB, 0% signal.

 

[oncewaslost]

Success!

I purchased a Twinhan 1025 and spent the last few days trying to get it to work with mythtv via knoppmyth. I was having similar problems as das hammer. During the backend setup "connect source to input" I was scanning for channels using full tune for one specific frequency. It would lock and find the channels for the mux. After installation, I could get no lock or signal at all when trying to watch tv.

I just reinstalled again, but this time after finishing the input connections, I went in to channel editor and looked at the transponder information for the channels I just scanned in. I am not using a config file, so the transponder I just scanned is the only one listed. For some reason, the transponder was set to V instead of H polarity. Why it was now V after I just scanned it as H I have no idea.

So now I can watch the channels I scanned in.
Your situation may be different, but It won't hurt to double check your settings under the channel editor.

 

[Das Hammer]

oncewaslost, I am having the same problem as you described now. Was able to scan in channels, but 0% sig when trying to watch them. I'll take a look at the polarity in the channel editor to see if it has changed as you described. Thanks for the tip! :

One thing that still bugs me is why I can seemingly scan in everything else now except for the TVU/Spirit mux on AMC3. It just times out and says "no tables" as if it can't find channels. I know that even on an stb this mux takes a while to scan in and I don't believe the channels have a name because they just show up as "1" and "2" on the stb. Perhaps I can just manually add the channels in the channel editor.

By the way, I saw this HERE:

With the recent kernel drivers the DST front end may fail to load. Kernel 2.6.17 for example. In the source edit drivers/media/dvb/bt8xx/dst.c at about line 89. In the function "int dst_gpio_outb" look for udelay(1000). Change that to msleep(200). Compile and install the modules and your 1025 will work just fine.

This seems to coincide with the problem I was having trying to get the card to tune through the command line. It acted like it could not connect to the front end (of the card, not the mythtv front end).


By the way, how do you like KnoppMyth? We have ATSC, 4DTV (via S-Video), and DVB-S FTA (with a motorized C/Ku setup nonetheless) all through the same box. It is awesome! I'm no expert, but I've been through a lot so if you have any questions I would be happy to try and help.

 

[TheKrell]

Well, so far so bad... My 1025 does not appear to operate through a DP34 switch, even with a DP legacy adapter in between. I get zero signal strength when scanning using DigitalTV 3.3's DiSEqC 1.0 (or any of the other switch) settings. According to Dish, the DP34 is a DiSEqC 2.0 switch, which differs from a 1.2 switch only in being 2-way. I was hoping it would still respond to 1.0 commands to switch inputs. No such luck.

Interestingly enough, the 1025 can indeed handle the bandstacked frequency range used by DP equipment. But nevertheless I get zero signal strength when selecting Echostar 1-9 for any of the sats configurable in DigitalTV.

Or I could have fabricated a bad extension cable. Or I could have a dead 1025. Or DigitalTV 3.3 might not be working. In numerous fabs, I have never once built a bum cable, and the 1025 was sold to me, and appears to be, brand new. And my installation of DigitalTV 3.3 and the card went without a hitch. So I doubt those possibilities. I think it's my DP34, which was working fine on this port the last time I plugged a Dish receiver into it.

Barring any better suggestions here, I am going to brave the attic temperature and plug the 1025 directly into the 119 passthru of my DP34. Too bad because I kinda wanted to check out the fish channel before cranking up audiorip on 119.

 

[Das Hammer]

TheKrell - Bypassing the switch sounds like your last viable option in troubleshooting this.

Good news on one of my issues. The polarity did indeed get changed somehow after I had scanned in channels, just as it had happened to oncewaslost as well. Changing the polarity made things come out just dandy.

Had a little snafu with the motorized setup, but that should be worked out now. It worked out a lot better when I kept different satellites on different DVB Inputs. What this means is this: When you go to scan channels, you'll see "New DVB Input". Scan for channels on one satellite. When you want to scan a different satellite, go back to the input connections menu and select "New DVB Input" again. The first satellite you scanned will be named "DVB Input#1". You can use the same video source (listings data) for all DVB Inputs (satellites).


So, as it turns out, we've got a Home Theater PC now which has Dual ATSC tuners, 4DTV (X4 package via S-Video input), and now motorized C Band (soon to be Ku also) FTA......all with guide data, all with PVR and recording, my media library (pics, music, and those great videos we get in emails). Wow. A dream come true!

The only problem I still have is it won't find any channels when scanning the TVU/Spirit Mux on AMC3. I suppose that I could modify a channels.conf file to suit these two channels and import it. However, I can not create my own channels.conf file because the command line tuning procedure isn't working (see first post). So, if someone has a channels.conf file for DVB-S that they would be willing to email to me, I'd appreciate it. Just reply or send a PM.

 

[TheKrell]

I had another thought. The 1025 has an LNB in and an LNB out. I plugged one of the DP34 receiver outputs into the1025's LNB in. Suppose I patch in a spare Dish receiver on that LNB out F jack? Couldn't I control the switch from the Dish receiver? (I'm a little worried about the DC voltage of the receiver fighting with the 1025. Perhaps Twinhan put in a DC blocking capacitor to prevent problems.)

Anyhow, with a Dish receiver on the LNB out, I should simultaneously be able to verify switch port and cable integrity, select the sat I want, and know for a certainty that the 1025 is getting a signal for half (or all with the legacy adapter removed) of the transponders. Is that correct?

 

[Das Hammer]

I think you're on the right track, but I don't think you're receiver is going to control the switching connected to the output of the twinhan. I'm not an expert on the DVB PCI cards, but with a normal STB, if you connect something to the output jack, it can only do what the first STB is doing. If the first STB is on a vertical TP, you can't select a horizontal TP with the second. I'm guessing that switches are the same way.

Of course, I have been documented to be incorrect before .

 

[Anole]

no problem here

Well, so far so bad... My 1025 does not appear to operate through a DP34 switch, even with a DP legacy adapter in between.

When I got my 1025 (about a year ago?), the first thing I did to get familiar with it, was to plug it into a spare output of my house DP34 switch.
Nothing like having a known and working dish/signal to play with to wring the bugs out of your new hardware!

It's been a while and the equipment is currently off-line, but as I recall, both DVBdream and MyTheatre had no trouble talking through the DP34 and getting all three satellites.
There is a handy slate on 148, and I think one saying "Congrats, you have a Dish500" over on 110.
119 has NASA and maybe the FTA 101 channel?

The DP34 just took diseqc commands with no tricks.
Of course, MyTheatre needed a setup file that maps bandstacked LNBs , but DVBdream just knew how to do bandstacked.
I also have a Satpros 500 FTA receiver that I brought up the first time, the same way - right through the DP34.
I was so impressed, that I've considered recycling Dish FSS LNBs and a DP34 for linear FTA birds.

As long as your LNBs are DishPro, the DP34 should work fine.
However, if you are mixing Legacy LNBs with a DP34, that's not going to work for Dish, and not going to work for FTA.
edit: oh, and make sure there is at least one powered Dish receiver hooked to any output on the DP34!

Barring any better suggestions here, I am going to brave the attic temperature and plug the 1025 directly into the 119 passthru of my DP34.

Works for me.
6am might be the coolest time.

 

[TheKrell]

It's been a while and the equipment is currently off-line, but as I recall, both DVBdream and MyTheatre had no trouble talking through the DP34 and getting all three satellites.

Interesting. Sounds like DigitalTV 3.3 might be the culprit in my case.

Thanks for the pointers. I'm going to try an un-subbed receiver both before and after the 1025 to make sure the signal is present. Then I may try another app. The attic is the last resort. Yes, all LNBs are DP, and there are 3 DP receivers on the other ports.

BTW - for some strange reason I thought the HD Demo Channel on 61.5 was broadcast ITC... Now I can't verify that from Iceberg's "What Can I Get WIth An 18" Dish" thread. And why aren't the Pentagon Channel and HHS both ITC like the NASA channel and for the same reason?