[mythtv-users] Hauppauge 1609 and Pixelation Tests

[Barry Martin]

Hi Stephen!


>> 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.

Probably got a bit sloppy in my writing again. “RF36” and “RF38” refer 
to two specific channels within the U.S. television allocation: RF36 
from 602 – 608 MHz and RF38 614 to 620 MHz. My assumption is as these 
are essentially the same frequency, the same power, the same tower 
except for height, then they should be received the same. (I’m about to 
learn some good stuff! :) )


>> 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.


No:

--------1600

Antenna ---- 4x -----1600

                 --------2500

                 ----------------------------------1609


(If the diagram gets clobbered the antenna feeds to the 4x splitter.  
The four tuners feed from the 4x splitter.)



“4x” is a 4-way signal splitter.

The 1600 and 2250 tuners are inside the old Backend (BE1); the 1609 is 
inside the new Backend (BE3). The signal strength to the 1609 should be 
the same as what is going to the 1600 and 2250. What happens inside the 
tuner card with single, dual and quad tuner devices is another level.


Barry – the advanced neophyte; the more I learn the better


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