I've been using one of the VisionPlus DVB-Ter cards for a few months now. I could only ever get two channels on it, but thought that was just poor signal strength (as reported by mythtv-setup, it's 32%).

A couple of days ago, I had an antenna guy over and he checked out our signal strength and quality. He said we should have no problems getting a good HDTV signal and suggested I purchase a teac STB and test it out. So, I purchased a AU$177 teac STB and it works fine. It gets 100% signal strength on all channels, though HDTV channels are still unwatchable on it.

Thinking that the twinhan cards (of which, I have 2) are total duds, I started trolling the boards looking for an answer. Last night I gave in and installed WinXP and the drivers that came with the card on a separate hard drive and tried it in the machine. I got 80% signal strength, and 91% quality. All the SD channels are watchable, and one of the HD channels is watchable.

According to this post, an updated kernel is the answer. Unfortunately, according Xsecrets in this post, installing another kernel will break stuff. I know from experience that trying to install 2.6 will definitely break the system (I've tried it before).

So, does anybody have any clues on what I should do? I want my mythbox to work, but it appears I may need to use a different distribution so I can upgrade the kernel.

Alternatively, is there a guide on how to upgrade the kernel on a knoppmyth box? I did try once using nigel's guide, but couldn't get it to work and ended up having to do an install from scratch.

I was surprised to find that PSU problems had a big impact on reception. One weekend, everything started breaking up. After much frustration, removing one of my VisionPlus cards fixed wverything. A little head-scratching later, swapping my 180W PSU for a 300W one fixed the twin card setup.

I also think that old PC cards like these need a stronger signal than the newer cards or STBs. An antenna signal amplifier is very helpful.

_________________
| Nigel Pearson, nigel.pearson.au@gmail.com
| "Things you own end up owning you" - Tyler, Fight Club

Thanks for the response Nigel.

Hmm, I wouldn't imagine the PSU is a dud. I have this system in a Coolermaster Cavalier case with the included 300W power supply.

One review I read did recommend replacing the PSU if you have water cooling, a high end CPU or high end graphics card. I doubt the reviewer considered my Athlon 2800+ to be high-end (the review was written in September this year). The tuner card is also the only card in the whole system. The motherboard has the nForce2 chipset with video, audio, lan and firewire on board.

Umm, I didn't think the Twinhan cards were all that old (but I could be mistaken). I already have a mast head amplifier in the system. If I turn the amp down, the analog TV signal is unwatchable where I am. Funnily enough, the set top box still has signal without the amp (although the signal breaks up a lot).

Anyway, the card works almost flawlessly under Windoze (using the same hardware), so it is definitely a problem on the Linux side. Somebody has recommended upgrading the kernel (which I will try after I've backed up my recordings), but I'm not sure what that will break.

i am running an Aopen 250w in my machine with one twinhan card at this stage, just saving up to get another for it.

Now I have the system running fine, I must say though, not sure what it is, but mythtv does show a low signal input one my system, but all the channels work quite well unless there is vert stormy weather. Then I can get 7 playing up a little. My signal shows around 35% on mythtv, I don't know what windows shows since I have never run windows on this machine before.

Now I have made no changes to the knoppmyth system other than,

1. Compile and set up the card drivers.
2. Recompile mythtv to support DVB.

I am guessing you have both of these done as you can check the signal strength.

What happens with only one card installed, and how are you joining both the cards to the antenna?

My signal strength shows at about 30-32% on mythtv. ABC and SBS are the only consistently watchable channels (but only in standard def). 7 is occasionally watchable, but more so that I've spent some time over the last couple of days trying to get as much out of my antenna as I can. I've upgraded a few of the cables and connections, and I'll upgrade the whole system to rg6 when I can.

Yep, definitely have done both. One of the follow-ups I received on this indicated that I may need to upgrade to a 2.6 kernel. I can only assume that it might be driver related.

I actually only have 1 card installed. I purchased a second card a week before I had my antenna system installed.

Since I have a spare 40gb drive around, I'm going to play around with a couple of other distros (particularly suse and debian) and the 2.6 kernel to see what the results are like.