[mythtv-users] Semi OT: Directv questions

[Rod Smith]

On Sunday 11 May 2008 21:39:58 Dewey Smolka wrote:
>
> 1) I've heard that the HD boxes put out a better signal, even over the
> SD ports. I'm running my current box (D12-100) though a PVR-250 via
> S-video. The signal is strong and there aren't really any problems
> other than a clear sense that the signal is more compressed than the
> cable signal I was used to.  Can anyone confirm or deny that the
> HD-capable boxes are cleaner in this configuration? My landlord has
> several spare HD boxes and he's more than willing to loan me one if
> this is true.

I can't comment on the quality of the signal, but you could always test it. 
DirectTV transmits a small number of channels without encryption, so that 
even an unsubscribed box can view them. These are just channels that run 
infomercial-type stuff for new subscribers, but you could tune your box to 
that channel, then swap in an HD box and compare the picture.

> 2) I'm pretty sure I know the answer to this one already, but I
> thought I'd ask just to get confirmation. As I mentioned I have a
> PVR-250 and a decided lack of spare PCI slots on my backend. With a
> PVR-500 (and add-on bracket) it would support two inputs from two
> boxes over two S-Video ports and two audio-ins, right?

I believe so, but as I don't own a PVR-500, I can't say this with certainty. 
Another option would be to add a USB-based tuner, such as a Hauppauge 
WinTV-PVR-USB2 or a Plextor ConvertX.

> 4) I asked the installer a number of questions, but wasn't really
> convinced by any of his answers so took all of it with a grain of
> salt. For example I asked him if I got another box if it would be
> enough to add a coaxial 2-way splitter at the end to connect both. He
> didn't think that would be too good an idea, and said that if it was
> another standard box, I should call service and tell them my picture
> was out, then when a guy showed up to fix it offer him $10 to drill
> another hole and run a new cable from outside.

The installer was correct. DirectTV uses two-way transmissions over coaxial; 
the tuner needs to tell the dish what sort of signals to tune for (there are 
two options), and in the case of a multi-satellite dish, which satellite to 
tune to. Thus, you need at least two lines to support two or more boxes, and 
a regular cable TV splitter won't work reliably, since it'll combine the 
signals from the boxes to the dish. If you've got two lines, a 
single-satellite dish, and three or more SD boxes, you can use a device 
called a multiswitch to do the job, but of course these are more expensive 
than regular cable TV splitters. If you receive signals from two satellites 
(for instance, if your locals are on the 119 satellite or if you receive HD 
content), then you may need as many as four incoming lines to service four or 
more receivers. There are ways to halve the number of cables, but these 
methods require more hardware.

> He also said that if it 
> was an HD box I was adding they'd have to add another piece of
> hardware outside. But either way, splitting the signal inside wouldn't
> work very well. Thoughts or opinions?

I'm guessing that the installer was referring to a multi-satellite dish vs. a 
single-satellite dish, but maybe he was referring to an exterior-mounted 
multiswitch. (DirecTV puts most of its national SD content on a satellite at 
101 degrees and most or all HD content on satellites at 110 and 119 degrees, 
so you need a multi-satellite dish to receive HD content.)

-- 
Rod Smith