Cause For Ghosting w/ COmcast DVR? - AVS Forum
HDTV Technical > Cause For Ghosting w/ COmcast DVR?
mcaldwell's Avatar mcaldwell 04:54 PM 02-12-2006
Recently switched form DirecTV to Comcast to get access to the twin-tuner HD DVR. User interface sucks, and the HD is too small, but.... anyway, picture is great except for high contrast situations. If there is a roughly vertical dark area with relatively light field to the right of it, I get several iterations of the edge into the light field, each iteration a bit more faint than its brother to the left. I have not crappy but not expensive component cables between the settop and the Yamaha RCVR, 6' long. Another 6' connects the Yamaha component_out to the Toshiba 65" rear projection TV. Never had this problem with HD media before, so I think the Yamaha_to_TV connection is OK. Would shorter, perhaps higher quality component cables between settop and amp cure this? They are sitting side by side.


TerryB's Avatar TerryB 06:56 PM 02-12-2006
I would recommend taking the receiver out of the setup on the video side to see if the symptom is in the output of the Comcast STB. Also, I don't get the comment about "HD is too small".

mcaldwell's Avatar mcaldwell 08:28 AM 02-13-2006
Excellent idea; I'll switch cables and see what turns up.

"HD is too small": hard drive is way too small. Recording all-HDTV eats it up in a hurry. Would really like to see the USB port available as an access to an external HD that I could add myself. 300 Gb drives are pretty cheap here in Silicon Valley.
walford's Avatar walford 09:39 AM 02-13-2006
What do you mean by "HD is too small"?
What resolution(s) are you using over the component interface and which Comcast dual tuner PVR are you using?
Do you notice a difference between 720P channels (ABC, FOX and ESPN-HD) and the 1080i channels (CBS, NBC and the rest)?
Cable quality normally is not even an issue till you get over 15-20 feet long cables.
TerryB's Avatar TerryB 11:25 AM 02-13-2006
Ah Hah, HD as in Hard Drive not HD as in High Def...... The 8300HD with SARA software can be connected to a SADA drive. Check the HD Recorders forum, your local forum may have information on the cableco capability in your community.

airedale's Avatar airedale 11:25 AM 02-13-2006
Not that I have a fix for you, but I have started to notice it on my Comcast DVR box too.

Hopefully someone knows why this is happeneing. I also agree with you about the Hard Drive space. Way too low.

Why did you switch from DTV to comcast anyway? I was thinking of doing just the opposite!
TerryB's Avatar TerryB 11:27 AM 02-13-2006
There is a phenominum called ringing which causes sharp, high contrast edges to have a ghost, you might try a search on ringing in these HD forums. My recollection is that it was a cable/hardware issue.

walford's Avatar walford 12:50 PM 02-13-2006
Originally Posted by TerryB
Ah Hah, HD as in Hard Drive not HD as in High Def...... The 8300HD with SARA software can be connected to a SADA drive. Check the HD Recorders forum, your local forum may have information on the cableco capability in your community
That makes sense I am used to the Hard disk drive be referred to as an HDD not as andHD drive. I assume you are referring to SATA drives unless there is a drive type called SADA that I am not aware of.
TerryB's Avatar TerryB 04:46 AM 02-14-2006
Yup, SATA.
I don't have one, I'm waiting for the DVD writer to come out.

mcaldwell's Avatar mcaldwell 07:16 AM 02-14-2006
I guess being knee deep in Silicon Valley biz (patent law) I get tunnel vision on digital electronics, so HD always means Hard Drive!

Being a cable issue makes sense to me; capacitance causes phase shift and ringing. What I was looking for in the forum was experience with short, expensive cables vs long cheapies. I usually consider the Monster info as hype, but maybe in this case it's worth it. I'll be able to try it out in a few days.

I have the Comcast Moto unit with two tuners; can I hook up the SATA drive to that? How do I loan and run special software?
TerryB's Avatar TerryB 07:33 AM 02-14-2006
Sorry, AFAIK the only unit running external drives is the SA8300HD.

mcaldwell's Avatar mcaldwell 04:42 PM 02-18-2006
I did the cable swap and found that the culpret was the 12' cable from amp to the TV. Plugging the STB directly into the TV was fine.
TerryB's Avatar TerryB 06:44 PM 02-18-2006
If the amp is out of the circuit when the picture is clean, it may be part of the problem.

Did you swap in the long cable by itself?

mcaldwell's Avatar mcaldwell 08:02 PM 02-18-2006
Yes. I think it is simply the high capacitance and inductance of a cheapie cable that is 12' long. My TV is a 65" Toshiba rear projection that weighs 450 pounds and is in a built in cabinet in a hole that it just fits, so I have to roll it waaaaay out to get behind it, then the cable has to get up enough to plug into the amp. I'll probably just live with it for a while, since a 12' Monster set is about $140.
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