[mythtv-users] Nova T 500 - Possible reception problems?

Dan Harper dan at kingdomsolutions.com.au
Mon Sep 24 03:23:19 UTC 2007


I've been having some problems with my Myth box with my Nova T 500  
card dropping out and I have a suspicion that it's due to reception  
problems.  If I run a tzap on each adaptor, I get the following results:

Tuner 1:
-----------
beastie:~# tzap -a 0 "ABC TV Melbourne"
using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
tuning to 226500000 Hz
video pid 0x0200, audio pid 0x028a
status 07 | signal 8380 | snr 0000 | ber 001fffff | unc 0000003e |
status 1f | signal 839a | snr 0000 | ber 0000e3f0 | unc 00000cb6 |  
FE_HAS_LOCK
status 1f | signal 83a8 | snr 0000 | ber 00005fe0 | unc 00000000 |  
FE_HAS_LOCK
status 1f | signal 83a3 | snr 0000 | ber 00004cf0 | unc 00000000 |  
FE_HAS_LOCK

beastie:~# tzap -a 0 "ABC TV Melbourne"
using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
tuning to 226500000 Hz
video pid 0x0200, audio pid 0x028a
status 1f | signal 820c | snr 0000 | ber 001fffff | unc 00000011 |  
FE_HAS_LOCK
status 1f | signal 8268 | snr 0000 | ber 0001b5b0 | unc 00000db5 |  
FE_HAS_LOCK
status 1f | signal 8231 | snr 0000 | ber 00017a80 | unc 00000000 |  
FE_HAS_LOCK

Tuner 2:
-----------
beastie:~# tzap -a 1 "ABC TV Melbourne"
using '/dev/dvb/adapter1/frontend0' and '/dev/dvb/adapter1/demux0'
tuning to 226500000 Hz
video pid 0x0200, audio pid 0x028a
status 07 | signal 85e9 | snr 0000 | ber 001fffff | unc 00000000 |
status 1f | signal 85eb | snr 0000 | ber 00013040 | unc 000008d9 |  
FE_HAS_LOCK
status 1f | signal 85f6 | snr 0000 | ber 00012cc0 | unc 00000315 |  
FE_HAS_LOCK
status 1f | signal 85ef | snr 0000 | ber 0000bc90 | unc 00000009 |  
FE_HAS_LOCK
status 1f | signal 85c9 | snr 0000 | ber 00012990 | unc 0000002c |  
FE_HAS_LOCK

beastie:~# tzap -a 1 "ABC TV Melbourne"
using '/dev/dvb/adapter1/frontend0' and '/dev/dvb/adapter1/demux0'
tuning to 226500000 Hz
video pid 0x0200, audio pid 0x028a
status 07 | signal 83e8 | snr 0000 | ber 001fffff | unc 0000002a |
status 1f | signal 8442 | snr 0000 | ber 00013de0 | unc 00000973 |  
FE_HAS_LOCK
status 1f | signal 8457 | snr 0000 | ber 0001c6b0 | unc 00000576 |  
FE_HAS_LOCK
status 1f | signal 8457 | snr 0000 | ber 000111b0 | unc 00000030 |  
FE_HAS_LOCK
status 1f | signal 844e | snr 0000 | ber 0001bea0 | unc 00000000 |  
FE_HAS_LOCK


Now, I see three possible issues here:

1.  The high BER and occasional UNC values are a concern.

2.  When the card tunes, sometimes I get a better result than  
others.  I see this in Mythtv as well, sometimes if I get a bad  
signal on a channel, I can changes channels and then back again and  
get a better result (that doesn't help with automated recordings  
however).

3.  The second tuner seems to have worse issues, would this be fixed  
by the "reception patch" for the Nova T 500?

4.  I'm running an amplifier on the antenna, if I'm watching Myth OK,  
turn down the amp and then turn it up again, the signal freezes up  
and will not lock back onto any channel.  Something is going wrong  
with the card when the signal decreases or has quality issues.

Can anyone help with suggestions for finding the problem?

Cheers,
Dan



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