[mythtv-users] Antenna amplifier
yan at seiner.com
Tue Aug 5 04:01:33 UTC 2008
Brian Wood wrote:
> Yan Seiner wrote:
>> More on the Olympics. NBC is broadcasting it. I never watch NBC. It
>> comes in with the weakest signal - my pcHDTV won't lock in on it. (Now
>> I find out.)
>> So two alternatives:
>> 1. Get up on the roof and fsck with the antennas to the great amusement
>> of my family and neighbors.
> Certainly the cheaper approach.
>> 2. Get a 2 way amplified splitter. About 9 to 12 DB should be plenty.
>> Any suggestions on model/brand/suitability?
> Depends, you may just be boosting the noise floor by 9 - 12 db.
> To do it properly you need to know where the xmtr is, what it's ERP and
> countour is, your antenna specs, your height, losses in your signal path
> etc. etc.
> An antenna in good condition, properly aimed and mounted is a good
> start. More basically - can your neighbors get a usable signal on NBC
> from an antenna? If not, you are not likely to do much better.
> I've read that capture cards require more signal than TV sets, but this
> doesn't make sense to me as the card makers are almost certainly using
> off-the-shelf tuners. If you can get +10dbmv. great, even zero should be
Well, here's what's really bizarre.
I have two highly directional antennas at 90 degrees. They're far
enough apart where interference is not an issue. They go to an
unamplified splitter, there to an old Blonder-Tongue 6DB amp and 4 way
splitter, and then to the TV and the myth backend.
The TV has a passive splitter that splits the signals to the analog and
digital antenna inputs. The TV shows a consistent signal strength
across all channels of about 60% (meaningless except that the signal
strength is approximately the same). Myth gets a straight run from the
B-T amp to a pcHDTV card. That card *also* shows a consistent signal
strength across all channels of about 60% - except NBC on channel 16
which comes in at a dismal 7 to 13%. Can anyone take a shot at
Channel 16 is the closest station and has the strongest signal, so the
issue could be overfeeding, but I get dismal results with a straight run
to the pcHDTV with no splitters or amps....
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