Hi Devin,
Devin Heitmueller wrote:
On Sat, Dec 5, 2009 at 1:44 PM, faginbagin <[email protected]> wrote:
I have an HVR-1600 that can't find three clear QAM channels. Using
information from silicondust.com, I think these channels are on frequencies
543000000 and 549000000 (analog cable 77 & 78). I can see these channels on
HDTVs in other rooms of my home. And the HVR-1600 can tune 8 clear QAM
channels on 5 different frequencies:
three on 93, 639000000
one on 94, 645000000
two on 102, 663000000
one on 106, 687000000
one on 118, 759000000 (although this one is video on demand and is noisy)
So I guess I'm wondering if you can offer any insight as to why I'm having
trouble with frequencies 543000000 and 549000000. Could it be a clue as to
whether the problem is the coax cabling leading to the HVR-1600, an issue
with the PCI bus, or just the fact that a PCI card doesn't have the
shielding an HDTV has?
FWIW, I have yet to try connecting one of my HDTVs to the same coax input.
However, I did try connecting the HVR-1600 to the same input used by my
cable modem back in March/April (should be cleanest coax connection in my
house) and MythTV's scanner couldn't find these three channels there. It's
been so long, I don't remember if I tried the scan utility with that
connection. My focus at the time was an issue with audio noise on some
analog channels (which Andy was able to fix, Many Thanks).
TIA,
Helen
P.S. Thought Devin would like to know his recent cx18 fixes have improved
signal quality on the clear QAM channels I can tune. Tuning 7 channels for
about 23 seconds each and playing with mplayer 3 seconds after tuning
(excluding video on demand), I found that:
- Signal strength reported by azap increased from an average of 12c to 13F
- Reports of non-zero BERs and/or UNCs dropped from 6 in 147 samples to 1 in
147 samples
- mplayer reports of 'a52: CRC check failed!' dropped from 24 to 2
Subjectively, the audio and video quality is better. And MythTV seems much
happier as it's less likely to dump core playing back recordings from two of
these channels.
Hello Helen,
Thanks for taking the time to try out my patches before writing the
mailing list - since that would have been the first thing I suggested.
I would suggest trying the following:
See if the results differ with /usr/bin/scan. This could be some
issue with mythtv's channel scanner.
My most recent tests were with scan, using both w_scan output and various scan
files provided with dvb-apps. Guess I didn't make that clear.
Try an actual TV and see if it can receive the channel.
That is my next step. Either that or live without the channels.
Try the HVR-1600 under Windows, if possible. As far as I know, the
Linux driver is at the point where it should behave identically to the
Windows driver, so if there is some inconsistency, I would definitely
be interested in hearing about it.
I did try that back in March/April and the Hauppauge s/w couldn't find the
channels either. In order to do that test, I had to move the cards into another
machine with XP installed, and I don't have that computer anymore. The current
machine only has Win2000 (new computer, old win2k CD) and the Hauppauge s/w
wasn't happy with that OS.
I guess I was hoping mostly for some insight into where these frequencies are
on the VHF band, if they're somehow more vulnerable to signal quality, noise,
etc. Something that might explain why they're giving me trouble.
Thanks,
Helen
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