Hauppauge quadHD problems

[Graham]

Looks like the Hauppauge dualHD (USB) has the same issue.  It's dropping a lot of packets, when another tuner running in parallel is dropping none.

Apologies if I am suggesting the obvious ... What happens if you swap the coax between the two tuner devices?

[NumberFive]

Apologies if I am suggesting the obvious ... What happens if you swap the coax between the two tuner devices?

No problem.  Yes I've tried this, no difference.

[NumberFive]

Martin

I've seen this comment across the web quite a bit, but you 100% definitely can engineer for this.  It's kind of trivial as far as radio circuits go.  The first components after the antenna socket should be an amplifier and impedance matching circuits, then into the tuner ICs.  About 6 dB of amplification is needed, as each time you split the signal in two you lose 3 dB.  This amplification and matching stage would mostly consist of printed components on the PCB (i.e. PCB printed inductors, capacitors), just like you can see in masthead amplifiers, so minimal cost in terms of production.  Pennies/cents for a transistor or two.  

Some of the tuner ICs even have a buffered pass through for such daisy-chaining applications, but I don't know how the costs of those compare against the conventional approach above.

Just came across this Youtube video about a HDHomeRun dual tuner.  https://www.youtube.com/watch?v=fUc4Hvo1N-g

You can see clearly here that from the UHF connector at the bottom, the first 8-pin IC (tiny) is an RF amplifier with two outputs, and then into the two tuner ICs at the top.  The video goes on to show above these are the demod chips, then the CPU.  The RF amplifier and the tuner chips would normally be in a metal can (you can see the solder pads for it).  Lots of little resistors ®, capacitors ©, and inductors (L) presumably for various filters and matching circuits.  Nice piece of engineering.

Lots of close-ups in the video.  Worth a watch.

Anyway, I'm sure other brands with dual/quad/octo tuners will have similar designs with an RF amplifier up front.

[koijh65]

Are you still having problems with the quadHD? I were thinking about switching. I am having the same problems as you with Silicondust quad tuners.

[jobby99]

Are you still having problems with the quadHD? I were thinking about switching. I am having the same problems as you with Silicondust quad tuners.

Is it possibly CPU related like when the latency is too slow to keep up with the bitrate?  I know that sounds ridiculous with modern CPU, but maybe some bug or codec issue could cause trouble.  There used to be a Windows 7 tool to test latency, but not sure for Windows 10/11.

[koijh65]

Are you still having problems with the quadHD? I were thinking about switching. I am having the same problems as you with Silicondust quad tuners.

Is it possibly CPU related like when the latency is too slow to keep up with the bitrate?  I know that sounds ridiculous with modern CPU, but maybe some bug or codec issue could cause trouble.  There used to be a Windows 7 tool to test latency, but not sure for Windows 10/11.

I have had the Silicondust quad tuners for years without problems until recently. Nothing within my setup has changed. I have not downgraded to a lesser CPU.

[tesla1886]

I have a Hauppauge WinTV-quadHD. I have been using it since 2017 and have had no issues.

@Sub recommend to me that I use LAV codecs. I download them and have been using them ever since and again have had no issues.

[i0zjh02]

I have 2 x Hauppauge WinTV-quadHD tuner cards in my setup and dont see any dropped frames or issues at all, maybe the drivers have been updated since this thread started? I replaced DBS 6205 cards I had originally which were awful and tended to just die and never be recognised in my PC again. 
I find the Hauppauge cards much more stable and resiliant and would recommend. They are behind an 8 port amplifier in my setup so that also probably helps!!