[mythtv-users] Pre-amp for Hauppauge 1600
joe at thefrys.com
Sun May 16 14:53:04 UTC 2010
> Instead I tried to learn a little about antennas.
Glad to hear you went the extra mile and learned something new!
> I ended up building a single bay Gray-Hoverman (one hour at Home Depot and 3
> hours at the work bench).
Ok... two miles!
> And any thoughts on why with the SBGH the signal is good even with what
> before were pretty crappy SNR numbers.
Most SNR readings via consumer electronics are junk.
In an analog tuner (as I understand it) SNR is just a measure of the
strength of a particular channel vs the strength of frequencies
adjacent to it. It doesn't tell you that the signal is coming from
the same source, that it's not being reflected, or whatever. If your
blender were to emit the same frequency as a local tv station, you
might see an improvement in SNR when you run the blender... but your
tv would drop the signal due to a reduction in quality.
Reception is dependent upon more than just SNR anyway. Higher signal
strength, which was what likely changed most with the new antenna,
means that the signal that is fed to your tuner's preamp is
stronger... all tuners have a preamp that introduces some noise itself
(why some tuners are better than others), if the signal is not strong
enough the introduced noise can can still make it hard for the tuner
to keep a lock. Additionally things like multipath can wreck havock
on a high SNR signal.
Regardless, I wouldn't read too much into what an analog tuner says
about the signal.
Congrats on your new skills, and boost to the FAF!
More information about the mythtv-users