[mythtv-users] Hauppauge 1609 and Pixelation Tests

Stephen Worthington stephen_agent at jsw.gen.nz
Sat Jun 1 11:33:53 UTC 2019

On Sat, 1 Jun 2019 07:05:09 -0400, you wrote:

>On Sat, Jun 1, 2019, 01:57 Stephen Worthington <stephen_agent at jsw.gen.nz>
>> On Fri, 31 May 2019 14:12:17 -0500, you wrote:
>> >
>> >Hi James!
>> >
>> >> My wife berates me for talking funny! My appologies.
>> >
>> >Wow! You get to speak?! <bseg>
>> >
>> >
>> >> I?ve tried lots of tuners, the worst of which was unwatchable on the
>> worst channel on HD
>> >> Without changing anything in the signal path I?m now using the Haupague
>> Win TV usb tuners.
>> >> I?ve not seen a single block or stripe since getting them.
>> >
>> >Ah! OK, that is what I thought you intended: with various tuners the
>> >worst viewing was unwatchable on a weak/distant/incorrectly aimed station.
>> >
>> >“Everything” makes a difference: tuner, cable (coax), antenna. With the
>> >TV tuners seems none list the sensitivity (µV), so pretty much have to
>> >guess and reply on others’ experiences. (One reason why I posted my
>> >follow-up which started this thread.)
>> >
>> >Use of good-quality cable (coax): RG-6/U vs. RB-59/U – even then there
>> >are multiple options. Check your cable: I’ve had
>> >commercially-manufactured extension pieces (~18” long) where the center
>> >conductor slipped: was pushed during installation so one end barely
>> >touched the splitter’s connector and the other end extended into the
>> tuner.
>> And do not forget the joints - make sure they are screwed together
>> properly.
>> >Antenna aiming: where the studios are aren’t necessarily where the
>> >transmitter site is. At my location (house) the studios are in various
>> >surrounding cities west and south but all except one transmitter are at
>> >an Antenna Farm 20 mile south-southeaast.
>> >
>> >You probably know all that, just a good review (especially that quirky
>> >cable-slid one!)
>> >
>> >Most of the reception problem here seems to be external factors,
>> >combined with tuner specs, I think similar to your issues. Calm wind,
>> >good recordings. Windy conditions, start to get pixelation issues; seems
>> >to be some correlation with the RF Channel (the actual frequency the TV
>> >station is transmitting, not its virtual channel), though that tends to
>> >fall apart as locally there are two stations, one RF36 and the other
>> >RF38, both 1000KW, on literally the same tower. yet RF36 will pixelate
>> >horribly and RF38 will be a clear picture.
>> Tuners and aerials have a centre frequency they operate best on, and
>> performance tends to fall off gradually the further away from the
>> centre frequency a transmitter is operating on.  So for two stations
>> on the same tower at the same power, the difference in frequency will
>> usually explain different reception on the same tuner.
>> >As for the Backend tuners, LIS previously the newer Hauppauge 1609 tuner
>> >has worked well for me. Admittedly due to a little sloppiness in my
>> >quickly connecting to an antenna the Backend with the 1609 inside is
>> >connected to the antenna and splitter feeding the old Backend with the
>> >1600 and 2250 tuners. IOW the two Backends are on the same antenna and
>> >so getting the same signal. The new Backend (with 1609) is recording a
>> >1000% better under mediocre reception conditions compared to the old
>> >Backend.
>> So are you saying your 1609 tuner gets a direct feed from an aerial,
>> but the 1600 and 2250 tuners get a split feed?  If that is the case,
>> the 1600 and 2250 tuners will be getting a bit less than half the
>> signal level of the 1609, so you can not compare the performances that
>> way at all.
>> _______________________________________________
>But isn't this a comparison between a signalsplit for two separate tuners
>and a signal fed into a quad tuner?

With modern tuners it is difficult to tell.  It used to be that you
knew that a quad tuner card had to have a four way splitter on it. But
that is no longer the case - I have an 8 tuner DVB-T2 and an 8 tuner
DVB-S2 card where there is one aerial input feeding all the tuners,
but all tuners get the same signal level as the aerial input provides.
I do not know how they do that.  Some recent quad tuner cards also
work that way.

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