[mythtv-users] hd homerun and STB

Kevin J. Cummings cummings at kjchome.homeip.net
Tue Jun 3 03:54:50 UTC 2008

steve wrote:
> Anduin Withers wrote:
> |> lol, yes I did that first, and I got the unencrypted channels, about 10
> |> of them.  definately not worth what I paid for the box.
> |
> | The item you purchased doesn't do what you seem to think it does. Those 10
> | channels you see are probably exactly what you are supposed to see.
> Hooking
> | after the STB and expecting to tune, let alone, tune all 700 of those
> | channels is something you should realize will not work.
> I dont know, I guess I didnt realize it, the hdhomerun is pretty much
> useless if it cant be used with a STB (for me anyway) theres no hd ota
> broadcast within a 50 mile radius... but that still doesnt answer why it
> cant be used to at least tune what a pvr 150 can?  I still get nothing
> when I use the same identical cable pulled out of my pvr 150 and plug it
> into the hdhomerun.  Shouldnt I get at least what the pvr150 does? or am
> I way off base.

You are way off base in your expectations.

The HDHR receives ATSC signals, what we call in the USA, digital TV.

Your PVR150 is an NTSC board, it receives analog TV.  While your cable 
company may provide *both* types of signals on their cable, the 2 
recorders are mutually exclusive.  You also seem to have an expectation 
(correct me if I'm wrong) that channels numbers are absolute.  Just 
because your STB shows you the same programs that your PVR150 does on 
the same channel numbers does not mean that the STB is tuning in the 
same signal.  In fact, if it is a digital STB, then odds are its tuning 
into the digital signal on some other frequency when you tune the STB to 
that "channel".  In fact, many cable companies have been known to change 
underlying channels at their whim so long as they keep mapping them to 
the STB channel number so their customers don't get mad.

> I may have a bad tuner or something because I just hooked it up to a
> windows box and i get absolutely nothing when i scan for channels using
> the hdhomerun software provided..... from the stb or direct cable.  Im
> done for tonight, will investigate more tomorrow!  Thanks guys.

Most STBs put a signal out in analog on channel 3 or channel 4 on the RF 
output cable.  This is an analog signal.  Your HDHR doesn't know what to 
do with it.

I don't own an HDHR.  That said, it *should* be capable of finding all 
of the unencrypted channels on your direct cable so long as you can tell 
it which kind of QAM is being used.  8VSB is the method used by OTA, and 
QAM64, QAM128, or QAM256 are used by the cable companies.  Make sure 
that the HDHR is set up properly to look for QAM signals when you scan 
the cable with it (especially since you can find the 8VSB OTA with it).
No, I don't know how to do that.  Sorry.

I *do* own an HD5500 card for my PC.  I haven't gotten it to receive any 
more than the local OTA signals in my area.  [Before a storm removed the 
last of the horizontal receptors on my 35YO roof antenna this past 
winter.]  What I *can* tell you is that I was able to receive OTA some 
"not so local" channels in digital on the HD5500 that I cannot receive 
OTA in analog on any TVs in my house.  However, there is *ONE* local 
channel that I cannot receive at all.  While digital travels farther 
than analog in a use-able form, it is much more susceptible to in-line 
interference (there must be a tree, tall building, or a hill between me 
and that local broadcast tower).  I have not yet replaced my roof 

Kevin J. Cummings
kjchome at rcn.com
cummings at kjchome.homeip.net
cummings at kjc386.framingham.ma.us
Registered Linux User #1232 (http://counter.li.org)

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