[mythtv-users] Zenith DTT901

Marc Randolph mrand at pobox.com
Fri Feb 20 14:39:30 UTC 2009

On Thu, Feb 19, 2009 at 8:53 AM, stuart <stuart at xnet.com> wrote:
>> Bill Williamson wrote:
>>> On Fri, Feb 6, 2009 at 1:41 PM, Adam Siegel <agsiegel at gmail.com
>>> <mailto:agsiegel at gmail.com>> wrote:
>>>> I have a few Zenith DTT901's. It is the HD to SD converter that can be
>>>> purchased with the government $40 coupon. The unit really works well.
>>>> The tuner is much more sensitive than the AVerMedia AVerTVHD MCE A180
>>>> cards I have in my myth setup. And the picture quality is outstanding
>>>> for SD only ouput.
>>>>  Are there any electrical engineering types that could break down the
>>>> unit and see if we could hook up an HDMI or component output and
>>>> eventually integrate directly with myth somehow? I'd be happy to send
>>>> out a motherboard for examination. I saw on another site that someone
>>>> thought there was a "mysterious" 4 pin ribbon cable attachment that may
>>>> support YUV.
>>> This box is a digital to analog converter, not an HD to SD converter.
>>> Digital TV transmission does not mean "HD".
>> I think what Admin wants to do is use the box to receive ATSC and convert
>> it to SD so he can capture it on his SD mythtv box.  This puts the burden of
>> transcoding on the DTT901.  Not a bad idea.  And you don't need to re-spin
>> your mythtv box w/an ATSC tuner and all of it's problems (still do not have
>> full support of everything on my KWorld-120 card under linux).
>> If one could find a s-video output inside the box the picture should be
>> much improved (separating the video from the color information is nasty
>> business).  I doubt component will help much more and I doubt there is much
>> of a chance of getting an hdmi output.  Besides, at that point you are
>> really asking for the mpeg2 stream are you not?  Might as well get the
>> HDHome run.
>> I have one of these boxes, I'll take a look and see if there's something
>> to be done with it.
> Follow up:
> I finally took a scope to the 4 pin connector on the processor card that is
> connected to nothing (there are 2 cards, power and processor - for lack of a
> better description).  Regretfully, I didn't see anything that hinted there
> was a signal on any of the pins.  I compared this with what I could see on
> the composite output (a rather good video signal at the time).  This doesn't
> rule out the possibility of an s-video port on the DTT901.  However, I did
> not see missing components on the processor board (it's common practice to
> design all features in but remove and add  parts later for different
> models).  It's more likely, if this is the s-video port, the feature is
> turned off in software.  Finally, not to dash anyone's hopes, the most
> common way to build a card w/an s-video connector is to provide a target
> (not a connector) on the edge of the board.  I don't see one here.

Interesting block diagram (page makes mention of the LGDT1111 that is
used in the DTT901):


(don't leave that web page up forever... depending on your browser, it
may slowly eat up all your memory)


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