[mythtv-users] Alternative to Silicondust HDHR3-6CC-2X3?

[Joseph Fry]

>
>
>>>>  I've been trying to order one of these, but no one seems to have them
>>>>> in stock, and one retailer told me that they're discontinued. I could
>>>>> get two of the three-tuner model, but I'd prefer one piece of
>>>>> equipment.  Any good alternatives?  Anyone know if Silicondust working
>>>>> on a replacement for this unit?
>>>>>
>>>>
>>>>
>>>> http://www.amazon.com/KG48348MR-Instant-Advanced-Precision-0-18-Ounce/dp/B000BKO6DG/
>>>>
>>>>
>>>> AIUI, it would be little different from the 6CC unit, save the
>>>> additional power supply.  :)
>>>>
>>>
>>> The 6CC literally was two 3CC boards in a shared case. There were two
>>> network jacks, two cablecard slots, two coaxial inputs, two USB ports for
>>> tuning adatpers, two....
>>>
>>> The only thing stopping someone from making their own is the warranty.
>>>
>>
>>  Well, if I'm going to get two units, is there any reason to get the 3CC
>> over an InfiniTV USB?  I kind of like the idea of an ethernet interface but
>> I'd be getting four tuners per unit rather than three with the
>> Silicondust...
>>
>>
>  I can think of a few reasons:
>
>  1. Cost... can typically find a HDHR Prime for about $129 if your
> patient (woot, groupon, etc)
>  2. Ethernet interface... arguably more reliable than usb, infinitely more
> flexible as far as install options go.
> 3. Ethernet interface... yeah, again... works great for a virtualized
> backend if you choose to do that.
> 4. Ethernet interface.... yep, one more... future proof (nearly)... no
> underlying driver or hardware support (other than ethernet), very unlikely
> to find a computer that can't use the HDHR in the next 20 years.  More
> likely to replace it for some sort of IPTV adapter before then.
> 5. Very Mythtv friendly manufacturer... the folks at Silicondust actually
> contribute to the development of Mythtv to ensure support and are very
> active in the support of the HDHR with Mythtv, even dedicating entire
> sections in their forums to it.
>
>  Item #5 is reason enough for me, Ceton doesn't even advertise that it is
> compatible with Linux.
>
>
> Thanks for the feedback, I actually already went and ordered two of the
> HDHR Prime 3CCs.  The price from Amazon was $129, guess I got lucky there.
>
> Now, obviously I'm going to have to split my coax connection, what's the
> best way to go about that?  Just a plain splitter, or is a
> powered/amplified one recommended?  My TV provider is Comcast, if that
> makes a difference.
>
>
No amp.

Amplifiers do boost a signal, but they add noise.  The weaker the signal
into the amp, the lower the SNR (signal-to-noise ratio) coming out of the
amp.  SNR is the ratio, in dB, of how much of the desired signal comes
through in relation to the amount of noise in the signal.  If you have  X
dB of signal, and X dB of noise, then no tuner in the world can tune it.

Amplifiers are best added as close to the source as possible, to output a
very strong signal with a very high SNR.  This allows you to add long cable
runs, splitters, etc, and still have a strong, high SNR, signal at the end.
 Putting the amp close to the end of the line has the opposite effect, you
get a strong signal with a lot of noise that your tuner will likely have
more difficulty discarding because it is almost the same strength as the
signal.

Think of it like this.... lets say you go to listen to a popular speaker
give a speech... so popular in fact that your stuck standing out the hall
and around a corner.  The noise is the sound of the room, including people
coughing, chairs squeaking, cheers, etc.  By the time his voice makes it to
you it's completely drowned out by the noise.  You have 2 choices, silence
the noise, or amplify the speaker.  If you put a microphone in the hall
around the corner from you, you will be able to better hear him speak, but
you'd also amplify all that noise so he's likely still going to be drowned
out.  But if you put the microphone on the stage, you will still hear some
noise, but the speaker will be very loud in comparison.

The microphone around the corner is like putting your amp right near the
tuner... the desired signal is so weak that the noise from the amp will
nearly drown it out... better to not have the amp there at all.  In our
example, you would need to strain to hear, but the speaker isn't drowned
out by noise.  But if you put the amplifier further upstream...say where it
enters your house (before it is split and has the greatest strength and
least noise), you can then split it several times before the signal gets so
weak that the tuner must strain to hear it... and the noise level is much
lower  (like the mic on the stage).

If your signal is so weak that you do need an amp, be sure to get one with
a reputation for very low noise and put it as far upstream as possible.
 Most amplifiers are quite horrible, and are only suitable for amplifying a
strong signal to offset losses in cable/splits... but there are gems out
there that will work wonders with a weak signal.
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