Clear QAM Issues

[mets3145]

Hey everyone. So my HTPC has hit a problem that I have no idea how to fix.

I have a Hauppauge 1600 that has started acting all funky lately. It seems to have lost the signal to a couple of digital channels I still have through my TV cable.

Here's the scenario: I live in an apartment with Comcast cable so I do not need a cable box. For the past 2 years, I've been able to use my 1600 to receive the local channels in HD. That all stopped like 2 days ago.

I'm not sure what the problem is. My TV still receives all the local channels in HD so I know I'm getting a signal. My 1600 though, can't find it. I've lost FOX, CBS, and ABC. I still get NBC in HD.

Anyone know what would cause my 1600 to suddenly lose FOX, CBS, and ABC feeds in HD?

[bnh]

has Comcast announced changes to your lineup recently? I've seen movement of analogs into SD digital, and at the same time the previous local HD digital channels changed frequency. Check out http://www.silicondust.com/hdhomerun/channels_us for your area. You may just simply have to rescan the channels in Sage setup.

[mets3145]

I'm thinking Comcast changed the signal... but here's the thing:

1) My TV still gets the signal
2) I've been re-scanning at least 2x a day since the problem occurred. No luck.

I know I get the signal since my TV still gets the local HD, but for some reason, my HVR-1600 can't seem to find FOX, CBS, or ABC.

[mets3145]

Ok, so I used the website you linked, entered in my zip code 94109... and here's my question:

Is the CHANNEL column the Frequency? If so, for me, I'm still getting KNTVDT at (88-11-1)

The virtual channels are still what my TV is getting, so KNTVDT is 11-1 and KGODT is still 7-1 when I use my TV.

So these are the channels I'm concerned with:

114-1 - KPIXDT - CBS HD
114-2 - KTVUDT - FOX HD
117-1 - KGODT - ABC HD
118-8 - KRONDT - KRON4 HD

Entering these frequencies in manually brings nothing to the table. How can my HVR-1600 suddenly lose these feeds?

[bnh]

i think the HVR-1600 can still tune to those channels, but i had to enter the right physical channel for it tune to. I remember when my comcast provider was switching stuff around, i couldn't always simply do a scan reliably, and had to use my television to discover the physical frequency (the first number of the sage channel xx-xx-xx), and then added the logical after. It seemed to work for me, although i confess i don't know why, nor if it would work in your case.

I also used the Hauppage WinTV software to scan and see if i could discover actual physical mappings, but that didn't always seem to fit. In the end, i used the first number of the hdhomerun utility's CHANNEL (before the dash), and added the VIRTUAL number to that replacing the . with -, and supplied that to Sage's "Map to different physical channel number" option in setup. It seemed to work for all the unencrypted channels i receive. Although everything works for me now, i did go through a period of trial and error trying to discover the right channel to tune to.

I don't understand why built-in television tuners don't seem to be affected by these frequency moves, as much as other set top and pc tuners are. I expect more changes like this to my lineups in the near future.

[mets3145]

can you feed me a channel example?

for me, the HDHOMERUN site had FOX HD as 114-2, and the virtual is 2.1

I entered in 114-2-1, 114-0-2, 114-2-0, and 114-2-2 without any success. I'm at wits end trying to figure this out.

[bnh]

Originally Posted by mets3145

can you feed me a channel example?

for me, the HDHOMERUN site had FOX HD as 114-2.

I entered in 114-2-1, 114-0-2, 114-2-0, and 114-2-2 without any success. I'm at wits end trying to figure this out.

based on what my experience was, 114-2-1 should have worked, but the hdhomerun utility isn't showing the virtual channels for your area. Perhaps your local comcast isn't setup the same way that mine was when i had this issue.

Two others things i can suggest:

1) Does your TV that can tune in these channels, display the physical QAM frequency? I have a Toshiba DLP that displays signal strength and channel, which is how i verified it.

2) Do you have a QAM_FRQ_CACHE.ENABLE in your SageTV directory? If so, rename it to something else. I think the presence of this file, will prevent Sage instructing the tuner to seek out additional tunable channels when scanning.

[mets3145]

"based on what my experience was, 114-2-1 should have worked, but the hdhomerun utility isn't showing the virtual channels for your area. Perhaps your local comcast isn't setup the same way that mine was when i had this issue."

-Yeah, based on mine, that should've worked too. That's how it was working till 3 days ago.

1) Does your TV that can tune in these channels, display the physical QAM frequency? I have a Toshiba DLP that displays signal strength and channel, which is how i verified it.

No. My TV does not have this functionality.

2) Do you have a QAM_FRQ_CACHE.ENABLE in your SageTV directory? If so, rename it to something else. I think the presence of this file, will prevent Sage instructing the tuner to seek out additional tunable channels when scanning.

What is the file type of this QAM_FRQ_CACHE.ENABLE file? I ran a file search inside the SAGETV folder, and could not find the file. The file I do have is called QAMSCAN - Hauppauge WinTV 418 TS Capture.frq, which I have deleted before running a channel scan.

My gut feeling is that the HDHOMERUN site has not been updated and that the frequencies have changed. However, if this was true, how come my TV still gets the channels without running a new scan? - Just thinking out loud.

[bnh]

QAM_FRQ_CACHE.ENABLE may be a hidden file. The contents of my QAMScan-Hauppauge WinTV 418 TS Capture-0.frq are:

#This QAM frequency cache file will be used to speed QAM scanning channel, if an empty file of QAM_FRQ_CACHE.ENABLE exist in sagetv directory.

#SCHEME:UNKNOW (0)
#TUNER:Hauppauge WinTV 418 TS Capture-0
#Format: CH:nn frq:nnn [mod:nnn] [inv:nnn]

CH:999 frq:0000
#END

But this is after i rescanned channels. I renamed it to QAM_FRQ_CACHE.DISABLE as an empty file in my SageTV directory. Turn on "Show hidden files and folders" in Windows, Explorer, Tools, Folder Options, View.

[mets3145]

Originally Posted by bnh

QAM_FRQ_CACHE.ENABLE may be a hidden file. The contents of my QAMScan-Hauppauge WinTV 418 TS Capture-0.frq are:

#This QAM frequency cache file will be used to speed QAM scanning channel, if an empty file of QAM_FRQ_CACHE.ENABLE exist in sagetv directory.

#SCHEME:UNKNOW (0)
#TUNER:Hauppauge WinTV 418 TS Capture-0
#Format: CH:nn frq:nnn [mod:nnn] [inv:nnn]

CH:999 frq:0000
#END

But this is after i rescanned channels. I renamed it to QAM_FRQ_CACHE.DISABLE as an empty file in my SageTV directory. Turn on "Show hidden files and folders" in Windows, Explorer, Tools, Folder Options, View.

Did everything and it seems that my QAM_FRQ_CACHE.ENABLE file does not exist. How do i make one?

[Ender]

After Feb 17, Time Warner changed the frequency assignments of most of my QAM channels. Upon a rescan, I could not find the channels. What I have learned since is the 1600 is highly sensitive to signal level. Basically the signal going into my 1600 was too strong. I removed a 15 db amp I had before an 8 way split, now the 1600 can tune all the available clear QAM channels that I can get.

Short story long for you, try attenuating the signal going in, and see what you get. It may be just that simple. A quick and dirty way to do it, is to cascade a few splitters before the input.

[Ender]

Originally Posted by mets3145

Did everything and it seems that my QAM_FRQ_CACHE.ENABLE file does not exist. How do i make one?

Create a new text document, leave it empty, then rename it QAM_FRQ_CACHE.ENABLE.

[mets3145]

Originally Posted by Ender

After Feb 17, Time Warner changed the frequency assignments of most of my QAM channels. Upon a rescan, I could not find the channels. What I have learned since is the 1600 is highly sensitive to signal level. Basically the signal going into my 1600 was too strong. I removed a 15 db amp I had before an 8 way split, now the 1600 can tune all the available clear QAM channels that I can get.

Short story long for you, try attenuating the signal going in, and see what you get. It may be just that simple. A quick and dirty way to do it, is to cascade a few splitters before the input.

I created the QAM file, re-scanned... no luck. Changed the file name... no luck...

I think you are right about the strong signal... what does "cascading a few splitters" mean? Does that mean attach a splitter? Currently from the wall I have a 4 way splitter from the wall going to my TV, 2 analog tuners and 1 digital tuner.

-If you did mean attach a splitter, I put a 3 way splitter between the wall and the 4 way splitter and then a 2 way splitter between the 4 way splitter and the 1600 digital input; that did not do anything. Still could not get my FOX HD on the 1600.

My next attempt will be going from the 4 way splitter to the 3 way splitter then the 2 way splitter then the digital tuner on the 1600... friggin' signal strength... i knew it was weird that my signal strength jumped from 79% to mid 80s on most digital channels my 1600 is picking up. Thank god I can still get NBC HD.

I'll let you know how my straight 4-3-2 setup works out. I ran out of RF cables.

BTW, is there something I can buy other than splitters to decrease the signal strength?

[mets3145]

Originally Posted by mets3145

I created the QAM file, re-scanned... no luck. Changed the file name... no luck...

I think you are right about the strong signal... what does "cascading a few splitters" mean? Does that mean attach a splitter? Currently from the wall I have a 4 way splitter from the wall going to my TV, 2 analog tuners and 1 digital tuner.

-If you did mean attach a splitter, I put a 3 way splitter between the wall and the 4 way splitter and then a 2 way splitter between the 4 way splitter and the 1600 digital input; that did not do anything. Still could not get my FOX HD on the 1600.

My next attempt will be going from the 4 way splitter to the 3 way splitter then the 2 way splitter then the digital tuner on the 1600... friggin' signal strength... i knew it was weird that my signal strength jumped from 79% to mid 80s on most digital channels my 1600 is picking up. Thank god I can still get NBC HD.

I'll let you know how my straight 4-3-2 setup works out. I ran out of RF cables.

BTW, is there something I can buy other than splitters to decrease the signal strength?

Using a 4 way splitter to a 3 way splitter then a 2 way splitter leading up to my digital tuner on the 1600 did nothing. I'm out of ideas.

[bnh]

Originally Posted by mets3145

I'm out of ideas.

Can you watch the QAM channels using the WinTV software that came with the 1600? You may have to rescan first using its utility. If not, it may be time to update drivers, get a different tuner card, or file a support ticket with Hauppage.

[mets3145]

Originally Posted by bnh

Can you watch the QAM channels using the WinTV software that came with the 1600? You may have to rescan first using its utility. If not, it may be time to update drivers, get a different tuner card, or file a support ticket with Hauppage.

Get a different tuner card? More money down the pisser...

Yeah, no luck watching QAM channels with WinTV.

Currently, I get only channels 91-1 thru 91-10

NBC HD is officially dead.

Maybe Comcast is having signal problems thru its transition from analog to digital

I'm pissed though that other people have been able to fix their problems, and I still can't figure it out.

[bnh]

Originally Posted by mets3145

Get a different tuner card? More money down the pisser...

It's not a total waste, since you can still use it to record analog signals right?

Originally Posted by mets3145

Maybe Comcast is having signal problems thru its transition from analog to digital

Since your TV can decode the signal, i would guess there's something in the stream that the 1600 can't recognize, but the built-in TV tuner does. I wouldn't doubt your local Comcast may not have everything setup right, as I've seen numerous posts on other forums about stuff not working quite right. Call 'em up. Or as suggested, it could still be that the signal is TOO strong for the 1600.

Originally Posted by mets3145

I'm pissed though that other people have been able to fix their problems, and I still can't figure it out.

don't give up!

[mets3145]

Yeah, I'm guessing i'm going to have to wait it out... With any massive transition, there will be bugs. I'm hoping this isn't a sign of things to come. I loved being able to record 3 shows at the same time (2 analog, 1 digital), while watching another show with my TV.

If the signal is too strong for the 1600... is there anyway to weaken it other than using splitters. My current 4 splitter to 3 splitter to 2 splitter isn't working.

My guess is that I'll have to wait it out.

Ok, here's an update: I ran a scan at 6pm PST

I have KRON HD and NBC HD back...

My gut feeling is that everything should be back to normal in a few days... I'll update this thread if I get channels back. But there is a glimpse of hope!

[bnh]

i confess i'm selfishly motivated to see you have success, since my local Comcast provider announced some lineup changes coming in April, so i wouldn't be surprised to see myself having similar issues as you when that happens. I've been through one such lineup change, which is why i responded to your original post.

Hopefully, the support between Hauppage, Comcast, Sage, and this forum, you can figure it out.

I'm currently having the opposite problem where my big screen HDTV can't reliably pick up QAM signals anymore, but the 1600/Sage works wonderfully. My workaround is to use a different QAM tuner (a Samsung) for my TV when watching live direct TV. At any rate, i'm trying to be patient and recognize that i might be on the cutting edge, which begs to have these kind of frustrating issues until it becomes a mainstream technology.

[bnh]

Originally Posted by mets3145

Ok, here's an update: I ran a scan at 6pm PST

I have KRON HD and NBC HD back...

My gut feeling is that everything should be back to normal in a few days... I'll update this thread if I get channels back. But there is a glimpse of hope!

Woah! good deal.