PC receivers sensitivity

Martin Bednar

Hi,

I'm experiencing a consistent difference between PC DVB-[TS] dongles and dedicated receivers (be it integrated in TV sets or a satellite receiver box), with the PC side of the equation faring worse.

Hardware this happens with :
* dual AF-9015 (dvb-t)
* DVBSky S950C (dvb-s)
* Some pinnacle dvb-t usb dongle.
This is likely not a tvheadend issue (also tried with Kaffeine).
What this basically means is that on my HTPC I consistently get less channels than with the dedicated receivers.

Anyone experiencing this too? Any ideas if it is fixable?

Thanks.

Jonathan Thomson

Unfortunately the inside of a PC case is very noisy from an electrical perspective, there's a lot of components that can (and do) cause interference so if your signal is less than perfect you will notice issues.

Anecdotally I've noticed the opposite, our DVB-T feed to the house is patch, we have a TV in the kitchen that on some days struggles to keep a stable picture whilst my TVHeadend/Kodi setup works almost perfectly from the same feed.

Further anecdotally I've just switched from the closed source to open source TBS DVB drivers and noticed the signal strength/quality has improved by about 20% over the closed source variants so drivers do impact the equation too.

In short, it's not an exact science unfortunately.

Martin Bednar

I tried a different DVB-S receiver (TBS 6981) and it seems the S950C just has shitty sensitivity (under linux?); Now I get all channels I expect, based on kingofsat.net.

I'll try whether this is linux specific (will finally try the pci passthrough feature of qemu)

Thanks.

Jonathan Thomson

I found exactly the same - I "replaced" my TBS cards with DVBSky ones after getting a new motherboard and finding it wasn't backwards compatible with PCI-E v1.0 (WTF?!) but found the DVBSky cards to be very flaky in terms of signal quality/strength from the same feed. Thankfully I've switched back to the TBS cards which are rock solid.

I've been running the open source TBS drivers (from https://github.com/ljalves/linux_media/wiki) and have to say they are far more reliable/stable than the TBS ones (which to be fair were pretty good). Worth giving them a bash to see if it improves things.

Martin Bednar

Running the TBS 6981 with OSS drivers now, works great. The S950C simply sees only half the channels. Some day I'll try the windows drivers, just to know.